LEAP2 reduces postprandial glucose excursions and ad libitum food intake in healthy men

GLP-1 and ghrelin inversely regulate insulin secretion and action in pancreatic islets, vagal afferents, and hypothalamus for controlling glycemia and feeding

Glucagon-like peptide-1 (GLP-1) was discovered as an incretin hormone, which is released from the intestine upon nutrient intake and stimulates insulin secretion from the pancreatic islet β-cells. Subsequently, its ability to suppress appetite was recognized. Ghrelin, discovered as the ligand for growth hormone secretagogue-receptor (GHS-R), is released from the stomach and produces appetite. Later, its ability to inhibit insulin secretion and elevate blood glucose was found. Thus, GLP-1 and ghrelin regulate insulin secretion and appetite toward opposite directions. The receptor agonists for GLP-1 and ghrelin have been developed and are now used to treat metabolic diseases, in which insulin plays a key role. However, underlying action mechanism and possible interplay of these hormones have remained elusive. Here, we describe that GLP-1 and ghrelin reciprocally regulate the insulin system. GLP-1 enhances and ghrelin suppresses insulin secretion in pancreatic β-cells. Moreover, GLP-1 cooperates with and ghrelin counteracts insulin action in the vagal afferent and hypothalamic arcuate nucleus (ARC) neurons, the interfaces between the peripheral metabolism and brain. Notably, ghrelin rises and works preprandially and GLP-1 rises and works postprandially. The interplay of ghrelin, GLP-1, and insulin leads to optimal circadian control of feeding, glycemia, and metabolism.

Ghrelin-LEAP2 interactions along the stomach-liver axis

Ghrelin produced in the stomach promotes food intake and GH secretion, and acts as an anabolic peptide during starvation. Ghrelin binds to the growth hormone secretagogue receptor, a G protein-coupled receptor (GPCR), whose high-resolution complex structures have been determined in the apo state and when bound to an antagonist. Anamorelin, a low-molecular-weight ghrelin agonist, has been launched in Japan for the treatment of cancer cachexia, and its therapeutic potential has attracted attention due to the various biological activities of ghrelin. In 2019, liver-expressed antimicrobial peptide (LEAP2), initially discovered as an antimicrobial peptide produced in the liver, was identified to be upregulated in the stomach of diet-induced obese mice after vertical sleeve gastrectomy. LEAP2 binds to the GHSR and antagonizes ghrelin's activities. The serum concentrations of human LEAP2 are positively correlated with body mass index, body fat accumulation, and fasting serum concentrations of glucose and triglyceride. Serum LEAP2 elevated and ghrelin reduced in obesity. Ghrelin and LEAP2 regulate body weight, food intake, and GH and blood glucose concentrations, and other physiological phenomena through their interactions with the same receptor, GHSR.

Peptide with Dual Roles in Immune and Metabolic Regulation: Liver-Expressed Antimicrobial Peptide-2 (LEAP-2)

Liver-expressed antimicrobial peptide 2 (LEAP-2) was originally discovered as an antimicrobial peptide that plays a vital role in the host innate immune system of various vertebrates. Recent research discovered LEAP-2 as an endogenous antagonist and inverse agonist of the GHSR1a receptor. By acting as a competitive antagonist to ghrelin, LEAP-2 influences energy balance and metabolic processes via the ghrelin-GHSR1a signaling pathway. LEAP-2 alone or the LEAP-2/ghrelin molar ratio showed potential as therapeutic targets for obesity, diabetes, and metabolic disorders. This review explores the recent advances of LEAP-2 in immune modulation and energy regulation, highlighting its potential in treating the above diseases.

Critical Insights Into LEAP2 Biology and Physiological Functions: Potential Roles Beyond Ghrelin Antagonism

Liver-expressed antimicrobial peptide 2 (LEAP2) has recently emerged as a novel hormone that reduces food intake and glycemia by acting through the growth hormone secretagogue receptor (GHSR), also known as the ghrelin receptor. This discovery has led to a fundamental reconceptualization of GHSR's functional dynamics, now understood to be under a dual and opposing regulation. LEAP2 exhibits several distinctive features. LEAP2 is released by hepatocytes and enterocytes, 2 cell types that lack classical regulatory secretory mechanisms and may respond differently to nutrient signals. LEAP2 is also found in higher concentrations in plasma than ghrelin, even under energy deficit conditions, and modulates GHSR by inhibiting both ghrelin-dependent and ghrelin-independent activities. Given these characteristics, LEAP2 appears to play a major role in regulating GHSR activity in vivo, extending beyond simple ghrelin antagonism and being crucial for the long-term regulation of energy balance. A deeper understanding of how LEAP2 functions may clarify the functional implications of GHSR in different physiological contexts and unlock new therapeutic strategies for treating obesity, diabetes, and other metabolic disorders.

LEAP2 in Physiology-A Narrative Review

Liver Enriched Antimicrobial Peptide 2 (LEAP2) is a fascinating peptide that has gained significant attention since its discovery in 2003. Initially identified as an antimicrobial peptide, LEAP2 has more recently been found to play a key role in the regulation of energy metabolism. One of the most notable functions of LEAP2 is its interaction with the ghrelin hormone, which is known for stimulating hunger. LEAP2 acts as an inhibitor of ghrelin, thereby reducing food intake and influencing energy balance. The physiological roles of LEAP2 extend beyond appetite suppression. Studies have shown that LEAP2 has an impact on insulin secretion, suggesting its potential involvement in glucose metabolism and possibly insulin sensitivity, which is crucial in managing conditions like type 2 diabetes. Moreover, LEAP2 levels appear to fluctuate based on factors such as gender, developmental stage, and even interventions like bariatric surgery, which is known for its role in managing obesity and diabetes. Given these findings, LEAP2 shows potential as a therapeutic target, particularly for addressing obesity and metabolic diseases such as type 2 diabetes. Its ability to influence food intake and energy balance makes it a promising candidate for further research into therapies aimed at weight regulation and glycemic control. In the future, LEAP2 could become an important agent in the development of treatments aimed at curbing obesity and its associated metabolic disorders.

Satiety Hormone LEAP2 After Low-Calorie Diet With/Without Endobarrier Insertion in Obesity and Type 2 Diabetes Mellitus

Context

The liver/foregut satiety hormone liver-expressed antimicrobial peptide 2 (LEAP2) is an inverse agonist at the acyl ghrelin receptor (GHSR), increasing after food intake and decreasing after bariatric surgery and short-term nonsurgical weight loss, but effects of long-term dietary weight loss are unknown.

Objective

The objective of this study was to examine and compare the effects of these interventions on fasting and postprandial plasma LEAP2 and investigate potential metabolic mediators of changes in plasma LEAP2.

Methods

Plasma LEAP2 was measured in a previously published 2-year trial comparing standard medical management (SMM) (including 600-kcal/day deficit) with duodenal-jejunal bypass liner (DJBL, Endobarrier) insertion (explanted after 1 year) in adults with obesity and inadequately controlled type 2 diabetes mellitus.

Results

In the SMM group (n = 25-37), weight decreased by 4.3%, 8.1%, 7.8%, and 6.4% at 2, 26, 50, and 104 weeks and fasting plasma LEAP2 decreased from baseline mean ± SD 15.3 ± 0.9 ng/mL by 1.7, 3.8, 2.1, and 2.0 ng/mL, respectively. Absolute/decreases in fasting plasma LEAP2 positively correlated with absolute/decreases in body mass index, glycated hemoglobin A1c, fasting plasma glucose, serum insulin, homeostatic model assessment for insulin resistance, and serum triglycerides. Despite greater weight loss in the DJBL group (n = 23-30) at 26 to 50 weeks (10.4%-11.4%), the decrease in fasting plasma LEAP2 was delayed and attenuated (vs SMM), which may contribute to greater weight loss by attenuating GHSR signaling. Plasma LEAP2 did not increase with weight regain from 50 to 104 weeks after DJBL explant, suggesting a new set point with weight loss maintenance. Increases in plasma LEAP2 after a 600-kcal meal (10.8%-16.1% at 1-2 hours) were unaffected by weight loss, improved glucose metabolism, or DJBL insertion (n = 9-25), suggesting liver rather than duodenum/jejunum may be the primary source of postprandial LEAP2 secretion.

Conclusion

These findings add to our understanding of the regulation and potential physiological role of plasma LEAP2.

Liver-expressed antimicrobial peptide 2 is a hepatokine regulated by ghrelin, nutrients, and body weight

Liver-expressed antimicrobial peptide 2 (LEAP2) is a peptide that counteracts the hunger hormone ghrelin-induced functions. Recently, we showed that vertical sleeve gastrectomy (VSG) did not alter the serum LEAP2 concentration in individuals with obesity. Here, we investigated the effects of VSG in both chow diet (CD)-fed and high-fat diet (HFD)-fed mice. In CD-fed mice, VSG increased plasma LEAP2 levels and hepatic Leap2 mRNA levels while decreasing body weight, blood glucose levels, and ghrelin levels. Intraperitoneal (ip) administration of ghrelin reversed these changes. These effects were found in both male and female mice. In contrast, VSG or weight loss in HFD-induced obese mice decreased LEAP2 levels. After fasting, the plasma LEAP2 concentration was in the following order: hepatic vein > abdominal aorta > portal vein. A high glucose concentration robustly increased the plasma LEAP2 concentration in the hepatic vein and abdominal aorta but not in the portal vein. In addition, corn oil or palmitate increased LEAP2 expression and secretion. The increase in LEAP2 levels after the meal tolerance test was delayed in the human subjects with diabetes. Our data suggest that various factors (metabolic, hormonal, and nutritional) regulate LEAP2, and the liver is the predominant site for the production and secretion of LEAP2. Furthermore, the interaction between ghrelin and LEAP2 is involved in the pathogenesis of obesity and diabetes.

LEAP2, a ghrelin receptor inverse agonist, and its effect on alcohol-related responses in rodents

The underlying neurobiology of alcohol use disorder (AUD) is complex and needs further unraveling, with one of the key mechanisms being the gut-brain peptide ghrelin and its receptor (GHSR). However, additional substrates of the ghrelin pathway, such as liver-expressed antimicrobial peptide 2 (LEAP2), an endogenous GHSR inverse agonist, may contribute to this neurobiological framework. While LEAP2 modulates feeding and reward through central mechanisms, its effects on alcohol responses are unknown. The aim of the present study was therefore to identify the impact of central LEAP2 on the ability of alcohol to activate the mesolimbic dopamine system and to define its ability to control alcohol intake. These experiments revealed that central LEAP2 (i.e. into the third ventricle) prevented the ability of alcohol to cause locomotor stimulation in male mice, suppressed the memory of alcohol reward and attenuated the dopamine release in the nucleus accumbens caused by alcohol. Moreover, central LEAP2 reduced alcohol consumption in both male and female rats exposed to alcohol for 6 weeks before treatment. However, the serum levels of LEAP2 were similar between high- and low- alcohol-consuming (male) rats. Furthermore, central LEAP2 lowered the food intake in the alcohol-consuming male rats and reduced the body weight in the females. Collectively, the present study revealed that central LEAP2 mitigates alcohol-related responses in rodents, contributing to our understanding of the ghrelin pathway's role in alcohol effects.

LEAP2 is associated with impulsivity and reward sensitivity depending on the nutritional status and decreases with protein intake in humans

AIM

Liver-expressed antimicrobial peptide 2 (LEAP2) dynamics in human plasma and its association with feeding behaviour remain poorly understood. Therefore, this study aims: (a) to investigate fasting LEAP2 in participants with normal weight or with overweight or mild obesity (OW/OB); (b) to study the association between fasting LEAP2 and anthropometric and metabolic traits, feeding behaviour, LEAP2 genetic variants and blood cell DNA methylation status; and (c) to ascertain postprandial changes in LEAP2 after high protein intake and the association with feeding behaviour and food intake.

METHODS

Anthropometric and behavioural measures, genotyping, methylation profiling, plasma glucose and LEAP2 concentrations were assessed in 327 females and males. A subgroup of 123 participants received an ad libitum high-protein meal, and postprandial LEAP2 concentration and behavioural measures were assessed.

RESULTS

LEAP2 concentration was higher in participants with OW/OB (p < 0.001) and in females (p < 0.001), and was associated with LEAP2 single nucleotide polymorphisms rs765760 (p = 0.012) and rs803223 (p = 0.019), but not with LEAP2 methylation status. LEAP2 concentration was directly related to glycaemia (p = 0.001) and fullness (p = 0.003) in participants with normal weight, whereas it was associated with body mass index (p = 0.018), waist circumference (p = 0.014) and motor impulsivity in participants with OW/OB (p = 0.005). A negative association with reward responsiveness was observed in participants with OW/OB (p = 0.023). LEAP2 concentration was inversely associated with food intake (p = 0.034) and decreased after a high-protein meal (p < 0.001), particularly in women (p = 0.002).

CONCLUSION

Increased LEAP2 in participants with OW/OB is associated with behavioural characteristics of obesity. Our results show sexual dimorphism in LEAP2 concentration before and after food intake and highlight the role of LEAP2 in feeding regulation.

The LEAP2 Response to Cancer-Related Anorexia-Cachexia Syndrome in Male Mice and Patients

The hormone ghrelin serves a protective role in cancer-related anorexia-cachexia syndrome (CACS)-a condition in which plasma levels of ghrelin rise, its administration lessens CACS severity, and experimentally reduced signaling by its receptor (GHSR) worsens fat loss and anorexia and accelerates death. Yet, actions for the related hormone liver-expressed antimicrobial peptide-2 (LEAP2), which is an endogenous GHSR antagonist, are unexplored in CACS. Here, we found that plasma LEAP2 and LEAP2/ghrelin ratio were lower in Lewis lung carcinoma (LLC) and RM-9 prostate cancer CACS mouse models. Ghrelin deletion exaggerated losses of tumor-free body weight and fat mass, reduced food intake, reduced soleus muscle weight, and/or lowered grip strength in LLC or RM-9 tumor-bearing mice. LEAP2 deletion lessened reductions in tumor-free body weight and fat mass and increased food intake in LLC or RM-9 tumor-bearing mice. In a 55-subject cohort of patients with CACS or weight-stable cancer, the plasma LEAP2/total ghrelin ratio was negatively correlated with 6-month weight change preceding blood collection. These data demonstrate that ghrelin deletion exacerbates CACS in the LLC and RM-9 tumor-bearing mouse models while contrastingly, LEAP2 deletion reduces measures of CACS in these tumor-bearing mouse models. Further, they suggest that lower plasma LEAP2/ghrelin ratio protects against worsened CACS.

Genetic variants of LEAP2 are associated with anthropometric traits and circulating insulin-like growth factor-1 concentration: A UK Biobank study

AIM

To test the hypothesis that liver-expressed antimicrobial peptide 2 (LEAP2) genetic variants might influence the susceptibility to human obesity.

METHODS

Using data from the UK Biobank, we identified independent LEAP2 gene single nucleotide polymorphisms (SNPs) and examined their associations with obesity traits and serum insulin-like growth factor-1 (IGF-1) concentration. These associations were evaluated for both individual SNPs and after combining them into a genetic risk score (GRSLEAP2) using linear and logistic regression models. Sex-stratified analyses were also conducted.

RESULTS

Five SNPs showed positive associations with obesity-related traits. rs57880964 was associated with body mass index (BMI) and waist-to-hip ratio adjusted for BMI (WHRadjBMI), in the total population and among women. Four independent SNPs were positively associated with higher serum IGF-1 concentrations in both men and women. GRSLEAP2 was associated with BMI and WHRadjBMI only in women and with serum IGF-1 concentration in both sexes.

CONCLUSIONS

These findings reveal sex-specific associations between key LEAP2 gene variants and several obesity traits, while also indicating a strong independent association of LEAP2 variants with serum IGF-1 concentration.

Quail GHRL and LEAP2 gene cloning, polymorphism detection, phylogenetic analysis, tissue expression profiling and its association analysis with feed intake

The GHRL, LEAP2, and GHSR system have recently been identified as important regulators of feed intake in mammals and chickens. However, the complete cloning of the quail GHRL (qGHRL) and quail LEAP2 (qLEAP2) genes, as well as their association with feed intake, remains unclear. This study cloned the entire qGHRL and qLEAP2 cDNA sequence in Chinese yellow quail (Coturnix japonica), including the 5' and 3' untranslated regions. Sanger sequencing analysis revealed no missense mutations in the coding region of qGHRL and qLEAP2. Subsequently, phylogenetic analysis and protein homology alignment were conducted on the qGHRL and qLEAP2 in major poultry species. The findings of this research indicated that the qGHRL and qLEAP2 sequences exhibit a high degree of similarity with those of chicken and turkey. Specifically, the N-terminal 6 amino acids of GHRL mature peptides and all the mature peptide sequence of LEAP2 exhibited consistent patterns across all species examined. The analysis of tissue gene expression profiles indicated that qGHRL was primarily expressed in the proventriculus and brain tissue, whereas qLEAP2 exhibited higher expression levels in the intestinal tissue, kidney, and liver tissue, differing slightly from previous studies conducted on chicken. It is necessary to investigate the significance of elevated expression of qGHRL in brain and qLEAP2 in kidney in the future. Further research has shown that the expression of qLEAP2 can quickly respond to changes in different energy states, whereas qGHRL does not exhibit the same capability. Overall, this study successfully cloned the complete cDNA sequences of qGHRL and qLEAP2, and conducted a comprehensive examination of their tissue expression profiles and gene expression levels in the main expressing organs across different energy states. Our current findings suggested that qLEAP2 is highly expressed in the liver, intestine, and kidney, and its expression level is regulated by feed intake.

Novel Pharmaceuticals in Appetite Regulation: Exploring emerging gut peptides and their pharmacological prospects

Obesity, a global health challenge, necessitates innovative approaches for effective management. Targeting gut peptides in the development of anti-obesity pharmaceuticals has already demonstrated significant efficacy. Ghrelin, peptide YY (PYY), cholecystokinin (CCK), and amylin are crucial in appetite regulation offering promising targets for pharmacological interventions in obesity treatment using both peptide-based and small molecule-based pharmaceuticals. Ghrelin, a sole orexigenic gut peptide, has a potential for anti-obesity therapies through various approaches, including endogenous ghrelin neutralization, ghrelin receptor antagonists, ghrelin O-acyltransferase, and functional inhibitors. Anorexigenic gut peptides, peptide YY, cholecystokinin, and amylin, have exhibited appetite-reducing effects in animal models and humans. Overcoming substantial obstacles is imperative for translating these findings into clinically effective pharmaceuticals. Peptide YY and cholecystokinin analogues, characterized by prolonged half-life and resistance to proteolytic enzymes, present viable options. Positive allosteric modulators emerge as a novel approach for modulating the cholecystokinin pathway. Amylin is currently the most promising, with both amylin analogues and dual amylin and calcitonin receptor agonists (DACRAs) progressing to advanced stages of clinical trials. Despite persistent challenges, innovative pharmaceutical strategies provide a glimpse into the future of anti-obesity therapies.

Impacts of Central Administration of the Novel Peptide, LEAP-2, in Different Food Intake Models in Conscious Rats

Liver-expressed antimicrobial peptide-2 (LEAP-2) has mutual antagonism with ghrelin, which evokes food intake under a freely fed state. Nevertheless, the impact of LEAP-2 on ghrelin under time-restricted feeding (TRF), which has benefits in the context of metabolic disease, is still unknown. This study aims to explore the impact of central administration of LEAP-2 on the ingestion behavior of rats, which was evaluated using their cumulative food intake in the TRF state. Before intracerebroventricular (ICV) administration of O-n-octanoylated ghrelin (0.1 nmol/rat), as a food-stimulatory model, the rats received various doses of LEAP-2 (0.3, 1, 3 nmol/rat, ICV). Cumulative food intake was recorded at 1, 2, 4, 8, 12, and 24 h after ICV injection under 12 h freely fed and TRF states in a light phase. In 12 h freely fed and TRF states, central administration of ghrelin alone induced feeding behavior. Pre-treatment with LEAP-2 (1 and 3 nmol/rat, ICV) suppressed ghrelin-induced food intake in a dose-dependent manner in a 12 h freely fed state instead of a TRF state, which may have disturbed the balance of ghrelin and LEAP-2. This study provides neuroendocrine-based evidence that may explain why TRF sometimes fails in fighting obesity/metabolic dysfunction-associated steatotic liver disease in clinics.

Preliminary study on the diagnostic value of LEAP-2 and CK18 in biopsy-proven MAFLD

Metabolic Dysfunction-Associated Fatty Liver Disease (MAFLD) has become the leading cause of chronic liver disease. Liver biopsy, as the diagnostic gold standard, is invasive and has sampling bias, making it particularly important to search for sensitive and specific biomarkers for diagnosis. Cytokeratin 18 (CK18) M30 and M65 are products of liver cell apoptosis and necrosis, respectively, and liver-expressed antimicrobial peptide 2 (LEAP-2) is a related indicator of glucose and lipid metabolism. Correlation studies have found that all three indicators positively correlate with the liver enzymes alanine aminotransferase (ALT) and aspartate aminotransferase (AST). Through comparison of diagnostic values, it was found that CK18 M65 can better distinguish between healthy individuals and MAFLD; LEAP-2 can effectively distinguish MAFLD from other liver diseases, especially ALD.

Dual and Triple Incretin-Based Co-agonists: Novel Therapeutics for Obesity and Diabetes

The discovery of long-acting incretin receptor agonists represents a major stride forward in tackling the dual epidemic of obesity and diabetes. Here we outline the evolution of incretin-based pharmacotherapy, from exendin-4 to the discovery of the multi-incretin hormone receptor agonists that look set to be our next step toward curing diabetes and obesity. We discuss the multiagonists currently in clinical trials and the improvement in efficacy each new generation of these drugs bring. The success of these agents in preclinical models and clinical trials suggests a promising future for multiagonists in the treatment of metabolic diseases, with the most recent glucose-dependent insulinotropic peptide receptor:glucagon-like peptide 1 receptor:glucagon receptor (GIPR:GLP-1R:GCGR) triagonists rivaling the efficacy of bariatric surgery. However, further research is needed to fully understand how these therapies exert their effect on body weight and in the last section we cover open questions about the potential mechanisms of multiagonist drugs, and the understanding of how gut-brain communication can be leveraged to achieve sustained body weight loss without adverse effects.

Impact of Ghrelin on Islet Size in Nonpregnant and Pregnant Female Mice

Reducing ghrelin by ghrelin gene knockout (GKO), ghrelin-cell ablation, or high-fat diet feeding increases islet size and β-cell mass in male mice. Here we determined if reducing ghrelin also enlarges islets in females and if pregnancy-associated changes in islet size are related to reduced ghrelin. Islet size and β-cell mass were larger (P = .057 for β-cell mass) in female GKO mice. Pregnancy was associated with reduced ghrelin and increased liver-expressed antimicrobial peptide-2 (LEAP2; a ghrelin receptor antagonist) in wild-type mice. Ghrelin deletion and pregnancy each increased islet size (by ∼19.9-30.2% and ∼34.9-46.4%, respectively), percentage of large islets (>25 µm2×103, by ∼21.8-42% and ∼21.2-41.2%, respectively), and β-cell mass (by ∼15.7-23.8% and ∼65.2-76.8%, respectively). Neither islet cross-sectional area, β-cell cross-sectional area, nor β-cell mass correlated with plasma ghrelin, although all positively correlated with LEAP2 (P = .081 for islet cross-sectional area). In ad lib-fed mice, there was an effect of pregnancy, but not ghrelin deletion, to change (raise) plasma insulin without impacting blood glucose. Similarly, there was an effect of pregnancy, but not ghrelin deletion, to change (lower) blood glucose area under the curve during a glucose tolerance test. Thus, genetic deletion of ghrelin increases islet size and β-cell cross-sectional area in female mice, similar to males. Yet, despite pregnancy-associated reductions in ghrelin, other factors appear to govern islet enlargement and changes to insulin sensitivity and glucose tolerance in the setting of pregnancy. In the case of islet size and β-cell mass, one of those factors may be the pregnancy-associated increase in LEAP2.

Pre-prandial plasma liver-expressed antimicrobial peptide 2 (LEAP2) concentration in humans is inversely associated with hunger sensation in a ghrelin independent manner

PURPOSE

The liver-expressed antimicrobial peptide 2 (LEAP2) is a newly recognized peptide hormone that acts via the growth hormone secretagogue receptor (GHSR) blunting the effects of ghrelin and displaying ghrelin-independent actions. Since the implications of LEAP2 are beginning to be elucidated, we investigated if plasma LEAP2 concentration varies with feeding status or sex and whether it is associated with glucose metabolism and appetite sensations.

METHODS

We performed a single test meal study, in which plasma concentrations of LEAP2, ghrelin, insulin and glucose as well as visual analogue scales for hunger, desire to eat, prospective food consumption, fullness were assessed before and 60 min after breakfast in 44 participants (n = 21 females) with normal weight (NW) or overweight/obesity (OW/OB).

RESULTS

Pre-prandial plasma LEAP2 concentration was ~ 1.6-fold higher whereas ghrelin was ~ 2.0-fold lower in individuals with OW/OB (p < 0.001) independently of sex. After adjusting for body mass index (BMI) and sex, pre-prandial plasma LEAP2 concentration displayed a direct relationship with BMI (β: 0.09; 95%CI: 0.05, 0.13; p < 0.001), fat mass (β: 0.05; 95%CI: 0.01, 0.09; p = 0.010) and glycemia (β: 0.24; 95%CI: 0.05, 0.43; p = 0.021), whereas plasma ghrelin concentration displayed an inverse relationship with BMI and fat mass but not with glycemia. Postprandial plasma LEAP2 concentration increased ~ 58% in females with OW/OB (p = 0.045) but not in females with NW or in males. Pre-prandial plasma LEAP2 concentration displayed an inverse relationship with hunger score (β: - 11.16; 95% CI: - 18.52, - 3.79; p = 0.004), in a BMI-, sex- and ghrelin-independent manner.

CONCLUSIONS

LEAP2 emerges as a key hormone implicated in the regulation of metabolism and appetite in humans.

TRIAL REGISTRATION

The study was retrospectively registered in clinicaltrials.gov (April 2023).

CLINICALTRIALS

gov Identifier: NCT05815641.

The intersection between ghrelin, metabolism and circadian rhythms

Despite the growing popular interest in sleep and diet, many gaps exist in our scientific understanding of the interaction between circadian rhythms and metabolism. In this Review, we explore a promising, bidirectional role for ghrelin in mediating this interaction. Ghrelin both influences and is influenced by central and peripheral circadian systems. Specifically, we focus on how ghrelin impacts outputs of circadian rhythm, including neuronal activity, circulating growth hormone levels, locomotor activity and eating behaviour. We also consider the effects of circadian rhythms on ghrelin expression and the consequences of disrupted circadian patterns, such as shift work and jet lag, on ghrelin secretion. Our Review is aimed at both the casual reader interested in gaining more insight into the scientific context surrounding the trending topics of sleep and metabolism, as well as experienced scientists in the fields of ghrelin and circadian biology seeking inspiration and a comprehensive overview of how these fields are related.

Obesity surgery and neural correlates of human eating behaviour: A systematic review of functional MRI studies

Changes in eating behaviour including reductions in appetite and food intake, and healthier food cue reactivity, reward, hedonics and potentially also preference, contribute to weight loss and its health benefits after obesity surgery. Functional magnetic resonance imaging (fMRI) has been increasingly used to interrogate the neural correlates of eating behaviour in obesity, including brain reward-cognitive systems, changes after obesity surgery, and links with alterations in the gut-hormone-brain axis. Neural responses to food cues can be measured by changes in blood oxygen level dependent (BOLD) signal in brain regions involved in reward processing, including caudate, putamen, nucleus accumbens, insula, amygdala, orbitofrontal cortex, and top-down inhibitory control, including dorsolateral prefrontal cortex (dlPFC). This systematic review aimed to examine: (i) results of human fMRI studies involving obesity surgery, (ii) important methodological differences in study design across studies, and (iii) correlations and associations of fMRI findings with clinical outcomes, other eating behaviour measures and mechanistic measures. Of 741 articles identified, 23 were eligible for inclusion: 16 (69.6%) longitudinal, two (8.7%) predictive, and five (21.7%) cross-sectional studies. Seventeen studies (77.3%) included patients having Roux-en-Y gastric bypass (RYGB) surgery, six (26.1%) vertical sleeve gastrectomy (VSG), and five (21.7%) laparoscopic adjustable gastric banding (LAGB). The majority of studies (86.0%) were identified as having a very low risk of bias, though only six (27.3%) were controlled interventional studies, with none including randomisation to surgical and control interventions. The remaining studies (14.0%) had a low risk of bias driven by their control groups not having an active treatment. After RYGB surgery, food cue reactivity often decreased or was unchanged in brain reward systems, and there were inconsistent findings as to whether reductions in food cue reactivity was greater for high-energy than low-energy foods. There was minimal evidence from studies of VSG and LAGB surgeries for changes in food cue reactivity in brain reward systems, though effects of VSG surgery on food cue reactivity in the dlPFC were more consistently found. There was consistent evidence for post-operative increases in satiety gut hormones glucagon-like-peptide 1 (GLP-1) and peptide YY (PYY) mediating reduced food cue reactivity after RYGB surgery, including two interventional studies. Methodological heterogeneity across studies, including nutritional state, nature of food cues, post-operative timing, lack of control groups for order effects and weight loss or dietary/psychological advice, and often small sample sizes, limited the conclusions that could be drawn, especially for correlational analyses with clinical outcomes, other eating behaviour measures and potential mediators. This systematic review provides a detailed data resource for those performing or analysing fMRI studies of obesity surgery and makes suggestions to help improve reporting and design of such studies, as well as future directions.

G protein-coupled receptors and obesity

G protein-coupled receptors (GPCRs) have emerged as important drug targets for various chronic diseases, including obesity and diabetes. Obesity is a complex chronic disease that requires long term management predisposing to type 2 diabetes, heart disease, and some cancers. The therapeutic landscape for GPCR as targets of anti-obesity medications has undergone significant changes with the approval of semaglutide, the first peptide glucagon like peptide 1 receptor agonist (GLP-1RA) achieving double digit weight loss (≥10%) and cardiovascular benefits. The enhanced weight loss, with the expected beneficial effect on obesity-related complications and reduction of major adverse cardiovascular events (MACE), has propelled the commercial opportunity for the obesity market leading to new players entering the space. Significant progress has been made on approaches targeting GPCRs such as single peptides that simultaneously activate GIP and/or GCGR in addition to GLP1, oral tablet formulation of GLP-1, small molecules nonpeptidic oral GLP1R and fixed-dose combination as well as add-on therapy for patients already treated with a GLP-1 agonist.

High-Fat Diet Induces Resistance to Ghrelin and LEAP2 Peptide Analogs in Mice

Recent data suggest that the orexigenic peptide ghrelin and liver-expressed antimicrobial peptide 2 (LEAP2) have opposing effects on food intake regulation. Although circulating ghrelin is decreased in obesity, peripheral ghrelin administration does not induce food intake in obese mice. Limited information is available on ghrelin resistance in relation to LEAP2. In this study, the interplay between ghrelin and LEAP2 in obesity induced by a high-fat (HF) diet in mice was studied. First, the progression of obesity and intolerance to glucose together with plasma levels of active and total ghrelin, leptin, as well as liver LEAP2 mRNA expression at different time points of HF diet feeding was examined. In addition, the impact of switch from a HF diet to a standard diet on plasma ghrelin and LEAP2 production was studied. Second, sensitivity to the stable ghrelin analogue [Dpr3]Ghrelin or our novel LEAP2 analogue palm-LEAP2(1-14) during the progression of HF diet-induced obesity and after the switch for standard diet was investigated. Food intake was monitored after acute subcutaneous administration. HF diet feeding decreased both active and total plasma ghrelin and increased liver LEAP2 mRNA expression along with intolerance to glucose and the switch to a standard diet normalized liver LEAP2 mRNA expression and plasma level of active ghrelin, but not of total ghrelin. Additionally, our study demonstrates that a HF diet causes resistance to [Dpr3]Ghrelin, reversible by switch to St diet, followed by resistance to palm-LEAP2(1-14). Further studies are needed to determine the long-term effects of LEAP2 analogues on obesity-related ghrelin resistance.

The role of dysregulated ghrelin/LEAP-2 balance in anorexia nervosa

LEAP-2 is a ghrelin antagonist with an anorexigenic drive. This study investigates the evolution of plasma ghrelin and LEAP-2 concentrations in 29 patients with anorexia nervosa (AN) before and after refeeding and compares it to physiological adaptations during fasting in healthy controls or to mouse model of chronic food restriction and refeeding. Acute and chronic food restriction decrease LEAP-2 and increase ghrelin concentrations in both humans and mice, while patients with AN displayed higher ghrelin and LEAP-2 concentrations before than after refeeding (p = 0.043). After 6 months follow-up, patients with unstable weight gain (n = 17) had significantly decreased LEAP-2 concentrations after refeeding (p = 0.044), in contrast to patients with stable weight gain (n = 12). We provide evidence that the ghrelin/LEAP-2 system is not regulated according to the nutritional status in AN, in contrast to what is physiologically expected when coping with food restriction.

LEAP2 is associated with cardiometabolic markers but is unchanged by antidiabetic treatment in people with prediabetes

To examine whether fasting plasma liver-expressed antimicrobial peptide 2 (FP-LEAP2) is associated with markers of cardiometabolic disease susceptibility in a cohort with prediabetes and overweight/obesity and whether antidiabetic interventions affect FP-LEAP2 levels. The analysis included 115 individuals with prediabetes [hemoglobin A1c (HbA1c) 39-47 mmol/mol, 5.7%-6.4%] and overweight/obesity [body mass index (BMI) ≥ 25 kg/m2] from a randomized controlled trial. Changes in FP-LEAP2 levels were assessed in relation to treatment with dapagliflozin (10 mg once daily), metformin (1,700 mg daily), or interval-based exercise (5 days/wk, 30 min/session) compared with control (habitual lifestyle) after 6 and 13 wk of treatment. FP-LEAP2 levels were positively associated with [standardized beta coefficient (95% CI)]: BMI 0.22 (0.03:0.41), P = 0.027; body weight 0.27 (0.06:0.48), P = 0.013; fat mass 0.2 (0.00:0.4), P = 0.048; lean mass 0.47 (0.13:0.8), P = 0.008; HbA1c 0.35 (0.17:0.53), P < 0.001; fasting plasma glucose (FPG) 0.32 (0.12:0.51), P = 0.001; fasting serum insulin 0.28 (0.09:0.47), P = 0.005; total cholesterol 0.19 (0.01:0.38), P = 0.043; triglycerides 0.31 (0.13:0.5), P < 0.001; and transaminases and fatty liver index (standardized beta coefficients 0.23-0.32), all P < 0.020. FP-LEAP2 levels were inversely associated with insulin sensitivity [-0.22 (-0.41: -0.03), P = 0.022] and kidney function [estimated glomerular filtration rate (eGFR) -0.34 (-0.56: -0.12), P = 0.003]. FP-LEAP2 levels were not associated with fat distribution or body fat percentage, fasting glucagon, postload glucose, β-cell function, or low-density lipoprotein. The interventions were not associated with changes in FP-LEAP2. FP-LEAP2 is associated with body mass, impaired insulin sensitivity, liver-specific enzymes, and kidney function. The findings highlight the importance of studying LEAP2 in obesity, type 2 diabetes, and nonalcoholic fatty liver disease. FP-LEAP2 was not affected by metformin, dapaglifloxin, or exercise in this population.NEW & NOTEWORTHY LEAP2, primarily secreted by the liver, increases with greater body mass, insulin resistance, and liver-specific enzymes in individuals with prediabetes and overweight or obesity. Fasting glucose, body mass, and alanine aminotransferase independently predict LEAP2 levels. LEAP2 is inversely linked to impaired kidney function. Elevated LEAP2 levels might indicate an increased metabolic risk, warranting further investigation into its potential involvement in glucose and body weight control.

Postprandial Increases in Liver-Gut Hormone LEAP2 Correlate with Attenuated Eating Behavior in Adults Without Obesity

Background

The novel liver-gut hormone liver-expressed antimicrobial peptide-2 (LEAP2) is a centrally acting inverse agonist, and competitive antagonist of orexigenic acyl ghrelin (AG), at the GH secretagogue receptor, reducing food intake in rodents. In humans, the effects of LEAP2 on eating behavior and mechanisms behind the postprandial increase in LEAP2 are unclear, though this is reciprocal to the postprandial decrease in plasma AG.

Methods

Plasma LEAP2 was measured in a secondary analysis of a previous study. Twenty-two adults without obesity attended after an overnight fast, consuming a 730-kcal meal without or with subcutaneous AG administration. Postprandial changes in plasma LEAP2 were correlated with postprandial changes in appetite, high-energy (HE) or low-energy (LE) food cue reactivity using functional magnetic resonance imaging, ad libitum food intake, and plasma/serum AG, glucose, insulin, and triglycerides.

Results

Postprandial plasma LEAP2 increased by 24.5% to 52.2% at 70 to 150 minutes, but was unchanged by exogenous AG administration. Postprandial increases in LEAP2 correlated positively with postprandial decreases in appetite, and cue reactivity to HE/LE and HE food in anteroposterior cingulate cortex, paracingulate cortex, frontal pole, and middle frontal gyrus, with similar trend for food intake. Postprandial increases in LEAP2 correlated negatively with body mass index, but did not correlate positively with increases in glucose, insulin, or triglycerides, nor decreases in AG.

Conclusions

These correlational findings are consistent with a role for postprandial increases in plasma LEAP2 in suppressing human eating behavior in adults without obesity. Postprandial increases in plasma LEAP2 are unrelated to changes in plasma AG and the mediator(s) remain uncertain.

Liver-expressed antimicrobial peptide 2 elevation contributes to age-associated cognitive decline

Elderly individuals frequently report cognitive decline, while various studies indicate hippocampal functional declines with advancing age. Hippocampal function is influenced by ghrelin through hippocampus-expressed growth hormone secretagogue receptor (GHSR). Liver-expressed antimicrobial peptide 2 (LEAP2) is an endogenous GHSR antagonist that attenuates ghrelin signaling. Here, we measured plasma ghrelin and LEAP2 levels in a cohort of cognitively normal individuals older than 60 and found that LEAP2 increased with age while ghrelin (also referred to in literature as "acyl-ghrelin") marginally declined. In this cohort, plasma LEAP2/ghrelin molar ratios were inversely associated with Mini-Mental State Examination scores. Studies in mice showed an age-dependent inverse relationship between plasma LEAP2/ghrelin molar ratio and hippocampal lesions. In aged mice, restoration of the LEAP2/ghrelin balance to youth-associated levels with lentiviral shRNA Leap2 downregulation improved cognitive performance and mitigated various age-related hippocampal deficiencies such as CA1 region synaptic loss, declines in neurogenesis, and neuroinflammation. Our data collectively suggest that LEAP2/ghrelin molar ratio elevation may adversely affect hippocampal function and, consequently, cognitive performance; thus, it may serve as a biomarker of age-related cognitive decline. Moreover, targeting LEAP2 and ghrelin in a manner that lowers the plasma LEAP2/ghrelin molar ratio could benefit cognitive performance in elderly individuals for rejuvenation of memory.

RISING STARS: Targeting G protein-coupled receptors to regulate energy homeostasis

G protein-coupled receptors (GPCRs) have a critical role in energy homeostasis, contributing to food intake, energy expenditure and glycaemic control. Dysregulation of energy expenditure can lead to metabolic syndrome (abdominal obesity, elevated plasma triglyceride, LDL cholesterol and glucose, and high blood pressure), which is associated with an increased risk of developing obesity, diabetes mellitus, non-alcoholic fatty liver disease and cardiovascular complications. As the prevalence of these chronic diseases continues to rise worldwide, there is an increased need to understand the molecular mechanisms by which energy expenditure is regulated to facilitate the development of effective therapeutic strategies to treat and prevent these conditions. In recent years, drugs targeting GPCRs have been the focus of efforts to improve treatments for type-2 diabetes and obesity, with GLP-1R agonists a particular success. In this review, we focus on nine GPCRs with roles in energy homeostasis that are current and emerging targets to treat obesity and diabetes. We discuss findings from pre-clinical models and clinical trials of drugs targeting these receptors and challenges that must be overcome before these drugs can be routinely used in clinics. We also describe new insights into how these receptors signal, including how accessory proteins, biased signalling, and complex spatial signalling could provide unique opportunities to develop more efficacious therapies with fewer side effects. Finally, we describe how combined therapies, in which multiple GPCRs are targeted, may improve clinical outcomes and reduce off-target effects.

Liver-expressed antimicrobial peptide 2 is associated with improved pancreatic insulin secretion in adults with overweight and obesity

AIMS

To examine association of liver-expressed antimicrobial peptide 2 (LEAP2), an endogenous ghrelin antagonist with anorexiant effects, to key cardiometabolic risk factors in people with overweight and obesity.

METHODS

In this cross-sectional study, we sought to identify associations between LEAP2 levels and cardiometabolic risk factors, including body composition (dual X-ray absorptiometry), insulin and glucose metabolism (oral and intravenous glucose tolerance tests and hyperinsulinaemic-euglycaemic clamps), plasma lipids and inflammation markers (ELISA and multiplex assays).

RESULTS

In 65 participants with overweight or obesity (63.1% male, mean age 31.3 ± 8.5 years), LEAP2 levels were associated with total body fat, but not with body mass index or waist-hip ratio in both univariable and age- and sex-adjusted models (P < 0.05). Higher LEAP2 level was also positively associated with higher insulin secretion in univariable (P = 0.047) and multivariable models adjusted for age, sex and body fat (P = 0.03), but not with fasting glucose levels (P ≥ 0.05). Higher LEAP2 levels were associated insulin resistance (P = 0.07) after adjustment for age and sex, but the association disappeared after an additional adjustment for body fat (P = 0.2). There was an inverse association between LEAP2 levels and nuclear factor kappa-B (NFκB) activity in the peripheral blood mononuclear cells in age-, sex- and body fat-adjusted models (P = 0.04). There were no associations with cardiovascular risk factors (lipids, blood pressure) or other inflammation markers.

CONCLUSIONS

These results provide important insights into the association between LEAP2 and cardiometabolic health in a high-risk population of individuals with overweight and obesity. This is a first report of an association between LEAP2 and insulin secretion, insulin sensitivity and NFκB activity. LEAP2 may represent an important potential therapeutic target to promote insulin secretion in people with type 2 diabetes and obesity.

Liver-Expressed Antimicrobial Peptide 2 Is a Hepatokine That Predicts Weight Loss and Complete Remission of Type 2 Diabetes Mellitus after Vertical Sleeve Gastrectomy in Japanese Individuals

INTRODUCTION

Vertical sleeve gastrectomy (VSG) is considered one of the most effective treatments for sustained weight loss and complete remission of type 2 diabetes mellitus (CR-T2DM). Liver-expressed antimicrobial peptide 2 (LEAP2), a ghrelin receptor antagonist peptide, is a metabolic hormone regulated by VSG. However, it is unknown whether LEAP2 can be used to predict the outcomes of VSG. This study aimed to evaluate LEAP2 as a predictive factor for weight loss and CR-T2DM after VSG.

METHODS

This retrospective study included 39 Japanese participants with obesity who underwent VSG. Serum LEAP2, des-acyl ghrelin (DAG), and other metabolic and anthropometric parameters were studied before and at 12 months after VSG. Receiver operating characteristics (ROC) curve was generated to evaluate predictive score for weight loss with cut-off value of >50 percent excess weight loss. ROC curve was also generated to assess CR-T2DM.

RESULTS

Serum LEAP2 levels were significantly higher in participants with body mass index (BMI) 32-50 kg/m2 than in those with normal weight. Participants with BMI >50 kg/m2 had lower serum LEAP2 concentrations than those with BMI 32-50 kg/m2. VSG caused a significant reduction in serum DAG concentrations, but it did not affect serum LEAP2 concentrations in either male or female participants. Preoperative serum LEAP2 concentration of 2.88 pmol/mL was the optimal cutoff value for predicting weight loss after VSG, with sensitivity of 80.0% and specificity of 75.9%. Preoperative serum LEAP2 level higher than 4.67 pmol/mL predicted CR-T2DM after VSG with sensitivity of 100% and specificity of 58.8%.

CONCLUSION

Preoperative serum LEAP2 could predict weight loss and CR-T2DM as outcomes of VSG.

Protocol for assessing the effects of exogenous hormone administration on human postprandial glucose metabolism, appetite sensations, and food intake

Here, we present a protocol for a randomized, double-blind, placebo-controlled, crossover trial to evaluate the effects of a continuous intravenous infusion of a native liver-derived hormone, liver-expressed antimicrobial peptide 2 (LEAP2), on postprandial glucose metabolism, appetite and satiety sensations, and ad libitum food intake in humans. We describe the preparation of the exogenous hormone administration and participants. We then detail the liquid mixed meal, ad libitum meal test, and blood sampling procedures for assessing postprandial glucose metabolism and food intake. For complete details on the use and execution of this protocol, please refer to Hagemann et al. (2022).1.

Feeding-induced hepatokines and crosstalk with multi-organ: A novel therapeutic target for Type 2 diabetes

Hyperglycemia, which can be caused by either an insulin deficit and/or insulin resistance, is the main symptom of Type 2 diabetes, a significant endocrine metabolic illness. Conventional medications, including insulin and oral antidiabetic medicines, can alleviate the signs of diabetes but cannot restore insulin release in a physiologically normal amount. The liver detects and reacts to shifts in the nutritional condition that occur under a wide variety of metabolic situations, making it an essential organ for maintaining energy homeostasis. It also performs a crucial function in glucolipid metabolism through the secretion of hepatokines. Emerging research shows that feeding induces hepatokines release, which regulates glucose and lipid metabolism. Notably, these feeding-induced hepatokines act on multiple organs to regulate glucolipotoxicity and thus influence the development of T2DM. In this review, we focus on describing how feeding-induced cross-talk between hepatokines, including Adropin, Manf, Leap2 and Pcsk9, and metabolic organs (e.g.brain, heart, pancreas, and adipose tissue) affects metabolic disorders, thus revealing a novel approach for both controlling and managing of Type 2 diabetes as a promising medication.

Plasma LEAP-2 Following a Low-Calorie Diet with or without Interval Exercise in Women with Obesity

Liver-expressed antimicrobial peptide-2 (LEAP-2) is associated with caloric intake and glucose metabolism. Purpose: Assess if a low-calorie diet with interval exercise (LCD+INT) raises LEAP-2 more than LCD in relation to appetite and cardiometabolic health. Methods: Women with obesity were randomized to either 2 weeks of LCD (n = 13, ~1200 kcal/d) or LCD+INT (n = 12; 60 min/d) of INT at 3 min of 90% and 50% HRpeak, respectively. LEAP-2 and acylated ghrelin (AG) were measured at 0, 30, and 60 min, while glucose, insulin, C-peptide, and free fatty acids (FFA) were obtained up to 180 min of a 75 g OGTT. Fasting and 120 min OGTT appetite were assessed via visual analog scales. Results: LCD reduced the BMI (p < 0.001) compared with LCD+INT, but only LCD+INT increased the VO2 max (p = 0.04). Treatments reduced fasting LEAP-2 (p = 0.05), but only LCD increased LEAP-2 iAUC60 min (p = 0.06) and post-prandial LEAP-2 stimulation (p = 0.02). Higher post-LEAP-260 min tended to relate to a lower desire to eat 120 min of sweet (r = 0.40, p = 0.07) and salty foods (r = 0.41, p = 0.06), as well as lower AG30 min (r = -0.51, p = 0.01) and higher FFA iAUC180 min (r = 0.56, p = 0.007) post-treatment. Conclusion: LCD, with or without INT, reduced fasting LEAP-2, but only LCD raised post-prandial LEAP-2. How diet and exercise impact LEAP-2 for lower chronic disease risk awaits further investigation.

Role of the ghrelin system in alcohol use disorder and alcohol-associated liver disease: A narrative review

Unhealthy alcohol consumption is a global health problem. Adverse individual, public health, and socioeconomic consequences are attributable to harmful alcohol use. Epidemiological studies have shown that alcohol use disorder (AUD) and alcohol-associated liver disease (ALD) are the top two pathologies among alcohol-related diseases. Consistent with the major role that the liver plays in alcohol metabolism, uncontrolled drinking may cause significant damage to the liver. This damage is initiated by excessive fat accumulation in the liver, which can further progress to advanced liver disease. The only effective therapeutic strategies currently available for ALD are alcohol abstinence or liver transplantation. Any molecule with dual-pronged effects at the central and peripheral organs controlling addictive behaviors and associated metabolic pathways are a potentially important therapeutic target for treating AUD and ALD. Ghrelin, a hormone primarily derived from the stomach, has such properties, and regulates both behavioral and metabolic functions. In this review, we highlight recent advances in understanding the peripheral and central functions of the ghrelin system and its role in AUD and ALD pathogenesis. We first discuss the correlation between blood ghrelin concentrations and alcohol use or abstinence. Next, we discuss the role of ghrelin in alcohol-seeking behaviors and finally its role in the development of fatty liver by metabolic regulations and organ crosstalk. We propose that a better understanding of the ghrelin system could open an innovative avenue for improved treatments for AUD and associated medical consequences, including ALD.

Involvement of POMC neurons in LEAP2 regulation of food intake and body weight

Liver-expressed antimicrobial peptide 2 (LEAP2) is a newly discovered antagonist of the growth hormone secretagogue receptor (GHSR) and is considered the first endogenous peptide that can antagonize the metabolic actions of ghrelin. The effects of ghrelin administration on feeding behavior, body weight, and energy metabolism involve the activation of orexigenic neurons in the arcuate nucleus (ARC) of the hypothalamus. It is unclear, however, if LEAP2 applied directly to the ARC of the hypothalamus affects these metabolic processes. Here, we show that overexpression of LEAP2 in the ARC through adeno-associated virus (AAV) reduced food intake and body weight in wild-type (WT) mice fed chow and a high-fat diet (HFD) and improved metabolic disorders. LEAP2 overexpression in the ARC overrides both central and peripheral ghrelin action on a chow diet. Interestingly, this AAV-LEAP2 treatment increased proopiomelanocortin (POMC) expression while agouti-related peptide (AGRP)/neuropeptide Y (NPY) and GHSR levels remained unchanged in the hypothalamus. Additionally, intracerebroventricular (i.c.v.) administration of LEAP2 decreased food intake, increased POMC neuronal activity, and repeated LEAP2 administration to mice induced body weight loss. Using chemogenetic manipulations, we found that inhibition of POMC neurons abolished the anorexigenic effect of LEAP2. These results demonstrate that central delivery of LEAP2 leads to appetite-suppressing and body weight reduction, which might require activation of POMC neurons in the ARC.