Search

OBJECTIVE: The aim of this study was to investigate glucose tolerance, glucagon response, and beta cell function during a 1-year maintenance period with either exercise, the glucagon-like peptide-1 receptor agonist liraglutide, or the combination after diet-induced weight loss.METHODS: In this randomized placebo-controlled trial, adults with obesity (BMI: 32-43 kg/m 2 ) without diabetes underwent an 8-week low-calorie diet (800 kcal/d) and were randomized to 52 weeks of aerobic exercise, liraglutide 3.0 mg/d, exercise and liraglutide combined, or placebo. Change in glucose and glucagon response to a 3-hour mixed meal test and disposition index, as a measure of beta cell function, were measured. RESULTS: A total of 195 participants were randomized. After 1 year of treatment, the combination group had decreased postprandial glucose response by -9% (95% CI: -14% to -3%; p = 0.002), improved beta cell function by 49% (95% CI: 16% to 93%; p = 0.002), and decreased glucagon response by -18% (95% CI: -34% to -3%; p = 0.024) compared with placebo. Compared with placebo, liraglutide alone improved postprandial glucose response by -7% (95% CI: -12% to -1%; p = 0.018), but not beta cell function or glucagon. Exercise alone had similar postprandial glucose response, beta cell function, and glucagon response as placebo.CONCLUSIONS: Only the combination of exercise and liraglutide improved glucose tolerance, beta cell function, and glucagon responses after weight loss.

Endogenous reprogramming of pancreas-derived non-beta cells into insulin-producing cells is a promising approach to treat type 1 diabetes (T1D). One strategy that has yet to be explored is the specific delivery of insulin-producing essential genes, Pdx1 and MafA, to pancreatic alpha cells to reprogram the cells into insulin-producing cells in an adult pancreas. In this study, we utilized an alpha cell-specific glucagon (GCG) promoter to drive Pdx1 and MafA transcription factors to reprogram alpha cells to insulin-producing cells in chemically induced and autoimmune diabetic mice. Our results showed that a combination of a short glucagon-specific promoter with AAV serotype 8 can be used to successfully deliver Pdx1 and MafA into alpha cells in the mouse pancreas. Pdx1 and MafA expression specifically in alpha cells was also able to correct hyperglycemia in both induced and autoimmune diabetic mice. With this technology, targeted gene specificity and reprogramming were accomplished with an alpha-specific promotor combined with an AAV-specific serotype and provide an initial basis to develop a novel therapy for the treatment of T1D.

Glucose control in patients after total pancreatectomy is problematic because of the complete absence of α- and β-cells, leading to impaired quality of life. A novel, bihormonal artificial pancreas (BIHAP), using both insulin and glucagon, may improve glucose control, but studies in this setting are lacking.To assess the efficacy and safety of the BIHAP in patients after total pancreatectomy.This randomized crossover clinical trial compared the fully closed-loop BIHAP with current diabetes care (ie, insulin pump or pen therapy) in 12 adult outpatients after total pancreatectomy. Patients were recruited between August 21 and November 16, 2020. This first-in-patient study began with a feasibility phase in 2 patients. Subsequently, 12 patients were randomly assigned to 7-day treatment with the BIHAP (preceded by a 5-day training period) followed by 7-day treatment with current diabetes care, or the same treatments in reverse order. Statistical analysis was by Wilcoxon signed rank and Mann-Whitney U tests, with significance set at a 2-sided P.05.The primary outcome was the percentage of time spent in euglycemia (70-180 mg/dL [3.9-10 mmol/L]) as assessed by continuous glucose monitoring.In total, 12 patients (7 men and 3 women; median [IQR] age, 62.5 [43.1-74.0] years) were randomly assigned, of whom 3 did not complete the BIHAP phase and 1 was replaced. The time spent in euglycemia was significantly higher during treatment with the BIHAP (median, 78.30%; IQR, 71.05%-82.61%) than current diabetes care (median, 57.38%; IQR, 52.38%-81.35%; P = .03). In addition, the time spent in hypoglycemia (70 mg/dL [3.9 mmol/L]) was lower with the BIHAP (median, 0.00% [IQR, 0.00%-0.07%] vs 1.61% [IQR, 0.80%-3.81%]; P = .004). No serious adverse events occurred.Patients using the BIHAP after total pancreatectomy experienced an increased percentage of time in euglycemia and a reduced percentage of time in hypoglycemia compared with current diabetes care, without apparent safety risks. Larger randomized trials, including longer periods of treatment and an assessment of quality of life, should confirm these findings.trialregister.nl Identifier: NL8871.

Background Pancreatic islet transplantation via infusion through the portal vein, has become an established clinical treatment for patients with type 1 diabetes. Because the engraftment efficiency is low, new approaches for pancreatic islets implantation are sought. The goal of this study is to explore the possibility that a non-thermal irreversible electroporation (NTIRE) decellularized matrix in the liver could be used as an engraftment site for pancreatic islets. Materials and methods Pancreatic islets or saline controls were injected at sites pre-treated with NTIRE in the livers of 7 rats, 16 hours after NTIRE treatment. Seven days after the NTIRE treatment, islet graft function was assessed by detecting insulin and glucagon in the liver with immunohistochemistry. Results Pancreatic islets implanted into a NTIRE-treated volume of liver became incorporated into the liver parenchyma and produced insulin and glucagon in 2 of the 7 rat livers. Potential reasons for the failure to observe pancreatic islets in the remaining 5/7 rats may include local inflammatory reaction, graft rejection, low numbers of starting islets, timing of implantation. Conclusions This study shows that pancreatic islets can become incorporated and function in an NTIRE-generated extracellular matrix niche, albeit the success rate is low. Advances in the field could be achieved by developing a better understanding of the mechanisms of failure and ways to combat these mechanisms.

The evolution of glucagon has seen the transition from an impurity in the preparation of insulin to the development of glucagon receptor agonists for use in type 1 diabetes. In type 2 diabetes, glucagon receptor antagonists have been explored to reduce glycemia thought to be induced by hyperglucagonemia. However, the catabolic actions of glucagon are currently being leveraged to target the rise in obesity that paralleled that of diabetes, bringing the pharmacology of glucagon full circle. During this evolution, the physiological importance of glucagon advanced beyond the control of hepatic glucose production, incorporating critical roles for glucagon to regulate both lipid and amino acid metabolism. Thus, it is unsurprising that the study of glucagon has left several paradoxes that make it difficult to distill this hormone down to a simplified action. Here, we describe the history of glucagon from the past to the present and suggest some direction to the future of this field.

Treating hyperglycaemia and obesity in individuals with type 2 diabetes using multi-receptor agonists can improve short-term and long-term outcomes. LY3437943 is a single peptide with agonist activity for glucagon, glucose-dependent insulinotropic polypeptide (GIP), and glucagon-like peptide 1 (GLP-1) receptors that is currently in development for the treatment of type 2 diabetes and for the treatment of obesity and associated comorbidities. We investigated the safety, pharmacokinetics, and pharmacodynamics of multiple weekly doses of LY3437943 in people with type 2 diabetes in a 12-week study.In this phase 1b, proof-of-concept, double-blind, placebo-controlled, randomised, multiple-ascending dose trial, adults (aged 20-70 years) with type 2 diabetes for at least 3 months, a glycated haemoglobin ABetween Dec 18, 2019, and Dec 28, 2020, 210 people were screened, of whom 72 were enrolled, received at least one dose of study drug, and were included in safety analyses. 15 participants had placebo, five had dulaglutide 1·5 mg and, for LY3437943, nine had 0·5 mg, nine had 1·5 mg, 11 had 3 mg, 11 had 3/6 mg, and 12 had 3/6/9/12 mg. 29 participants discontinued the study prematurely. Treatment-emergent adverse events were reported by 33 (63%), three (60%), and eight (54%) participants who received LY3437943, dulaglutide 1·5 mg, and placebo, respectively, with gastrointestinal disorders being the most frequently reported treatment-emergent adverse events. The pharmacokinetics of LY3437943 were dose proportional and its half-life was approximately 6 days. At week 12, placebo-adjusted mean daily plasma glucose significantly decreased from baseline at the three highest dose LY3437943 groups (least-squares mean difference -2·8 mmol/L [90% CI -4·63 to -0·94] for 3 mg; -3·1 mmol/L [-4·91 to -1·22] for 3/6 mg; and -2·9 mmol/L [-4·70 to -1·01] for 3/6/9/12 mg). Placebo-adjusted sHbAIn this early phase study, LY3437943 showed an acceptable safety profile, and its pharmacokinetics suggest suitability for once-weekly dosing. This finding, together with the pharmacodynamic findings of robust reductions in glucose and bodyweight, provides support for phase 2 development.Eli Lilly and Company.

Objectives The antimalarial drug artemether is suggested to effect pancreatic islet cell transdifferentiation, presumably through activation γ-aminobutyric acid receptors, but this biological action is contested. Methods We have investigated changes in α-cell lineage in response to 10-days treatment with artemether (100 mg/kg oral, once daily) on a background of β-cell stress induced by multiple low-dose streptozotocin (STZ) injection in GluCreERT2; ROSA26-eYFP transgenic mice. Key findings Artemether intervention did not affect the actions of STZ on body weight, food and fluid intake or blood glucose. Circulating insulin and glucagon were reduced by STZ treatment, with a corresponding decline in pancreatic insulin content, which were not altered by artemether. The detrimental changes to pancreatic islet morphology induced by STZ were also evident in artemether-treated mice. Tracing of α-cell lineage, through co-staining for glucagon and yellow fluorescent protein (YFP), revealed a significant decrease of the proportion of glucagon+YFP− cells in STZ-diabetic mice, which was reversed by artemether. However, artemether had no effect on transdifferentiation of α-cells into β-cells and failed to augment the number of bi-hormonal, insulin+glucagon+, islet cells. Conclusions Our observations confirm that artemisinin derivatives do not impart meaningful benefits on islet cell lineage transition events or pancreatic islet morphology.

Unfortunately, humanity is exposed to mixed plasticizers such as bisphenol-A (BPA) and dibutyl phthalate (DBP) that are leached from the daily used plastic products. Previous studies have demonstrated their potential in pancreatic beta cell injury and diabetes induction. The study hypothesized that both compounds would affect the pancreatic alpha cells in albino rats when administered at environmentally relevant doses. Heat shock protein 60 (HSP60) and caspase-3 protein expression was also investigated as potential mechanisms. Thirty-six male Wistar albino rats were separated into four equal groups: control, BPA alone, DBP alone, and BPA + DBP combined groups. BPA and DBP were given in drinking water for 45 days in a dose of 4.5 and 0.8 µg/L, respectively. Fasting blood glucose, serum insulin, pancreatic tissue levels of malondialdehyde, and superoxide dismutase were measured. Pancreatic sections were subjected to hematoxylineosin (HE) staining, glucagon, HSP60, and caspase-3 immunohistochemistry. Although all three experimental groups showed diffuse islet cell HSP60 immunoreactivity, rats exposed to BPA alone showed α-cell-only apoptosis, indicated by HE changes and caspase-3 immunoreactivity, associated with reduced glucagon immunoreaction. However, rats exposed to DBP alone showed no changes in either α or β-cells. Both combined-exposed animals displayed α and β apoptotic changes associated with islet atrophy and reduced glucagon expression. In conclusion, the study suggested HSP60/caspase-3 interaction, caspase-3 activation, and initiation of apoptosis in α-cell only for BPA-alone exposure group, meanwhile DBP alone did not progress to apoptosis. Interestingly, both α/β cell effect was observed in the mixed group implying synergetic/additive action of both chemicals when combined.

Oral delivery of therapeutic peptides has been challenging due to multiple physiological factors and physicochemical properties of peptides. We report a systematic approach to identify formulation compositions combining a permeation enhancer and a peptidase inhibitor that minimize proteolytic degradation and increase absorption of a peptide across the small intestine.An acylated glucagon-like peptide-1/glucagon co-agonist peptide (4.5 kDa) was selected as a model peptide. Proteolytic stability of the peptide was investigated in rat and pig SIF. Effective PEs and multiple component formulations were identified in rats. Relative bioavailability of the peptide was determined in minipigs via intraduodenal administration (ID) of enteric capsules.The peptide degraded rapidly in the rat and pig SIF. Citric acid, SBTI, and SBTCI inhibited the enzymatic degradation. The peptide self-associated into trimers in solution, however, addition of PEs monomerized the peptide. C10 was the most effective PE among tested PEs (DPC, LC, rhamnolipid, C12-maltosides, and SNAC) to improve intestinal absorption of the peptide in the rat IJ-closed loop model. A combination of C10 and SBTI or SBTCI increased the peptide exposure 5-tenfold compared to the exposure with the PE alone in the rat IJ-cannulated model, and achieved 1.06 ± 0.76% bioavailability in minipigs relative to subcutaneous via ID administration using enteric capsules.We identified SBTI and C10 as an effective peptidase inhibitor and PE for intestinal absorption of the peptide. The combination of SBTI and C10 addressed the peptide physiochemical properties and provides a formulation strategy to achieve intestinal delivery of this peptide.

Artificial pancreas (AP) algorithms can be divided into single-hormone (SH) and dual-hormone (DH). SH algorithms regulate glycemia using insulin as their control input. On the other hand, DH algorithms also use glucagon to counteract insulin. While SH-AP systems are already commercially available, DH-AP systems are still in an earlier research phase. DH-AP systems have been questioned since the added complexity of glucagon infusion does not always guarantee hypoglycemia prevention and might significantly raise insulin delivery. In this work, a DH multicontroller is proposed based on a SH linear quadratic gaussian (LQG) algorithm with an additional LQG controller to deliver glucagon. This strategy has a switched structure that allows activating one of the following three controllers when necessary: a conservative insulin LQG controller to modulate basal delivery ( K

Amino acids stimulate the secretion of glucagon, and glucagon receptor signaling regulates amino acid catabolism via ureagenesis, together constituting the liver-α cell axis. Impairment of the liver-α cell axis is observed in metabolic diseases such as diabetes. It is, however, unknown whether glucose affects the liver-α cell axis. We investigated the role of glucose on the liver-α cell axis in vivo and ex vivo. The isolated perfused mouse pancreas was used to evaluate the direct effect of low (3.5 mmol/L) and high (15 mmol/L) glucose levels on amino acid (10 mmol/L arginine)-induced glucagon secretion. High glucose levels alone lowered glucagon secretion, but the amino acid-induced glucagon responses were similar in high and low glucose conditions (

The aim of this study was to assess the effect of four isocaloric meals with different macronutrient compositions on postprandial blood glucose, lipids, and glucagon in adults with type 1 diabetes (T1D). Seventeen subjects tested four isocaloric meals in a randomized crossover design. The meal compositions were as follows: high-carbohydrate (HC); high-carbohydrate with extra fiber (HC-fiber); low-carbohydrate high-protein (HP); and low-carbohydrate high-fat (HF). Blood glucose and lipid measurements were collected up to 4 h and glucagon up to 3 h postprandially. Mean postprandial glucose excursions were lower after the HP compared to the HC (p = 0.036) and HC-fiber meals (p = 0.002). There were no differences in mean glucose excursions after the HF meal compared to the HC and HP meals. The HF meal resulted in higher triglyceride excursions compared to the HP meal (p < 0.001) but not compared to the HC or HC-fiber meals. Glucagon excursions were higher at 180 min after the HP meal compared to the HC and HF meals. In conclusion, the low-carbohydrate HP meal showed the most favorable glycemic and metabolic effects during a 4 h postprandial period in subjects with T1D.

The mechanisms behind reported decreases in plasma insulin and glucagon during hemodialysis (HD) are not clear. Here, we investigated these mechanisms during HD treatment and the characteristics of insulin and glucagon removal when using two super high-flux membranes. In an experimental study, clearance, adsorption rates, and reduction rates of insulin and glucagon were investigated when using cellulose triacetate (CTA) and polysulfone (PS) membranes in a closed circuit using bovine blood. In a clinical study, 20 diabetes patients with end-stage kidney disease who were stable on HD were randomly selected for two HD sessions with two different membranes. At 1 h after the initiation of HD, insulin and glucagon clearance were measured, and the reduction rates were also investigated. In the experimental study, the PS membrane showed significantly higher clearance, adsorption rates, and reduction rates of insulin and glucagon compared with the CTA membrane. Although glucagon was detected in the ultrafiltration fluids in both membranes, insulin was absent in the PS membrane. In the clinical study, both membranes showed significant reductions in plasma insulin and glucagon at each time point. The PS membrane showed significantly higher insulin clearance and reduction rates compared with the CTA membrane. The two membranes showed no significant difference in glucagon clearance, but the glucagon reduction rate was significantly higher with the PS membrane. Our findings show that HD with the two super high-flux membranes used removes significant amounts of glucoregulatory peptide hormones from plasma in patients with diabetes and end-stage kidney disease, potentially affecting their glucose metabolism.

(1) Background: Deficiencies of mitochondrial fatty acid oxidation (FAO) define a subgroup of inborn errors of metabolism, with medium-chain acyl-CoA dehydrogenase deficiency (MCAD) and very long-chain acyl-CoA dehydrogenase deficiency (VLCAD) being two of the most common. Hypoketotic hypoglycemia is a feared clinical complication and the treatment focuses on avoiding hypoglycemia. In contrast, carnitine uptake deficiency (CUD) is treated as a mild disease without significant effects on FAO. Impaired FAO has experimentally been shown to impair glucagon secretion. Glucagon is an important glucose-mobilizing hormone. If and how glucagon is affected in patients with VLCAD or MCAD remains unknown. (2) Methods: A cross-sectional study was performed with plasma hormone concentrations quantified after four hours of fasting. Patients with VLCAD (n = 10), MCAD (n = 7) and CUD (n = 6) were included. (3) Results: The groups were similar in age, sex, weight, and height. The glucagon and insulin levels were significantly lower in the VLCAD group compared to the CUD group (p < 0.05, respectively). The patients with CUD had glucagon concentrations similar to the normative data. No significant differences were seen in GLP-1, glicentin, glucose, amino acids, or NEFAs. (4) Conclusions: Low fasting concentrations of glucagon are present in patients with VLCAD and cannot be explained by altered stimuli in plasma.

Pancreatic islet transplantation has therapeutic potential in type 1 diabetes and is also an established therapy in chronic pancreatitis. However, the long-term transplant outcomes are modest. Identifying indicators of graft function will aid the preservation of transplanted islets and glycemic control. We analyzed beta cell prohormone peptide levels in a retrospective cohort of total pancreatectomy autologous islet transplant patients (n = 28). Proinsulin-to-C-peptide (PI/C) and proIAPP-to-total IAPP (proIAPP/IAPP) ratios measured at 3 months post-transplant were significantly higher in patients who remained insulin dependent at 1 year follow-up. In an immuno-deficient mouse model of human islet transplantation, recipient mice that later became hyperglycemic displayed significantly higher PI/C ratios than mice that remained normoglycemic. Histological analysis of islet grafts showed reduced proportional insulin- and proinsulin-positive area, but elevated glucagon-positive area in grafts that experienced greater secretory demand. Increased prohormone convertase 1/3 was detected in glucagon-positive cells, and glucagon-like peptide 1 (GLP-1) area was elevated in grafts from mice that displayed hyperglycemia or elevated plasma PI/C ratios, demonstrating intra-islet incretin production in metabolically challenged human islet grafts. These data indicate that in failing grafts, alpha cell prohormone processing is likely altered, and incomplete beta cell prohormone processing may be an early indicator of insulin dependency.

Context Exaggerated postprandial incretin and insulin responses are well documented in postbariatric surgery hypoglycemia (PBH) after Roux-en-Y gastric bypass (RYGB). However, less is known about PBH after sleeve gastrectomy (SG). Objective We sought to compare meal-stimulated hormonal response in those with PBH after SG vs RYGB. Methods We enrolled 23 post-SG (12 with and 11 without PBH) and 20 post-RYGB (7 with and 13 without PBH) individuals who underwent bariatric surgery at our institution. PBH was defined as plasma glucose less than 60 mg/dL on 4-hour mixed-meal tolerance test (MTT). Islet and incretin hormones were compared across the 4 groups. Results Participants (N = 43) were on average 5 years post surgery, with a mean age of 48 years, mean preoperative body mass index of 48.4, 81% female, 61% White, and 53% post SG. Regardless of PBH, the SG group showed lower glucose, glucagon, and glucagon-like peptide 1 (GLP-1) responses to MTT and similar insulin and glucose-dependent insulinotropic polypeptide (GIP) responses compared to the RYGB group. Among those with PBH, the SG group following the MTT showed a lower peak glucose (P = .02), a similar peak insulin (90.3 mU/L vs 171mU/L; P = .18), lower glucagon (P Conclusion Among individuals with PBH, those who underwent SG were significantly different compared to RYGB in meal-stimulated hormonal responses, including lower glucagon and GLP-1 responses, but similar insulin and GIP responses. Future studies are needed to better understand the differential contribution of insulin and non–insulin-mediated mechanisms behind PBH after SG vs RYGB.

Ablation of glucagon receptor (GCGR) signalling is a potential treatment option for diabetes, whilst glucagon-like peptide-1 (GLP-1) receptor agonists are clinically approved for both obesity and diabetes. There is a suggestion that GCGR blockade enhances GLP-1 secretion and action, whilst GLP-1 receptor activation is known to inhibit glucagon release, implying potential for positive interactions between both therapeutic avenues. The present study has examined the ability of sustained GCGR antagonism, using desHis

Abnormal increases in glucagon (GCG) are the primary cause of type II diabetes mellitus. When GCG interacts with a glucagon receptor (GCGR), GCG can increase the blood glucose level. In this paper, a compound that could interfere with the binding of GCG and GCGR to inhibit the increase of blood glucose was investigated. First, molecular docking was used to conduct preliminary screening of compounds whose active components could combine with GCGR by AutoDock Vina. The binding of the receptor-ligand complex was analyzed by PyMOL. Results showed that dauricine could tightly bind to the receptor pocket. Second, the plasmid pcDNA3.1(+)-GCGR containing the target gene was transfected into HEK293 cells for expression, which was the cell model established to screen GCGR antagonist. Dauricine, the lead compound of glucagon receptor antagonist (GRA), was screened using the GRA screening model in vitro. Finally, using [Des-His1, Glu9]-Glucagon amide as the positive control, flow cytometry was used to express the antagonistic effect of the compound. Consequently, dauricine can antagonize the GCGR.

The contribution of endogenous glucagon-like peptide (GLP)-1 to β-cell function after Roux-en-Y gastric bypass surgery (RYGB) is well established in normoglycaemic individuals, but not in those with postoperative hyperglycaemia. We, therefore, studied the effect of GLP-1 on β-cell function in individuals with varying degrees of type 2 diabetes mellitus (T2D) control after RYGB.Glucose, insulin secretion rates, β-cell glucose sensitivity and glucagon were measured during an oral glucose tolerance test before (saline only) and at 3, 12 and 24 months after RYGB with and without infusion of the GLP-1 receptor blocker exendinEX9 blunted the increase in β-cell glucose sensitivity at 3 months (-44.1%, p .001) and 12 months (-43.3%, p .001), but not at 24 months (-12.4%, p = .243). EX9 enhanced postprandial glucagon concentrations by 62.0% at 3 months (p = .008), 46.5% at 12 months (p = .055), and 30.4% at 24 months (p = .017). EX9 counterintuitively decreased glucose concentrations at 3 months in the entire cohort (p .001) but had no effect on glycaemia at 12 and 24 months in persistent T2D and impaired glucose tolerance; it minimally worsened glycaemia in REM at 12 months.GLP-1 blockade reversed the improvement in β-cell function observed after RYGB, but this effect varied temporally and by REM status. GLP-1 blockade transiently and minimally worsened glycaemia only in REM, and lowered postprandial glucose values at 3 months, regardless of REM status.

Pharmacological AMPK activation represents an attractive approach for the treatment of type 2 diabetes (T2D). AMPK activation increases skeletal muscle glucose uptake, but there is controversy as to whether AMPK activation also inhibits hepatic glucose production (HGP) and pharmacological AMPK activators can have off-target effects that contribute to their anti-diabetic properties. The main aim was to investigate the effects of 991 and other direct AMPK activators on HGP and determine whether the observed effects were AMPK-dependent. In incubated hepatocytes, 991 substantially decreased gluconeogenesis from lactate, pyruvate and glycerol, but not from other substrates. Hepatocytes from AMPKβ1−/− mice had substantially reduced liver AMPK activity, yet the inhibition of glucose production by 991 persisted. Also, the glucose-lowering effect of 991 was still seen in AMPKβ1−/− mice subjected to an intraperitoneal pyruvate tolerance test. The AMPK-independent mechanism by which 991 treatment decreased gluconeogenesis could be explained by inhibition of mitochondrial pyruvate uptake and inhibition of mitochondrial sn-glycerol-3-phosphate dehydrogenase-2. However, 991 and new-generation direct small-molecule AMPK activators antagonized glucagon-induced gluconeogenesis in an AMPK-dependent manner. Our studies support the notion that direct pharmacological activation of hepatic AMPK as well as inhibition of pyruvate uptake could be an option for the treatment of T2D-linked hyperglycemia.

With the rising epidemics of obesity and nonalcoholic fatty liver disease (NAFLD) and its downstream consequences including steatohepatitis, cirrhosis, and type 2 diabetes in the U.S. and worldwide, new therapeutic approaches are urgently needed to treat these devastating conditions. Glucagon, known for a century to be a glucose-raising hormone and clearly demonstrated to contribute to fasting and postprandial hyperglycemia in both type 1 and type 2 diabetes, represents an unlikely target to improve health in those with metabolic syndrome. However, recent work from our group and others’ identifies an unexpected role for glucagon as a potential means of treating NAFLD, improving insulin sensitivity, and improving the lipid profile. We propose a unifying, calcium-dependent mechanism for glucagon’s effects both to stimulate hepatic gluconeogenesis and to enhance hepatic mitochondrial oxidation: signaling through the inositol 1,4,5-trisphosphate receptor type 1 (INSP3R1), glucagon activates phospholipase C (PKC)/protein kinase A (PKA) signaling to enhance adipose triglyceride lipase (ATGL)-dependent intrahepatic lipolysis and, in turn, increase cytosolic gluconeogenesis by allosteric activation of pyruvate carboxylase. Simultaneously in the mitochondria, calcium transferred through mitochondria-associated membranes activates several dehydrogenases in the tricarboxylic acid cycle, correlated with an increase in mitochondrial energy expenditure and reduction in ectopic lipid. This model suggests that short-term, cyclic treatment with glucagon or other INSP3R1 antagonists could hold promise as a means to reset lipid homeostasis in patients with NAFLD.

Producción Científica, Aims/hypothesis Type 2 diabetes is characterised by hyperglucagonaemia and perturbed function of pancreatic glucagon secreting alpha cells but the molecular mechanisms contributing to these phenotypes are poorly understood. Insulin-degrading enzyme (IDE) is present within all islet cells, mostly in alpha cells, in both mice and humans. Furthermore, IDE can degrade glucagon as well as insulin, suggesting that IDE may play an important role in alpha cell function in vivo. Methods We have generated and characterised a novel mouse model with alpha cell-specific deletion of Ide, the A-IDE-KO mouse line. Glucose metabolism and glucagon secretion in vivo was characterised; isolated islets were tested for glucagon and insulin secretion; alpha cell mass, alpha cell proliferation and α-synuclein levels were determined in pancreas sections by immunostaining. Results Targeted deletion of Ide exclusively in alpha cells triggers hyperglucagonaemia and alpha cell hyperplasia, resulting in elevated constitutive glucagon secretion. The hyperglucagonaemia is attributable in part to dysregulation of glucagon secretion, specifically an impaired ability of IDE-deficient alpha cells to suppress glucagon release in the presence of high glucose or insulin. IDE deficiency also leads to α-synuclein aggregation in alpha cells, which may contribute to impaired glucagon secretion via cytoskeletal dysfunction. We showed further that IDE deficiency triggers impairments in cilia formation, inducing alpha cell hyperplasia and possibly also contributing to dysregulated glucagon secretion and hyperglucagonaemia. Conclusions/interpretation We propose that loss of IDE function in alpha cells contributes to hyperglucagonaemia in type 2 diabetes, Ministerio de Economía, Industria y Competitividad (SAF2016-77871-C2-1-R to IC and BFU2016-77125-R to IQ), Ministerio de Ciencia, Innovación y Universidades (PID2019-110496RB-C21 to IC and PID2019-110496RB-C22 to GP), La Caixa Foundation (grant LCF/PR/PR18/51130007 to GP), National Institutes of Health from USA (GM115617), Publicación en abierto financiada por el Consorcio de Bibliotecas Universitarias de Castilla y León (BUCLE), con cargo al Programa Operativo 2014ES16RFOP009 FEDER 2014-2020 DE CASTILLA Y LEÓN, Actuación:20007-CL - Apoyo Consorcio BUCLE

Considerable evidence confirms the importance of Cyp26a1 to all-trans-retinoic acid (RA) homeostasis during embryogenesis. In contrast, despite its presence in postnatal liver as a potential major RA catabolizing enzyme and its acute sensitivity to induction by RA, some data suggested that Cyp26a1 contributes only marginally to endogenous RA homeostasis postnatally. We report reevaluation of a conditional Cyp26a1 knockdown in the postnatal mouse. The current results show that Cyp26a1 mRNA in WT mouse liver increases 16-fold upon refeeding after a fast, accompanied by an increased rate of RA elimination and a 41% decrease in the RA concentration. In contrast, Cyp26a1 mRNA in the refed homozygotic knockdown reached only 2% of its extent in WT during refeeding, accompanied by a slower rate of RA catabolism and no decrease in liver RA, relative to fasting. Refed homozygous knockdown mice also had decreased Akt1 and 2 phosphorylation and pyruvate dehydrogenase kinase 4 (Pdk4) mRNA and increased glucokinase (Gck) mRNA, glycogen phosphorylase (Pygl) phosphorylation, and serum glucose, relative to WT. Fasted homozygous knockdown mice had increased glucagon/insulin relative to WT. These data indicate that Cyp26a1 participates prominently in moderating the postnatal liver concentration of endogenous RA and contributes essentially to glucoregulatory control.

Visceral adipose tissue (VAT) metabolic fingerprints differ according to body mass index (BMI) and glycemic status. Glucagon-like peptide 1 (GLP-1), glucose-dependent insulinotropic polypeptide (GIP) and glucagon are gut-associated hormones that play an important role in regulating energy and glucose homeostasis, although their metabolic actions in VAT are still poorly characterized. Our aim was to assess whether GLP-1, GIP and glucagon influence the VAT metabolite profile. To achieve this goal, VAT harvested during elective surgical procedures from individuals (N = 19) with different BMIs and glycemic statuses was stimulated with GLP-1, GIP or glucagon, and culture media was analyzed using proton nuclear magnetic resonance. In the VAT of individuals with obesity and prediabetes, GLP-1 shifted its metabolic profile by increasing alanine and lactate production while also decreasing isoleucine consumption, whereas GIP and glucagon decreased lactate and alanine production and increased pyruvate consumption. In summary, GLP-1, GIP and glucagon were shown to distinctively modulate the VAT metabolic profile depending on the subject’s BMI and glycemic status. In VAT from patients with obesity and prediabetes, these hormones induced metabolic shifts toward gluconeogenesis suppression and oxidative phosphorylation enhancement, suggesting an overall improvement in AT mitochondrial function.

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. 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.

Pancreatic islets are highly vascularized endocrine units. Accordingly, their adequate revascularization is of major importance for successful islet transplantation. The proteoglycan, nerve/glial antigen 2 (NG2) expressed in pericytes is a crucial regulator of angiogenesis. Therefore, we herein analyze whether this surface protein contributes to the revascularization of grafted islets. Islets were isolated from NG2+/+ (wild-type) and NG2-/- mice and their cellular composition was analyzed by immunohistochemical detection of insulin, glucagon, somatostatin and CD31. Moreover, insulin secretion was assessed by enzyme-linked immunosorbent assay (ELISA). In addition, isolated islets were transplanted into dorsal skinfold chambers of wild-type mice and their revascularization was determined by intravital fluorescence microscopy and immunohistochemistry. NG2+/+ and NG2-/- islets did not differ in their cellular composition and insulin secretion. However, transplanted NG2-/- islets exhibited a significantly lower functional capillary density and a reduced number of CD31-positive microvessels. These findings demonstrate that the loss of NG2 impairs the revascularization of transplanted islets, underlining the importance of this pericytic proteoglycan for islet engraftment.

There are a number of factors and agents that change the population of endocrinocytes and their secretory activity depending on various conditions and experimentally formed pathologies. These include the impact of intermittent hypoxic hypoxia; experimentally formed pathology (diabetes); genetically formed pathology (arterial hypertension), direct effect on endocrinocytes of the pancreas with their own pathophysiological mechanism. In this context, it is interesting to analyze the state of the progenitor potential of alpha cells depending on the living conditions of the organism, its effects, and developing pathological conditions in it. The aim of the work is to determine the activity of the proliferative factor c-kit in alpha cells under exogenous factors – intermittent hypoxic hypoxia and endogenously formed pathology – arterial hypertension and diabetes. Materials and methods. The study was conducted on the pancreas of SHR and Wistar rats. Glucagon and c-kit in pancreatic islets were determined by the immunofluorescence method. The immunofluorescence reaction was studied with an AxioImager-M2 fluorescence microscope. Results. Analysis of the c-kit positive alpha-cell index in rats with diabetes showed a 5-fold increase. This was explained by the fact, that the development of hyperglycemia in diabetes mellitus was characterized not only by an increased level of glucose in the blood due to insufficient insulin production but also due to an increase in the number of alpha cells, their active proliferation and possible transdifferentiation from beta cells. The number of c-kit positive alpha cells in SHR rats decreased. This may indicate that these changes were not so related to a violation of the modulation of the transcription factor, but to the participation of neurogenic mechanisms. The decrease in c-kit positive alpha cells in animals with hypoxic hypoxia can be explained by transdifferentiation (remodeling) changes, aimed at suppressing proliferative processes in alpha endocrinocytes. Conclusions. The increase in the number of c-kit positive alpha cells in rats with diabetes is explained by the fact, that the development of hyperglycemia in diabetes is characterized not only by an increased level of glucose in the blood due to insufficient insulin production but also by an increase in the number of alpha cells, their active proliferation and possible transdifferentiation from beta cells. A decrease in the number of c-kit positive alpha cells in SHR rats may indicate that these changes are not so much related to a violation of the modulation of the transcription factor, but to the participation of neurogenic mechanisms. The decrease in c-kit positive alpha cells in animals with hypoxic hypoxia can be explained by transdifferentiation (remodeling) changes, aimed at suppressing proliferative processes in alpha endocrinocytes., Є низка факторів, що змінюють популяцію ендокриноцитів і їхню секреторну активність залежно від різних умов та експериментально сформованих патологій. Так, переривчаста гіпоксична гіпоксія, експериментально сформована патологія – цукровий діабет, генетично сформована патологія – артеріальна гіпертензія мають прямий вплив на ендокриноцити підшлункової залози зі своїм патофізіологічним механізмом. У цьому контексті цікавим є аналіз стану прогеніторного потенціалу альфа-клітин залежно від умов життєдіяльності організму, впливів і патологічних станів, що в ньому виникають. Мета роботи – визначення активності проліферативного фактора с-kit в альфа-клітинах при екзогенних факторах: переривчастій гіпоксичній гіпоксії, а також ендогенно сформованій патології – артеріальній гіпертензії та цукровому діабеті. Матеріали та методи. Дослідження здійснили на підшлунковій залозі щурів лінії SHR та Wistar. Глюкагон і с-kit в острівцях підшлункової залози визначали імунофлуоресцентним методом. Реакцію імунофлуоресценції вивчали флуоресцентним мікроскопом AxioImager-M2. Результати. Аналіз показника с-kit позитивних альфа-клітин у щурів, хворих на цукровий діабет, показав його підвищення вп’ятеро. Це можна пояснити тим, що виникнення гіперглікемії при цукровому діабеті характеризується не тільки підвищеним рівнем глюкози в крові внаслідок недостатнього вироблення інсуліну, але й шляхом збільшення кількості альфа-клітин, їхньої активної проліферації та можливого трансдиференціювання з бета-клітин. У щурів лінії SHR кількість с-kit позитивних альфа-клітин знижувалась, а отже такі зміни не стільки пов’язані з порушенням модуляції транскрипційного фактора, скільки з участю нейрогенних механізмів. Зниження с-kit позитивних альфа-клітин у тварин із гіпоксичною гіпоксією можна пояснити трансдиференційними (ремоделювальними) змінами, що спрямовані на пригнічення проліферативних процесів в альфа-ендокриноцитах. Висновки. Збільшення показника с-kit позитивних альфа-клітин у хворих на цукровий діабет щурів пояснюється тим, що виникнення гіперглікемії при цукровому діабеті характеризується не тільки підвищеним рівнем глюкози в крові внаслідок недостатнього вироблення інсуліну, але й шляхом збільшення кількості альфа-клітин, їхньої активної проліферації та можливого трансдиференціювання з бета-клітин. Зниження показника кількості с-kit позитивних альфа-клітин у щурів лінії SHR може свідчити про те, що ці зміни не стільки пов’язані з порушенням модуляції транскрипційного фактора, скільки з участю саме нейрогенних механізмів. Зниження с-kit позитивних альфа-клітин у тварин із гіпоксичною гіпоксією можна пояснити спрямованими на пригнічення проліферативних процесів в альфа-ендокриноцитах трансдиференційними (ремоделювальними) змінами.

A physiological feedback system exists between hepatocytes and the alpha cells, termed the liver-alpha cell axis and refers to the relationship between amino acid-stimulated glucagon secretion and glucagon-stimulated amino acid catabolism. Several reports indicate that non-alcoholic fatty liver disease (NAFLD) disrupts the liver-alpha cell axis, because of impaired glucagon receptor signaling (glucagon resistance). However, no experimental test exists to assess glucagon resistance in humans. The objective was to develop an experimental test to determine glucagon sensitivity with respect to amino acid and glucose metabolism in humans. The proposed glucagon sensitivity test (comprising two elements: 1) i.v. injection of 0.2 mg glucagon and 2) infusion of mixed amino acids 331 mg/hour/kg) is based on nine pilot studies which are presented. Calculation of a proposed glucagon sensitivity index with respect to amino acid catabolism is also described. Secondly, we describe a complete study protocol (GLUSENTIC) according to which the glucagon sensitivity test will be applied in a cross-sectional study currently taking place. 65 participants including 20 individuals with a BMI 18.6–25 kg/m2, 30 individuals with a BMI ≥ 25–40 kg/m2, and 15 individuals with type 1 diabetes with a BMI between 18.6 and 40 kg/m2 will be included. Participants will be grouped according to their degree of hepatic steatosis measured by whole-liver magnetic resonance imaging (MRI). The primary outcome measure will be differences in the glucagon sensitivity index between individuals with and without hepatic steatosis. Developing a glucagon sensitivity test and index may provide insight into the physiological and pathophysiological mechanism of glucagon action and glucagon-based therapies.

The inotropic effects of glucagon have been recognized for many years, but it has remained unclear whether glucagon signaling is beneficial to cardiac function. We evaluated the effects of glucagon alone and in combination with the glucagon-like peptide 1 (GLP-1) receptor agonist exenatide in the isolated perfused rat heart. The isolated perfused rat heart was used to investigate the initial inotropic and chronotropic effects of glucagon and exenatide during aerobic perfusion, and recovery of contractile function following ischaemia/reperfusion. Glucagon, but not exenatide, elicited an acute chronotropic and inotropic response during aerobic perfusion of the rat heart. Compared with control, glucagon improved recovery of left ventricular developed pressure (LVDP) by 33% (p < 0.05) and rate-pressure product (RPP) by 66% (p < 0.001) following ischaemia/reperfusion and amplified the mild recovery enhancement elicited by exenatide in a dose-dependent manner. Glucagon shows inotropic properties in the isolated perfused rat heart and improves contractile recovery following ischaemia/reperfusion, both alone and when co-administered with a GLP-1 receptor agonist. Glucagon and exenatide, a GLP-1 receptor agonist, combine to stimulate greater recovery of postischaemic contractile function in the Langendorff heart. Glucagon was inotropic and chronotropic, yet this initial effect decreased over time and did not account for the increased contractility observed postischaemia/reperfusion.

Prompt and reliable management of hypoglycemia in youth with diabetes is important to prevent serious medical complications.To determine efficacy, pharmacodynamics (PD), pharmacokinetics (PK), safety, and tolerability of a ready-to-use, liquid stable glucagon formulation administered subcutaneously via an autoinjector pen to youth with type 1 diabetes (T1D).After plasma glucose concentration was 80 mg/dL ( 4.4 mmol/L) after insulin, participants aged 2 to 12 years with T1D were administered 0.5 mg of glucagon; participants aged 12 to 18 years instead received 1 mg of glucagon. Then, adolescents were challenged with 0.5 mg after a 7- to 28-day washout period. Primary endpoint was mean plasma glucose concentration at 30 min after glucagon.Plasma glucose concentrations significantly (p 0.001) increased from baseline to 30 min after glucagon, with mean change in plasma glucose concentration between baseline and 30 min for each age cohort as follows: 2 to 6 years (n = 7; 81.4 mg/dL [4.5 mmol/L]); 6 to 12 years (13; 84.2 mg/dL [4.7 mmol/L]); 12 to 18 years (11; dose, 1 mg; 54.0 mg/dL [3.0 mmol/L]); and 12 to 18 years (11; 0.5 mg; 52.4 mg/dL [2.9 mmol/L]). Among age cohorts, no clinically relevant differences were observed for PD and PK parameters. Common adverse events were nausea, vomiting, and hypoglycemia.Age-appropriate dosing of this glucagon formulation was effective at 30 min in reversing plasma glucose concentrations from 80 mg/dL in youth with T1D.

Antipsychotic (AP) medications, such as olanzapine (OLZ), are used in the treatment of schizophrenia and a growing number of 'off-label' conditions. A single dose of OLZ causes robust increases in blood glucose within minutes of treatment. The purpose of the current study was to investigate whether interventions that increase circulating ketone bodies (fasting, β-hydroxybutyrate (βHB), ketone esters or a ketogenic diet (KD)) would be sufficient to protect against the acute metabolic side effects of OLZ. We demonstrate that fasting or the short-term consumption of a KD protects against OLZ-induced hyperglycaemia, independent of alterations in whole-body insulin action, and in parallel with a blunted rise in serum glucagon. Interestingly, the effects of fasting and KDs were not recapitulated by acutely increasing circulating concentrations of ketone bodies through treatment with βHB or oral ketone esters, approaches which increase ketone bodies to physiological or supra-physiological levels, respectively. Collectively, our findings demonstrate that fasting and the short-term consumption of a KD can protect against acute AP-induced perturbations in glucose homeostasis, whereas manipulations which acutely increase circulating ketone bodies do not elicit the same beneficial effects. KEY POINTS: Antipsychotic medications cause rapid and robust increases in blood glucose. Co-treatment approaches to offset these harmful metabolic side effects have not been identified. We demonstrate that fasting or the consumption of a short-term ketogenic diet, but not treatment with β-hydroxybutyrate or oral ketone esters, protects against acute antipsychotic-induced hyperglycaemia. The protective effects of fasting and ketogenic diets were paralleled by reductions in serum glucagon, but not improvements in whole-body insulin action.

Background The differential diagnosis of diabetes insipidus is challenging. The most reliable approaches are copeptin measurements after hypertonic saline infusion or arginine, which is a known growth hormone secretagogue but has recently also been shown to stimulate the neurohypophysis. Similar to arginine, glucagon stimulates growth hormone release, but its effect on the neurohypophysis is poorly studied. Design Double-blind, randomized, placebo-controlled trial including 22 healthy participants, 10 patients with central diabetes insipidus, and 10 patients with primary polydipsia at the University Hospital Basel, Switzerland. Methods Each participant underwent the glucagon test (s.c. injection of 1 mg glucagon) and placebo test. The primary objective was to determine whether glucagon stimulates copeptin and to explore whether the copeptin response differentiates between diabetes insipidus and primary polydipsia. Copeptin levels were measured at baseline, 30, 60, 90, 120, 150, and 180 min after injection. Results In healthy participants, glucagon stimulated copeptin with a median increase of 7.56 (2.38; 28.03) pmol/L, while placebo had no effect (0.10 pmol/L (−0.70; 0.68); P < 0.001). In patients with diabetes insipidus, copeptin showed no relevant increase upon glucagon, with an increase of 0.55 (0.21; 1.65) pmol/L, whereas copeptin was stimulated in patients with primary polydipsia with an increase of 15.70 (5.99; 24.39) pmol/L. Using a copeptin cut-off level of 4.6pmol/L had a sensitivity of 100% (95% CI: 100–100) and a specificity of 90% (95% CI: 70–100) to discriminate between diabetes insipidus and primary polydipsia. Conclusion Glucagon stimulates the neurohypophysis, and glucagon-stimulated copeptin has the potential for a safe, novel, and precise test in the differential diagnosis of diabetes insipidus.

This study was designed to provide more detailed knowledge on the stomach histochemistry and immunohistochemistry in the southern white-breasted hedgehog (Erinaceus concolor). Two animals were used in the present work. Periodic acid Schiff's (PAS) and Alcian blue were used for histochemical purposes. SOX9, gastrin, serotonin, and glucagon markers were traced immunohistochemically. The mucosa was extremely folded in the fundus with numerous opening of glands. The body and pylorus mucosa were almost smooth and equipped with gastric gland openings. A simple columnar epithelium covered the stomach entirely. Cardiac glands region was mucus secreting with both positive and negative reactions to PAS. Fundic mucosa was contained cardiac glands near to the cardia, and toward the body it was divided into the light and dark zones. These zones and body contained proper gastric gland, which constituted of parietal, chief, and mucous neck cells. These glands contained PAS-positive cells on their basal portions. The pyloric glands were mucus secreting but negative for PAS. All gastric glands were Alcian blue-negative, but epithelium showed moderate reaction especially in the pylorus. SOX and gastrin were express highly in the body and fundus. The expression of serotonin and glucagon was rare. Comparatively, some similarities between the stomach of hedgehog and dog can be assumed. The present findings provide additional information concerning the histochemical characteristics and endocrine cells distribution in the stomach of the southern white-breasted hedgehog (Erinaceus concolor). Further detailed studies are required to enhance the current knowledge on histophysiology of the digestive system in this species as a pet and exotic animal. HIGHLIGHTS: The stomach was simple glandular type. The fundus was divided into light and dark zones similar to the dog. The proper gastric glands were periodic acid Schiff's positive at their basal parts.

Objectives Sodium-glucose cotransporter 2 inhibitors (SGLT2i) modulate lipid metabolism and improve cardiovascular morbidity and mortality in patients with type 2 diabetes mellitus (T2DM). The exact cardioprotective mechanism of SGLT2i is unclear. We evaluated the effects of SGLT2i on postprandial lipids, lipoprotein concentrations, glucose and fatty acids. Design A placebo-controlled randomized, proof-of-concept study. Methods Fourteen male patients with T2DM on intensive insulin regimen were randomly and double-blind allocated to 12 weeks dapagliflozin (10 mg) or placebo. Postprandial effects were assessed with an 8-h standardized oral fat loading test. Results Mean glycated A1c did not change by dapagliflozin, but the mean daily insulin dose was significantly reduced. Although dapagliflozin did not affect fasting or postprandial levels of glucose and insulin, it increased the postprandial levels of glucagon. While fasting levels of free fatty acids and beta-hydroxybutyrate (bHBA) were unchanged, dapagliflozin significantly increased the postprandial bHBA response. This was seen in the context of increased postprandial glucagon levels by dapagliflozin, without influencing postprandial insulin or glucose levels. Dapagliflozin did not affect fasting or postprandial plasma cholesterol and triglycerides nor postprandial inflammatory markers. Fasting apolipoprotein B48 was decreased without affecting the postprandial response. Markers of inflammation and vascular function did not change. Conclusion Treatment with dapagliflozin of patients with T2DM led to a reduction of fasting chylomicron remnants and increased postprandial ketone bodies compared to placebo suggesting enhanced hepatic fatty acid oxidation. The latter may have been caused by decreasing the insulin–glucagon ratio. The beneficial clinical effects seen in the trials using dapagliflozin most likely are not due to effects on postprandial inflammation nor postprandial lipemia.

To evaluate ease of use, user preference, and effort required to use nasal glucagon (NG) versus injectable glucagon needing reconstitution (IG) in simulations of severe hypoglycemia (SH)-a challenge for caregivers of a person with diabetes (PWD) in real-life.In this randomized, crossover study, high-fidelity manikins placed in mock representative high-stress environments were used to simulate an SH rescue. Thirty-two trained (by PWDs) and 33 untrained participants attempted NG and IG administrations and then completed questionnaires regarding ease of use, preference, and workload for each device.More trained users agreed that NG was easy to use (87.1% vs 54.8%) and prepare (80.6% vs 51.6%) and had confidence to use NG correctly (93.5% vs 54.8%) than those who agreed the same for IG (P.05). Untrained users reported similar differences, favoring NG in all parameters. In direct device comparison across all simulations, 80.6% of trained users and 93.5% of untrained users preferred NG over IG-a preference largely sustained regardless of the success or failure of administration. Among PWDs, 90.3% considered NG device as safer than IG during an SH event. In the assessment of workload required to administer glucagon, the weighted mean National Aeronautics and Space Administration Task Load Index scores were 37.8 for NG and 48.4 for IG (P = .0020).Participants in this study considered NG easier, more preferred, required less effort for administration, and more intuitive to use than reconstitutable IG, irrespective of whether there was prior training. NG improves the potential for successful administration of glucagon, better preparedness, and increased adoption of glucagon for SH rescue.

Hypoglycemia is a major complication associated with insulin therapy in people with diabetes that could cause life-threatening conditions if untreated. Glucagon, a counter-acting hormone, is thus administered for rescue of severe hypoglycemia. However, due to the instability of glucagon, only limited medications are available for emergency use, which are unsuitable for patients with hypoglycemia unawareness or with the inability to self-administer, especially during sleep (namely, nocturnal hypoglycemia). To prevent unattended and extended hypoglycemia, we designed a "smart" composite microneedle (cMN) patch capable of stabilizing glucagon, sensing hypoglycemia, and delivering glucagon automatically on demand. In this design, native glucagon was encapsulated in glucose-responsive microgels containing a glucagon-stabilizing component rationally selected by molecular dynamics (MD) simulation. A cMN patch was then prepared by incorporating the glucagon microgels with poly(methyl vinyl ether

AIM: α7nAChR agonist GTS-21 is potentially a new treatment for type 2 diabetes (T2D) owing to its ability to stimulate GLP-1 secretion. This study sought to establish if GTS-21 exerts a blood glucose-lowering action in db/db mice, and to test if this action requires coordinate α7nAChR and GLP-1 receptor (GLP-1R) stimulation by GTS-21 and endogenous GLP-1, respectively. MATERIALS AND METHODS: Blood glucose levels were measured during an oral glucose tolerance test (OGTT) using db/db mice administered intraperitoneal GTS-21. Plasma GLP-1, PYY(1–36), GIP, glucagon, and insulin levels were measured by ELISA. A GLP-1R-mediated action of GTS-21 that is secondary to α7nAChR stimulation was evaluated using α7nAChR and GLP-1R knockout (KO) mice, or by co-administration of GTS-21 with DPP-4 inhibitor sitagliptin, or GLP-1R antagonist Exendin(9–39). Insulin sensitivity was assessed in an insulin tolerance test (ITT). RESULTS: Single or multiple dose GTS-21 (0.5–8.0 mg/kg) acted in a dose-dependent manner to lower levels of blood glucose in the OGTT using 10–14 week-old male and female db/db mice. This action of GTS-21 was reproduced by α7nAChR agonist PNU-282987, was enhanced by sitagliptin, was counteracted by Exendin(9–39), and was absent in α7nAChR and GLP-1R KO mice. Plasma GLP-1, PYY(1–36), GIP, glucagon, and insulin levels increased in response to GTS-21, but insulin sensitivity, body weight, and food intake were unchanged. CONCLUSIONS: α7nAChR agonists improve oral glucose tolerance in db/db mice. This action is contingent on coordinate α7nAChR and GLP-1R stimulation. Thus, α7nAChR agonists administered in combination with sitagliptin might serve as a new treatment for T2D.

In the United States, hypoglycemic events contribute to 100 000 emergency department (ED) visits, costing $120 million annually. Hypoglycemia hinders glycemic management in people living with diabetes. Glucagon is the first line of treatment for severe hypoglycemia that is administrable by a caregiver in a nonclinical setting. However, there is a paucity of evidence on how frequently glucagon is prescribed for the anticipatory management of hypoglycemia, especially in ED.A retrospective study of patients seen with hypoglycemic events in an urban ED between 2016 and 2018 was performed to characterize gaps in prescription and use of glucagon for the anticipatory management of severe hypoglycemia.We identified 232 patients with a documented history of type 1 diabetes mellitus or type 2 diabetes mellitus who were seen in the ED with hypoglycemia. The majority of the patients were women (59%), African American (57%), and covered by public insurance (76%). Eighty-four percent of the patients had type 2 diabetes mellitus, 75% were receiving treatment with hypoglycemic medications, and 61% were receiving treatment with insulin. The prevalence of glucagon prescription was only 3% in this sample, and only 12% of the patients had received formal diabetes education in the year before the ED visit.Despite its proven efficacy in the management of severe hypoglycemia, glucagon is underused. This may be due to the lack of awareness, education, or training among both providers and patients. ED providers should be educated on prescribing glucagon and its use as a tool for the self-management of hypoglycemia. Patients at risk of hypoglycemia and their families need to be educated on the efficacy and use of glucagon.

Gestational diabetes mellitus (GDM) is known to be a significant risk factor for the future development of type 2 diabetes. Here, we investigated whether a precise evaluation of β- and α-cell functions helps to identify women at high risk of developing glucose intolerance after GDM. Fifty-six women with GDM underwent a 75-g oral glucose tolerance test (OGTT) at early (6–12 weeks) postpartum. We measured their concentrations of glucose, insulin, proinsulin and glucagon at fasting and 30, 60 and 120 min. At 1-year post-delivery, we classified the women into a normal glucose tolerance (NGT) group or an impaired glucose tolerance (IGT)/diabetes mellitus (DM) group. Forty-three of the 56 women completed the study. At 1-year post-delivery, 17 women had developed IGT/DM and 26 women showed NGT. In the early-postpartum OGTTs, the IGT/DM group showed a lower insulinogenic index, a less glucagon suppression evaluated by the change from fasting to 30 min (ΔGlucagon 30 min), and a higher glucagon-to-insulin ratio at 30 min compared to the NGT group. There were no significant between-group differences in proinsulin levels or proinsulin-to-insulin ratios. Insulinogenic index 0 pg/mL were identified as predictors for the development of IGT/DM after GDM, independent of age, body mass index, and lactation intensity. These results suggest that the bihormonal disorder of insulin and glucagon causes the postpartum development of glucose intolerance. The measurement of plasma insulin and glucagon during the initial OGTT at early postpartum period can help to make optimal decisions regarding the postpartum management of women with GDM., 長崎大学学位論文 学位記番号:共博(医歯薬)甲第20号 学位授与年月日:令和4年3月18日, Author: Riyoko Shigeno, Ichiro Horie, Masaki Miwa, Ayako Ito, Ai Haraguchi, Shoko Natsuda, Satoru Akazawa, Ai Nagata, Yuri Hasegawa, Shoko Miura, Kiyonori Miura, Atsushi Kawakami, Norio Abiru, Citation: Endocrine Journal, 68(8), pp. 919-931; 2021

AIMS. Post-bariatric hypoglycemia (PBH) is an increasingly-recognized complication of bariatric surgery, but current therapies are limited. We hypothesized pramlintide would reduce hypoglycemia by slowing gastric emptying and reducing postprandial glucagon secretion, thus limiting postprandial glycemic excursions and insulin secretion. We thus determined the efficacy of pramlintide on frequency and severity of hypoglycemia in PBH. MATERIALS AND METHODS. Participants with PBH following gastric bypass were recruited from outpatient clinics at Joslin Diabetes Center, Boston, MA for an open-label study of pramlintide efficacy over 8 weeks. 23 participants were assessed for eligibility, 20 participants had at least 1 pramlintide dose, and 14 completed the study. Mixed meal tolerance test (MMTT) was performed at baseline and following 8 weeks of subcutaneous pramlintide with sequential dose increase to maximum of 120 micrograms (mean 69±32 mcg) 3 times daily. The primary endpoint was change in glucose excursions during MMTT. Secondary measures included MMTT insulin response, satiety and dumping score, percentage time with sensor glucose

Glucagon is a potent glucose-elevating hormone that is secreted by pancreatic α-cells. While well-controlled glucagon secretion plays an important role in maintaining systemic glucose homeostasis and preventing hypoglycaemia, it is increasingly apparent that defects in the regulation of glucagon secretion contribute to impaired counter-regulation and hyperglycaemia in diabetes. It has therefore been proposed that pharmacological interventions targeting glucagon secretion/signalling can have great potential in improving glycaemic control of patients with diabetes. However, despite decades of research, a consensus on the precise mechanisms of glucose regulation of glucagon secretion is yet to be reached. Second messengers are a group of small intracellular molecules that relay extracellular signals to the intracellular signalling cascade, modulating cellular functions. There is a growing body of evidence that second messengers, such as cAMP and Ca2+, play critical roles in α-cell glucose-sensing and glucagon secretion. In this review, we discuss the impact of second messengers on α-cell electrical activity, intracellular Ca2+ dynamics and cell exocytosis. We highlight the possibility that the interaction between different second messengers may play a key role in the glucose-regulation of glucagon secretion.

Evidence for involvement of the central nervous system (CNS) in the regulation of glucose metabolism dates back to the 19th century, although the majority of the research on glucose metabolism has focused on the peripheral metabolic organs. Due to recent advances in neuroscience, it has now become clear that the CNS is indeed vital for maintaining glucose homeostasis. To achieve normoglycemia, specific populations of neurons and glia in the hypothalamus sense changes in the blood concentrations of glucose and of glucoregulatory hormones such as insulin, leptin, glucagon-like peptide 1, and glucagon. This information is integrated and transmitted to other areas of the brain where it eventually modulates various processes in glucose metabolism (i.e., hepatic glucose production, glucose uptake in the brown adipose tissue and skeletal muscle, pancreatic insulin and glucagon secretion, renal glucose reabsorption, etc.). Errors in these processes lead to hyper- or hypoglycemia. We here review the current understanding of the brain regulation of glucose metabolism.

Context Incretins are crucial stimulators of insulin secretion following food intake. Data on incretin secretion and action during pregnancy are sparse. Objective The aim of the study was to investigate the incretin response during an oral glucose tolerance test (OGTT) in pregnant women with and without gestational diabetes mellitus (GDM). Design We analyzed data from the ongoing observational PREG study (NCT 04270578). Setting The study was conducted at the University Hospital Tübingen. Participants We examined 167 women (33 with GDM) during gestational week 27 ± 2.2. Intervention Subjects underwent 5-point OGTT with a 75-g glucose load. Main outcome measures We assessed insulin secretion and levels of total glucagon-like peptide-1 (GLP-1), glucose-dependent insulinotropic peptide (GIP), glicentin, and glucagon during OGTT. Linear regression was used to analyze the relation of GLP-1 and glucose with insulin secretion and the association of incretin levels on birth outcome. Results Insulin secretion was significantly lower in women with GDM (P Conclusions The more pronounced GLP-1 increase in women with GDM could be part of a compensatory mechanism counteracting GLP-1 resistance. Higher GLP-1 levels might be protective against fetal overgrowth.

Treatments for severe hypoglycemia aim to restore blood glucose through successful administration of rescue therapy, and choosing the most effective and cost-effective option will improve outcomes for patients and may reduce costs for healthcare payers. The present analysis aimed to compare costs and use of medical services with nasal glucagon and injectable glucagon in people with type 1 and 2 diabetes in Canada when used to treat severe hypoglycemic events when impaired consciousness precludes treatment with oral carbohydrates using an economic model, based on differences in the frequency of successful administration of the two interventions.A decision tree model was prepared in Microsoft Excel to project outcomes with nasal glucagon and injectable glucagon. The model structure reflected real-world decision-making and treatment outcomes, based on Canada-specific sources. The model captured the use of glucagon, emergency medical services (EMS), emergency room, inpatient stay, and follow-up care. Costs were accounted for in 2019 Canadian dollars (CAD).Nasal glucagon was associated with reduced use of all medical services compared with injectable glucagon. EMS call outs were projected to be reduced by 45%, emergency room treatments by 52%, and inpatient stays by 13%. Use of nasal glucagon was associated with reduced direct, indirect, and combined costs of CAD 1,249, CAD 460, and CAD 1,709 per severe hypoglycemic event, respectively, due to avoided EMS call outs and hospital costs, resulting from a higher proportion of successful administrations.When a patient with type 1 or type 2 diabetes is being treated for a severe hypoglycemic event when impaired consciousness precludes treatment with oral carbohydrate, use of nasal glucagon was projected to be dominant versus injectable glucagon in Canada reducing costs and use of medical services.

Sodium–glucose cotransporter 2 inhibitor (SGLT2i) treatment is a therapeutic approach for type 2 diabetes mellitus (T2DM). Some reports have shown that SGLT2i treatment improves insulin resistance; however, few studies have evaluated insulin resistance by the glucose clamp method. Hepatic insulin clearance (HIC) is a new pathophysiological mechanism of T2DM. The effect of SGLT2i treatment on hepatic insulin clearance and insulin resistance is not well known. We investigated the effect of SGLT2i treatment on insulin resistance, insulin secretion, incretin levels, body composition, and hepatic insulin clearance. We conducted a meal tolerance test (MTT) and a hyperinsulinemic-euglycemic clamp test in 9 T2DM patients. Ipragliflozin (50 mg/day) was administered, and the MTT and clamp test were performed after 4 months. We calculated HIC as the postprandial C-peptide AUC-to-insulin AUC ratio. We also measured GLP-1, GIP, and glucagon levels during the MTT. Body weight and HbA1c were decreased, although not significantly, after 4 months of treatment. Postprandial glucose, fasting insulin and postprandial insulin were significantly decreased. Insulin resistance with the glucose clamp was not changed, but the HOMA-IR and insulin sensitivity indices were significantly improved. Incretin and glucagon levels were not changed. Hepatic insulin clearance was significantly increased, but whole-body insulin clearance was not changed. The FIB-4 index and fatty liver index were significantly reduced. The HOMA-beta and insulinogenic indices were not changed, but the C-peptide index was significantly increased. Although the number of patients was small, these results suggested that SGLT2i treatment improved liver function, decreased hepatic insulin resistance, and increased hepatic insulin clearance, despite the small weight reduction.

Aim: The objective of the CRASH (Conversations and Reactions Around Severe Hypoglycemia) survey was to further our understanding of the characteristics, experience, behavior and conversations with healthcare professionals (HCPs) of people with diabetes (PWD) receiving insulin, and of caregivers (CGs) caring for such people, concerning hypoglycemia requiring external assistance (severe hypoglycemic events [SHEs]). Methods: CRASH was an online cross-sectional survey conducted across eight countries. PWD with self-reported type 1 (T1D) or insulin-treated type 2 (T2D) diabetes were aged ≥ 18 years and had experienced one or more SHEs in the past 3 years; CGs were non-medical professionals aged ≥ 18 years, caring for PWD meeting all the above criteria except for PWD age (≥ 4 rather than ≥ 18 years). The present report is a descriptive analysis of data from France. Results: Among PWD who had ever discussed SHEs with an HCP, 38.9% of T1D PWD and 50.0% of T2D PWD reported that SHEs were discussed at every consultation; 26.3% and 8.8%, respectively, had not discussed the most recent SHE with an HCP. In total, 35.7% of T1D PWD and 53.8% of T2D PWD reported that glucagon was not available to them at the time of their most recent SHE. Only 16.9% of T1D PWD and 6.5% of T2D PWD who had discussed their most recent SHE with an HCP reported that the HCP recommended obtaining a glucagon kit or asked them to confirm that they already had one. High proportions of PWD and CGs reported that the most recent SHE had made them feel unprepared, scared and helpless and had affected mood, emotional state and activities. Conclusion: CRASH survey data from France identify a need for greater discussion about SHEs between HCPs and PWD and the CGs of such people, and reveal gaps in the diabetes education of PWDs and CGs.

Insulin and glucagon signalling pathways operate in a synchronised manner to regulate metabolic homeostasis in different physiological conditions (like postprandial, fastingexercise). Non-linear positive feedback loops involving effector molecules such as AKT and PKA in anabolic and catabolic signalling modules have a key role in eliciting bistable response in these networks.We have reviewed literature on insulin and glucagon signaling pathways in metabolic regulation along with the relevance of bistability in homeostasis. An ODE-based integrated signalling network model is used to simulate insulin and glucagon resistance conditions. Modifications in homeostatic to anabolic and catabolic switch activation thresholds are analyzed, indicating the effectiveness of insulin and glucagon signalling pathways in normal and diseased conditions.Perturbation analysis of the kinetic model provides valuable insights on bistability and its characterization with respect to endocrine inputs. Disturbance in bistability is linked with dysregulation of plasma macronutrient levels (glucose, fatty acids and amino acids) in abnormal conditions like insulin and glucagon resistance, which is associated with obesity, type 2 diabetes mellitus and non-alcoholic fatty liver disease.This article highlights the role of Systems biology approach in explaining plausible mechanisms underlying metabolic abnormalities. It captures essential crosstalk and feedback mechanisms that play a key role in inducing bistable response in a variety of physiological situations, as well as hints at how to reverse insulin and glucagon resistance.