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BACKGROUND: Equal access to health care is considered a key in Scandinavian healthcare policy. However, problematic differences between the socio-economic situation of immigrants and that of native Scandinavians are increasingly challenging this aspect of the Scandinavian welfare model. The present study focuses on how socio-economic characteristics and country of birth are associated with induced abortion. METHODS: A structured questionnaire was used to collect information among 1351 women requesting abortion and a control group of 1306 women intending birth. RESULTS: The strongest factor associated with the decision to have an abortion was being single (OR 39.1; 23.8-64.2), followed by being aged 19 years or below (OR 29.6; 13.4-65.5), having two children or more (OR 7.05; 5.29-9.39) and being unskilled (OR 2.48; 1.49-4.10), student (OR 2.29; 1.52-3.43) or unemployed (OR 1.65; 1.11-2.46). When evaluating the effect of social exposure on abortion among Danish-born and foreign-born women, the higher rate of abortion among non-Westerners was found to be caused by the composition of non-Westerners more often being unemployed, having a low income and having two or more children rather than the fact that they are coming from a non-Western country. CONCLUSION: Immigrant women comprise a vulnerable group, with a poor socio-economic status. This situation exposes immigrant women to increased risk of induced abortion. In a society with an increasing heterogeneous population, the vulnerable situation of immigrant women has to be addressed, if equal access to health care is to be maintained. [ABSTRACT FROM AUTHOR]

The hypothalamus is a brain region that plays a key role in coordinating fundamental biological functions 1 . However, our understanding of the underlying cellular components and neurocircuitries have, until recently, emerged primarily from rodent studies 2,3 . Here we combine single-nucleus sequencing of 433,369 human hypothalamic cells with spatial transcriptomics, generating a comprehensive spatio-cellular transcriptional map of the hypothalamus, the 'HYPOMAP'. Although conservation of neuronal cell types between humans and mice, as based on transcriptomic identity, is generally high, there are notable exceptions. Specifically, there are significant disparities in the identity of pro-opiomelanocortin neurons and in the expression levels of G-protein-coupled receptors between the two species that carry direct implications for currently approved obesity treatments. Out of the 452 hypothalamic cell types, we find that 291 neuronal clusters are significantly enriched for expression of body mass index (BMI) genome-wide association study genes. This enrichment is driven by 426 'effector' genes. Rare deleterious variants in six of these (MC4R, PCSK1, POMC, CALCR, BSN and CORO1A) associate with BMI at population level, and CORO1A has not been linked previously to BMI. Thus, HYPOMAP provides a detailed atlas of the human hypothalamus in a spatial context and serves as an important resource to identify new druggable targets for treating a wide range of conditions, including reproductive, circadian and metabolic disorders., Competing Interests: Competing interests: S.L., J.P.-W., L.B.K. and C.P. are Novo Nordisk employees and/or shareholders. J.R.B.P. is an employee and shareholder of Insmed. J.R.B.P. also receives research funding from GSK and consultancy fees from WW International. B.Y.H.L. provides remunerated consultancy for Nuntius Therapeutics. G.S.H.Y. receives grant funding from Novo Nordisk and consults for both Novo Nordisk and Eli Lilly and Company. J.C.B. is co-founder of Cerapeutix and has received research funding through collaborations with Sanofi Aventis and Novo Nordisk Inc., he also consulted for Eli Lilly and Company and Novo Nordisk, all of which did not affect the content of this article. The other authors declare no competing interests., (© 2025. The Author(s).)

Obesity and type 2 diabetes are prevalent chronic diseases effectively managed by semaglutide. Here we studied the effects of semaglutide on the circulating proteome using baseline and end-of-treatment serum samples from two phase 3 trials in participants with overweight or obesity, with or without diabetes: STEP 1 (n = 1,311) and STEP 2 (n = 645). We identified evidence supporting broad effects of semaglutide, implicating processes related to body weight regulation, glycemic control, lipid metabolism and inflammatory pathways. Several proteins were regulated with semaglutide, after accounting for changes in body weight and HbA 1c at end of trial, suggesting effects of semaglutide on the proteome beyond weight loss and glucose lowering. A comparison of semaglutide with real-world proteomic profiles revealed potential benefits on disease-specific proteomic signatures including the downregulation of specific proteins associated with cardiovascular disease risk, supporting its reported effects of lowering cardiovascular disease risk and potential drug repurposing opportunities. This study showcases the potential of proteomics data gathered from randomized trials for providing insights into disease mechanisms and drug repurposing opportunities. These data also highlight the unmet need for, and importance of, examining proteomic changes in response to weight loss pharmacotherapy in future trials., Competing Interests: Competing interests: L.S., K.S., M. Galanakis, M.T.I., J.S., A.S., L.B.K. and A.A.T. are employees and shareholders of Novo Nordisk. D.G., L.M. and M. Geybels were employees and shareholders of Novo Nordisk at the time of the analysis. M. Galanakis, M. Geybels and D.V. have received a grant from the Danish Innovation Fund (204000005B). J.Q.P. has received consulting fees from Boehringer Ingelheim and Novo Nordisk. L.Z. declares no competing interests., (© 2025. The Author(s).)

Glucagon-like peptide-1 (GLP-1) and leptin signal recent feeding and long-term energy stores, respectively, and play complementary roles in the modulation of energy balance. Previous work using single-cell techniques in mice revealed the existence of a population of leptin receptor ( Lepr )-containing dorsomedial hypothalamus (DMH) neurons marked by the expression of GLP-1 receptor ( Glp1r ; LepR Glp1r neurons) that play important roles in the control of feeding and body weight by leptin. Here, we demonstrate the existence of a population of LepR Glp1r neurons in the DMHs of nonhuman primates (NHPs), suggesting the potential translational relevance of these neurons. Consequently, we developed a GLP-1R/LepR dual agonist and demonstrated the physiological activity of both components in vivo using leptin-deficient and Lepr- deficient murine models. We further found roles for LepR Glp1r neurons in mediating the dual agonist's efficacy on food intake and body weight loss. Ablating Lepr in Glp1r -expressing neurons (Lepr Glp1r KO mice) abrogated the suppression of food intake by the dual agonist. Furthermore, reactivation of Glp1r expression in Lepr neurons on an otherwise Glp1r -null background (Glp1r Lepr Re mice) was sufficient to permit the suppression of food intake and body weight by the dual agonist. Hence, LepR Glp1r neurons represent targets for a GLP-1R/LepR dual agonist that potently reduces food intake and body weight.

Classic hereditary hemochromatosis (HH) is an autosomal recessive iron-overload disorder resulting from loss-of-function mutations of the HFE gene. Patients with HH exhibit excessive hepatic iron accumulation that predisposes these patients to liver disease, including the risk for developing liver cancer. Chronic iron overload also poses a risk for the development of metabolic disorders such as obesity, type 2 diabetes, and insulin resistance. We hypothesized that liraglutide, GLP1 receptor agonist, alters iron metabolism while also reducing body weight and glucose tolerance in a mouse model of HH (global HFE knockout, HFE KO) and diet-induced obesity and glucose intolerance. The total body HFE KO and wild-type control mice were fed high-fat diet for 8 weeks. Mice were subdivided into liraglutide and vehicle-treated groups and received daily subcutaneous administration of the respective treatment once daily for 18 weeks. Liraglutide improved glucose tolerance and hepatic lipid markers and reduced body weight in a mouse model of HH, the HFE KO mouse, similar to wild-type controls. Importantly, our data show that liraglutide alters iron metabolism in HFE KO mice, leading to decreased circulating and stored iron levels in HFE KO mice. These observations highlight the potential that GLP1 receptor agonist could be used to reduce iron overload in addition to reducing body weight and improving glucose regulation in HH patients., (© The Author(s) 2024. Published by Oxford University Press on behalf of the Endocrine Society. All rights reserved. For commercial re-use, please contact reprints@oup.com for reprints and translation rights for reprints. All other permissions can be obtained through our RightsLink service via the Permissions link on the article page on our site—for further information please contact journals.permissions@oup.com. See the journal About page for additional terms.)

Phenotypic heterogeneity at genomic loci encoding drug targets can be exploited by multivariable Mendelian randomization to provide insight into the pathways by which pharmacological interventions may affect disease risk. However, statistical inference in such investigations may be poor if overdispersion heterogeneity in measured genetic associations is unaccounted for. In this work, we first develop conditional F statistics for dimension-reduced genetic associations that enable more accurate measurement of phenotypic heterogeneity. We then develop a novel extension for two-sample multivariable Mendelian randomization that accounts for overdispersion heterogeneity in dimension-reduced genetic associations. Our empirical focus is to use genetic variants in the GLP1R gene region to understand the mechanism by which GLP1R agonism affects coronary artery disease (CAD) risk. Colocalization analyses indicate that distinct variants in the GLP1R gene region are associated with body mass index and type 2 diabetes (T2D). Multivariable Mendelian randomization analyses that were corrected for overdispersion heterogeneity suggest that bodyweight lowering rather than T2D liability lowering effects of GLP1R agonism are more likely contributing to reduced CAD risk. Tissue-specific analyses prioritized brain tissue as the most likely to be relevant for CAD risk, of the tissues considered. We hope the multivariable Mendelian randomization approach illustrated here is widely applicable to better understand mechanisms linking drug targets to diseases outcomes, and hence to guide drug development efforts., (© 2024 The Authors. Genetic Epidemiology published by Wiley Periodicals LLC.)

Glucagon like peptide-1 (GLP-1) is a hormone produced and released by cells of the gastrointestinal tract following meal ingestion. GLP-1 receptor agonists (GLP-1RA) exhibit kidney-protective actions through poorly understood mechanisms. Here we interrogated whether the receptor for advanced glycation end products (RAGE) plays a role in mediating the actions of GLP-1 on inflammation and diabetic kidney disease. Mice with deletion of the GLP-1 receptor displayed an abnormal kidney phenotype that was accelerated by diabetes and improved with co-deletion of RAGE in vivo. Activation of the GLP-1 receptor pathway with liraglutide, an anti-diabetic treatment, downregulated kidney RAGE, reduced the expansion of bone marrow myeloid progenitors, promoted M2-like macrophage polarization and lessened markers of kidney damage in diabetic mice. Single cell transcriptomics revealed that liraglutide induced distinct transcriptional changes in kidney endothelial, proximal tubular, podocyte and macrophage cells, which were dominated by pathways involved in nutrient transport and utilization, redox sensing and the resolution of inflammation. The kidney-protective action of liraglutide was corroborated in a non-diabetic model of chronic kidney disease, the subtotal nephrectomised rat. Thus, our findings identify a novel glucose-independent kidney-protective action of GLP-1-based therapies in diabetic kidney disease and provide a valuable resource for exploring the cell-specific kidney transcriptional response ensuing from pharmacological GLP-1R agonism., (Copyright © 2023 International Society of Nephrology. All rights reserved.)

Aims/hypothesis: Glucagon-like peptide-1 receptor agonists (GLP-1RAs) have been suggested to possess antineoplastic properties against prostate cancer. We examined the association between GLP-1RA use and prostate cancer risk in a real-world setting., Methods: We performed a nationwide register-based cohort study using an active-comparator, new-user design. We included all men in Denmark aged ≥50 years who commenced use of GLP-1RAs or basal insulin during 2007-2019. HRs and 95% CIs for incident prostate cancer were estimated using multivariable Cox regression in 'intention-to-treat' (ITT)- and 'per-protocol'-like analyses., Results: Among 14,206 initiators of GLP-1RAs and 21,756 initiators of basal insulin, we identified 697 patients with prostate cancer during a mean follow-up period of about 5 years from initiation of the study drugs. In comparison with basal insulin use, GLP-1RA use was associated with an adjusted HR of 0.91 (95% CI 0.73, 1.14) in the 'ITT' analysis and 0.80 (95% CI 0.64, 1.01) in the 'per-protocol' analysis. Stronger inverse associations were seen among older men (≥70 years) ('ITT' HR 0.56; 95% CI 0.38, 0.82; 'per-protocol' HR 0.47; 95% CI 0.30, 0.74), and in patients with CVD ('ITT' HR 0.75; 95% CI 0.53, 1.06; 'per-protocol' HR 0.60; 95% CI 0.39, 0.91)., Conclusions/interpretation: GLP-1RA use was inversely associated with prostate cancer risk compared with use of basal insulin in the 'per-protocol' analysis. Older men and patients with CVD exhibited stronger inverse associations in both the 'ITT' and 'per-protocol' analyses. Our results may indicate that GLP-1RA use could protect against prostate cancer., (© 2023. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

The adipose-derived hormone leptin acts via its receptor (LepRb) in the brain to control energy balance. A potentially unidentified population of GABAergic hypothalamic LepRb neurons plays key roles in the restraint of food intake and body weight by leptin. To identify markers for candidate populations of LepRb neurons in an unbiased manner, we performed single-nucleus RNA-Seq of enriched mouse hypothalamic LepRb cells, identifying several previously unrecognized populations of hypothalamic LepRb neurons. Many of these populations displayed strong conservation across species, including GABAergic Glp1r-expressing LepRb (LepRbGlp1r) neurons, which expressed more Lepr than other LepRb cell populations. Ablating Lepr from LepRbGlp1r cells provoked hyperphagic obesity without impairing energy expenditure. Similarly, improvements in energy balance caused by Lepr reactivation in GABA neurons of otherwise Lepr-null mice required Lepr expression in GABAergic Glp1r-expressing neurons. Furthermore, restoration of Glp1r expression in LepRbGlp1r neurons in otherwise Glp1r-null mice enabled food intake suppression by the GLP1R agonist, liraglutide. Thus, the conserved GABAergic LepRbGlp1r neuron population plays crucial roles in the suppression of food intake by leptin and GLP1R agonists.

Obesity-related heart failure with preserved ejection fraction (HFpEF) has become a well-recognized HFpEF subphenotype. Targeting the unfavorable cardiometabolic profile may represent a rational treatment strategy. This study investigated semaglutide, a glucagon-like peptide-1 receptor agonist that induces significant weight loss in patients with obesity and/or type 2 diabetes mellitus and has been associated with improved cardiovascular outcomes. In a mouse model of HFpEF that was caused by advanced aging, female sex, obesity, and type 2 diabetes mellitus, semaglutide, compared with weight loss induced by pair feeding, improved the cardiometabolic profile, cardiac structure, and cardiac function. Mechanistically, transcriptomic, and proteomic analyses revealed that semaglutide improved left ventricular cytoskeleton function and endothelial function and restores protective immune responses in visceral adipose tissue. Strikingly, treatment with semaglutide induced a wide array of favorable cardiometabolic effects beyond the effect of weight loss by pair feeding. Glucagon-like peptide-1 receptor agonists may therefore represent an important novel therapeutic option for treatment of HFpEF, especially when obesity-related., Competing Interests: This study was supported in part by Novo Nordisk, the manufacturer of semaglutide, who financed the laboratory supplies and -omics studies. The University Medical Center Groningen, which employs several of the authors, has received research grants and/or fees from AstraZeneca, Abbott, Boehringer Ingelheim, Cardior Pharmaceuticals GmbH, Ionis Pharmaceuticals, Inc, Novo Nordisk, and Roche. Dr Lam has received support from a Clinician Scientist Award from the National Medical Research Council of Singapore; has received research support from Bayer and Roche Diagnostics; has served as consultant or on the Advisory Board/Steering Committee/ Executive Committee for Abbott, Actelion, Alleviant Medical, Allysta Pharma, Amgen, AnaCardio AB, Applied Therapeutics, AstraZeneca, Bayer, Boehringer Ingelheim, Boston Scientific, Cytokinetics, Darma Inc, EchoNous Inc, Impulse Dynamics, Ionis Pharmaceutical, Janssen Research and Development LLC, Medscape/WebMD Global LLC, Merck, Novartis, Novo Nordisk, Prosciento Inc, Radcliffe Group Ltd, Roche Diagnostics, Sanofi, Siemens Healthcare Diagnostics, and Us2.ai; and is a co-founder and a nonexecutive director of Us2.ai. Dr de Boer has received speaker fees from Abbott, AstraZeneca, Bayer, Novartis, and Roche. All Novo Nordisk authors disclose the company markets semaglutide for the treatment of diabetes and obesity, separately, and have multiple clinical studies ongoing. Also, all Novo Nordisk authors report they have minor amount of shares as part of employee benefits. All other authors have reported that they have no relationships relevant to the contents of this paper to disclose., (© 2023 The Authors.)

Evidence on the validity of drug targets from randomized trials is reliable but typically expensive and slow to obtain. In contrast, evidence from conventional observational epidemiological studies is less reliable because of the potential for bias from confounding and reverse causation. Mendelian randomization is a quasi-experimental approach analogous to a randomized trial that exploits naturally occurring randomization in the transmission of genetic variants. In Mendelian randomization, genetic variants that can be regarded as proxies for an intervention on the proposed drug target are leveraged as instrumental variables to investigate potential effects on biomarkers and disease outcomes in large-scale observational datasets. This approach can be implemented rapidly for a range of drug targets to provide evidence on their effects and thus inform on their priority for further investigation. In this review, we present statistical methods and their applications to showcase the diverse opportunities for applying Mendelian randomization in guiding clinical development efforts, thus enabling interventions to target the right mechanism in the right population group at the right time. These methods can inform investigators on the mechanisms underlying drug effects, their related biomarkers, implications for the timing of interventions, and the population subgroups that stand to gain the most benefit. Most methods can be implemented with publicly available data on summarized genetic associations with traits and diseases, meaning that the only major limitations to their usage are the availability of appropriately powered studies for the exposure and outcome and the existence of a suitable genetic proxy for the proposed intervention., Competing Interests: Declaration of interests W.G.H., G.K.H., L.B.K., and D.G. are employed by Novo Nordisk., (Copyright © 2022 American Society of Human Genetics. Published by Elsevier Inc. All rights reserved.)

Introduction: The incretin hormone glucagon-like peptide-1 (GLP-1) slows gastric emptying, increases satiety and enhances insulin secretion. GLP-1 receptor agonists, such as liraglutide, are used therapeutically in humans to improve glycaemic control and delay the onset of type 2 diabetes mellitus (T2DM). In UCD-T2DM rats, a model of polygenic obesity and insulin resistance, we have previously reported that daily liraglutide administration delayed diabetes onset by >4 months. Growth hormone (GH) may exert anti-diabetic effects, including increasing β-cell mass and insulin secretion, while disrupting GH signalling in mice reduces both the size and number of pancreatic islets. We therefore hypothesized that GH supplementation would augment liraglutide's anti-diabetic effects., Methods: Male UCD-T2DM rats were treated daily with GH (0.3 mg/kg) and/or liraglutide (0.2 mg/kg) from 2 months of age. Control (vehicle) and food-restricted (with food intake matched to liraglutide-treated rats) groups were also studied. The effects of treatment on diabetes onset and weight gain were assessed, as well as measures of glucose tolerance, lipids and islet morphology., Results: Liraglutide treatment significantly reduced food intake and body weight and improved glucose tolerance and insulin sensitivity, relative to controls. After 4.5 months, none of the liraglutide-treated rats had developed T2DM (overall p = .019). Liraglutide-treated rats also displayed lower fasting triglyceride (TG) concentrations and lower hepatic TG content, compared to control rats. Islet morphology was improved in liraglutide-treated rats, with significantly increased pancreatic insulin content (p < .05 vs. controls). Although GH treatment tended to increase body weight (and gastrocnemius muscle weight), there were no obvious effects on diabetes onset or other diabetes-related outcomes., Conclusion: GH supplementation did not augment the anti-diabetic effects of liraglutide., (© 2022 The Authors. Endocrinology, Diabetes & Metabolism published by John Wiley & Sons Ltd.)

Background and Aims: Randomized clinical studies have shown a reduction in cardiovascular outcomes with glucagon-like peptide 1 receptor agonist (GLP-1RA) treatment with the hypothesized mechanisms being an underlying effect on atherosclerosis. Here, we aimed to assess the pharmacological effects of semaglutide in an atheroprone murine model that recapitulates central mechanisms related to vascular smooth muscle cell (VSMC) phenotypic switching and endothelial dysfunction known to operate within the atherosclerotic plaque., Methods: In study A, we employed an electrical current to the carotid artery in ApoE-/- mice to induce severe VSMC injury and death, after which the arteries were allowed to heal for 4 weeks. In study B, a constrictive cuff was added for 6 h at the site of the healed segment to induce a disturbance in blood flow., Results: Compared to vehicle, semaglutide treatment reduced the intimal and medial area by ∼66% (p = 0.007) and ∼11% ( p  = 0.0002), respectively. Following cuff placement, expression of the pro-inflammatory marker osteopontin and macrophage marker Mac-2 was reduced ( p  < 0.05) in the semaglutide-treated group compared to vehicle. GLP-1R were not expressed in murine carotid artery and human coronary vessels with and without atherosclerotic plaques, and semaglutide treatment did not affect proliferation of cultured primary human VSMCs., Conclusions: Semaglutide treatment reduced vessel remodelling following electrical injury and blood flow perturbation in an atheroprone mouse model. This effect appears to be driven by anti-inflammatory and -proliferative mechanisms independent of GLP-1 receptor-mediated signalling in the resident vascular cells. This mechanism of action may be important for cardiovascular protection., Competing Interests: The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: The authors BR, LMV, MKEO, JCB, AU, CP, RKK, HH, LBK and MN are employees at Novo Nordisk. Novo Nordisk markets semaglutide for the treatment of diabetes and obesity. DMJ, GFS, and JL are present or former employees at University of Copenhagen and have collaborated with Novo Nordisk on this project., (© 2022 The Author(s).)

Exocrine glands in the submucosa of the proximal duodenum secrete alkaline fluid containing mucus to protect the intestinal mucosa from acidic stomach contents. These glands, known as Brunner's glands, express high glucagon-like peptide 1 receptor (GLP-1R) levels. Previous studies have suggested that activation of the GLP-1R induces expression of barrier protective genes in Brunner's glands. Still, the lack of a viable in vitro culture of Brunner's glands has hampered additional studies of the functional consequences of GLP-1R activation. In this study, we established a procedure to isolate and culture cells derived from murine Brunner's glands. The isolated glandular cells retained functional GLP-1R expression in culture, making this in vitro system suitable for the study of GLP-1R activation. We found that cells derived from the Brunner's glands of mice pretreated with semaglutide contained significantly more mucus compared with Brunner's glands from vehicle-treated mice. Our data suggest a protective intestinal response upon semaglutide treatment, but further studies are required to leverage the full potential of cultured Brunner's gland cells.

Introduction: People with type 2 diabetes have increased risk of dementia. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are among the promising therapies for repurposing as a treatment for Alzheimer's disease; a key unanswered question is whether they reduce dementia incidence in people with type 2 diabetes., Methods: We assessed exposure to GLP-1 RAs in patients with type 2 diabetes and subsequent diagnosis of dementia in two large data sources with long-term follow-up: pooled data from three randomized double-blind placebo-controlled cardiovascular outcome trials (15,820 patients) and a nationwide Danish registry-based cohort (120,054 patients)., Results: Dementia rate was lower both in patients randomized to GLP-1 RAs versus placebo (hazard ratio [HR]: 0.47 (95% confidence interval [CI]: 0.25-0.86) and in the nationwide cohort (HR: 0.89; 95% CI: 0.86-0.93 with yearly increased exposure to GLP-1 RAs)., Discussion: Treatment with GLP-1 RAs may provide a new opportunity to reduce the incidence of dementia in patients with type 2 diabetes., Competing Interests: CHN, TG, EH, and CTP report no conflicts of interests. SF reports grants from Novo Nordisk related to the manufacture of GLP‐1 RAs during the conduct of the study and support for attending meetings and/or travel from the German Research Foundation (payments made to institution); she has also been secretary of the German Consortium in Statistics (DAGStat). CTMH, DVM, KK are Novo Nordisk employees and report personal fees from Novo Nordisk A/S related to the manufacture of GLP‐1 RAs (salary and shareholder), during the conduct of the study. KK also reports Novo Nordisk stock in pension funds. CTMH is also inventor on a patent application related to GLP‐1 compounds and indications (patent is owned by Novo Nordisk and she receives no financial or other benefits from it) and is a minor stockholder of Novo Nordisk A/S. CB reports grants and personal fees from Acadia, Addex, Exciva, Janssen, Suven, and Lundbeck; personal fees from Roche, Otsuka, Biogen, Eli Lilly, Sunovion, Novo Nordisk, and AARP; grants and personal fees from Synexus, outside the submitted work; he also reports the following grants to his institution (UoE) from: 2021 ADDF, 2020 UKRI, 2019 IMI2, NIH, Charles Wolfson Foundation, Novo Nordisk, 2018 MRC, Synexus, Capital, award from Dennis and Mireille Gillings Foundation, Novartis, and Oryzon; honoraria from Harvard University (to institution, UoE), GE Healthcare, Acadia, AARP, and Addex. LBK is a Novo Nordisk employee and an inventor on numerous patents and applications related to GLP‐1 compounds and indications; all patents are owned by Novo Nordisk, which markets liraglutide and semaglutide, and she receives no financial or other benefits from them. BZ reports grants and personal fees from Novo Nordisk during the conduct of the study, and personal fees from Eli Lilly, Merck, Boehringer Ingelheim, and Janssen, outside the submitted work. LSM is a Novo Nordisk employee and reports personal fees from Novo Nordisk A/S related to the manufacture of GLP‐1 RA (salary) during the conduct of the study; she is also vice chair of the Danish Society for Pharmacoepidemiology and is on the executive committee for the Nordic PharmacoEpidemiological Network., (© 2022 The Authors. Alzheimer's & Dementia: Diagnosis, Assessment & Disease Monitoring published by Wiley Periodicals, LLC on behalf of Alzheimer's Association.)

Therapies based on glucagon-like peptide-1 receptor (GLP-1R) agonism are highly effective in treating type 2 diabetes and obesity, but the localization of GLP-1Rs mediating the antidiabetic and other possible actions of GLP-1 is still debated. The purpose with this study was to identify sites of GLP-1R mRNA and protein expression in the mouse gastrointestinal system by means of GLP-1R antibody immunohistochemistry, Glp1r mRNA fluorescence in situ hybridization, and 125I-exendin (9-39) autoradiography. As expected, GLP-1R staining was observed in almost all β-cells in the pancreatic islets, but more rarely in α- and δ-cells. In the stomach, GLP-1R staining was found exclusively in the gastric corpus mucous neck cells, known to protect the stomach mucosa. The Brunner glands were strongly stained for GLP-1R, and pretreatment with GLP-1 agonist exendin-4 caused internalization of the receptor and mucin secretion, while pretreatment with phosphate-buffered saline or antagonist exendin (9-39) did not. In the intestinal mucosa, GLP-1R staining was observed in intraepithelial lymphocytes, lamina propria lymphocytes, and enteroendocrine cells containing secretin, peptide YY, and somatostatin, but not cholecystokinin. GLP-1R staining was seen in nerve fibers within the choline acetyl transferase- and nitric oxide-positive myenteric plexuses from the gastric corpus to the distal large intestine being strongest in the mid- and hindgut area. Finally, intraperitoneal administration of radiolabeled exendin (9-39) strongly labeled myenteric fibers. In conclusion, this study expands our knowledge of GLP-1R localization and suggests that GLP-1 may serve an important role in modulating gastrointestinal health and mucosal protection., (© The Author(s) 2021. Published by Oxford University Press on behalf of the Endocrine Society.)

Aims/hypothesis: The aim of this study was to leverage human genetic data to investigate the cardiometabolic effects of glucose-dependent insulinotropic polypeptide (GIP) signalling., Methods: Data were obtained from summary statistics of large-scale genome-wide association studies. We examined whether genetic associations for type 2 diabetes liability in the GIP and GIPR genes co-localised with genetic associations for 11 cardiometabolic outcomes. For those outcomes that showed evidence of co-localisation (posterior probability >0.8), we performed Mendelian randomisation analyses to estimate the association of genetically proxied GIP signalling with risk of cardiometabolic outcomes, and to test whether this exceeded the estimate observed when considering type 2 diabetes liability variants from other regions of the genome., Results: Evidence of co-localisation with genetic associations of type 2 diabetes liability at both the GIP and GIPR genes was observed for five outcomes. Mendelian randomisation analyses provided evidence for associations of lower genetically proxied type 2 diabetes liability at the GIP and GIPR genes with lower BMI (estimate in SD units -0.16, 95% CI -0.30, -0.02), C-reactive protein (-0.13, 95% CI -0.19, -0.08) and triacylglycerol levels (-0.17, 95% CI -0.22, -0.12), and higher HDL-cholesterol levels (0.19, 95% CI 0.14, 0.25). For all of these outcomes, the estimates were greater in magnitude than those observed when considering type 2 diabetes liability variants from other regions of the genome., Conclusions/interpretation: This study provides genetic evidence to support a beneficial role of sustained GIP signalling on cardiometabolic health greater than that expected from improved glycaemic control alone. Further clinical investigation is warranted., Data Availability: All data used in this study are publicly available. The scripts for the analysis are available at: https://github.com/vkarhune/GeneticallyProxiedGIP ., (© 2021. The Author(s).)

Objective: The area postrema (AP) and nucleus tractus solitarius (NTS) located in the hindbrain are key nuclei that sense and integrate peripheral nutritional signals and consequently regulate feeding behaviour. While single-cell transcriptomics have been used in mice to reveal the gene expression profile and heterogeneity of key hypothalamic populations, similar in-depth studies have not yet been performed in the hindbrain., Methods: Using single-nucleus RNA sequencing, we provide a detailed survey of 16,034 cells within the AP and NTS of mice in the fed and fasted states., Results: Of these, 8,910 were neurons that group into 30 clusters, with 4,289 from mice fed ad libitum and 4,621 from overnight fasted mice. A total of 7,124 nuclei were from non-neuronal cells, including oligodendrocytes, astrocytes, and microglia. Interestingly, we identified that the oligodendrocyte population was particularly transcriptionally sensitive to an overnight fast. The receptors GLP1R, GIPR, GFRAL, and CALCR, which bind GLP1, GIP, GDF15, and amylin, respectively, are all expressed in the hindbrain and are major targets for anti-obesity therapeutics. We characterise the transcriptomes of these four populations and show that their gene expression profiles are not dramatically altered by an overnight fast. Notably, we find that roughly half of cells that express GIPR are oligodendrocytes. Additionally, we profile POMC-expressing neurons within the hindbrain and demonstrate that 84% of POMC neurons express either PCSK1, PSCK2, or both, implying that melanocortin peptides are likely produced by these neurons., Conclusion: We provide a detailed single-cell level characterisation of AP and NTS cells expressing receptors for key anti-obesity drugs that are either already approved for human use or in clinical trials. This resource will help delineate the mechanisms underlying the effectiveness of these compounds and also prove useful in the continued search for other novel therapeutic targets., (Copyright © 2021 The Author(s). Published by Elsevier GmbH.. All rights reserved.)

The brainstem dorsal vagal complex (DVC) is known to regulate energy balance and is the target of appetite-suppressing hormones, such as glucagon-like peptide 1 (GLP-1). Here we provide a comprehensive genetic map of the DVC and identify neuronal populations that control feeding. Combining bulk and single-nucleus gene expression and chromatin profiling of DVC cells, we reveal 25 neuronal populations with unique transcriptional and chromatin accessibility landscapes and peptide receptor expression profiles. GLP-1 receptor (GLP-1R) agonist administration induces gene expression alterations specific to two distinct sets of Glp1r neurons-one population in the area postrema and one in the nucleus of the solitary tract that also expresses calcitonin receptor (Calcr). Transcripts and regions of accessible chromatin near obesity-associated genetic variants are enriched in the area postrema and the nucleus of the solitary tract neurons that express Glp1r and/or Calcr, and activating several of these neuronal populations decreases feeding in rodents. Thus, DVC neuronal populations associated with obesity predisposition suppress feeding and may represent therapeutic targets for obesity.

The GLP-1 receptor (GLP-1R) in the kidney is expressed exclusively in vascular smooth muscle cells in arteries and arterioles. Downstream effects of the activation of the renal vascular GLP-1R are elusive but may involve regulation of the renin-angiotensin-aldosterone system (RAAS). The expression of Ren1 in the mouse renal vasculature was investigated by in situ hybridization after a single subcutaneous dose of liraglutide, semaglutide and after repeated injections of liraglutide. Single and repeated exposure to GLP-1R agonists induced expression of Ren1 in the renal vascular smooth muscle cell compartment compared with vehicle injected controls ( p  < .0001) for both semaglutide and liraglutide. The present data show a robust induction of Ren1 expression in the vascular smooth muscle cells of the kidney after single and repeated GLP-1R activation and this renin recruitment may be involved in the effects of GLP-1R agonist treatment on kidney disease., Competing Interests: MEO, LBK and CP are employed by Novo Nordisk A/S, which markets liraglutide and semaglutide for the treatment of diabetes and weight management. LBK and CP hold minor stock portions as part of an employee‐offering programme., (© 2021 The Authors. Endocrinology, Diabetes & Metabolism published by John Wiley & Sons Ltd.)

Glucagon-like peptide-1 (GLP-1) exerts its anorexigenic effect at least partly via the proopiomelanocortin (POMC) neurons of the arcuate (ARC) nucleus. These neurons are known to express GLP-1 receptor (GLP-1R). The aim of the study was to determine whether in addition to its direct effect, GLP-1 also modulates how neuronal inputs can regulate the POMC neurons by acting on presynaptic terminals, ultrastructural and electrophysiological studies were performed on tissues of adult male mice. GLP-1R-immunoreactivity was associated with the cell membrane of POMC neurons and with axon terminals forming synapses on these cells. The GLP-1 analog exendin 4 (Ex4) markedly increased the firing rate of all examined POMC neurons and depolarized these cells. These effects of Ex4 were prevented by intracellular administration of the G-protein blocker guanosine 5'-[β-thio]diphosphate trilithium salt (GDP-β-S). Ex4 also influenced the miniature postsynaptic currents (mPSCs) and evoked PSCs of POMC neurons. Ex4 increased the frequency of miniature excitatory PSCs (EPSCs) and the amplitude of the evoked EPSCs in half of the POMC neurons. Ex4 increased the frequency of miniature inhibitory PSCs (IPSCs) and the amplitudes of the evoked IPSCs in one-third of neurons. These effects of Ex4 were not influenced by intracellular GDP-β-S, indicating that GLP-1 signaling directly stimulates a population of axon terminals innervating the POMC neurons. The different Ex4 responsiveness of their mPSCs indicates the heterogeneity of the POMC neurons of the ARC. In summary, our data demonstrate that in addition to its direct excitatory effect on the POMC neurons, GLP-1 signaling also facilitates the presynaptic input of these cells by acting on presynaptically localized GLP-1R., (© 2020 S. Karger AG, Basel.)

Glucagon-like peptide-1 (GLP-1) inhibits food intake and regulates glucose homeostasis. These actions are at least partly mediated by central GLP-1 receptor (GLP-1R). Little information is available, however, about the subcellular localization and the distribution of the GLP-1R protein in the rat brain. To determine the localization of GLP-1R protein in the rat brain, immunocytochemistry was performed at light and electron microscopic levels. The highest density of GLP-1R-immunoreactivity was observed in the circumventricular organs and regions in the vicinity of these areas like in the arcuate nucleus (ARC) and in the nucleus tractus solitarii (NTS). In addition, GLP-1R-immunreactive (IR) neuronal profiles were also observed in a number of telencephalic, diencephalic and brainstem areas and also in the cerebellum. Ultrastructural examination of GLP-1R-immunoreactivity in energy homeostasis related regions showed that GLP-1R immunoreactivity is associated with the membrane of perikarya and dendrites but GLP-1R can also be observed inside and on the surface of axon varicosities and axon terminals. In conclusion, in this study we provide a detailed map of the GLP-1R-IR structures in the CNS. Furthermore, we demonstrate that in addition to the perikaryonal and dendritic distribution, GLP-1R is also present in axonal profiles suggesting a presynaptic action of GLP-1. The very high concentration of GLP-1R-profiles in the circumventricular organs and in the ARC and NTS suggests that peripheral GLP-1 may influence brain functions via these brain areas.

Semaglutide, a glucagon-like peptide 1 (GLP-1) analog, induces weight loss, lowers glucose levels, and reduces cardiovascular risk in patients with diabetes. Mechanistic preclinical studies suggest weight loss is mediated through GLP-1 receptors (GLP-1Rs) in the brain. The findings presented here show that semaglutide modulated food preference, reduced food intake, and caused weight loss without decreasing energy expenditure. Semaglutide directly accessed the brainstem, septal nucleus, and hypothalamus but did not cross the blood-brain barrier; it interacted with the brain through the circumventricular organs and several select sites adjacent to the ventricles. Semaglutide induced central c-Fos activation in 10 brain areas, including hindbrain areas directly targeted by semaglutide, and secondary areas without direct GLP-1R interaction, such as the lateral parabrachial nucleus. Automated analysis of semaglutide access, c-Fos activity, GLP-1R distribution, and brain connectivity revealed that activation may involve meal termination controlled by neurons in the lateral parabrachial nucleus. Transcriptomic analysis of microdissected brain areas from semaglutide-treated rats showed upregulation of prolactin-releasing hormone and tyrosine hydroxylase in the area postrema. We suggest semaglutide lowers body weight by direct interaction with diverse GLP-1R populations and by directly and indirectly affecting the activity of neural pathways involved in food intake, reward, and energy expenditure.

Background: Chronic kidney disease (CKD) is a global health burden, and the current treatment options only slow down the disease progression. GLP-1 receptor agonists (GLP-1 RA) have shown a renal protective effect in models of CKD; however, the mechanism behind the beneficial effect is not understood. In this study, we investigate the effect of the GLP-1 RA liraglutide in the nephrotoxic serum nephritis (NTN) CKD model. Moreover, we compare the gene expression pattern of liraglutide-treated mice to the gene expression pattern of mice treated with the angiotensin converting enzyme inhibitor, enalapril., Methods: The effect of liraglutide was tested in the NTN model by evaluating the glomerular filtration rate (GFR), albuminuria, mesangial expansion, renal fibrosis, and renal inflammation. Furthermore, the regulation of selected genes involved in CKD and in glomerular, cortical tubulointerstitial, and whole kidney structures was analyzed using a gene expression array on samples following laser capture microdissection., Results: Treatment with liraglutide improved CKD hallmarks including GFR, albuminuria, mesangial expansion, renal inflammation, and renal fibrosis. The gene expression revealed that both liraglutide and enalapril reversed the regulation of several fibrosis and inflammation associated genes, which are also regulated in human CKD patients. Furthermore, liraglutide and enalapril both regulated genes in the kidney involved in blood pressure control., Conclusions: Treatment with liraglutide improved the kidney function and diminished renal lesions in NTN-induced mice. Both liraglutide and enalapril reversed the regulation of genes involved in CKD and regulated genes involved in blood pressure control., (© 2020 S. Karger AG, Basel.)

Parkinson's disease (PD) is a basal ganglia movement disorder characterized by progressive degeneration of the nigrostriatal dopaminergic system. Immunohistochemical methods have been widely used for characterization of dopaminergic neuronal injury in animal models of PD, including the MPTP (1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine) mouse model. However, conventional immunohistochemical techniques applied to tissue sections have inherent limitations with respect to loss of 3D resolution, yielding insufficient information on the architecture of the dopaminergic system. To provide a more comprehensive and non-biased map of MPTP-induced changes in central dopaminergic pathways, we used iDISCO immunolabeling, light-sheet fluorescence microscopy (LSFM) and deep-learning computational methods for whole-brain three-dimensional visualization and automated quantitation of tyrosine hydroxylase (TH)-positive neurons in the adult mouse brain. Mice terminated 7 days after acute MPTP administration demonstrated widespread alterations in TH expression. Compared to vehicle controls, MPTP-dosed mice showed a significant loss of TH-positive neurons in the substantia nigra pars compacta and ventral tegmental area. Also, MPTP dosing reduced overall TH signal intensity in basal ganglia nuclei, i.e. the substantia nigra, caudate-putamen, globus pallidus and subthalamic nucleus. In contrast, increased TH signal intensity was predominantly observed in limbic regions, including several subdivisions of the amygdala and hypothalamus. In conclusion, mouse whole-brain 3D imaging is ideal for unbiased automated counting and densitometric analysis of TH-positive cells. The LSFM-deep learning pipeline tracked brain-wide changes in catecholaminergic pathways in the MPTP mouse model of PD, and may be applied for preclinical characterization of compounds targeting dopaminergic neurotransmission., Competing Interests: Competing interestsU.R., C.B.G.S., D.D.T., J.L.S., K.F., P.B., H.H.H. and J.H.-S. are employed by Gubra; L.M.J., V.I.J. and L.B.K. are employed by Novo Nordisk; N.V. and J.J. are owners of Gubra., (© 2019. Published by The Company of Biologists Ltd.)

The discovery of glucagon-like peptide-1 (GLP-1), an incretin hormone with important effects on glycemic control and body weight regulation, led to efforts to extend its half-life and make it therapeutically effective in people with type 2 diabetes (T2D). The development of short- and then long-acting GLP-1 receptor agonists (GLP-1RAs) followed. Our article charts the discovery and development of the long-acting GLP-1 analogs liraglutide and, subsequently, semaglutide. We examine the chemistry employed in designing liraglutide and semaglutide, the human and non-human studies used to investigate their cellular targets and pharmacological effects, and ongoing investigations into new applications and formulations of these drugs. Reversible binding to albumin was used for the systemic protraction of liraglutide and semaglutide, with optimal fatty acid and linker combinations identified to maximize albumin binding while maintaining GLP-1 receptor (GLP-1R) potency. GLP-1RAs mediate their effects via this receptor, which is expressed in the pancreas, gastrointestinal tract, heart, lungs, kidneys, and brain. GLP-1Rs in the pancreas and brain have been shown to account for the respective improvements in glycemic control and body weight that are evident with liraglutide and semaglutide. Both liraglutide and semaglutide also positively affect cardiovascular (CV) outcomes in individuals with T2D, although the precise mechanism is still being explored. Significant weight loss, through an effect to reduce energy intake, led to the approval of liraglutide (3.0 mg) for the treatment of obesity, an indication currently under investigation with semaglutide. Other ongoing investigations with semaglutide include the treatment of non-alcoholic fatty liver disease (NASH) and its use in an oral formulation for the treatment of T2D. In summary, rational design has led to the development of two long-acting GLP-1 analogs, liraglutide and semaglutide, that have made a vast contribution to the management of T2D in terms of improvements in glycemic control, body weight, blood pressure, lipids, beta-cell function, and CV outcomes. Furthermore, the development of an oral formulation for semaglutide may provide individuals with additional benefits in relation to treatment adherence. In addition to T2D, liraglutide is used in the treatment of obesity, while semaglutide is currently under investigation for use in obesity and NASH.

The glucagon-like peptide-1 receptor agonists (GLP-1RAs) liraglutide and semaglutide reduce cardiovascular risk in type 2 diabetes patients. The mode of action is suggested to occur through modified atherosclerotic progression. In this study, both of the compounds significantly attenuated plaque lesion development in apolipoprotein E-deficient (ApoE -/- ) mice and low-density lipoprotein receptor-deficient (LDLr -/- ) mice. This attenuation was partly independent of weight and cholesterol lowering. In aortic tissue, exposure to a Western diet alters expression of genes in pathways relevant to the pathogenesis of atherosclerosis, including leukocyte recruitment, leukocyte rolling, adhesion/extravasation, cholesterol metabolism, lipid-mediated signaling, extracellular matrix protein turnover, and plaque hemorrhage. Treatment with semaglutide significantly reversed these changes. These data suggest GLP-1RAs affect atherosclerosis through an anti-inflammatory mechanism.

Oral administration of therapeutic peptides is hindered by poor absorption across the gastrointestinal barrier and extensive degradation by proteolytic enzymes. Here, we investigated the absorption of orally delivered semaglutide, a glucagon-like peptide-1 analog, coformulated with the absorption enhancer sodium N -[8-(2-hydroxybenzoyl) aminocaprylate] (SNAC) in a tablet. In contrast to intestinal absorption usually seen with small molecules, clinical and preclinical dog studies revealed that absorption of semaglutide takes place in the stomach, is confined to an area in close proximity to the tablet surface, and requires coformulation with SNAC. SNAC protects against enzymatic degradation via local buffering actions and only transiently enhances absorption. The mechanism of absorption is shown to be compound specific, transcellular, and without any evidence of effect on tight junctions. These data have implications for understanding how highly efficacious and specific therapeutic peptides could be transformed from injectable to tablet-based oral therapies., (Copyright © 2018 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works.)

Semaglutide is a human glucagon-like peptide-1 (GLP-1) analogue that is in development for the treatment of type 2 diabetes. In the pre-approval cardiovascular outcomes trial SUSTAIN 6, semaglutide was associated with a significant increase in the risk of diabetic retinopathy (DR) complications vs placebo. GLP-1 receptor (GLP-1R) expression has previously been demonstrated in the retina in animals and humans; however, antibodies used to detect expression have been documented to be non-specific and fail to detect the GLP-1R using immunohistochemistry (IHC), a problem common for many G-protein coupled receptors. Using a validated GLP-1R antibody for IHC and in situ hybridization for GLP-1R mRNA in normal human eyes, GLP-1Rs were detected in a small fraction of neurons in the ganglion cell layer. In advanced stages of DR, GLP-1R expression was not detected at the protein or mRNA level. Specifically, no GLP-1R expression was found in the eyes of people with long-standing proliferative DR (PDR). In conclusion, GLP-1R expression is low in normal human eyes and was not detected in eyes exhibiting advanced stages of PDR., (© 2018 The Authors. Diabetes, Obesity and Metabolism published by John Wiley & Sons Ltd.)

Light Sheet Fluorescence Microscopy (LSFM) of whole organs, in particular the brain, offers a plethora of biological data imaged in 3D. This technique is however often hindered by cumbersome non-automated analysis methods. Here we describe an approach to fully automate the analysis by integrating with data from the Allen Institute of Brain Science (AIBS), to provide precise assessment of the distribution and action of peptide-based pharmaceuticals in the brain. To illustrate this approach, we examined the acute central nervous system effects of the glucagon-like peptide-1 (GLP-1) receptor agonist liraglutide. Peripherally administered liraglutide accessed the hypothalamus and brainstem, and led to activation in several brain regions of which most were intersected by projections from neurons in the lateral parabrachial nucleus. Collectively, we provide a rapid and unbiased analytical framework for LSFM data which enables quantification and exploration based on data from AIBS to support basic and translational discovery.

Glucagonlike peptide 1 (GLP-1) is a physiological regulator of appetite, and long-acting GLP-1 receptor (GLP-1R) agonists lower food intake and body weight in both human and animal studies. The effects are mediated through brain GLP-1Rs, and several brain nuclei expressing the GLP-1R may be involved. To date, the mapping of the complete location of GLP-1R protein in the brain has been challenged by lack of good antibodies and the discrepancy between mRNA and protein, especially relevant in neuronal axonal processes. Here, we present a specific monoclonal GLP-1R antibody for immunohistochemistry with murine tissue and show detailed distribution of GLP-1R expression, as well as mapping of GLP-1R mRNA by nonradioactive in situ hybridization. Semiautomated image analysis was performed to map the GLP-1R distribution to atlas plates from the Allen Institute for Brain Science. The GLP-1R was abundantly expressed in numerous regions, including the septal nucleus, hypothalamus, and brain stem. GLP-1R protein expression was also observed on neuronal projections in brain regions devoid of any mRNA that has not been observed in earlier reports. Taken together, these findings provide knowledge on GLP-1R expression in neuronal cell bodies and neuronal projections., (Copyright © 2018 Endocrine Society.)

Aims: Glucagon-like peptide-1 (GLP-1) is an incretin hormone which stimulates insulin release and inhibits glucagon secretion from the pancreas in a glucose-dependent manner. Incretin-based therapies, consisting of GLP-1 receptor (GLP-1R) agonists and dipeptidyl peptidase-4 (DPP-4) inhibitors, are used for the treatment of type 2 diabetes (T2D). Immunohistochemical studies for GLP-1R expression have been hampered previously by the use of unspecific polyclonal antibodies. This study aimed to assess the expression levels of GLP-1R in a set of T2D donor samples obtained via nPOD., Methods: This study used a new monoclonal antibody to assess GLP-1R expression in pancreatic tissue from 23 patients with T2D, including 7 with a DPP-4 inhibitor and 1 with a history of GLP-1R agonist treatment. A software-based automated image analysis algorithm was used for quantitating intensities and area fractions of GLP-1R positive compartments., Results: The highest intensity GLP-1R immunostaining was seen in beta-cells in islets (average signal intensity, 76.1 [±8.1]). GLP-1R/insulin double-labelled single cells or small clusters of cells were also frequently located within or in close vicinity of ductal epithelium in all samples and with the same GLP-1R immunostaining intensity as found in beta-cells in islets. In the exocrine pancreas a large proportion of acinar cells expressed GLP-1R with a 3-fold lower intensity of immunoreactivity as compared to beta-cells (average signal intensity 25.5 [±3,3]). Our studies did not unequivocally demonstrate GLP-1R immunoreactivity on normal-appearing ductal epithelium. Pancreatic intraepithelial neoplasia (PanINs; a form of non-invasive pancreatic ductular neoplasia) was seen in most samples, and a minority of these expressed low levels of GLP-1R., Conclusion: These data confirm the ubiquity of early stage PanIN lesions in patients with T2D and do not support the hypothesis that incretin-based therapies are associated with progression towards the more advanced stage PanIN lesions., (© 2017 John Wiley & Sons Ltd.)

Background: Beneficial roles for glucagon-like peptide 1 (GLP-1)/GLP-1R signaling have recently been described in diseases, where low-grade inflammation is a common phenomenon. We investigated the effects of GLP-1 in Brunner's glands and duodenum with abundant expression of GLP-1 receptors, as well as GLP-1 effect on colonic inflammation., Methods: RNA from Brunner's glands of GLP-1R knockout and wild-type mice were subjected to full transcriptome profiling. Array results were validated by quantitative reverse transcription polymerase chain reaction in wild-type mice and compared with samples from inflammatory bowel disease (IBD) patients and controls. In addition, we performed a detailed investigation of the effects of exogenous liraglutide dosing in a T-cell driven adoptive transfer (AdTr) colitis mouse model., Results: Analyses of the Brunner's gland transcriptomes of GLP-1R knockout and wild-type mice identified 722 differentially expressed genes. Upregulated transcripts after GLP-1 dosing included IL-33, chemokine ligand 20 (CCL20), and mucin 5b. Biopsies from IBD patients and controls, as well as data from the AdTr model, showed deregulated expression of GLP-1R, CCL20, and IL-33 in colon. Circulating levels of GLP-1 were found to be increased in mice with colitis. Finally, the colonic cytokine levels and disease scores of the AdTr model indicated reduced levels of colonic inflammation in liraglutide-dosed animals., Conclusions: We demonstrate that IL-33, GLP-1R, and CCL20 are deregulated in human IBD, and that prophylactic treatment with 0.6 mg/kg liraglutide improves disease in AdTr colitis. In addition, GLP-1 receptor agonists upregulate IL-33, mucin 5b, and CCL20 in murine Brunner's glands. Taken together, our data indicate that GLP-1 receptor agonists affect gut homeostasis in both proximal and distal parts of the gut.

Exendin-4, a glucagon-like peptide-1 (GLP-1) receptor agonist, have been demonstrated to promote neuroprotection in the rat 6-hydroxydopamine (6-OHDA) neurotoxin model of Parkinson's disease (PD), a neurodegenerative disorder characterized by progressive nigrostriatal dopaminergic neuron loss. In this report, we characterized the effect of a long-acting GLP-1 receptor agonist, liraglutide (500µg/kg/day, s.c.) in the context of a partial or advanced (full) 6-OHDA induced nigral lesion in the rat. Rats received a low (3µg, partial lesion) or high (13.5µg, full lesion) 6-OHDA dose stereotaxically injected into the right medial forebrain bundle (n=17-20 rats per experimental group). Six weeks after induction of a partial nigral dopaminergic lesion, vehicle or liraglutide was administered for four weeks. In the full lesion model, vehicle dosing or liraglutide treatment was applied for a total of six weeks starting three weeks pre-lesion, or administered for three weeks starting on the lesion day. Quantitative stereology was applied to assess the total number of midbrain tyrosine hydroxylase (TH) positive dopaminergic neurons. As compared to vehicle controls, liraglutide had no effect on the rotational responsiveness to d-amphetamine or apomorphine, respectively. In correspondence, while numbers of TH-positive nigral neurons were significantly reduced in the lesion side (partial lesion ≈55%; full lesion ≈90%) liraglutide administration had no influence dopaminergic neuronal loss in either PD model setting. In conclusion, liraglutide showed no neuroprotective effects in the context of moderate or substantial midbrain dopaminergic neuronal loss and associated functional motor deficits in the rat 6-OHDA lesion model of PD., (Copyright © 2016. Published by Elsevier B.V.)

One of the major histopathological hallmarks of Alzheimer's disease (AD) is cerebral deposits of extracellular β-amyloid peptides. Preclinical studies have pointed to glucagon-like peptide 1 (GLP-1) receptors as a potential novel target in the treatment of AD. GLP-1 receptor agonists, including exendin-4 and liraglutide, have been shown to promote plaque-lowering and mnemonic effects of in a number of experimental models of AD. Transgenic mouse models carrying genetic mutations of amyloid protein precursor (APP) and presenilin-1 (PS1) are commonly used to assess the pharmacodynamics of potential amyloidosis-lowering and pro-cognitive compounds. In this study, effects of long-term liraglutide treatment were therefore determined in two double APP/PS1 transgenic mouse models of Alzheimer's disease carrying different clinical APP/PS1 mutations, i.e. the 'London' (hAPPLon/PS1A246E) and 'Swedish' mutation variant (hAPPSwe/PS1ΔE9) of APP, with co-expression of distinct PS1 variants. Liraglutide was administered in 5 month-old hAPPLon/PS1A246E mice for 3 months (100 or 500 ng/kg/day, s.c.), or 7 month-old hAPPSwe/PS1ΔE9 mice for 5 months (500 ng/kg/day, s.c.). In both models, regional plaque load was quantified throughout the brain using stereological methods. Vehicle-dosed hAPPSwe/PS1ΔE9 mice exhibited considerably higher cerebral plaque load than hAPPLon/PS1A246E control mice. Compared to vehicle-dosed transgenic controls, liraglutide treatment had no effect on the plaque levels in hAPPLon/PS1A246E and hAPPSwe/PS1ΔE9 mice. In conclusion, long-term liraglutide treatment exhibited no effect on cerebral plaque load in two transgenic mouse models of low- and high-grade amyloidosis, which suggests differential sensitivity to long-term liraglutide treatment in various transgenic mouse models mimicking distinct pathological hallmarks of AD.

Liraglutide is a glucagon-like peptide-1 receptor (GLP-1R) agonist marketed for the treatment of type 2 diabetes. Besides lowering blood glucose, liraglutide reduces bodyweight, and has recently also been approved for the obesity indication. Acutely, GLP-1 markedly reduces gastric emptying, and this effect was previously believed to at least partly explain the effect on bodyweight loss. However, recent studies in both humans and animals have shown that GLP-1R agonists, such as liraglutide, that lead to pharmacological concentrations for 24 h/day only have a minor effect on gastric emptying; such an effect is unlikely to have lasting effects on appetite reduction. Liraglutide has been shown to have direct effects in the arcuate nucleus of the rodent brain, activating pro-opiomelanocortin neurons and increasing levels of the cocaine- and amphetamine-stimulated transcript neuropeptide messenger ribonucleic acid, which correlate nicely to clinical studies where liraglutide was shown to increase feelings of satiety. However, despite the lack of a GLP-1R on agouti-related peptide/neuropeptide Y neurons, liraglutide also was able to prevent a hunger associated increase in agouti-related peptide and neuropeptide Y neuropeptide messenger ribonucleic acid, again with a strong correlation to clinical studies that document reduced hunger feelings in patients while taking liraglutide. Studies using fluorescent labeled liraglutide, as well as other GLP-1R agonists, and analysis using single-plane illumination microscopy show that such medium-sized peptide-based compounds can directly access not only circumventricular organs of the brain, but also directly access discrete regions in the hypothalamus. The direct effects of long-acting GLP-1R agonists in the hypothalamus are likely to be an important new pathway in understanding GLP-1R agonist mediated weight loss.

In addition to a prominent role in glycemic control, glucagon-like peptide 1 (GLP-1) receptor agonists exhibit neuroprotective properties. There is mounting experimental evidence that GLP-1 receptor agonists, including liraglutide, may enhance synaptic plasticity, counteract cognitive deficits and ameliorate neurodegenerative features in preclinical models of Alzheimer's disease (AD), predominantly in the context of β-amyloid toxicity. Here we characterized the effects of liraglutide in a transgenic mutant tau (hTauP301L) mouse tauopathy model, which develops age-dependent pathology-specific neuronal tau phosphorylation and neurofibrillary tangle formation with progressively compromised motor function (limb clasping). Liraglutide (500 µg/kg/day, s.c., q.d., n=18) or vehicle (n=18) was administered to hTauP301L mice for 6 months from the age of three months. Vehicle-dosed wild-type FVB/N mice served as normal control (n=17). The onset and severity of hind limb clasping was markedly different in liraglutide and vehicle-dosed transgenic mice. Clasping behavior was observed in 61% of vehicle-dosed hTauP301L mice with a 55% survival rate in 9-month old transgenic mice. In contrast, liraglutide treatment reduced the clasping rate to 39% of hTauP301L mice, and fully prevented clasping-associated lethality resulting in a survival rate of 89%. Stereological analyses demonstrated that hTauP301L mice exhibited hindbrain-dominant neuronal accumulation of phosphorylated tau closely correlated to the severity of clasping behavior. In correspondence, liraglutide treatment significantly reduced neuronal phospho-tau load by 61.9±10.2% (p<0.001) in hTauP301L mice, as compared to vehicle-dosed controls. In conclusion, liraglutide significantly reduced tau pathology in a transgenic mouse tauopathy model., (Copyright © 2015 Elsevier B.V. All rights reserved.)

Liraglutide is an acylated glucagon-like peptide-1 (GLP-1) analogue that binds to serum albumin in vivo and is approved for once-daily treatment of diabetes as well as obesity. The aim of the present studies was to design a once weekly GLP-1 analogue by increasing albumin affinity and secure full stability against metabolic degradation. The fatty acid moiety and the linking chemistry to GLP-1 were the key features to secure high albumin affinity and GLP-1 receptor (GLP-1R) potency and in obtaining a prolonged exposure and action of the GLP-1 analogue. Semaglutide was selected as the optimal once weekly candidate. Semaglutide has two amino acid substitutions compared to human GLP-1 (Aib(8), Arg(34)) and is derivatized at lysine 26. The GLP-1R affinity of semaglutide (0.38 ± 0.06 nM) was three-fold decreased compared to liraglutide, whereas the albumin affinity was increased. The plasma half-life was 46.1 h in mini-pigs following i.v. administration, and semaglutide has an MRT of 63.6 h after s.c. dosing to mini-pigs. Semaglutide is currently in phase 3 clinical testing.

Infertility and fertility treatment have the potential to impact and disrupt a couple's overall life. In order to study the associations between the impact of childlessness on one's life, and men and women's attitudes towards fertility treatment continuation and/or adoption, we analysed data from a one-year follow-up questionnaire in a prospective, longitudinal cohort study of consecutive couples initiating fertility treatment in Denmark. The study comprised 302 couples with no children at baseline and no joint children at one-year follow-up. In total, 71.9% of women and 72.5% of men reported that they wished to continue fertility treatment, while 20.2% of women and 19.2% of men reported that they wished to pursue adoption. The attitudes of nearly 8 in 10 couples were congruent towards further fertility treatments, while nearly 7 in 10 couples were congruent in their attitudes to pursuing adoption. Significantly more men who reported a lower impact of childlessness on their daily life wished to continue fertility treatment, compared with those reporting that childlessness had a greater impact on their life. Among women, significantly more were undecided about whether or not to pursue adoption when reporting a greater impact of childlessness on social life, compared with those reporting a lower impact of their childlessness.

Glucagon-like peptide-1 (GLP-1) is released from endocrine L-cells lining the gut in response to food ingestion. However, GLP-1 is also produced in the nucleus of the solitary tract, where it acts as an anorectic neurotransmitter and key regulator of many autonomic and neuroendocrine functions. The expression and projections of GLP-1-producing neurons is highly conserved between rodent and primate brain, although a few key differences have been identified. The GLP-1 receptor (GLP-1R) has been mapped in the rodent brain, but no studies have described the distribution of GLP-1Rs in the nonhuman primate central nervous system. Here, we characterized the distribution of GLP-1R mRNA and protein in the adult macaque brain using in situ hybridization, radioligand receptor autoradiography, and immunohistochemistry with a primate specific GLP-1R antibody. Immunohistochemistry demonstrated that the GLP-1R is localized to cell bodies and fiber terminals in a very selective distribution throughout the brain. Consistent with the functional role of the GLP-1R system, we find the highest concentration of GLP-1R-immunoreactivity present in select hypothalamic and brainstem regions that regulate feeding, including the paraventricular and arcuate hypothalamic nuclei, as well as the area postrema, nucleus of the solitary tract, and dorsal motor nucleus of the vagus. Together, our data demonstrate that GLP-1R distribution is highly conserved between rodent and primate, although a few key species differences were identified, including the amygdala, where GLP-1R expression is much higher in primate than in rodent.

Recent studies indicate that glucagon-like peptide 1 (GLP-1) receptor agonists, currently used in the management of type 2 diabetes, exhibit neurotrophic and neuroprotective effects in amyloid-β (Aβ) toxicity models of Alzheimer's disease (AD). We investigated the potential pro-cognitive and neuroprotective effects of the once-daily GLP-1 receptor agonist liraglutide in senescence-accelerated mouse prone 8 (SAMP8) mice, a model of age-related sporadic AD not dominated by amyloid plaques. Six-month-old SAMP8 mice received liraglutide (100 or 500 μg/kg/day, s.c.) or vehicle once daily for 4 months. Vehicle-dosed age-matched 50% back-crossed as well as untreated young (4-month-old) SAMP8 mice were used as control groups for normal memory function. Vehicle-dosed 10-month-old SAMP8 mice showed significant learning and memory retention deficits in an active-avoidance T-maze, as compared to both control groups. Also, 10-month-old SAMP8 mice displayed no immunohistological signatures of amyloid-β plaques or hyperphosphorylated tau, indicating the onset of cognitive deficits prior to deposition of amyloid plaques and neurofibrillary tangles in this AD model. Liraglutide significantly increased memory retention and total hippocampal CA1 pyramidal neuron numbers in SAMP8 mice, as compared to age-matched vehicle-dosed SAMP8 mice. In conclusion, liraglutide delayed or partially halted the progressive decline in memory function associated with hippocampal neuronal loss in a mouse model of pathological aging with characteristics of neurobehavioral and neuropathological impairments observed in early-stage sporadic AD.

Increased pancreas mass and glucagon-positive adenomas have been suggested to be a risk associated with sitagliptin or exenatide therapy in humans. Novo Nordisk has conducted extensive toxicology studies, including data on pancreas weight and histology, in Cynomolgus monkeys dosed with two different human glucagon-like peptide-1 (GLP-1) receptor agonists. In a 52-week study with liraglutide, a dose-related increase in absolute pancreas weight was observed in female monkeys only. Such dose-related increase was not found in studies of 4, 13, or 87 weeks' duration. No treatment-related histopathological abnormalities were observed in any of the studies. Quantitative histology of the pancreas from the 52-week study showed an increase in the exocrine cell mass in liraglutide-dosed animals, with normal composition of endocrine and exocrine cellular compartments. Proliferation rate of the exocrine tissue was low and comparable between groups. Endocrine cell mass and proliferation rates were unaltered by liraglutide treatment. Semaglutide showed no increase in pancreas weight and no treatment-related histopathological findings in the pancreas after 13 or 52 weeks' dosing. Overall, results in 138 nonhuman primates showed no histopathological changes in the pancreas associated with liraglutide or semaglutide, two structurally different GLP-1 receptor agonists., (© 2014 by the American Diabetes Association.)

Glucagon-like peptide 1 (GLP-1) analogs are increasingly being used in the treatment of type 2 diabetes. It is clear that these drugs lower blood glucose through an increase in insulin secretion and a lowering of glucagon secretion; in addition, they lower body weight and systolic blood pressure and increase heart rate. Using a new monoclonal antibody for immunohistochemistry, we detected GLP-1 receptor (GLP-1R) in important target organs in humans and monkeys. In the pancreas, GLP-1R was predominantly localized in β-cells with a markedly weaker expression in acinar cells. Pancreatic ductal epithelial cells did not express GLP-1R. In the kidney and lung, GLP-1R was exclusively expressed in smooth muscle cells in the walls of arteries and arterioles. In the heart, GLP-1R was localized in myocytes of the sinoatrial node. In the gastrointestinal tract, the highest GLP-1R expression was seen in the Brunner's gland in the duodenum, with lower level expression in parietal cells and smooth muscle cells in the muscularis externa in the stomach and in myenteric plexus neurons throughout the gut. No GLP-1R was seen in primate liver and thyroid. GLP-1R expression seen with immunohistochemistry was confirmed by functional expression using in situ ligand binding with (125)I-GLP-1. In conclusion, these results give important new insight into the molecular mode of action of GLP-1 analogs by identifying the exact cellular localization of GLP-1R.