Small molecule glucagon release inhibitors with activity in human islets.

Purpose: Type 1 diabetes (T1D) accounts for an estimated 5% of all diabetes in the United States, afflicting over 1.25 million individuals. Maintaining long-term blood glucose control is the major goal for individuals with T1D. In T1D, insulin-secreting pancreatic islet ß-cells are destroyed by the immune system, but glucagon-secreting islet α-cells survive. These remaining α-cells no longer respond properly to fluctuating blood glucose concentrations. Dysregulated α-cell function contributes to hyper- and hypoglycemia which can lead to macrovascular and microvascular complications. To this end, we sought to discover small molecules that suppress α-cell function for their potential as preclinical candidate compounds. Prior high-throughput screening identified a set of glucagon-suppressing compounds using a rodent α-cell line model, but these compounds were not validated in human systems. Results: Here, we dissociated and replated primary human islet cells and exposed them to 24 h treatment with this set of candidate glucagon-suppressing compounds. Glucagon accumulation in the medium was measured and we determined that compounds SW049164 and SW088799 exhibited significant activity. Candidate compounds were also counter-screened in our InsGLuc-MIN6 ß-cell insulin secretion reporter assay. SW049164 and SW088799 had minimal impact on insulin release after a 24 h exposure. To further validate these hits, we treated intact human islets with a selection of the top candidates for 24 h. SW049164 and SW088799 significantly inhibited glucagon release into the medium without significantly altering whole islet glucagon or insulin content. In concentration-response curves SW088799 exhibited significant inhibition of glucagon release with an IC50 of 1.26 µM. Conclusion: Given the set of tested candidates were all top hits from the primary screen in rodent α-cells, this suggests some conservation of mechanism of action between human and rodents, at least for SW088799. Future structure-activity relationship studies of SW088799 may aid in elucidating its protein target(s) or enable its use as a tool compound to suppress α-cell activity in vitro.

Assessment of T2-weighted Image Quality at Prostate MRI in Patients with and Those without Intramuscular Injection of Glucagon.

Purpose To assess whether administration of intramuscular (IM) glucagon improves T2-weighted image quality at multiparametric MRI (mpMRI) of the prostate. Materials and Methods In this Health Insurance Portability and Accountability Act-compliant single-center study, the authors retrospectively analyzed radiology reports from 3960 mpMRI examinations (2495 after exclusions) performed between September 2013 and September 2019 and performed outcome comparisons and semiquantitative image assessment of axial T2-weighted images from 120 consecutive mpMRI examinations performed between May 2015 and February 2016. Three experienced radiologists blinded to administration of IM glucagon assessed images using a five-point Likert scale (5 = no motion or blur) for overall image quality, anatomic delineation (prostate capsule, rectum, and lymph nodes), and identification of benign prostatic hyperplasia nodules. Wilcoxon rank sum and χ2 tests were used to assess quantitative parameters. Results The number of mpMRI radiology reports (599 examinations performed with glucagon; 1896, without glucagon) mentioning blur or motion were similar between groups (P = .82). Regression analysis of semiquantitative image quality assessments of T2-weighted images from mpMRI examinations (60 performed with glucagon; 60, without glucagon) demonstrated that images with glucagon were more likely to receive higher scores (4 or 5 rating) than those without glucagon only when the rectum (P = .001) and lymph nodes (P = .01) were evaluated, not when the prostatic capsule, benign prostatic hyperplasia nodules, or overall image quality was evaluated. No evidence of differences was found in identified Prostate Imaging Reporting and Data System (PI-RADS) lesions or targeted-biopsy Gleason scores. Conclusion Administration of IM glucagon did not improve T2-weighted image quality in prostate MRI examinations and showed similar PI-RADS scores and biopsy yields compared with examinations without glucagon. Keywords: MRI, Genital/Reproductive, Urinary, Prostate, Oncology, Observer Performance © RSNA, 2023 Online supplemental material is available for this article. See also commentary by Eberhardt in this issue.

Salivary Hormones Leptin, Ghrelin, Glucagon, and Glucagon-Like Peptide 1 and Their Relation to Sweet Taste Perception in Diabetic Patients.

Diabetes mellitus (DM) is one of the most common diseases worldwide. DM may disrupt hormone regulation. Metabolic hormones, leptin, ghrelin, glucagon, and glucagon-like peptide 1, are produced by the salivary glands and taste cells. These salivary hormones are expressed at different levels in diabetic patients compared to control group and may cause differences in the perception of sweetness. This study is aimed at assessing the concentrations of salivary hormones leptin, ghrelin, glucagon, and GLP-1 and their correlations with sweet taste perception (including thresholds and preferences) in patients with DM. A total of 155 participants were divided into three groups: controlled DM, uncontrolled DM, and control groups. Saliva samples were collected to determine salivary hormone concentrations by ELISA kits. Varying sucrose concentrations (0.015, 0.03, 0.06, 0.12, 0.25, 0.5, and 1 mol/l) were used to assess sweetness thresholds and preferences. Results showed a significant increase in salivary leptin concentrations in the controlled DM and uncontrolled DM compared to the control group. In contrast, salivary ghrelin and GLP-1 concentrations were significantly lower in the uncontrolled DM group than in the control group. In general, HbA1c was positively correlated with salivary leptin concentrations and negatively correlated with salivary ghrelin concentrations. Additionally, in both the controlled and uncontrolled DM groups, salivary leptin was negatively correlated with the perception of sweetness. Salivary glucagon concentrations were negatively correlated with sweet taste preferences in both controlled and uncontrolled DM. In conclusion, the salivary hormones leptin, ghrelin, and GLP-1 are produced either higher or lower in patients with diabetes compared to the control group. In addition, salivary leptin and glucagon are inversely associated with sweet taste preference in diabetic patients.

[Genetic aspects of type 1 glucagon peptide agonists clinical efficacy: A review].

A review of publications devoted to the analysis of genetic polymorphisms of the gene encoding the glucagon-like peptide type 1 receptor and some other genes directly and indirectly involved in the implementation of its physiological action is presented. The aim of the study: to search for information on genes polymorphism that can affect the effectiveness of glucagon-like peptide type 1 agonists. The review was carried out in accordance with the PRISMA 2020 recommendations, the search for publications was based on PubMed databases (including Medline), Web of Science, as well as Russian scientific electronic source eLIBRARY.RU from 1993 to 2022. The several genes polymorphisms (GLP1R, TCF7L2, CNR1, SORCS1, WFS1, PPARD, CTRB1/2) that may affect the course and therapy of type 2 diabetes mellitus, metabolic syndrome and obesity, was described. Single nucleotide substitutions in some regions of these genes can both decrease and increase the clinical efficacy of the treatment of diabetes mellitus and metabolic syndrome with the help of type 1 glucagon-like peptide agonists: exenatide, liraglutide. Data on the role of genetic variations in the structure of the products of these genes in the effectiveness of other type 1 glucacone-like peptide agonists have not been found.

Pancreatic ß-cell glutaminase 2 maintains glucose homeostasis under the condition of hyperglycaemia.

Glutaminase 2 (GLS2), a master regulator of glutaminolysis that is induced by p53 and converts glutamine to glutamate, is abundant in the liver but also exists in pancreatic ß-cells. However, the roles of GLS2 in islets associated with glucose metabolism are unknown, presenting a critical issue. To investigate the roles of GLS2 in pancreatic ß-cells in vivo, we generated ß-cell-specific Gls2 conditional knockout mice (Gls2 CKO), examined their glucose homeostasis, and validated the findings using a human islet single-cell analysis database. GLS2 expression markedly increased along with p53 in ß-cells from control (RIP-Cre) mice fed a high-fat diet. Furthermore, Gls2 CKO exhibited significant diabetes mellitus with gluconeogenesis and insulin resistance when fed a high-fat diet. Despite marked hyperglycaemia, impaired insulin secretion and paradoxical glucagon elevation were observed in high-fat diet-fed Gls2 CKO mice. GLS2 silencing in the pancreatic ß-cell line MIN6 revealed downregulation of insulin secretion and intracellular ATP levels, which were closely related to glucose-stimulated insulin secretion. Additionally, analysis of single-cell RNA-sequencing data from human pancreatic islet cells also revealed that GLS2 expression was elevated in ß-cells from diabetic donors compared to nondiabetic donors. Consistent with the results of Gls2 CKO, downregulated GLS2 expression in human pancreatic ß-cells from diabetic donors was associated with significantly lower insulin gene expression as well as lower expression of members of the insulin secretion pathway, including ATPase and several molecules that signal to insulin secretory granules, in ß-cells but higher glucagon gene expression in α-cells. Although the exact mechanism by which ß-cell-specific GLS2 regulates insulin and glucagon requires further study, our data indicate that GLS2 in pancreatic ß-cells maintains glucose homeostasis under the condition of hyperglycaemia.

The glucagon receptor antagonist desHis1Pro4Glu9-glucagon(Lys12PAL) alters alpha-cell turnover and lineage in mice, but does not cause alpha-cell hyperplasia.

OBJECTIVE: Glucagon receptor (GCGR) antagonism elicits antihyperglycemic effects in rodents and humans. The present study investigates whether the well characterised peptide-based GCGR antagonist, desHis1Pro4Glu9-glucagon (Lys12PAL), alters alpha-cell turnover or identity in mice. METHODS: Multiple low-dose streptozotocin (STZ) treated (50 mg/kg bw, 5 days) transgenic GluCreERT2;ROSA26-eYFP mice were employed. STZ mice received twice daily administration of saline vehicle or desHis1Pro4Glu9-glucagon (Lys12PAL), at low- or high-dose (25 and 100 nmol/kg, respectively) for 11 days. RESULTS: No GCGR antagonist induced changes in food or fluid intake, body weight or glucose homeostasis were observed. As expected, STZ dramatically reduced (P < 0.001) islet numbers and increased (P < 0.01) alpha-to beta-cell ratio, which was linked to elevated (P < 0.05) levels of beta-cell apoptosis. Whilst treatment with desHis1Pro4Glu9-glucagon (Lys12PAL) decreased (P < 0.05-P < 0.001) alpha- and beta-cell areas, it also helped restore the classic rodent islet alpha-cell mantle in STZ mice. Interestingly, low-dose desHis1Pro4Glu9-glucagon (Lys12PAL) increased (P < 0.05) alpha-cell apoptosis rates whilst high dose decreased (p < 0.05) this parameter. This difference reflects substantially increased (P < 0.001) alpha-to beta-cell transdifferentiation following high dose desHis1Pro4Glu9-glucagon (Lys12PAL) treatment, which was not fully manifest with low-dose therapy. CONCLUSIONS: Taken together, the present study indicates that peptidic GCGR antagonists can positively influence alpha-cell turnover and lineage in identity in multiple low-dose STZ mice, but that such effects are dose-related.

Single-cell transcriptome analysis of NEUROG3+ cells during pancreatic endocrine differentiation with small molecules.

The efficiency of inducing human embryonic stem cells into NEUROG3+ pancreatic endocrine cells is a bottleneck in stem cell therapy for diabetes. To understand the cell properties and fate decisions during differentiation, we analyzed the modified induction method using single-cell transcriptome and found that DAPT combined with four factors (4FS): nicotinamide, dexamethasone, forskolin and Alk5 inhibitor II (DAPT + 4FS) increased the expression of NEUROG3 to approximately 34.3%. The increased NEUROG3+ cells were mainly concentrated in Insulin + Glucagon + (INS + GCG+) and SLAC18A1 + Chromogranin A+(SLAC18A1 + CHGA +) populations, indicating that the increased NEUROG3+ cells promoted the differentiation of pancreatic endocrine cells and enterochromaffin-like cells. Single-cell transcriptome analysis provided valuable clues for further screening of pancreatic endocrine cells and differentiation of pancreatic islet cells. The gene set enrichment analysis (GSEA) suggest that we can try to promote the expression of INS + GCG+ population by up-regulating G protein-coupled receptor (GPCR) and mitogen-activated protein kinase signals and down-regulating Wnt, NIK/NF-KappaB and cytokine-mediated signal pathways. We can also try to regulate GPCR signaling through PLCE1, so as to increase the proportion of NEUROG3+ cells in INS+GCG+ populations. To exclude non-pancreatic endocrine cells, ALCAMhigh CD9low could be used as a marker for endocrine populations, and ALCAMhigh CD9lowCDH1low could remove the SLC18A1 + CHGA+ population.

Designer GLP1 poly-agonist peptides in the management of diabesity.

INTRODUCTION: To date, the 21st Century has witnessed key developments in the management of diabesity (a conflation of obesity and Type 2 Diabetes Mellitus [T2D]), including Glucagon Like Peptide 1 (GLP1) receptor agonist therapies, and recently the 'designer' GLP1 Poly-agonist Peptides (GLP1PPs). AREAS COVERED: A PubMed search of published data on the GLP1PP class of therapies was conducted. The gut-brain axis forms complex multi-directional interlinks that include autonomic nervous signaling, components of the gut microbiota (including metabolic by-products and gram-negative cell wall components [e.g. endotoxinaemia]), and incretin hormones that are secreted from the gut in response to the ingestion of nutrients. The development of dual-incretin agonist therapies includes combinations of the GLP1 peptide with Glucose-dependent Insulinotropic Polypeptide (GIP), Glucagon (Gcg), Cholecystokinin (CCK), Peptide YY (PYY), and Glucagon-Like Peptide 2 (GLP2). Triple incretin agonist therapies are also under development. EXPERT OPINION: At the dawn of a new era in the therapeutic management of diabesity, the designer GLP1PP class holds great promise, with each novel combination building on a preexisting palimpsest of clinical data and insights. Future innovations of the GLP1PP class will likely enable medically induced weight loss and glycemic control in diabesity to rival or even out-perform those resulting from bariatric surgery.

The ubiquitination status of the glucagon receptor determines signal bias.

The pancreatic hormone glucagon activates the glucagon receptor (GCGR), a class B seven-transmembrane G protein-coupled receptor that couples to the stimulatory heterotrimeric G protein and provokes PKA-dependent signaling cascades vital to hepatic glucose metabolism and islet insulin secretion. Glucagon-stimulation also initiates recruitment of the endocytic adaptors, ßarrestin1 and ßarrestin2, which regulate desensitization and internalization of the GCGR. Unlike many other G protein-coupled receptors, the GCGR expressed at the plasma membrane is constitutively ubiquitinated and upon agonist-activation, internalized GCGRs are deubiquitinated at early endosomes and recycled via Rab4-containing vesicles. Herein we report a novel link between the ubiquitination status and signal transduction mechanism of the GCGR. In the deubiquitinated state, coupling of the GCGR to Gs is diminished, while binding to ßarrestin is enhanced with signaling biased to a ßarrestin1-dependent p38 mitogen activated protein kinase (MAPK) pathway. This ubiquitin-dependent signaling bias arises through the modification of lysine333 (K333) on the cytoplasmic face of transmembrane helix V. Compared with the GCGR-WT, the mutant GCGR-K333R has impaired ubiquitination, diminished G protein coupling, and PKA signaling but unimpaired potentiation of glucose-stimulated-insulin secretion in response to agonist-stimulation, which involves p38 MAPK signaling. Both WT and GCGR-K333R promote the formation of glucagon-induced ßarrestin1-dependent p38 signaling scaffold that requires canonical upstream MAPK-Kinase3, but is independent of Gs, Gi, and ßarrestin2. Thus, ubiquitination/deubiquitination at K333 in the GCGR defines the activation of distinct transducers with the potential to influence various facets of glucagon signaling in health and disease.

Chemical Decrosslinking-Based Peptide Characterization of Formaldehyde-Fixed Rat Pancreas Using Fluorescence-Guided Single-Cell Mass Spectrometry.

Approaches for the characterization of proteins/peptides in single cells of formaldehyde-fixed (FF) tissues via mass spectrometry (MS) are still under development. The lack of a general method for selectively eliminating formaldehyde-induced crosslinking is a major challenge. A workflow is shown for the high-throughput peptide profiling of single cells isolated from FF tissues, here the rodent pancreas, which possesses multiple peptide hormones from the islets of Langerhans. The heat treatment is enhanced by a collagen-selective multistep thermal process assisting efficient isolation of islets from the FF pancreas and, subsequently, their dissociation into single islet cells. Hydroxylamine-based chemical decrosslinking helped restore intact peptide signals from individual isolated cells. Subsequently, an acetone/glycerol-assisted cell dispersion was optimized for spatially resolved cell deposition onto glass slides, while a glycerol solution maintained the hydrated state of the cells. This sample preparation procedure allowed peptide profiling in FF single cells by fluorescence-guided matrix-assisted laser desorption ionization MS. Here, 2594 single islet cells were analyzed and 28 peptides were detected, including insulin C-peptides and glucagon. T-distributed stochastic neighbor embedding (t-SNE) data visualization demonstrated that cells cluster based on cell-specific pancreatic peptide hormones. This workflow expands the sample availability for single-cell MS characterization to a wide range of formaldehyde-treated tissue specimens stored in biobanks.

Glucagon Promotes Gluconeogenesis through the GCGR/PKA/CREB/PGC-1α Pathway in Hepatocytes of the Japanese Flounder Paralichthys olivaceus.

In order to investigate the mechanism of glucagon regulation of gluconeogenesis, primary hepatocytes of the Japanese flounder (Paralichthys olivaceus) were incubated with synthesized glucagon, and methods based on inhibitors and gene overexpression were employed. The results indicated that glucagon promoted glucose production and increased the mRNA levels of glucagon receptor (gcgr), guanine nucleotide-binding protein Gs α subunit (gnas), adenylate cyclase 2 (adcy2), protein kinase A (pka), cAMP response element-binding protein 1 (creb1), peroxisome proliferator-activated receptor-γ coactivator 1α (pgc-1α), phosphoenolpyruvate carboxykinase 1 (pck1), and glucose-6-phosphatase (g6pc) in the hepatocytes. An inhibitor of GCGR decreased the mRNA expression of gcgr, gnas, adcy2, pka, creb1, pgc-1α, pck1, g6pc, the protein expression of phosphorylated CREB and PGC-1α, and glucose production. The overexpression of gcgr caused the opposite results. An inhibitor of PKA decreased the mRNA expression of pgc-1α, pck1, g6pc, the protein expression of phosphorylated-CREB, and glucose production in hepatocytes. A CREB-targeted inhibitor significantly decreased the stimulation by glucagon of the mRNA expression of creb1, pgc-1α, and gluconeogenic genes, and glucose production decreased accordingly. After incubating the hepatocytes with an inhibitor of PGC-1α, the glucagon-activated mRNA expression of pck1 and g6pc was significantly down-regulated. Together, these results demonstrate that glucagon promotes gluconeogenesis through the GCGR/PKA/CREB/PGC-1α pathway in the Japanese flounder.

Chromatin accessibility differences between alpha, beta, and delta cells identifies common and cell type-specific enhancers.

BACKGROUND: High throughput sequencing has enabled the interrogation of the transcriptomic landscape of glucagon-secreting alpha cells, insulin-secreting beta cells, and somatostatin-secreting delta cells. These approaches have furthered our understanding of expression patterns that define healthy or diseased islet cell types and helped explicate some of the intricacies between major islet cell crosstalk and glucose regulation. All three endocrine cell types derive from a common pancreatic progenitor, yet alpha and beta cells have partially opposing functions, and delta cells modulate and control insulin and glucagon release. While gene expression signatures that define and maintain cellular identity have been widely explored, the underlying epigenetic components are incompletely characterized and understood. However, chromatin accessibility and remodeling is a dynamic attribute that plays a critical role to determine and maintain cellular identity. RESULTS: Here, we compare and contrast the chromatin landscape between mouse alpha, beta, and delta cells using ATAC-Seq to evaluate the significant differences in chromatin accessibility. The similarities and differences in chromatin accessibility between these related islet endocrine cells help define their fate in support of their distinct functional roles. We identify patterns that suggest that both alpha and delta cells are poised, but repressed, from becoming beta-like. We also identify patterns in differentially enriched chromatin that have transcription factor motifs preferentially associated with different regions of the genome. Finally, we not only confirm and visualize previously discovered common endocrine- and cell specific- enhancer regions across differentially enriched chromatin, but identify novel regions as well. We compiled our chromatin accessibility data in a freely accessible database of common endocrine- and cell specific-enhancer regions that can be navigated with minimal bioinformatics expertise. CONCLUSIONS: Both alpha and delta cells appear poised, but repressed, from becoming beta cells in murine pancreatic islets. These data broadly support earlier findings on the plasticity in identity of non-beta cells under certain circumstances. Furthermore, differential chromatin accessibility shows preferentially enriched distal-intergenic regions in beta cells, when compared to either alpha or delta cells.

Postprandial dysfunction in fatty liver disease.

Fatty liver disease has mainly been characterized under fasting conditions. However, as the liver is essential for postprandial homeostasis, identifying postprandial disturbances may be important. Here, we investigated postprandial changes in markers of metabolic dysfunction between healthy individuals, obese individuals with non-alcoholic fatty liver disease (NAFLD) and patients with cirrhosis. We included individuals with biopsy-proven NAFLD (n = 9, mean age 50 years, mean BMI 35 kg/m2 , no/mild fibrosis), cirrhosis with hepatic steatosis (n = 10, age 62 years, BMI 32 kg/m2 , CHILD A/B) and healthy controls (n = 10, age 23, BMI 25 kg/m2 ), randomized 1:1 to fasting or standardized mixed meal test (postprandial). None of the patients randomized to mixed meal test had type 2 diabetes (T2D). Peripheral blood was collected for 120 min. After 60 min, a transjugular liver biopsy and liver vein blood was taken. Plasma levels of glucose, insulin, C-peptide, glucagon, and fibroblast growth factor 21 (FGF21) were measured. Postprandial peak glucose and C-peptide were significantly increased in NAFLD, and cirrhosis compared with healthy. Patients with NAFLD and cirrhosis had hyperglucagonemia as a potential sign of glucagon resistance. FGF21 was increased in NAFLD and cirrhosis independent of sampling from the liver vein versus peripheral blood. Glucagon levels were higher in the liver vein compared with peripheral blood. Patients with NAFLD and cirrhosis without T2D showed impaired glucose tolerance, hyperinsulinemia, and hyperglucagonemia after a meal compared to healthy individual. Postprandial characterization of patients with NAFLD may be important to capture their metabolic health.

Alterations of adipokines, pancreatic hormones and incretins in acute and convalescent COVID-19 children.

BACKGROUND: The Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2), accountable for Coronavirus disease 2019 (COVID-19), may cause hyperglycemia and additional systemic complexity in metabolic parameters. It is unsure even if the virus itself causes type 1 or type 2 diabetes mellitus (T1DM or T2DM). Furthermore, it is still unclear whether even recuperating COVID-19 individuals have an increased chance to develop new-onset diabetes. METHODS: We wanted to determine the impact of COVID-19 on the levels of adipokines, pancreatic hormones, incretins and cytokines in acute COVID-19, convalescent COVID-19 and control children through an observational study. We performed a multiplex immune assay analysis and compared the plasma levels of adipocytokines, pancreatic hormones, incretins and cytokines of children presenting with acute COVID-19 infection and convalescent COVID-19. RESULTS: Acute COVID-19 children had significantly elevated levels of adipsin, leptin, insulin, C-peptide, glucagon and ghrelin in comparison to convalescent COVID-19 and controls. Similarly, convalescent COVID-19 children had elevated levels of adipsin, leptin, insulin, C-peptide, glucagon, ghrelin and Glucagon-like peptide-1 (GLP-1) in comparison to control children. On the other hand, acute COVID-19 children had significantly decreased levels of adiponectin and Gastric Inhibitory Peptide (GIP) in comparison to convalescent COVID-19 and controls. Similarly, convalescent COVID-19 children had decreased levels of adiponectin and GIP in comparison to control children. Acute COVID-19 children had significantly elevated levels of cytokines, (Interferon (IFN)) IFNγ, Interleukins (IL)-2, TNFα, IL-1α, IL-1ß, IFNα, IFNß, IL-6, IL-12, IL-17A and Granulocyte-Colony Stimulating Factors (G-CSF) in comparison to convalescent COVID-19 and controls. Convalescent COVID-19 children had elevated levels of IFNγ, IL-2, TNFα, IL-1α, IL-1ß, IFNα, IFNß, IL-6, IL-12, IL-17A and G-CSF in comparison to control children. Additionally, Principal component Analysis (PCA) analysis distinguishes acute COVID-19 from convalescent COVID-19 and controls. The adipokines exhibited a significant correlation with the levels of pro-inflammatory cytokines. CONCLUSION: Children with acute COVID-19 show significant glycometabolic impairment and exaggerated cytokine responses, which is different from convalescent COVID-19 infection and controls.

Perspectives in weight control in diabetes - SGLT2 inhibitors and GLP-1-glucagon dual agonism.

Treatment of people with type 2 diabetes mellitus (T2D) and obesity should include glycemic control and sustained weight loss. However, organ protection and/or risk reduction for co-morbidities have also emerged as important goals. Here, we define this combined treatment approach as 'weight loss plus' and describe it as a metabolic concept where prolonged periods of energy consumption is central to outcomes. We suggest there are currently two drug classes - sodium-glucose cotransporter-2 inhibitors (SGLT2i) and glucagon-like peptide-1 (GLP-1)-glucagon dual agonists - that can facilitate this 'weight loss plus' approach. We describe evidence supporting that both classes address the underlying pathophysiology of T2D and facilitate normalization of metabolism through increased periods with a catabolic type of energy consumption, which effect other organ systems and may facilitate long-term cardio-renal benefits. These benefits have been demonstrated in trials of SGLT2is, and appear, to some degree, to be independent of glycemia and substantial weight loss. The combined effect of caloric restriction and metabolic correction facilitated by SGLT2i and GLP-1-glucagon dual agonists can be conceptualized as mimicking dietary restriction and physical activity, a phenomenon not previously observed with drugs whose benefits predominantly arise from absolute weight loss, and which may be key to achieving a 'weight loss plus' approach to treatment.

Treatment of insulin poisoning: A 100-year review.

BACKGROUND: Insulin poisoning, as opposed to hypoglycaemia induced by therapeutic doses of insulin, is rare, and guidelines on management differ. We have reviewed the evidence on treatment of insulin poisoning. METHODS: We searched PubMed, EMBASE and J-Stage with no restrictions of date or language for controlled studies on treatment of insulin poisoning, collected published cases of insulin poisoning from 1923, and used data from the UK National Poisons Information Service. RESULTS: We identified no controlled trials of treatment in insulin poisoning and few relevant experimental studies. Case reports described 315 admissions (301 patients) with insulin poisoning between 1923 and 2022. The insulin with the longest duration of action was long-acting in 83 cases, medium-acting in 116, short-acting in 36 and a rapid-acting analogue in 16. Decontamination by surgical excision of the injection site was reported in six cases. To restore and maintain euglycaemia, almost all cases were treated with glucose, infused for a median 51 hours, interquartile range 16-96 h in 179 cases; 14 patients received glucagon and nine octreotide; adrenaline was tried occasionally. Both corticosteroids and mannitol were occasionally given to mitigate hypoglycaemic brain damage. There were 29 deaths reported, 22/156 (86% survival) up to 1999 and 7/159 (96% survival) between 2000 and 2022 (p = 0.003). CONCLUSIONS: There is no randomized controlled trial to guide treatment of insulin poisoning. Treatment with glucose infusion, sometimes supplemented with glucagon, is almost always effective in restoring euglycaemia, but optimum treatments to maintain euglycaemia and restore cerebral function remain uncertain.

'Didn't See the Need': Misperceptions about glucagon from the perspectives of people with diabetes and their caregivers.

AIMS: Severe hypoglycaemia among people with diabetes who use insulin can be a life-threatening complication if left untreated. Although glucagon has been approved for treatment of hypoglycaemia since the 1960s, it has been underutilized. We aimed to understand the perceptions of people with diabetes and their caregivers about glucagon. METHODS: We conducted in-depth, one-on-one telephone interviews with people with diabetes and their caregivers in the United States. The interviews included questions around general awareness of glucagon, reasons for owning or not owning glucagon, and suggestions for improving understanding of glucagon as treatment for severe hypoglycaemia. Initial synopsis and inductive codebook schema were used to analyse the responses by two independent researchers. Themes were developed from the codes, and codes were re-mapped back to the themes. RESULTS: There were 60 dyads of people with diabetes and their caregivers (N = 120). Four themes developed from the interviews: (1) for most participants, the stated reasons for not owning or renewing a prescription for glucagon included unawareness of the medication, its advantages and its value; (2) misperceptions about glucagon occurred frequently; (3) caregivers often lacked confidence in administering reconstituted injectable glucagon; and (4) education and training from healthcare providers about glucagon would be welcomed. CONCLUSIONS: This study emphasizes the need for healthcare providers to discuss hypoglycaemia prevention and events at each clinical visit, including the use of glucagon in the case of severe hypoglycaemia. Healthcare providers are encouraged to assess the knowledge of people with diabetes and their caregivers regarding treatment and prevention of hypoglycaemia.

Revisiting the role of glucagon in health, diabetes mellitus and other metabolic diseases.

Insulin and glucagon exert opposing effects on glucose metabolism and, consequently, pancreatic islet ß-cells and α-cells are considered functional antagonists. The intra-islet hypothesis has previously dominated the understanding of glucagon secretion, stating that insulin acts to inhibit the release of glucagon. By contrast, glucagon is a potent stimulator of insulin secretion and has been used to test ß-cell function. Over the past decade, α-cells have received increasing attention due to their ability to stimulate insulin secretion from neighbouring ß-cells, and α-cell-ß-cell crosstalk has proven central for glucose homeostasis in vivo. Glucagon is not only the counter-regulatory hormone to insulin in glucose metabolism but also glucagon secretion is more susceptible to changes in the plasma concentration of certain amino acids than to changes in plasma concentrations of glucose. Thus, the actions of glucagon also include a central role in amino acid turnover and hepatic fat oxidation. This Review provides insights into glucagon secretion, with a focus on the local paracrine actions on glucagon and the importance of α-cell-ß-cell crosstalk. We focus on dysregulated glucagon secretion in obesity, non-alcoholic fatty liver disease and type 2 diabetes mellitus. Lastly, the future potential of targeting hyperglucagonaemia and applying dual and triple receptor agonists with glucagon receptor-activating properties in combination with incretin hormone receptor agonism is discussed.