Glucagon Receptor Agonist Research Articles

1813-P: Coadministration of a GLP-1/Glucagon Receptor Agonist with an FXR Agonist and ACC Inhibitor Reverses Nonalcoholic Steatohepatitis (NASH) in Diet-Induced and Biopsy-Confirmed Mice

Combination approaches for the treatment of NASH are being actively pursued. We examined the effects of administration of a dual GLP-1 and glucagon receptor agonist (GLP-1:GCG, 0.015 mg/kg, s.c., q.d.) alone and combined with an FXR agonist (cilofexor, CILO; 30 mg/kg) and/or an acetyl-CoA carboxylase inhibitor (firsocostat analog, ACCi; 5 mg/kg, both p.o., q.d) on NASH endpoints in the AMLN diet-induced and biopsy-confirmed DIO-NASH mouse (n=15-16/group). After 12 weeks of treatment, GLP-1:GCG reduced body weight 15%, being slightly greater in the GLP-1:GCG + CILO group (22%). Liver triglyceride was reduced by GLP-1:GCG (by 76% vs. vehicle, p<0.001). Addition of CILO, ACCi or both to GLP-1:GCG further reduced liver lipid (by 82%, 88% and 91%, respectively). Histopathological pre-to-post NAFLD activity score (NAS) was reduced in 7/16 (44%) of vehicle controls and in all mice (100%) in the GLP-1:GCG-containing groups. In vehicle controls, 0/16 mice had a final NAS of 0-1 whereas this increased to 5/15 mice (33%) with GLP-1:GCG, and was not significantly improved by addition of CILO (7/15, 47%) or ACCi (6/16, 38%). Triple therapy increased number of mice with NAS of 0-1 to 11/16 (69%). GLP-1:GCG was associated with 1/15 mice (7%) improving pre-to-post fibrosis stage which was not altered by addition of CILO or ACCi, but increased to 7/16 (44%) with triple therapy. Collagen-1a and α-SMA immunoreactivity (% area) revealed no significant effect of GLP-1:GCG for collagen (5.7%), but reduction in α-SMA (1.4%, p<0.001) vs. vehicle (6.8% and 4.9%, respectively). Triple therapy reduced both collagen and α-SMA area (3.8% and 1.5%, respectively, both p<0.001 vs. vehicle). In conclusion, GLP-1:GCG effectively reduced hepatic lipid and the addition of an FXR agonist and ACC inhibitor further improved pre-to-post NAS and fibrosis stage in DIO-NASH mice, supporting development of combination approaches for NASH. Disclosure J.L. Trevaskis: Employee; Self; Gilead Sciences, Inc. J. Norlin: Employee; Self; Novo Nordisk A/S. Stock/Shareholder; Self; Novo Nordisk A/S. D.A. Miranda: None. J.G. Bates: Employee; Self; Gilead Sciences, Inc. N.E. Zois: Employee; Self; Gubra. S. Veidal: None. M. Feigh: None. M. Latta: Employee; Self; Novo Nordisk A/S.

1798-P: Chronic Administration of a Long-Acting Glucagon Analogue Results in Enhanced Insulin Secretory Activity in a Directly-Observed Murine Model

Aims: GLP-1 (GLP-1R) and glucagon (GCGR) receptor co-agonists are in development to treat type 2 diabetes. The effect of chronic GCGR agonism on weight loss is well-documented, but its direct influence on islet function remains poorly understood. We investigated the effects of a long-acting glucagon analogue G778 on pancreatic islet calcium dynamics. Methods: C57Bl/6 (n=9 per group) mice with diet-induced obesity (DIO) received daily subcutaneous injections of G778 100nmol/kg or saline (and calorie restricted to achieve weight matching) for 40 days. All mice had syngeneic islets with beta-cell specific expression of the calcium fluorophore GCaMP6f implanted in the anterior chamber of the eye, providing a direct, longitudinal readout of beta-cell function in vivo using confocal microscopy. Such islets were tested in vitro to measure the effects of G778 on whole islet calcium dynamics. Another experiment measured the effects of G778 administration on oxygen consumption in a CLAMS system. Results: G778 produced a small but significant rise in energy expenditure (EE) in mice. At 40 days, there was non-significant difference in body weight loss between the saline and G778-treated groups (0.9g ±1.1 vs. 3.4g ±0.7 p=0.07), but a marked improvement in glucose tolerance in mice treated long term with the glucagon analogue (15 min glucose on a 2mg/kg IPGTT 15.9 mmol/L vs. 9.2 mmol/L p<0.001). Islet readouts over the course of the experiment revealed that glucagon receptor agonism was able to restore calcium activity of islets in DIO mice in vivo. In vitro findings confirmed that G778 promoted calcium waves of longer duration and heightened connectivity above 7mM glucose (p=0.05). Summary: Our data suggest that the glucagon element of a glucagon/GLP-1 analogue contributes to weight-loss partly through an elevation in EE but also has independent effects on insulin secretory function, promoting more robust and sustained beta-cell calcium responses. Disclosure K. Suba: None. Y.S. Patel: None. A. Martin Alonso: None. R. Scott: None. J.S. Minnion: None. I. Leclerc: Consultant; Spouse/Partner; Sun Pharmaceutical Industries Ltd. Research Support; Spouse/Partner; Servier. B. Owen: None. W. Distaso: None. T.M. Tan: None. K. Murphy: None. S. Bloom: None. G.A. Rutter: Consultant; Self; Sun Pharmaceutical Industries Ltd. Research Support; Self; Servier, Sun Pharmaceutical Industries Ltd. V. Salem: None. Funding Diabetes UK (15/0005317)

Incretin combination therapy for the treatment of non-alcoholic steatohepatitis.

To test specific mono-agonists to the glucagon-like peptide-1 receptor (GLP-1R), glucagon receptor (GCGR) and glucose-dependent insulinotropic peptide receptor (GIPR), individually and in combination, in a mouse model of diet-induced non-alcoholic steatohepatitis (NASH) and fibrosis in order to decipher the contribution of their activities and potential additive effects to improving systemic and hepatic metabolism. We induced NASH by pre-feeding C57BL/6J mice a diet rich in fat, fructose and cholesterol for 36 weeks. This was followed by 8 weeks of treatment with the receptor-specific agonists 1-GCG (20 μg/kg twice daily), 2-GLP1 (3 μg/kg twice daily) or 3-GIP (30 μg/kg twice daily), or the dual (1 + 2) or triple (1 + 2 + 3) combinations thereof. A dual GLP-1R/GCGR agonistic peptide, 4-dual-GLP1/GCGR (30 μg/kg twice daily), and liraglutide (100 μg/kg twice daily) were included as references. Whereas low-dose 1-GCG or 3-GIP alone did not influence body weight, liver lipids and histology, their combination with 2-GLP1 provided additional weight loss, reduction in liver triglycerides and improvement in histological disease activity score. Notably, 4-dual-GLP-1R/GCGR and the triple combination of selective mono-agonists led to a significantly stronger reduction in the histological non-alcoholic fatty liver disease activity score compared to high-dose liraglutide, at the same extent of body weight loss. GCGR and GIPR agonism provide additional, body weight-independent improvements on top of GLP-1R agonism in a murine model of manifest NASH with fibrosis.

Acute Effects of Glucagon on Reproductive Hormone Secretion in Healthy Men.

ContextGlucagon increases energy expenditure; consequently, glucagon receptor agonists are in development for the treatment of obesity. Obesity negatively affects the reproductive axis, and hypogonadism itself can exacerbate weight gain. Therefore, knowledge of the effects of glucagon receptor agonism on reproductive hormones is important for developing therapeutics for obesity; but reports in the literature about the effects of glucagon receptor agonism on the reproductive axis are conflicting.ObjectiveThe objective of this work is to investigate the effect of glucagon administration on reproductive hormone secretion in healthy young men.DesignA single-blinded, randomized, placebo-controlled crossover study was conducted.SettingThe setting of this study was the Clinical Research Facility, Imperial College Healthcare NHS Trust.ParticipantsEighteen healthy eugonadal men (mean ± SEM: age 25.1 ± 1.0 years; body mass index 22.5 ± 0.4 kg/m2; testosterone 21.2 ± 1.2 nmol/L) participated in this study.InterventionAn 8-hour intravenous infusion of 2 pmol/kg/min glucagon or rate-matched vehicle infusion was administered.Main Outcome MeasuresLuteinizing hormone (LH) pulsatility; LH, follicle-stimulating hormone (FSH), and testosterone levels were measured.ResultsAlthough glucagon administration induced metabolic effects (insulin area under the curve: vehicle 1065 ± 292 min.µU/mL vs glucagon 2098 ± 358 min.µU/mL, P < .001), it did not affect LH pulsatility (number of LH pulses/500 min: vehicle 4.7 ± 0.4, glucagon 4.2 ± 0.4, P = .22). Additionally, there were no significant differences in circulating LH, FSH, or testosterone levels during glucagon administration compared with vehicle administration.ConclusionsAcute administration of a metabolically active dose of glucagon does not alter reproductive hormone secretion in healthy men. These data are important for the continued development of glucagon-based treatments for obesity.

Self-Assembly of Exendin-4-Derived Dual Peptide Agonists is Mediated by Acylation and Correlated to the Length of Conjugated Fatty Acyl Chains

Dual glucagon-like peptide-1/glucagon receptor agonists have emerged as promising candidates for the treatment of diabetes and obesity. Issues of degradation sensitivity and rapid renal clearance are addressed, for example, by the conjugation of peptides to fatty acid chains, promoting reversible albumin binding. We use combined dynamic and static light scattering to directly measure the self-assembly of a set of dual peptide agonists based on the exendin-4 structure with varying fatty acid chain lengths in terms of apparent molecular mass and hydrodynamic radius (RS). We use NMR spectroscopy to gain an insight into the molecular architecture of the assembly. We investigate conformational changes of the monomeric subunits resulting from peptide self-assembly and assembly stability as a function of the fatty acid chain length using circular dichroism and fluorescence spectroscopy. Our results demonstrate that self-assembly of the exendin-4-derived dual agonist peptides is essentially driven by hydrophobic interactions involving the conjugated acyl chains. The fatty acid chain length affects assembly equilibria and the assembly stability, although the peptide subunits in the assembly retain a dynamic secondary structure. The assembly architecture is characterized by juxtaposition of the fatty acyl side chains and a hydrophobic cluster of the peptide moiety. This cluster experiences local conformational changes in the assembly compared to the monomeric unit leading to a reduction in solvent exposure. The N-terminal half of the peptide and a C-terminal loop are not in contact with neighboring peptide subunits in the assemblies. Altogether, our study contributes to a thorough understanding of the association characteristics and the tendency toward self-assembly in response to lipidation. This is important not only to achieve the desired bioavailability but also with respect to the physical stability of peptide solutions.

Cotadutide. Dual glucagon-like peptide 1 receptor (GLP-1R)/glucagon receptor (GCGR) agonist, Treatment of diabetes, Treatment of nonalcoholic steatohepatitis, Treatment of obesity

Cotadutide. Dual glucagon-like peptide 1 receptor (GLP-1R)/glucagon receptor (GCGR) agonist, Treatment of diabetes, Treatment of nonalcoholic steatohepatitis, Treatment of obesity

DR10601, a novel recombinant long-acting dual glucagon-like peptide-1 and glucagon receptor agonist for the treatment of obesity and type 2 diabetes mellitus.

Both glucagon-like peptide-1 (GLP-1) and glucagon (GCG) belong to the incretin family. This study aimed to investigate the pharmacokinetics and pharmacodynamics of DR10601, a fully recombinant hybrid peptide with dual GLP-1/GCG receptor agonistic activity. The agonistic ability of DR10601 was indirectly assessed by inducing cAMP accumulation in Chinese hamster ovary cells transfected with GLP-1R or GCGR in vitro. Following s.c. administration, the plasma pharmacokinetics of DR10601 were analysed in male Sprague-Dawley rats. The antiobesity effects and improved glycaemic control of DR10601 in vivo were evaluated by administering DR10601 to high-fat DIO mice and ICR mice as a single dose or repeated s.c. doses once every 4days for 24days. DR10601 exhibits dual agonistic activity on GLP-1 and glucagon receptors. The plasma half-life of DR10601 in Sprague-Dawley rats following s.c. administration was 51.9 ± 12.2h. In an IPGTT, a single s.c. dose of DR10601 (30nmol/kg) produced similar glycaemic control effects and a longer duration of action compared to dulaglutide (10nmol/kg). Compared with that achieved with liraglutide (40nmol/kg) s.c. administered daily, DR10601 administered s.c. once every 4days at 90nmol/kg exerted a nearly equivalent effect on food intake and significantly reduced the body weights of high-fat DIO mice at 24days. Repeated administration of DR1060 provides potent and sustained glycemic control and body weight loss effect in high-fat DIO mice. DR10601 is a promising long-acting agent deserving further investigation for the treatment of type 2 diabetes and obesity.

1965-P: Glucagon Receptor Agonism Stimulates Body Weight Loss in Antibiotic Treatment in Obese Mice

Glucagon, an essential regulator of glucose and lipid metabolism, also promotes weight loss in diet-induced obese (DIO) mice. Glucagon’s role as a primary counterregulatory hormone to insulin action has long received scientific attention, yet its broader therapeutic potential is an evolving research interest. We reported that chronic glucagon receptor (GCGR) activation increased energy expenditure and plasma bile acids (BA) in an farnesoid X receptor (FXR) dependent manner. Glucagon stimulates the conversion of cholesterol to BAs, with an increase in cholic and chenodeoxycholate species, critical regulators of FXR activity. Gut microbiota are known to alter the chemical structure of bile acids to produce secondary and tertiary BA. Thus, in these studies we tested the hypothesis that GCGR agonism regulates the gut microbiome to alter circulating BAs and stimulate FXR. GCGR agonism stimulated a profound change in the gut microbiome of DIO mice. These changes were largely associated with an increase in Actinobacteria and a decrease in Deferribacteria phylums. Assessment of functional microbiome composition via PICRUSt uncovered significant impacts on 130 out of 160 total KEGG pathways, including those involved in BA synthesis. To investigate the role of the gut microbiome on GCGR-stimulated weight loss we treated DIO mice with an antibiotic (AB) cocktail (ampicillin, vancomycin, metronidazole, neomycin, and amphotericin B) or vehicle. Mice were then treated with the GCGR agonist, IUB288, or vehicle for 14d to stimulate weight-loss. Surprisingly, AB-treated mice lost a similar amount of body-weight when treated with IUB288, suggesting that the gut microbiome may be dispensable for the weight loss effect. However, post hoc analysis of the cecal microbiome identified only a partial ablation of microbiota in AB-treated mice, with unexpected increases in Proteobacteria and Tenericutes. Thus, it is possible that GCGR-agonism acts via one of the resistant microbes to regulate weight loss. Disclosure T. Kim: None. J.P. Antipenko: None. S. Nason: None. N. Presedo: None. W.J. Van Der Pol: None. B. Finan: Employee; Self; Novo Nordisk A/S. R. DiMarchi: Employee; Self; Novo Nordisk Inc. C.D. Morrow: None. K.M. Habegger: Consultant; Self; Glyscend, Inc., Novo Nordisk Inc. Research Support; Self; Glyscend, Inc. Stock/Shareholder; Self; Glyscend, Inc. Funding National Institutes of Health

2023-P: OXM-001, a Novel Oxyntomodulin Analog, Improves Glucose Tolerance and Reduces Body Weight in High-Fat Diet Mice

The diabesity epidemic is steadily increasing every year. Therefore, we are searching for new treatments. The therapeutic potential of oxyntomodulin (OXM) is very promising. Based on evolutionary OXMs, we have identified a developmental OXM candidate known as OXM-001. Acute administration of OXM-001 resulted in hypophagia, and a numerical greater bodyweight loss, when compared to MEDI0382 (Dual GLP-1/Glucagon receptor agonist) treatment. MEDI0382-treated High-Fat-Diet (HFD), fed female C57BL/6J mice. We examined the effect of repeated administration of OXM-001 in HFD fed female C57BL/6J mice in a 20-day study. Repeated administration every third day of OXM-001 (10, 30 and 100 nmol/kg) significantly reduced body weight in a dose-depended manner. The mean body weight loss was 3.6% (10 nmol/kg, ns), 11% (30 nmol/kg, p &amp;lt;0.0001) and 13.9% (100 nmol/kg, (p &amp;lt;0.0001) compared to Vehicle-treated controls. OXM-001 administration lowered the cumulative food intake dose-dependably, 9.4% (10 nmol/kg, ns), 23.6% (30 nmol/kg, p &amp;lt;0.05) and 32.3% (100 nmol/kg, p &amp;lt;0.05) when compared to Vehicle-treated controls. We also examined the chronic OXM effect on glucose control at day 20 by performing an OGTT. Treatment with OXM significantly (p&amp;lt;0.0001) lowered BG levels (%) in a dose-depended manner compared to Vehicle-treated controls. OXM-001 treatment reduced visceral adipose tissue and liver weight when compared to Vehicle-treated controls. In summary, these preliminary data indicate that OXM-001 is superior to the current lead MEDI0382. OXM-001 treatment markedly enhanced glucose control. Furthermore, treatment with OXM-001 indicated a tendency toward visceral adipose tissue reduction and improved liver health. Disclosure A. Kayed: None. K.V. Andreassen: Employee; Self; Nordic Bioscience. M.A. Karsdal: Employee; Self; Nordic Bioscience. K. Henriksen: Employee; Self; Nordic Bioscience. Employee; Spouse/Partner; Novo Nordisk A/S. Stock/Shareholder; Self; Nordic Bioscience. Other Relationship; Self; Nordic Bioscience.

Glucagon Receptor Signaling and Lipid Metabolism.

Glucagon is secreted from the pancreatic alpha cells upon hypoglycemia and stimulates hepatic glucose production. Type 2 diabetes is associated with dysregulated glucagon secretion, and increased glucagon concentrations contribute to the diabetic hyperglycemia. Antagonists of the glucagon receptor have been considered as glucose-lowering therapy in type 2 diabetes patients, but their clinical applicability has been questioned because of reports of therapy-induced increments in liver fat content and increased plasma concentrations of low-density lipoprotein. Conversely, in animal models, increased glucagon receptor signaling has been linked to improved lipid metabolism. Glucagon acts primarily on the liver and by regulating hepatic lipid metabolism glucagon may reduce hepatic lipid accumulation and decrease hepatic lipid secretion. Regarding whole-body lipid metabolism, it is controversial to what extent glucagon influences lipolysis in adipose tissue, particularly in humans. Glucagon receptor agonists combined with glucagon-like peptide 1 receptor agonists (dual agonists) improve dyslipidemia and reduce hepatic steatosis. Collectively, emerging data support an essential role of glucagon for lipid metabolism.

OR28-5 Bile Acid Sequestration Accelerates Glucagon Receptor-Mediated Body Weight Loss in Obese Mice

Glucagon, an essential regulator of glucose and lipid metabolism, also promotes weight loss. Previously, we reported that chronic glucagon receptor (GCGR) activation increased energy expenditure and plasma bile acid (BA) levels. Hepatic Farnesoid X Receptor (FXR) has been associated with this GCGR-BA pathway, and liver-specific FXR-deficient mice showed diminished response to the anti-obesity effects of GCGR agonism as compared to WT mice (Diabetes 2018 PMID: 29925501). In this study we hypothesized that BAs play an important role in GCGR-mediated weight loss. To test this, we utilized an anion-exchange BA-binding resin (BABR, cholestyramine or Questran, SANDOZ Inc.) known to reduce plasma total cholesterol, LDL, and BAs. Diet-induced obese C57BL6 mice were weight stable during the 10 d Cholestyramine pretreatment (1.5% in high fat diet 58 kcal%). Daily administration of GCGR agonist, IUB288 (10 nmol/kg, s.c.), for 14 d reduced body weight by 15%; whereas IUB288+Cholestyramine doubled this effect (30%, 2-way ANOVA Time p<0.0001; Drug p=0.019; Time x Drug interaction p<0.0001). As expected, plasma cholesterol was reduced by BABR. However, unexpectedly total BA levels were increased in plasma and feces. Thus, suggesting that cholesterol and BA excretion to feces stimulated BA synthesis and increased whole body energy expenditure. With cholestyramine treatment was increased to 3%, cholestyramine-dependent body weight loss was observed (p<0.05). Combined with daily IUB288 treatment, body weight was further reduced (Time p<0.0001; Drug p=0.0009; Time x Drug interaction p<0.0001). Together, these studies suggest a combination of BABR and GCGR agonism as a novel therapeutic approach for obesity. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Nonconventional glucagon and GLP-1 receptor agonist and antagonist interplay at the GLP-1 receptor revealed in high-throughput FRET assays for cAMP

G protein-coupled receptors (GPCRs) for glucagon (GluR) and glucagon-like peptide-1 (GLP-1R) are normally considered to be highly selective for glucagon and GLP-1, respectively. However, glucagon secreted from pancreatic α-cells may accumulate at high concentrations to exert promiscuous effects at the β-cell GLP-1R, as may occur in the volume-restricted microenvironment of the islets of Langerhans. Furthermore, systemic administration of GluR or GLP-1R agonists and antagonists at high doses may lead to off-target effects at other receptors. Here, we used molecular modeling to evaluate data derived from FRET assays that detect cAMP as a read-out for GluR and GLP-1R activation. This analysis established that glucagon is a nonconventional GLP-1R agonist, an effect inhibited by the GLP-1R orthosteric antagonist exendin(9-39) (Ex(9-39)). The GluR allosteric inhibitors LY2409021 and MK 0893 antagonized glucagon and GLP-1 action at the GLP-1R, whereas des-His1-[Glu9]glucagon antagonized glucagon action at the GluR, while having minimal inhibitory action versus glucagon or GLP-1 at the GLP-1R. When testing Ex(9-39) in combination with des-His1-[Glu9]glucagon in INS-1 832/13 cells, we validated a dual agonist action of glucagon at the GluR and GLP-1R. Hybrid peptide GGP817 containing glucagon fused to a fragment of peptide YY (PYY) acted as a triagonist at the GluR, GLP-1R, and neuropeptide Y2 receptor (NPY2R). Collectively, these findings provide a new triagonist strategy with which to target the GluR, GLP-1R, and NPY2R. They also provide an impetus to reevaluate prior studies in which GluR and GLP-1R agonists and antagonists were assumed not to exert promiscuous actions at other GPCRs.

First-in-class positron emission tomography tracer for the glucagon receptor

The glucagon receptor (GCGR) is emerging as an important target in anti-diabetic therapy, especially as part of the pharmacology of dual glucagon-like peptide-1/glucagon (GLP-1/GCG) receptor agonists. However, currently, there are no suitable biomarkers that reliably demonstrate GCG receptor target engagement.MethodsTwo potent GCG receptor peptide agonists, S01-GCG and S02-GCG, were labeled with positron emission tomography (PET) radionuclide gallium-68. The GCG receptor binding affinity and specificity of the resulting radiopharmaceuticals [68Ga]Ga-DO3A-S01-GCG and [68Ga]Ga-DO3A-S02-GCG were evaluated in HEK-293 cells overexpressing the human GCG receptor and on frozen hepatic sections from human, non-human primate, and rat. In in vivo biodistribution, binding specificity and dosimetry were assessed in rat.Results[68Ga]Ga-DO3A-S01-GCG in particular demonstrated GCG receptor-mediated binding in cells and liver tissue with affinity in the nanomolar range required for imaging. [68Ga]Ga-DO3A-S01-GCG binding was not blocked by co-incubation of a GLP-1 agonist. In vivo binding in rat liver was GCG receptor specific with low non-specific binding throughout the body. Moreover, the extrapolated human effective doses, predicted from rat biodistribution data, allow for repeated PET imaging potentially also in combination with GLP-1R radiopharmaceuticals.Conclusion[68Ga]Ga-DO3A-S01-GCG thus constitutes a first-in-class PET tracer targeting the GCG receptor, with suitable properties for clinical development. This tool has potential to provide direct quantitative evidence of GCG receptor occupancy in humans.

Incretin Mimetics as Rational Candidates for the Treatment of Traumatic Brain Injury.

Traumatic brain injury (TBI) is becoming an increasing public health issue. With an annually estimated 1.7 million TBIs in the United States (U.S) and nearly 70 million worldwide, the injury, isolated or compounded with others, is a major cause of short- and long-term disability and mortality. This, along with no specific treatment, has made exploration of TBI therapies a priority of the health system. Age and sex differences create a spectrum of vulnerability to TBI, with highest prevalence among younger and older populations. Increased public interest in the long-term effects and prevention of TBI have recently reached peaks, with media attention bringing heightened awareness to sport and war related head injuries. Along with short-term issues, TBI can increase the likelihood for development of long-term neurodegenerative disorders. A growing body of literature supports the use of glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), and glucagon (Gcg) receptor (R) agonists, along with unimolecular combinations of these therapies, for their potent neurotrophic/neuroprotective activities across a variety of cellular and animal models of chronic neurodegenerative diseases (Alzheimer's and Parkinson's diseases) and acute cerebrovascular disorders (stroke). Mild or moderate TBI shares many of the hallmarks of these conditions; recent work provides evidence that use of these compounds is an effective strategy for its treatment. Safety and efficacy of many incretin-based therapies (GLP-1 and GIP) have been demonstrated in humans for the treatment of type 2 diabetes mellitus (T2DM), making these compounds ideal for rapid evaluation in clinical trials of mild and moderate TBI.

Design, screening and biological evaluation of novel fatty acid chain-modified oxyntomodulin-based derivatives with prolonged glucose-lowering ability and potent anti-obesity effects.

Recently, oxyntomodulin (OXM) has emerged as a treatment option for type 2 diabetes mellitus and obesity. In order to develop more promising novel OXM derivatives combining glycemic effects of glucagon-like peptide-1 (GLP-1) and lipolytic properties of glucagon, six 12-mer GLP-1 receptor agonists (PP01-PP06) were screened using a phage display method and then fused to OXM (3-37) to generate hybrid OXM derivatives (PP07-PP12). PP11, as a selected starting point, was further site-specifically modified with three lengths of fatty acid chains to provide long-acting conjugates PP13-PP24, among which PP18 was found not only to retain almost the entire balanced activation potency of PP11 in GLP-1/glucagon receptors but also to enhance plasma stability and prolong hypoglycemic activity. PP18 was further confirmed as an insulin secretagogue and glycemic agent in gene knockout mice. The protracted antidiabetic effects and in vivo half-life of PP18 were further proved by hypoglycemic efficacies in diet-induced obesity (DIO) mice and pharmacokinetics tests in Sprague Dawley (SD) rats, respectively. Nevertheless, administration of PP18 once per day normalized food intake, body weight, blood biochemical indexes, insulin resistance and islet function of DIO mice. These preclinical results suggested that PP18, as a novel OXM-based dual GLP-1 and glucagon receptor agonist, may serve as a novel therapeutic approach to treat T2DM and obesity.

Future Perspectives on GLP-1 Receptor Agonists and GLP-1/glucagon Receptor Co-agonists in the Treatment of NAFLD.

Along the obesity pandemic, the prevalence of non-alcoholic fatty liver disease (NAFLD), often regarded as the hepatic manifestation of the metabolic syndrome, increases worldwide representing now the prevalent liver disease in western countries. No pharmacotherapy is approved for the treatment of NAFLD and, currently, the cornerstone treatment is lifestyle modifications focusing on bodyweight loss, notoriously difficult to obtain and even more difficult to maintain. Thus, novel therapeutic approaches are highly demanded. Glucagon-like peptide-1 (GLP-1) receptor agonists (GLP-1RAs) are approved for the treatment of type 2 diabetes and obesity. They exert their body weight-lowering effect by reducing satiety and food intake. GLP-1RAs have also been shown to reduce liver inflammation and fibrosis. Furthermore, glucagon receptor agonism is being investigated for the treatment of NAFLD due to its appetite and food intake-reducing effects, as well as its ability to increase lipid oxidation and thermogenesis. Recent studies suggest that glucagon receptor signaling is disrupted in NAFLD, indicating that supra-physiological glucagon receptor agonism might represent a new NAFLD treatment target. The present review provides (1) an overview in the pathophysiology of NAFLD, including the potential involvement of GLP-1 and glucagon, (2) an introduction to the currently available GLP-1RAs and (3) outlines the potential of emerging GLP-1RAs and GLP-1/glucagon receptor co-agonists in the treatment of NAFLD.

Glucagon-like peptides-1 from phylogenetically ancient fish show potent anti-diabetic activities by acting as dual GLP1R and GCGR agonists

Glucagon-like peptides-1 (GLP-1)from phylogenetically ancient fish (lamprey, dogfish, ratfish, paddlefish and bowfin) and from a teleost, the rainbow trout produced concentration-dependent stimulations of insulin release from clonal β-cells and isolated mouse islets. Lamprey and paddlefish GLP-1 were the most potent and effective. Incubation of BRIN-BD11 cells with GLP-1 receptor (GLP1R) antagonist, exendin-4 (9–39) attenuated insulinotropic activity of all peptides whereas glucagon receptor (GCGR) antagonist [des-His1,Pro4,Glu9] glucagon amide significantly decreased the activities of lamprey and paddlefish GLP-1 only. The GIP receptor antagonist GIP (6–30) Cex-K40 [Pal] attenuated the activity of bowfin GLP-1. All peptides (1 μM) produced significant increases in cAMP concentration in CHL cells transfected with GLP1R but only lamprey and paddlefish GLP-1 stimulated cAMP production in HEK293 cells transfected with GCGR. Intraperitoneal administration of lamprey and paddlefish GLP-1 (25 nmol/kg body weight) in mice produced significant decreases in blood glucose and increased insulin concentrations comparable to the effects of human GLP-1. Lamprey and paddlefish GLP-1 display potent insulinotropic activity in vitro and glucose-lowering activity in vivo that is mediated through GLP1R and GCGR so that these peptides may constitute templates for design of new antidiabetic drugs.

A novel dual glucagon-like peptide and glucagon receptor agonist SAR425899: Results of randomized, placebo-controlled first-in-human and first-in-patient trials.

To evaluate the safety, pharmacokinetics and pharmacodynamics of SAR425899, a novel polypeptide, active as an agonist at both the glucagon-like peptide-1 receptor (GLP-1R) and the glucagon receptor (GCR), in healthy volunteers and in overweight/obese patients with type 2 diabetes (T2D). Subcutaneous administrations of SAR425899 were tested in two randomized, placebo-controlled, double-blind clinical trials. In the first trial, healthy overweight volunteers (body mass index [BMI] 25-30 kg/m2 ; n = 32) received single-ascending doses (0.01-0.1 mg) of SAR425899 or placebo. In the second, a multiple-ascending-dose trial (NCT02411825), healthy normal- to overweight volunteers (BMI 20-30 kg/m2 ; n = 40) and overweight/obese patients with T2D (BMI 28-42 kg/m2 ; n = 36) received daily doses of SAR425899 or placebo over 21 or 28 days, respectively. The most frequently reported adverse events were gastrointestinal; gastrointestinal side effects were less pronounced in patients with T2D compared with healthy volunteers. SAR425899 significantly reduced levels of fasting plasma glucose (P < 0.05 vs. placebo) and glycated haemoglobin (P < 0.001 versus placebo) in patients with T2D. Additionally, SAR425899 led to reductions in body weight, with a maximal reduction of 5.32 kg in healthy volunteers and 5.46 kg in patients with T2D (P < 0.001 vs. placebo) at end of treatment. SAR425899 was well tolerated and led to favourable glycaemic effects in patients with T2D and weight reduction in both healthy volunteers and patients. Whether dual GLP-1R/GCR agonism represents a treatment method that is superior to pure GLP-1R agonists for obesity and diabetes treatment remains to be confirmed.

Hepatic Glucagon Receptor Signaling Enhances Insulin-Stimulated Glucose Disposal in Rodents.

Glucagon receptor (GCGR) agonists cause hyperglycemia but also weight loss. However, GCG-like peptide 1 receptor (GLP1R)/GCGR mixed agonists do not exhibit the diabetogenic effects often attributed to GCGR activity. Thus, we sought to investigate the effect of glucagon agonism on insulin action and glucose homeostasis. Acute GCGR agonism induced immediate hyperglycemia, followed by improved glucose tolerance and enhanced glucose-stimulated insulin secretion. Moreover, acute GCGR agonism improved insulin tolerance in a dose-dependent manner in both lean and obese mice. Improved insulin tolerance was independent of GLP1R, FGF21, and hepatic glycogenolysis. Moreover, we observed increased glucose infusion rate, disposal, uptake, and suppressed endogenous glucose production during euglycemic clamps. Mice treated with insulin and GCGR agonist had enhanced phosphorylation of hepatic AKT at Ser473; this effect was reproduced in isolated mouse primary hepatocytes and resulted in increased AKT kinase activity. These data reveal that GCGR agonism enhances glucose tolerance, in part, by augmenting insulin action, with implications for the use of GCGR agonism in therapeutic strategies for diabetes.

Team Players or Opponents: Coadministration of Selective Glucagon and GLP-1 Receptor Agonists in Obese Diabetic Monkeys.

We assessed the therapeutic contribution of the individual components of glucagon-like peptide-1 receptor (GLP-1R) and glucagon receptor (GCGR) agonists alone and in combination upon energy homeostasis and glycemic control in diet-induced obese, diabetic nonhuman primates. The pharmacological active dose ranges of selective agonists were established through a dose-finding study, followed by a 6-week chronic study. Repeated subcutaneous administration of a selective GCGR agonist (30 µg/kg once daily) did not affect food intake or body weight, whereas the selective GLP-1R agonist (3 µg/kg once daily) alone decreased energy intake by 18% and body weight by 3.8% ± 0.9%. Combination of both agonists reduced significantly cumulative food intake by 27% and body weight by 6.6% ± 0.9%. Fasting plasma glucose (FPG) was improved by GLP-1R agonist (baseline vs end of study, 176.7 ± 34.0 vs 115.9 ± 16.1 mg/dL). In contrast, groups exposed to GCGR agonist experienced nonsignificant elevations of FPG. More accurate assessment of therapeutic interventions on glucose homeostasis was tested by an IV glucose tolerance test. Glucose excursion was significantly elevated by chronic GCGR agonist administration, whereas it was significantly decreased in GLP-1R agonist-treated monkeys. In the combination group, a nonsignificant increase of glucose excursion was seen, concomitantly with significantly increased insulin secretion. We conclude that chronic glucagon agonism does not affect energy homeostasis in nonhuman primates. In combination with GLP-1R agonism, glucagon agonism synergistically enhances negative energy balance with resulting larger body weight loss. However, adding GCGR to GLP-1R agonism diminishes glycemic control in diabetic monkeys. Therefore, long-term therapeutic implications of using GLP-1R/GCGR coagonists for weight management in diabetes warrants further scrutiny.