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Obesity is a complex, multifactorial disease wherein the excessive accumulation of adipose tissue leads to adverse health outcomes, such as diabetes, cardiovascular disease and musculoskeletal disorders. Obesity also impacts both the risk and the clinical prognosis of heart failure (HF). The accumulation of adipose tissue results in metabolic dysregulation, including increased levels of pro-inflammatory cytokines and adipokines. These alterations are strongly associated with the development and progression of HF. Another significant comorbidity in patients with HF is sarcopenia, characterized by progressive loss of muscle mass and strength, affecting the quality of life. The study aims to critically synthesize the mechanisms by which modern pharmacological treatments-sodium-glucose cotransporter-2 (SGLT2) inhibitors, glucagon-like peptide-1 receptor (GLP-1R) agonists, and dual GIPR/GLP-1R agonists-modulate body mass composition, and to analyze the specific implications of these changes (e.g., visceral fat reduction versus lean mass loss) for heart failure (HF) prognosis and management. Show less

Pancreatic alpha cells modulate beta cell function in a paracrine manner through the release of glucagon. However, the detailed molecular architecture underlying alpha-to-beta cell regulation remains poorly characterized. Here, we show that the glucagon-like peptide-1 receptor (GLP1R) is enriched as nanodomains on beta cell membranes that contact alpha cells, in keeping with increased single-molecule transcript expression. At low glucose, beta cells next to alpha cells directly sense micromolar glucagon release by pre-internalizing GLP1R. Pre-internalized GLP1R is associated with earlier beta cell Ca Show less

The incretin receptor agonists semaglutide and tirzepatide have transformed the medical management of obesity. The neural mechanisms by which incretin analogs regulate appetite remain incompletely understood, and dissecting this process is critical for the development of next-generation antiobesity drugs that are more targeted and tolerable. Moreover, the physiologic functions of incretins in appetite regulation and gut-brain communication have remained elusive. Using in vivo fiber photometry, we discovered distinct pharmacologic and physiologic roles for the incretin hormones glucose-dependent insulinotropic peptide (GIP) and glucagon-like peptide-1 (GLP-1). We showed that GIP, but not GLP-1, was required for normal nutrient-mediated inhibition of hunger-promoting AgRP neurons. By contrast, both GIP and GLP-1 analogs at pharmacologic doses were sufficient to inhibit AgRP neurons. The magnitude of neural inhibition was proportional to the effect of each incretin on food intake, and dual GIP and GLP-1 receptor agonism more potently inhibited AgRP neurons and suppressed food intake than either agonist alone. Our results have revealed a role for endogenous GIP in gut-brain appetite regulation and indicate that incretin analogs act in part via AgRP neurons to mediate their anorectic effects. Show less

Insulin secretory granule (ISG) maturation is a crucial aspect of insulin secretion and glucose homeostasis. The regulation of this maturation remains poorly understood, especially how secretory stimuli affect ISG maturity and subcellular localization. In this study, we used soft X-ray tomography (SXT) to quantitatively map ISG morphology, density, and location in single INS-1E and mouse pancreatic β cells under the effect of various secretory stimuli. We found that the activation of glucokinase (GK), gastric inhibitory polypeptide receptor (GIPR), glucagon-like peptide-1 receptor (GLP-1R), and G protein-coupled receptor 40 (GPR40) promotes ISG maturation. Each stimulus induces unique structural remodeling in ISGs, by altering size and density, depending on the specific signaling cascades activated. These distinct ISG subpopulations mobilize and redistribute in the cell, altering the overall cellular structural organization. Our results provide insight into how current diabetes and obesity therapies impact ISG maturation and may inform the development of future treatments that target maturation specifically. Show less

Metabolic dysfunction-associated steatotic liver disease (MASLD) is a leading cause of chronic liver disease globally, yet it lacks any approved pharmacological therapies. Dual glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) agonists have shown clinical promise, but their causal effect on MASLD remains unestablished. This study uses genetic evidence to evaluate the causal role of dual GLP-1R/GIPR agonists on MASLD and to explore its underlying mechanisms. Using a novel approach combining Mendelian randomization (MR) and Bayesian colocalization, we constructed a high-confidence genetic proxy for dual GLP-1R/GIPR agonists based on five genetic variants strongly associated with both mRNA expression and HbA1c levels. We then performed two-sample MR to assess the causal effect of this genetically proxied effect on MASLD and related metabolic risk abnormalities. Genetically proxied dual GLP-1R/GIPR agonists was causally associated with a substantially reduced risk of MASLD (OR: 0.24, 95 % CI: 0.08-0.75, P = 0.01). This protective effect was accompanied by significant improvements in systemic metabolic health, including increased high-density lipoprotein cholesterol (Beta: 0.39, 95 % CI: 0.13-0.66, P = 3.40 × 10 This study provides causal evidence that dual GLP-1R/GIPR agonists protects against MASLD. The mechanism likely involves broad improvements in lipid metabolism and insulin sensitivity. These findings offer strong genetic validation for this therapeutic strategy and provide a compelling rationale for its continued clinical development for the treatment of MASLD. Show less

In this study, to achieve more effective blood sugar lowering and weight-loss effects, eight glucagon-like peptide-1 (GLP-1)/glucose-dependent insulinotropic peptide (GIP)/glucagon (GCG) triple receptor agonists were designed and synthesized. Their sixteen related conjugates were obtained through Cys alkylation and Lys esterification modifications with two fatty acid side chains, respectively. After chemical structure confirmation using high-resolution mass spectrometry and peptide mapping, in vitro and in vivo biological effects of TRA01-24 were assessed. The structure-activity relationship (SAR) data on the amino acids, fatty acids, linkers and biological effects in vitro and in vivo of TRA01-24 have been summarized. Furthermore, peptide-protein molecular docking elucidated the structural basis for the biased agonist activity of TRA22 at GLP-1R, characterized by strong GLP-1R activation but weak GCGR and GIPR activation. In conclusion, a lead compound with excellent efficacy in vitro and in vivo, TRA24, was screened, which had better in vivo efficacy than tirzepatide in both normal and db/db mice. Show less

Epicardial adipose tissue (EAT), the visceral fat of the heart, is highly inflammatory fat depot with pro-inflammatory transcriptome and proteosome. EAT contributes to the development and progression of coronary artery disease (CAD) and atrial fibrillation (AF) through multifactorial inflammatory pathways. However, the paradigm linking EAT inflammation and cardiovascular risk was recently reevaluated. EAT inflammation may be also necessary process for adipose tissue remodeling and expansion to accommodate excess lipids. EAT inflammation may be also considered an adaptive response of adipose tissue to the effects of glucagon-like peptide-1 receptor (GLP-1Rs) and glucose-dependent insulinotropic polypeptide (GIP) analogs. The presence of GLP-1 (GLP-1R) and GIP receptors (GIP-R) suggest direct interaction of these agents with EAT. EAT GLP-1R and GIP-R activation can induce a beneficial balance between increased adipogenesis and reduced ectopic fat accumulation. Cardiovascular effects of liraglutide, semaglutide and tirzepatide can be mediated by EAT inflammation. Show less

The development of novel sophisticated medications that induce weight loss has revolutionized the management of people living with obesity (PwO). However, when body weight is reduced, muscle and bone are lost along with fat. In the present review, we quote and discuss existing evidence on the effects of the major anti-obesity medications on bone metabolism. Glucagon-like peptide-1 receptor (GLP-1R) agonists have shown a positive impact in preclinical studies but a neutral or negative, albeit not clinically significant, effect on bone turnover markers and bone mineral density in clinical studies. Nevertheless, fracture risk does not seem to increase with GLP-1R agonists use, at least in clinically relevant doses. Limited, mostly preclinical, data suggest that other incretin analogues, including dual GLP-1R and glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR) agonists, dual GLP-1R and glucagon receptor (GCGR) agonists, and triple GLP-1R, GIPR and GCGR agonists, may have a positive effect on bone. Preclinical data with amylin analogues imply the same. Activin type II receptor (ActRII) antagonists may combine anti-obesity effects with simultaneous muscle and bone mass preservation and could be used either as monotherapy or in combination with incretin analogues. The bone effects of opioid receptor antagonists and setmelanotide are largely unknown, while the impact of the combination of phentermine with topiramate is assumed to be negative. Finally, very limited clinical evidence suggests that orlistat may have a neutral effect on bone metabolism. Show less

G protein-coupled receptors (GPCRs) are transmembrane receptors that regulate intracellular signaling by interacting with G proteins and other effectors, influencing various physiological processes. The Glucose-dependent Insulinotropic Polypeptide Receptor (GIPR), a class B1 GPCR family member activated by GIP, regulates postprandial glycaemia by augmenting glucose-dependent insulin secretion, delaying gastric emptying, and suppressing appetite. Recent studies highlight the transmembrane domain (TMD) as the primary interface for dimerization, allowing GPCR to form homodimers or heterodimers with distinct physiological roles. However, the transient nature of these dimers challenges structural analysis, hindering experimental exploration and drug development. Computational methods now offer powerful tools for predicting such interactions. This study employs a hybrid approach, combining multiple protein docking software and dynamic structural optimization, to generate potential homodimeric models of GIPR-TMD. In addition, Next, validated models will provide insights into dimer activation mechanisms and support novel therapeutic discoveries. Show less

Glucagon-like peptide-1 receptor (GLP-1R)/glucose-dependent insulinotropic peptide receptor (GIPR) agonistic analogs have yielded superior results in enhancing glycemic control and weight management compared to GLP-1R agonism alone. Intriguingly, GIPR agonism appears to induce antiemetic effects, potentially alleviating part of the nausea and vomiting side effects common to GLP-1R agonists like semaglutide. Here, we show in rats and shrews that GIPR agonism blocks emesis and attenuates other malaise behaviors elicited by GLP-1R activation while maintaining reduced food intake and body weight loss and improved glucose tolerance. The GLP-1R/GIPR agonist tirzepatide induced significantly fewer side effects than equipotent doses of semaglutide. These findings underscore the therapeutic potential of combined pharmaceutical strategies activating both incretin systems, leading to enhanced therapeutic index and reduced occurrence of nausea and vomiting for obesity and diabetes treatments. Show less

The incretin peptides glucose-dependent insulinotropic polypeptide and glucagon-like peptide-1 receptors coordinate β cell secretion that is proportional to nutrient intake. This effect permits consistent and restricted glucose excursions across a range of carbohydrate intake. The canonical signaling downstream of ligand-activated incretin receptors involves coupling to Gαs protein and generation of intracellular cAMP. However, recent reports have highlighted the importance of additional signaling nodes engaged by incretin receptors, including other G proteins and β-arrestin proteins. Here, the importance of Gαs signaling was tested in mice with conditional, postdevelopmental β cell deletion of Gnas (encoding Gαs) under physiological and pharmacological conditions. Deletion of Gαs/cAMP signaling induced immediate and profound hyperglycemia that responded minimally to incretin receptor agonists, a sulfonylurea, or bethanechol. While islet area and insulin content were not affected in Gnasβcell-/-, perifusion of isolated islets demonstrated impaired responses to glucose, incretins, acetylcholine, and IBMX In the absence of Gαs, incretin-stimulated insulin secretion was impaired but not absent, with some contribution from Gαq signaling. Collectively, these findings validate a central role for cAMP in mediating incretin signaling, but also demonstrate broad impairment of insulin secretion in the absence of Gαs that causes both fasting hyperglycemia and glucose intolerance. Show less

In combatting the obesity crisis, leveraging mechanisms that lower body weight is critical. The finding that treatment with tirzepatide, a glucose-dependent insulinotropic polypeptide (GIP) and glucagon-like peptide 1 (GLP-1) receptor agonist, produces profound weight loss highlights the value of activating the incretin receptors. Supporting this, recent studies have revealed mechanisms by which GIP receptor (GIPR) activation is beneficial in pancreatic islets, the central nervous system (CNS), and adipose tissue. Paradoxically, a hypothesis has emerged that GIPR antagonism could be an additional option in treating obesity. This concept stems from concern that GIP facilitates lipid uptake and storage in adipose tissue, although the lipid-buffering capacity of adipocytes versus other cell types is metabolically favorable. In this article, we highlight the natural physiology of the incretins, noting GIP as the primary incretin. In the CNS, GIPR agonism attenuates nausea and suppresses appetite, features that also help GLP-1 receptor agonism promote a negative energy balance. Further, we provide rationale that, in protecting against ectopic fat distribution and augmenting substrate utilization to promote insulin sensitivity, GIPR activity in adipose tissue is advantageous. Collectively, these attributes support GIPR agonism in the treatment of obesity and metabolic disease. Show less

The prevailing treatment of Parkinson's disease (PD) is not yet satisfactory. The present investigate the neuroprotective effect of the GLP-1/GIP dual agonist tirzepatide and examine the potential mechanisms involved. Analysis of GLP1 receptor (GLP1R) and GIPR expression alterations in dopaminergic neurons from PD patients in the GSE238129 dataset. The MPTP-induced subacute PD mice was treated with tirzepatide, semaglutide and levodopa. Behavioral tests and brain histopathology of mice were evaluated. The transmission electron microscopy revealed the presence of ultrastructural alterations in the mitochondrial morphology. The ATP level was assessed in substantia nigra. Western blot and immunohistochemical staining were employed to quantify Drp1 and mitophagy proteins. Furthermore, Drp1 inhibitor and mitophagy activator were used to treat MPTP-induced subacute PD mice, and lysosome inhibitor chloroquine (CQ) and the autophagy inhibitor 3-methyladenine (3-MA) were used in SY5Y cells for validation. The gene expression levels of both GLP1R and GIPR were significantly downregulated in dopaminergic neurons derived from PD patients. Tirzepatide could significantly ameliorate MPTP-induced the loss of tyrosine hydroxylase (TH) protein in the substantia nigra. There was no statistically difference observed between one-third doses of tirzepatide when compared with semaglutide and levodopa. In addition, tirzepatide not only improved mitochondrial ultrastructure, but also enhanced mitochondrial ATP content. Tirzepatide was found to reduce Drp1 expression and reverse the expressions of mitophagy-related proteins, including Pink1, Parkin, and p62. There was no statistically difference observed between one-third doses of tirzepatide compared with semaglutide in mitochondrial energy control. In addition, we observed that MPTP-induced subacute PD mice treated with a Drp1 inhibitor and mitophagy activator exhibited therapeutic effects. In SY5Y cells, lysosomal and autophagy inhibitors significantly reduced mitochondrial membrane potential, ATP levels, and the NAD+/NADH ratio. This study demonstrates that the benefits of tirzepatide extend to mitochondrial networks, achieved by means of the inhibition of mitochondrial pathological fission, the promotion of mitophagy, in MPTP-induced subacute PD mice or cells model. Show less

The pervasiveness and versatility of G protein-coupled receptors (GPCRs) in virtually all physiological processes is based on the receptors' capability to activate intracellular signal transduction pathways in response to diverse extracellular stimuli. While the importance of GPCRs makes them the largest group of drug targets (comprising about one-third of marketed medicines), more than half of GPCRs lack preclinical drug candidates because of high structural conservatism of their orthosteric sites. Recognizing that the mechanisms of GPCR function and regulation are chiefly allosteric in nature, we explore their allosteric control and the potential for developing allosteric drugs with high specificity. First, we obtained a picture of allosteric signaling in 280 non-olfactory GPCRs in human and explored archetypal structure-based patterns and sequence-determined variations of allosteric communication. We showed how the causality of allosteric effects due to ligand binding can be quantified, using the β Show less

Glucagon-like peptide 1 receptor (GLP-1R) agonists exhibit anti-inflammatory actions, yet the importance of direct immune cell GLP-1R signaling remains uncertain. Although T cells respond to GLP-1, low receptor abundance and suboptimal antisera complicate efforts to characterize immune cell GLP-1R signaling. Here, we evaluate three frequently utilized GLP-1R antibodies, revealing that one of several antibodies, AGR-021, lack ideal specificity for detecting the GLP-1R in mice. Immunostaining with AGR-021 using tissues from two independent GLP-1R knockout mouse lines reveals persistent immunoreactive signals in GLP-1R-null pancreatic islets. Similarly, flow cytometry using AGR-021 reveals no reduction in AGR-021 immunoreactivity in GLP-1R-null splenic T cells. Moreover, western blotting detects AGR-021-immunoreactive proteins from a GLP-1R-negative cell line and fails to detect immunoreactive GLP-1R of the correct size upon overexpression of the receptor. Our findings reveal caveats governing use of multiple widely used GLP-1R antibodies, reemphasizing the importance of rigorous antibody validation for inferring accurate GLP-1R expression. Show less

In response to extracellular ligands, G protein-coupled receptors (GPCRs) undergo conformational changes that induce coupling to intracellular effectors such as heterotrimeric G proteins that trigger various downstream signaling pathways. These events have been shown to be highly regulated by concerted effects of post-translational modifications (PTMs) that occur in a ligand-dependent manner. Most notably, phosphorylation of residues in the C-terminal cytoplasmic tail of GPCRs has been strongly implicated in promoting receptor interactions with β-arrestins (βarrs), which are cytosolic adaptor proteins that modulate G protein coupling, receptor internalization, and perhaps also serve as signaling modules in their own right. Here, we use proteomic methods to identify C-tail residues that are phosphorylated in the glucagon family of class B1 GPCRs (GLP-1R, GCGR, and GIPR) upon agonist addition. We demonstrate that the phosphorylation of GLP-1R and GIPR is a critical determinant in the formation of GPCR-βarr complexes. However, our results suggest that ligand-induced βarr recruitment to GCGR proceeds in a phosphorylation-independent manner. These findings highlight the importance of recognizing phosphorylation as a component in the regulation of class B1 GPCR signaling but also the need to consider how such phenomena may not necessarily yield identical effects on intracellular signaling cascades. Show less

Glucose-dependent insulinotropic peptide receptor (GIPR) stimulates insulin release and regulates metabolic homeostasis. GIPR function is shaped by spatiotemporal trafficking of this G protein-coupled receptor (GPCR). While GPCR endocytosis is traditionally associated with β-arrestin, GIPR internalization is only modestly dependent on this pathway. In this study, we demonstrate that GIPR engages a cytoskeletal motor, myosin VI to drive receptor endocytosis. GIPR engages the adaptor-motor complex through a PDZ-binding motif (PBM) at its C-ail. Interestingly, β-arrestin binding to phosphorylated residues upstream of the PBM enhance myosin VI recruitment and activation. GIPR internalization is dependent on both receptor phosphorylation and the PBM site to recruit β-arrestin and myosin VI, respectively. Synergistic engagement of β-arrestin and myosin VI results in desensitization of GIP-stimulated cAMP signaling while activating pERK1/2 from endosomal compartments. Blocking myosin VI activity enhances insulin release in pancreatic beta cells, demonstrating a novel role for this pathway in regulating the physiological effects of GIPR. Our findings highlight the direct convergence of two independent trafficking pathways at the level of the receptor C-tail, with implications for the nuanced regulation of individual GPCRs through the differential engagement of β-arrestin and myosin VI. GIPR has emerged as a frontline drug target in type 2 diabetes and obesity. Cellular effects of GIPR are regulated by receptor internalization and desensitization through mechanisms that are unclear. Here, we identify a novel GIPR trafficking pathway through the engagement of a cytoskeletal motor, myosin VI. Myosin VI and β-arrestin synergistically regulate GIPR endocytosis, signaling and insulin response in pancreatic beta cells. Our study highlights the convergence of two parallel trafficking mechanisms in GPCR function with potential implications in targeting metabolic disorders. Show less

Obesity has become a common public health problem all over the world today. In recent years, studies on the genetic etiology of obesity have gained importance. As a result of these studies, 127 obesity-related loci have been identified. The aim of this work was to screen obesity-related genes and review the literature. In this retrospective study, 41 obesity-related genes were screened in 116 patients by next-generation sequencing. These genes are Seventy-six of our patients were female, and 40 were male. As a result, 43 variants were detected in 39 (34.4%) patients. Of these, Understanding the genetics of obesity is an essential step toward treating and preventing this disease, which has become a global health problem. With this study, we wanted to contribute to the literature by reporting previously reported and novel variants we detected in our patients with obesity. Show less

When retatrutide stimulates the glucagon receptor (GCGR), the glucose-dependent insulinotropic polypeptide (GIP) receptor (GIPR), and the glucagon-like peptide-1 receptor (GLP-1R), then 3',5'cyclic adenosine monophosphate (cAMP) is increased. We tested the hypothesis that retatrutide like the β-adrenoceptor agonist isoprenaline raises force of contraction (FOC) in isolated electrically driven (1 Hz) left atrial preparations (LA) and exerts positive chronotropic effects (PCE) in isolated spontaneously beating right atrial preparations (RA) from adult CD1 mice. While 100 nM isoprenaline increased FOC, retatrutide (100 nM) failed to increase FOC in LA. In isolated mouse right atrial preparations (RA), retatrutide exerted PCE that were potentiated by 100 nM rolipram but that were antagonized by adomeglivant, a GCGR antagonist. The PCE of retatrutide but not the PCE of isoprenaline were attenuated by H89, an inhibitor of the cAMP-dependent protein kinase (PKA). The PCE of retatrutide were not weakened by the β-adrenoceptor antagonist propranolol (1 µM) but were blocked by 1 µM carbachol, an agonist at M Show less

Peptide hormone-receptor interactions serve as critical regulators of metabolic homeostasis, a paradigm exemplified by the clinical efficacy of glucagon-like peptide-1 (GLP-1) receptor agonists. Building upon this framework, strategic design has yielded unimolecular dual and triple agonists targeting GLP-1R, glucose-dependent insulinotropic polypeptide receptor (GIPR), and glucagon receptor (GcgR), leveraging the sequence homology within the cognate native ligands of the class B G protein-coupled receptor (GPCR) family. However, the integration of Y2 receptor (Y2R) agonism─engaged by peptide YY (PYY) and belonging to the structurally divergent class A GPCR family─has remained an unaddressed challenge due to the topological and sequence disparities between these receptor classes. Y2R activation plays a pivotal role in appetite suppression, potentiating the metabolic benefits conferred by GLP-1R, GIPR, and GcgR agonism. Here, we report first-in-class, unprecedented tetra-agonists with high potency at GLP-1R, GIPR, GcgR, and Y2R. The chimeric peptides overcome the intrinsic sequence constraints imposed by class A and class B GPCR divergence, demonstrating the feasibility of rationally designed agonism mediated by single agents across receptor families. Lipidation of this template is well tolerated enhancing the promise of therapeutic viability. Furthermore, we show that biased agonism at GLP-1R selectively boosts cyclic AMP (cAMP) signaling while minimizing β-arrestin recruitment, thereby decoupling receptor desensitization from metabolic efficacy. Additionally, we introduce a tunable framework to modulate β-arrestin engagement without compromising cAMP potency, providing insight into the fine-tuning of GPCR-mediated signaling for next-generation peptide therapeutics. Show less

Unimolecular peptides targeting the receptors for glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon (GCG) have been shown to improve glycaemic management in both mice and humans. Yet the identity of the downstream signalling events mediated by these peptides remain to be elucidated. Here, we aimed to assess the mechanisms by which a validated peptide triagonist for GLP-1/GIP/GCG receptors (IUB447) stimulates insulin secretion in murine pancreatic islets. Islets were isolated from wild-type (WT), Gipr-knockout (Gipr The triagonist promoted glucose-stimulated insulin secretion (GSIS) to a greater degree than co-administration of conventional mono-agonists in WT mouse islets. The triagonist-induced increase in GSIS was unchanged in the absence of either Gipr or Gcgr. However, the triagonist failed to enhance insulin secretion in islets lacking both Glp-1r and Gipr and upon treatment with the GLP-1 receptor-specific antagonist exendin-3 (9-39). Similarly, the specific blocking of Gαq signalling with YM254890 or transient receptor potential melastatin 5 (TRPM5) with triphenylphosphine oxide (TPPO) suppressed the triagonist-induced enhancement of GSIS. In vivo assessment of high-fat-fed Trpm5 Triagonist-induced augmentation of GSIS is primarily mediated through its interaction with the GLP-1 receptor and subsequent activation of the Gαq-TRPM5 signalling pathway. Given that Gαq is a key player in the amplification of GSIS, particularly under diabetic conditions, these findings highlight a GLP-1 receptor-centric pharmacological profile that underlies the potent effects of this multi-receptor agonist. Show less

Pharmacological modulation of glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) through dual GIP/GLP-1 receptor agonists, commonly used for diabetes and obesity, shows promise in reducing alcohol consumption. We applied drug-target Mendelian randomization (MR) using genetic variation at these loci to assess their long-term effects on problematic alcohol use (PAU), binge drinking, alcohol misuse classifications, liver health, and other substance use behaviors. Genetic proxies for lowered BMI, modeling the appetite-suppressing and weight-reducing effects of variants in both the GIPR and GLP1R loci ("GIPR/GLP1R"), were linked with reduced binge drinking in the primary (β = -0.44, 95% CI [-0.72, -0.15], P = 2.42 × 10 Show less

The glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR) are important incretin receptors that are therapeutic targets for the treatment of type 2 diabetes and obesity. This study extensively characterised the metabolic phenotype of mice with global deletion of either the GLP-1R or GIPR side by side under identical conditions. Age-matched male wild-type (WT) C57Bl6NTac, GLP-1RKO or GIPRKO mice were placed on a high-fat or chow diet for 12 weeks, and a range of in vivo (weight gain, food intake, glucose tolerance, insulin tolerance, and whole-body energy metabolism) and ex vivo (white adipocyte lipolysis, brown adipose tissue and liver mitochondrial function, adipocyte and islet size, and hepatic steatosis) parameters were measured. While both WT and GLP-1RKO mice gained weight similarly on a HFD, obese high-fat-fed GLP-1RKO mice had altered glucose and insulin tolerance, and exhibited hepatic steatosis, highlighting the physiological importance of the GLP-1R in the regulation of blood glucose and lipid homoeostasis. In contrast, GIPRKO mice were partially resistant to diet-induced obesity compared to the WT mice, which was associated with a small reduction in food intake and intact epididymal and subcutaneous white adipocyte β-adrenoceptor-mediated lipolysis. Similarly, WT mice treated with a GIPR antagonist prevented weight gain due to a reduction in food intake on a HFD. These findings provide further support that the GLP-1R is important for normal glycaemic control, whereas the GIPR may play a role in the regulation of body weight. Show less

We aimed to discover the biomarkers associated with UI and their correlation with immune cell infiltration. The GSE165004 data set was extracted from the Gene Expression Omnibus and IRGs were obtained from Immport and InnateDB databases. Differential expression analysis, WGCNA, and three machine learning algorithms (LASSO, SVM, and random forest) were used to determine the immune-related hub biomarkers for UI. The diagnostic performance of these markers was evaluated in GSE165004 and validation set (GSE16532). Furthermore, single-sample GSEA was employed to analyze the infiltration level of immune cells and Spearman analysis was conducted to assess the correlation between biomarker and immune cells. The functional enrichment and potential drugs for each biomarker were explored. The biomarker genes were validated in clinical samples by real time PCR assay. Six shared genes (ANXA2, CD300E, IL27RA, SEMA3F, GIPR, and WFDC2) were identified as diagnostic biomarkers by integration analysis. ROC analysis revealed that these markers had diagnostic value for UI both in training and validation sets. Moreover, these biomarkers are closely associated with immune cells, such as natural killer T cells and effector memory CD8 T cells. GSEA analysis showed that these genes were mainly involved in chromosome and mitochondria-related biological functions. Drug prediction indicated that all genes targeted Benzo(a)pyrene. All the biomarker genes, expect for GIPR were differentially expressed in endometrium tissues of UI patients, compared with controls. This study identified immune-related diagnostic biomarkers in UI, providing new insights into understanding the molecular mechanisms and therapeutic targets of UI. Show less

Aortic valve sclerosis affects 30 % of individuals over 65 and is associated with coronary artery disease, with risk of progression to aortic stenosis. Endothelial dysfunction, mediated by oxidative stress, impaired nitric oxide (NO) signaling, inflammation, and lipoprotein deposition, plays a central role in disease initiation and progression. This study investigated whether a combination of bioactive compounds could counteract these mechanisms and support vascular health. The effects of curcuma longa, coenzyme Q10, black garlic, vitamin B1, and vitamin D3 were tested in vitro on aortic valve endothelial cells. Cell viability, reactive oxygen species (ROS), and NO levels were quantified by commercially available kits, while gene expression was analyzed by RNA sequencing. A 4-week prospective pilot clinical study in 10 healthy volunteers without cardiovascular disease evaluated endothelial function and arterial stiffness. The compounds reduced ROS production (>27 %; p < 0.05), enhanced endothelial viability (>33 %; p < 0.05; except curcuma and black garlic), and increased NO production (>6 %; p < 0.05; except black garlic). Beneficial effects were reflected in upregulation of anti-atherosclerotic (GIPR, +0.058 copies per million, CPM; p < 0.05), antioxidant (GADL1, +0.55 CPM; p < 0.001), and anti-inflammatory (IL12A, +0.17 CPM; p < 0.01) genes. Clinically, daily supplementation improved endothelial function in participants found to have pre-existing endothelial dysfunction (p = 0.0336), with 50 % achieving normal levels after 4 weeks, while all subjects exhibited reduced arterial stiffness (p = 0.0016) without hepatic toxicity. The oral supplementation of the combination of these bioactive compounds improved endothelial function and vascular health, particularly in individuals with endothelial dysfunction, offering potential therapeutic benefits for cardiovascular health. Show less

Chronic intakes of functional foods (probiotics, apples and oats) have been reported to have beneficial effects on hepatic lipid regulation and glycaemic control, but mechanistic human studies humans are limited. An ex-vivo study was performed to determine the chronic effects of probiotics, oats, and apples on the expression of genes related to markers of cardiometabolic health in peripheral blood monocular cells (PBMC). In this CABALA sub-study (n = 59/61, age: 52 ± 12y), blood PBMC were also isolated before and 8 weeks after the daily consumption of either a probiotic with bile salt hydrolase activity (Lactobacillus reuteri), porridge oats, Renetta Canada apples or a control. Relative PBMC mRNA gene expression was determined and correlations performed between the fold change in response to the functional interventions and change in cardiometabolic disease risk markers. Relative to baseline, there was an upregulation in the PBMC TLR4 mRNA expression in the control compared with the probiotics and apples groups (p[Formula: see text]0.024). Moderate inverse correlations were found between the fold change in GPBAR1 mRNA expression and change in plasma total and secondary BAs, HMGCR and SREBF1 mRNA gene expressions and high-density lipoprotein-cholesterol, and SREBF1 and GIPR mRNA gene expressions and glucose. TLR4 and TNFSF14 mRNA gene expressions were associated with pro-inflammatory cytokines (p=0.05). Probiotic and apples interventions attenuated the upregulation in PBMC TLR4 mRNA expression observed with the control. Correlations between fold change in mRNA gene expression and changes in cardiometabolic disease risk markers in response to the functional interventions were in agreement with previous studies. The study was registered at clinical trials.gov (ref. NCT03369548). Show less

Multi-target peptide therapeutics targeting glucagon receptor (GCGR), glucagon-like peptide-1 receptor (GLP1R), and glucose-dependent insulinotropic polypeptide receptor (GIPR) represent a promising approach for treating diabetes and obesity. Triple agonist peptides demonstrate promising therapeutic potential compared to single-target approaches, yet rational design remains computationally challenging due to complex sequence-structure activity relationships. Existing methods, primarily based on convolutional neural networks, impose limitations including fixed sequence lengths and inadequate representation of molecular topology. Graph Attention Networks (GAT) offer advantages in capturing molecular structures and variable-length peptide sequences while providing interpretable insights into receptor-specific binding determinants. A dataset of 234 peptide sequences with experimentally determined binding affinities was compiled from multiple sources. Peptides were represented as molecular graphs with seven-dimensional node features encoding physicochemical properties and positional information. The GAT architecture employed a shared encoder with task-specific prediction heads, implementing transfer learning to address limited GIPR training data. Performance was evaluated using 5-fold cross-validation and independent validation on 24 literature-derived sequences. A genetic algorithm framework was developed for peptide sequence optimization, incorporating multi objective fitness evaluation based on predicted binding affinity, biological plausibility, and sequence novelty. Cross-validation demonstrated robust GAT performance across all receptors, with GCGR achieving high accuracy (AUC ROC: 0.915 ± 0.050), followed by GLP1R (AUC-ROC: 0.853 ± 0.059), and GIPR showing acceptable performance despite limited data (AUC-ROC: 0.907 ± 0.083). Comparative analysis revealed receptor-specific advantages: GAT significantly outperformed CNN for GCGR prediction (RMSE: 0.942 vs. 1.209, p = 0.0013), while CNN maintained superior GLP1R performance (RMSE: 0.552 vs. 0.723). Genetic algorithm optimization measurable improvement over baseline, with 4.0% fitness Enhancement and generation of 20 candidates exhibiting mean binding probabilities exceeding 0.5 across all targets. The GAT-based framework provides a computational approach in computational peptide design, demonstrating receptor-specific advantages and robust optimization capabilities. Genetic algorithm optimization enables systematic exploration of sequence space within existing agonist scaffolds while maintaining biological constraints. This approach provides a rational framework for prioritizing experimental validation efforts in triple agonist development. Show less

Chronic cold exposure in mice increases metabolic demand and food intake; the gut correspondingly expands its absorptive surface area. Gut enteroendocrine cells produce peptide hormones including glucagon-like peptide-1 (GLP-1), GLP-2, and glucose-dependent insulinotropic polypeptide (GIP) in response to a meal to facilitate nutrient absorption and post-prandial metabolism. The requirement of GLP-1, GLP-2, and GIP receptor signaling for small intestinal adaptations to chronic cold stress has not been investigated. Here, we show that male and female wild-type, double incretin receptor knockout (Glp1r Show less

The association between obesity and atrial fibrillation (AF) has garnered increasing attention. Obesity is a significant risk factor for cardiovascular diseases and promotes the occurrence of AF through multiple mechanisms. This study aims to explore the molecular mechanisms of obesity-induced AF using GLP-1R/GIPR dual-target agonist fusion protein (Fc) loaded into adipose-derived mesenchymal stem cell (ADSC) exosome-liposome hybrid nanoparticles (LE@Fc NPs). We successfully constructed and purified the Fc, verifying its purity and functional activity through SDS-PAGE and UV absorption spectroscopy. The fusion protein was then loaded into nanovesicles, and their morphology, size, and stability were assessed using transmission electron microscopy (TEM), nanoparticle tracking analysis (NTA), and dynamic light scattering (DLS). In vitro experiments demonstrated that LE@Fc NPs exhibit high fusion efficiency and targeted delivery capability. In vivo experimental results show that LE@Fc NPs significantly inhibit ferroptosis in the epicardial adipose tissue (EAT) of obese mice (iron content: 3.69 ± 0.36 vs. 0.88 ± 0.09), by restoring GSH levels (0.45 ± 0.08 vs. 0.87 ± 0.08) and Gpx4 expression (0.32 ± 0.06 vs. 1.01 ± 0.16), and reducing ROS (12.01 ± 0.95 vs. 2.68 ± 0.17), MDA (3.17 ± 0.29 vs. 0.95 ± 0.09), and 4-HNE (3.74 ± 0.51 vs. 0.91 ± 0.09) levels. Furthermore, LE@Fc NPs treatment significantly improved the inflammatory response (IL-1β: 44.08 ± 3.74 vs. 12.07 ± 0.65, IL-6: 515.59 ± 47.70 vs. 288.43 ± 16.81, MCP-1: 1401.04 ± 194.88 vs. 600.28 ± 45.54, TNF-α: 39.96 ± 2.48 vs. 18.01 ± 0.85). LE@Fc NPs also reduced atrial fibrosis, thereby effectively lowering the incidence of AF. Echocardiography and electrocardiogram monitoring revealed that LE@Fc NPs treatment significantly improved atrial remodeling and reduced the occurrence of AF in obese mice. In addition, LE@Fc NPs significantly improved obesity-induced systemic inflammation and metabolic disorders. In conclusion, LE@Fc NPs show great potential for the treatment of obesity-related AF. Show less