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BackgroundHeart failure with preserved ejection fraction (HFpEF) is an emerging major unmet need and one of the most significant clinic challenges in cardiology. The pathogenesis of HFpEF is associated with multiple risk factors. Hypertension and metabolic disorders associated with obesity are the 2 most prominent comorbidities observed in patients with HFpEF. Although hypertension-induced mechanical overload has long been recognized as a potent contributor to heart failure with reduced ejection fraction, the synergistic interaction between mechanical overload and metabolic disorders in the pathogenesis of HFpEF remains poorly characterized.MethodWe investigated the functional outcome and the underlying mechanisms from concurrent mechanic and metabolic stresses in the heart by applying transverse aortic constriction in lean C57Bl/6J or obese/diabetic B6.Cg-Lepob/J (ob/ob) mice, followed by single-nuclei RNA-seq and targeted manipulation of a top-ranked signaling pathway differentially affected in the 2 experimental cohorts.ResultsIn contrast to the post-trans-aortic constriction C57Bl/6J lean mice, which developed pathological features of heart failure with reduced ejection fraction over time, the post-trans-aortic constriction ob/ob mice showed no significant changes in ejection fraction but developed characteristic pathological features of HFpEF, including diastolic dysfunction, worsened cardiac hypertrophy, and pathological remodeling, along with further deterioration of exercise intolerance. Single-nuclei RNA-seq analysis revealed significant transcriptome reprogramming in the cardiomyocytes stressed by both pressure overload and obesity/diabetes, markedly distinct from the cardiomyocytes singularly stressed by pressure overload or obesity/diabetes. Furthermore, glucagon signaling was identified as the top-ranked signaling pathway affected in the cardiomyocytes associated with HFpEF. Treatment with a glucagon receptor antagonist significantly ameliorated the progression of HFpEF-related pathological features in 2 independent preclinical models. Importantly, cardiomyocyte-specific genetic deletion of the glucagon receptor also significantly improved cardiac function in response to pressure overload and metabolic stress.ConclusionsThese findings identify glucagon receptor signaling in cardiomyocytes as a critical determinant of HFpEF progression and provide proof-of-concept support for glucagon receptor antagonism as a potential therapy for the disease.

Over several decades the JCI has published key advances in our understanding of glucagon-like peptide 1 (GLP-1) biology. The first incretin peptide characterized in the 1970s, glucose-dependent insulinotropic polypeptide (GIP), [...]

The article in the New England Journal of Medicine discusses the discovery and development of GLP-1-based drugs for the treatment of obesity. Scientists have made significant progress in understanding gut-hormone biology and the role of GLP-1 in regulating hunger, satiety, and energy assimilation. The development of GLP-1 receptor agonists has revolutionized the treatment of obesity, with medications like liraglutide and semaglutide showing promising results in reducing weight and improving metabolic health. The article highlights the scientific advancements and translational importance of GLP-1-based drugs in addressing obesity and related complications. [Extracted from the article]

Background: Anti‐inflammatory effects of incretin signaling through the glucagon‐like peptide‐1 receptor (GLP‐1R) and the glucose‐dependent insulinotropic polypeptide receptor (GIPR) in mice have been reported. Therefore, we hypothesized that signaling through the endogenous GLP‐1R and the GIPR individually decreases allergic airway inflammation and that the combination of GLP‐1R and GIPR signaling together additively inhibits allergen‐induced lung and airway inflammation. Methods: WT (C57BL/6J), GLP‐1R knockout (KO), GIPR KO, and GLP‐1R/GIPR double KO (DKO) mice were challenged intranasally with Alternaria alternata extract (Alt‐Ext) or vehicle to evaluate the impact of signaling through these receptors on the innate allergen‐induced inflammatory response that is primarily driven by group 2 innate lymphoid cells (ILC2). Results: Alt‐Ext‐induced IL‐33 release in the bronchoalveolar lavage fluid (BALF) was not different between the mouse strains, but thymic stromal lymphopoietin (TSLP) was significantly increased in GLP‐1R/GIPR DKO mice challenged with Alt‐Ext compared to the other strains. Furthermore, Alt‐Ext‐induced protein expression of IL‐5, IL‐13, CCL11, and CCL24 in the lung homogenates, the number of eosinophils, lymphocytes, and neutrophils in the BALF, and the number of lung GATA3+ ILC2 were significantly increased in GLP‐1R/GIPR DKO mice compared to the other 3 strains. Furthermore, ICAM‐1 expression on lung epithelial cells was increased in GLP‐1R/GIPR DKO mice challenged with Alt‐Ext compared to the other 3 strains. Conclusions: Deficiency of both GLP‐1R and GIPR signaling together increased TSLP release, ILC2 activation, and early type 2 innate immune responses to aeroallergen exposure. Combined GLP‐1R and GIPR signaling should be explored for the treatment of asthma. [ABSTRACT FROM AUTHOR]

The development of glucagon-like peptide 1 receptor agonists (GLP-1RA) for type 2 diabetes and obesity was followed by data establishing the cardiorenal benefits of GLP-1RA in select patient populations. In ongoing trials investigators are interrogating the efficacy of these agents for new indications, including metabolic liver disease, peripheral artery disease, Parkinson disease, and Alzheimer disease. The success of GLP-1–based medicines has spurred the development of new molecular entities and combinations with unique pharmacokinetic and pharmacodynamic profiles, exemplified by tirzepatide, a GIP-GLP-1 receptor coagonist. Simultaneously, investigational molecules such as maritide block the GIP and activate the GLP-1 receptor, whereas retatrutide and survodutide enable simultaneous activation of the glucagon and GLP-1 receptors. Here I highlight evidence establishing the efficacy of GLP-1–based medicines, while discussing data that inform safety, focusing on muscle strength, bone density and fractures, exercise capacity, gastrointestinal motility, retained gastric contents and anesthesia, pancreatic and biliary tract disorders, and the risk of cancer. Rapid progress in development of highly efficacious GLP-1 medicines, and anticipated differentiation of newer agents in subsets of metabolic disorders, will provide greater opportunities for use of personalized medicine approaches to improve the health of people living with cardiometabolic disorders. [ABSTRACT FROM AUTHOR]

BackgroundGenomewide association studies can be used to identify disease-relevant genomic regions, but interpretation of the data is challenging. The FTO region harbors the strongest genetic association with obesity, yet the mechanistic basis of this association remains elusive.MethodsWe examined epigenomic data, allelic activity, motif conservation, regulator expression, and gene coexpression patterns, with the aim of dissecting the regulatory circuitry and mechanistic basis of the association between the FTO region and obesity. We validated our predictions with the use of directed perturbations in samples from patients and from mice and with endogenous CRISPR-Cas9 genome editing in samples from patients.ResultsOur data indicate that the FTO allele associated with obesity represses mitochondrial thermogenesis in adipocyte precursor cells in a tissue-autonomous manner. The rs1421085 T-to-C single-nucleotide variant disrupts a conserved motif for the ARID5B repressor, which leads to derepression of a potent preadipocyte enhancer and a doubling of IRX3 and IRX5 expression during early adipocyte differentiation. This results in a cell-autonomous developmental shift from energy-dissipating beige (brite) adipocytes to energy-storing white adipocytes, with a reduction in mitochondrial thermogenesis by a factor of 5, as well as an increase in lipid storage. Inhibition of Irx3 in adipose tissue in mice reduced body weight and increased energy dissipation without a change in physical activity or appetite. Knockdown of IRX3 or IRX5 in primary adipocytes from participants with the risk allele restored thermogenesis, increasing it by a factor of 7, and overexpression of these genes had the opposite effect in adipocytes from nonrisk-allele carriers. Repair of the ARID5B motif by CRISPR-Cas9 editing of rs1421085 in primary adipocytes from a patient with the risk allele restored IRX3 and IRX5 repression, activated browning expression programs, and restored thermogenesis, increasing it by a factor of 7.ConclusionsOur results point to a pathway for adipocyte thermogenesis regulation involving ARID5B, rs1421085, IRX3, and IRX5, which, when manipulated, had pronounced pro-obesity and anti-obesity effects. (Funded by the German Research Center for Environmental Health and others.).