exenatide and Diabetes-Mellitus--Type-1

There are presently no reliable ways to quantify human pancreatic beta cell mass (BCM) in vivo, which prevents an accurate understanding of the progressive beta cell loss in diabetes or following islet transplantation. Furthermore, the lack of beta cell imaging hampers the evaluation of the impact of new drugs aiming to prevent beta cell loss or to restore BCM in diabetes. We presently discuss the potential value of BCM determination as a cornerstone for individualized therapies in diabetes, describe the presently available probes for human BCM evaluation, and discuss our approach for the discovery of novel beta cell biomarkers, based on the determination of specific splice variants present in human beta cells. This has already led to the identification of DPP6 and FXYD2ga as two promising targets for human BCM imaging, and is followed by a discussion of potential safety issues, the role for radiochemistry in the improvement of BCM imaging, and concludes with an overview of the different steps from pre-clinical validation to a first-in-man trial for novel tracers.

Topics: 5-Hydroxytryptophan; Animals; Biomarkers; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dipeptidyl-Peptidases and Tripeptidyl-Peptidases; Exenatide; Fluorine Radioisotopes; Humans; Insulin-Secreting Cells; Islets of Langerhans Transplantation; Magnetic Resonance Imaging; Nerve Tissue Proteins; Positron Emission Tomography Computed Tomography; Potassium Channels; Radiopharmaceuticals; Single-Domain Antibodies; Sodium-Potassium-Exchanging ATPase; Technetium; Tetrabenazine; Tomography, Emission-Computed, Single-Photon

The role of glucagon-like peptide 1 receptor agonists (GLP-1 RAs) in the treatment of type 1 diabetes mellitus (T1DM), including efficacy and safety evidence, is reviewed.. Currently approved treatment options for glycemic control in T1DM include insulin, which combats insulin deficiency but does not effectively target disease progression or alpha cell dysfunction; and pramlintide, whose use requires multiple daily doses and involves a high likelihood of gastrointestinal side effects. GLP-1 RAs have a unique mechanism of action in T1DM, addressing alpha cell dysfunction and thereby suppressing inappropriate glucagon secretion. GLP-1 RA dosing varies from once weekly to twice daily, and the class is well tolerated in patients with type 2 diabetes. Among the GLP-1 RAs, exenatide and liraglutide have been studied in patients with T1DM, with published evidence consistently demonstrating weight loss, decreases in total daily insulin requirements, and modest improvements in glycemic control. GLP-1 RA therapy appears to be well tolerated in patients with T1DM and is associated with nonsignificant increases in hypoglycemia risk.. GLP-1 RA therapy represents an important add-on therapy option for achieving decreased insulin doses, weight loss, and modest improvements in HbA1c levels without significantly increasing hypoglycemia risk in patients with T1DM. Patients who have detectable C-peptide and/or are overweight or cannot achieve glycemic goals without hypoglycemia have been found to benefit the most from GLP-1 RA therapy. Further studies are warranted to evaluate these agents' potential impact on clinical outcomes such as microvascular and macrovascular complications.

Topics: Blood Glucose; Clinical Trials as Topic; Diabetes Mellitus, Type 1; Exenatide; Glucagon; Glucagon-Like Peptide-1 Receptor; Glucagon-Secreting Cells; Humans; Hypoglycemia; Hypoglycemic Agents; Incretins; Insulin; Liraglutide; Treatment Outcome; Weight Loss

A large proportion of patients with type 1 diabetes do not reach their glycaemic target of glycated hemoglobin (HbA1c) <7.0% (53 mmol/mol) and, furthermore, an increasing number of patients with type 1 diabetes are overweight and obese. Treatment of type 1 diabetes is based on insulin therapy, which is associated with well-described and unfortunate adverse effects such as hypoglycaemia and increased body weight. Glucagon-like peptide-1 (GLP-1) receptor agonists (RAs) are the focus of increasing interest as a possible adjunctive treatment to insulin in type 1 diabetes because of their glucagonostatic and extrapancreatic effects. So far, the focus has mainly been on the long-acting GLP-1RAs, but the risk-benefit ratio emerging from studies evaluating the effect of long-acting GLP-1RAs as adjunctive therapy to insulin therapy in patients with type 1 diabetes has been disappointing. This might be attributable to a lack of glucagonostatic effect of these long-acting GLP-1RAs in type 1 diabetes, alongside development of tachyphylaxis to GLP-1-induced retardation of gastric emptying. In contrast, the short-acting GLP-1RAs seem to have a preserved and sustained effect on glucagon secretion and gastric emptying in patients with type 1 diabetes, which could translate into effective lowering of postprandial glucose excursions; however, these observations regarding short-acting GLP-1RAs are all derived from small open-label trials and should thus be interpreted with caution. In the present paper we review the potential role of GLP-1RAs, in particular short-acting GLP-1RAs, as add-on to insulin in the treatment of type 1 diabetes.

Topics: Diabetes Mellitus, Type 1; Drug Resistance; Drug Therapy, Combination; Exenatide; Gastric Emptying; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Half-Life; Humans; Hyperglycemia; Hypoglycemia; Hypoglycemic Agents; Insulin; Peptides; Venoms

To review the use of GLP-1 agonists in patients with type 1 diabetes mellitus (T1DM).. A search using the MEDLINE database, EMBASE, and Cochrane Database was performed through March 2016 using the search terms glucagon-like peptide 1 (GLP-1) agonists, incretin, liraglutide, exenatide, albiglutide, dulaglutide, type 1 diabetes mellitus. All English-language trials that examined glycemic end points using GLP-1 agonists in humans with T1DM were included.. A total of 9 clinical trials examining the use of GLP-1 agonists in T1DM were identified. On average, hemoglobin A1C (A1C) was lower than baseline, with a maximal lowering of 0.6%. This effect was not significant when tested against a control group, with a relative decrease in A1C of 0.1% to 0.2%. In all trials examined, reported hypoglycemia was low, demonstrating no difference when compared with insulin monotherapy. Weight loss was seen in all trials, with a maximum weight loss of 6.4 kg over 24 weeks. Gastrointestinal adverse effects are potentially limiting, with a significant number of patients in trials reporting nausea.. The use of GLP-1 agonists should be considered in T1DM patients who are overweight or obese and not at glycemic goals despite aggressive insulin therapy; however, tolerability of these agents is a potential concern. Liraglutide has the strongest evidence for use and would be the agent of choice for use in overweight or obese adult patients with uncontrolled T1DM.

Topics: Blood Glucose; Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Incretins; Liraglutide; Peptides; Recombinant Fusion Proteins; Venoms

Glucagon-like peptide-1 receptor agonists (GLP-1 RAs) are commonly used in combination with insulin to manage type 2 diabetes mellitus, and four agents are currently approved for this indication: exenatide, liraglutide, dulaglutide, and albiglutide. The distinctive properties of GLP-1 RAs-potential hemoglobin A1c (A1C) reduction, weight loss, potential to reduce insulin doses, and lower hypoglycemia risk-have made these agents potential treatment options for patients with type 1 diabetes mellitus (T1DM) as well. These positive effects are due to glucose-dependent insulin secretion, reduced glucagon secretion, increased satiety, and delayed gastric emptying. Patients with T1DM are unable to suppress glucagon during meals, which contributes to postprandial hyperglycemia and may be improved with GLP-1 therapy. In this review, we evaluated the available literature on the clinical efficacy and safety of GLP-1 RAs in patients with T1DM. We conducted a search of the PubMed (1966-May 2016) and Ovid (1946-May 2016) databases. Abstracts presented at the scientific and clinical sessions of the American Diabetes Association and the American Association of Clinical Endocrinologists were also searched. The references of the published articles were also reviewed to identify additional studies appropriate for inclusion. All identified articles published in English were evaluated. Studies were included if they evaluated the clinical use or safety of GLP-1 RAs in patients with T1DM. Twelve studies were included, with four evaluating exenatide, one evaluating exenatide extended release, and seven evaluating liraglutide. Both exenatide and liraglutide showed significant reductions in hemoglobin A1C, plasma glucose concentration, body weight, and insulin doses when administered to patients with T1DM already receiving insulin therapy, without increasing the occurrence of hypoglycemia. Adverse effects were mostly gastrointestinal in nature but were mild and transient. Patients who may benefit most are those experiencing adverse effects from insulin, those not at their A1C goal but hypoglycemia prevents insulin titration, and those who may benefit from weight loss.

Topics: Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Humans; Liraglutide; Peptides; Venoms

The increased prevalence of type 2 diabetes follows the increased prevalence of obesity. Both diseases share common pathophysiological pathways; obesity is in most cases the first step, whereas diabetes is the second one. Weight gain occurs during the treatment of diabetes with drugs causing endogenous or exogenous hyperinsulinemia. Insulin and sulfonylurea are making patients more obese and more insulin resistant. Glucagon-like peptide-1 receptor agonists (GLP-1 agonists) and sodium/glucose cotransporter 2 inhibitors (SGLT2 inhibitors) are antidiabetic drugs with weight loss property. GLP-1 agonists mimic an incretin action. They release insulin after a meal during hyperglycemia and suppress glucagon. The weight loss effect is a consequence of central action increased satiety. Some of GLP-1 agonists weight loss is a result of decelerated gastric emptying rate. SGLT2 inhibitors block sodium glucose cotransporter in proximal tubule brush border and produce glucose excretion with urinary loss. Urinary glucose leak results in calories and weight loss. Even a modest weight loss has positive outcome on metabolic features of diabetic patient; such drugs have important role in treatment of type 2 diabetic patients. However, there are some still unresolved questions. The weight loss they produce is modest. Those drugs are expensive and not available to many diabetic patients, they are significantly more expensive compared to "traditional" hypoglycemic drugs. The hypoglycemic endpoint of GLP-1 agonists and SGLT2 inhibitors often requires adding another antidiabetic drug. The most radical and most effective therapy of type 2 diabetes and obesity is bariatric surgery having significant number of diabetes remission.

Topics: Anti-Obesity Agents; Bariatric Surgery; Biological Transport; Clinical Trials as Topic; Comorbidity; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Therapy, Combination; Exenatide; Gastric Emptying; Glucagon; Glucagon-Like Peptide 1; Glucose; Glycosuria; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Resistance; Insulin Secretion; Islets of Langerhans; Kidney Tubules, Proximal; Microvilli; Multicenter Studies as Topic; Obesity; Peptides; Sodium-Glucose Transporter 2; Sodium-Glucose Transporter 2 Inhibitors; Venoms; Weight Loss

Glucagon-like peptide 1 receptor (GLP-1R) agonists provide good glycemic control combined with low hypoglycemia risk and weight loss. Here, we summarize the recently published data for this therapy class, focusing on sustainability of action, use in combination with basal insulin, and the efficacy of longer acting agents currently in development. The safety profile of GLP-1R agonists is also examined.. GLP-1R agonists provide sustained efficacy and their combination with basal insulin is well tolerated, providing additional glycemic control and weight benefits compared with basal insulin alone. Data suggest that the convenience of longer acting agents may be at the expense of efficacy. Despite the initial concerns, most evidence indicates that GLP-1R agonists do not increase the risk of pancreatitis or thyroid cancer. However, the extremely low incidence of these events means further investigations are required before a causal link can be eliminated. Large-scale clinical trials investigating the long-term cardiovascular safety of this therapy class are ongoing and may also provide important insights into pancreatic and thyroid safety.. GLP-1R agonists offer sustained glycemic efficacy, weight loss benefits, and a low risk of hypoglycemia. The results of ongoing trials should help to clarify the safety of this therapy class.

Topics: Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Angiopathies; Exenatide; Female; Glucagon-Like Peptide 1; Glucagon-Like Peptides; Humans; Hypoglycemia; Hypoglycemic Agents; Immunoglobulin Fc Fragments; Insulin; Liraglutide; Male; Pancreatitis; Peptides; Randomized Controlled Trials as Topic; Recombinant Fusion Proteins; Thyroid Neoplasms; Treatment Outcome; Venoms

Despite years of research in the field of type 1 diabetes, patients with the disease remain without a therapeutic agent that can alter the underlying immune response in a clinically beneficial way. Glucagon-like peptide 1 agonist therapies have shown some promising effects in terms of positively affecting overall beta cell health and increasing beta cell mass, primarily in mouse models. The three agents of this class currently available for patients with type 2 diabetes have shown beneficial clinical effects on glucose control in this patient population. The purpose of this article is to review the preclinical and clinical data of these agents to date with a focus on the potential immunological and clinical benefits these drugs may have on patients with type 1 diabetes.

Topics: Animals; Biomarkers; Blood Glucose; C-Peptide; Clinical Trials as Topic; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Glucagon-Like Peptide 1; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin-Secreting Cells; Liraglutide; Peptides; Venoms

The presence of cardiovascular disease (CVD) in Type 1 diabetes largely impairs life expectancy. Hyperglycemia leading to an increase in oxidative stress is considered to be the key pathophysiological factor of both micro- and macrovascular complications. In Type 1 diabetes, the presence of coronary calcifications is also related to coronary artery disease. Cardiac autonomic neuropathy, which significantly impairs myocardial function and blood flow, also enhances cardiac abnormalities. Also hypoglycemic episodes are considered to adversely influence cardiac performance. Intensive insulin therapy has been demonstrated to reduce the occurrence and progression of both micro- and macrovascular complications. This has been evidenced by the Diabetes Control and Complications Trial (DCCT) / Epidemiology of Diabetes Interventions and Complications (EDIC) study. The concept of a metabolic memory emerged based on the results of the study, which established that intensified insulin therapy is the standard of treatment of Type 1 diabetes. Future therapies may also include glucagon-like peptide (GLP)-based treatment therapies. Pilot studies with GLP-1-analogues have been shown to reduce insulin requirements.

Topics: Antihypertensive Agents; Autonomic Nervous System Diseases; Cardiovascular Diseases; Diabetes Mellitus, Type 1; Diabetic Angiopathies; Diabetic Neuropathies; Drug Therapy, Combination; Exenatide; Exercise Therapy; Glucagon-Like Peptide 1; Humans; Hydroxymethylglutaryl-CoA Reductase Inhibitors; Hypoglycemia; Hypoglycemic Agents; Insulin; Oxidative Stress; Peptides; Pyrazines; Sitagliptin Phosphate; Triazoles; Venoms

Type 1 diabetes is an autoimmune disease that gradually destructs insulin-producing beta cells. Over the years, clinicians' knowledge regarding the immunopathogenesis of this disease has greatly increased. Immunotherapies that can change the course of immune-mediated destruction and preserve and possibly regenerate the pancreatic beta cells seem to be promising in preclinical trials but so far have been unsuccessful in human studies. This article reviews the important immune interventions for type 1 diabetes that have been tried so far targeting the different stages of disease development and provides an insight into what the future might hold.

Topics: Abatacept; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Antibodies, Monoclonal, Murine-Derived; Antilymphocyte Serum; Azathioprine; Basiliximab; Chaperonin 60; Cyclosporine; Daclizumab; Diabetes Mellitus, Type 1; Diet; Etanercept; Exenatide; Fatty Acids, Unsaturated; Glutamate Decarboxylase; Humans; Hypoglycemic Agents; Immunoconjugates; Immunoglobulin G; Immunosuppressive Agents; Insulin; Interferon-alpha; Interleukin 1 Receptor Antagonist Protein; Islets of Langerhans Transplantation; Niacinamide; Peptide Fragments; Peptides; Primary Prevention; Pyrazines; Receptors, Tumor Necrosis Factor; Recombinant Fusion Proteins; Rituximab; Secondary Prevention; Sitagliptin Phosphate; Tertiary Prevention; Triazoles; Venoms; Vitamin D; Vitamins

Insulin administration is the primary therapy for type 1 diabetes mellitus (T1DM). Current available insulin therapies do not successfully enable children with T1DM to reach glycemic goals without side effects such as hypoglycemia and weight gain. Pramlintide is a synthetic analog of human amylin that acts in conjunction with insulin to delay gastric emptying and inhibit the release of glucagon and is indicated for use in patients with type 1 and type 2 diabetes. Recent studies in adult patients have examined the role of glucagon-like peptide 1 (GLP-1) and agents that bind to its receptor in type 1 diabetes. It is hypothesized that a major component of the glycemic effect is attributable to the known action of GLP-1 to delay gastric emptying and to inhibit glucagon secretion. Further studies with the use of amylin analogs and long-acting GLP-1 agonists as congeners with insulin in T1DM are indicated in children. In recent years, our better understanding of the pathophysiology of diabetes has led to the development of new therapies for diabetes. This article reviews the potential use of these newer pharmacologic agents as adjunctive therapy in T1DM in children and adolescents.

Topics: Amyloid; Blood Glucose; Body Weight; Child; Diabetes Mellitus, Type 1; Drug Therapy, Combination; Exenatide; Gastric Emptying; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Insulin; Islet Amyloid Polypeptide; Pancreas; Peptides; Treatment Outcome; Venoms

The purpose of this study was to review studies reporting on quality of life and treatment satisfaction of patients with diabetes mellitus being treated with long-acting insulin analogues.. A systematic literature search was made of trials published between January 1, 2000 and June 28, 2007. Retrieved studies were analysed, using predefined inclusion criteria as well as methodological and quality aspects.. Twelve studies were included, all of them dealing with insulin glargine as the trial drug or for comparison. With regard to treatment satisfaction, insulin glargine was superior in one head-to-head comparison with NPH (neutral protamine Hagedorn) and one head-to-head comparison with NPH as an add-on to oral glimepiride. There was no difference in comparisons with continuous subcutaneous insulin infusion (CSII), insulin aspart or exenatide. Regarding health related quality of life (HRQoL), insulin glargine was shown to be superior to rosiglitazone as an add-on to metformin and sulfonylurea. Again, there were no differences in comparisons with NPH, CSII or exenatide.. There are only a limited number of high quality studies showing that insulin glargine is superior regarding treatment satisfaction and HRQoL of patients with diabetes mellitus. There are fewer publications with good evidence of patient-reported outcomes than those reporting well-established outcomes using HbA1c levels or the incidence of hypoglycaemia.

Topics: Clinical Trials as Topic; Diabetes Mellitus, Type 1; Exenatide; Humans; Insulin; Insulin Glargine; Insulin Infusion Systems; Insulin, Isophane; Insulin, Long-Acting; Patient Satisfaction; Peptides; Quality of Life; Venoms

GLP-1 (glucagon-like peptide-1) is a peptide hormone secreted from endocrine cells in the intestinal mucosa in response to meals. The major effects of GLP-1 are to increase glucose-induced insulin secretion and reduce glucagon release, but GLP-1 also inhibits gastric emptying rate and reduces appetite and bodyweight in obese subjects. In vivo studies using animal models of type 2 diabetes and in vitro studies using human islet cells have suggested that GLP-1 or GLP-1 analogues are also able to increase beta-cell mass, but in animal models of type 1 diabetes, there is much less evidence for a beta-cell preserving effect. This review summarizes the present knowledge of GLP-1 and its analogues regarding its role as a possible treatment in patients with type 1 diabetes. The studies that address the effect of GLP-1 and GLP-1 analogues on beta-cell mass in both type 2 and type 1 diabetes, as well as the potential of GLP-1 as an adjuvant therapy in islet cell transplantation, will be reviewed. Suggestions for future studies of GLP-1 treatment in type 1 diabetes may include early treatment in order to preserve beta-cell mass and prolong the remission period, but should also take a potential insulin sparing effect and changes in the risk of hypoglycemia into account.

Topics: Animals; Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents; Peptides; Receptors, Glucagon; Venoms

The transplantation of human islets has come a long way since the first diabetic person became insulin independent in 1989. The advent of a steroid-free immunosuppressive protocol in 2000 resulted in most recipients becoming insulin independent and remaining so for a year. However, beta-cell function declines thereafter. Strategies to enhance the islet mass transplanted and preserve beta-cell function are necessary.. This review covers recent advances in determining the selection of appropriate enzymes for islet isolation, use of pancreases from heart-dead donors and techniques for predicting the functional capacity of isolated islets prior to transplantation. Changing the transplantation site away from the liver, where many islets are destroyed by an inflammatory process, is reviewed, and the possibility of seeding islets onto three-dimensional biodegradable scaffolds discussed. A method of preventing apoptosis of the beta cells prior to transplantation is detailed, as is the beneficial effect of using exenatide, after transplantation. Novel techniques to image islets are discussed, and this requires the labelling of the islets prior to implantation. Enhancing the vascularization of islets is shown to enhance functional outcomes. Encapsulation of the islets should obviate the need for using antirejection drugs, and it may be possible to expand beta cells in vitro.. The above strategies are likely to enhance the outcomes of clinical islet transplants.

Topics: Animals; Apoptosis; Cell Proliferation; Cells, Cultured; Collagenases; Diabetes Mellitus, Type 1; Exenatide; Graft Rejection; Graft Survival; Humans; Immunosuppressive Agents; Insulin-Secreting Cells; Islets of Langerhans; Islets of Langerhans Transplantation; Neovascularization, Physiologic; Peptides; Staining and Labeling; Thermolysin; Tissue Donors; Tissue Scaffolds; Venoms

Topics: Administration, Inhalation; Amyloid; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Drug Administration Schedule; Drug Delivery Systems; Exenatide; Family Practice; Female; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Islet Amyloid Polypeptide; Male; Peptides; Prognosis; Pyrazines; Randomized Controlled Trials as Topic; Risk Assessment; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Venoms

Learn how the newest weapons in the arsenal of antihyperglycemic drugs can help your patient manage her disease.

Topics: Amyloid; Benzamides; Biguanides; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Monitoring; Exenatide; Glycated Hemoglobin; Glycoside Hydrolase Inhibitors; Humans; Hypoglycemic Agents; Insulin; Insulin Resistance; Islet Amyloid Polypeptide; Patient Selection; Peptides; Sulfonylurea Compounds; Thiazolidinediones; Venoms

A systematic review was undertaken to analyse pharmaco-economic issues in diabetes, with evidence selected on the basis of relevance and immediacy. Pharmaco-economics in diabetes primarily relates to making choices about antidiabetic pharmaceuticals, and this is being influenced by global trends. Trends include increasing numbers of patients with diabetes, with increasing costs of caring for people with diabetes, and an ever-present focus on the costs of pharmaceuticals which are predicted to increase as the pace of development of new medications parallels the increasing incidence of the condition. These developments have influenced the demand for health care in diabetes in the last decade, and will continue to determine this in the coming decade. Recent national experiences are cited to illustrate current issues and to focus specifically upon the challenges facing a raft of new diabetes treatment options now hitting the marketplace, although supported by fewer completed long-term trials. It can be anticipated that these newer agents will be appraised for their cost-effectiveness or value for money. Economic analyses for some of the new technologies are summarized; in general, the peer-reviewed publications using well-accepted and validated models have reported that these technologies are cost-effective. Endorsement of any technology in a national setting is not awarded simply because the incremental cost-effectiveness ratio (ICER) falls below the threshold regarded as value for money. In most national observations the reviewers expressed concerns about assumptions used in economic modelling which resulted in the ICERs being deemed optimistic at best, generally highly uncertain, and resulting in the cost-effectiveness appearing better than it really would be in clinical practice. This has often led to the authorities concluding that the price advantage of new technologies over comparators could not be justified, essentially leading to restrictions in use compared to their licence. In general, a paucity of robust evidence on longer-term outcome data together with a lack of health-related quality of life (HRQOL) data collected in a reliable manner in appropriate patients and amenable to utility (and hence quality adjusted life year or QALY) estimation have resulted in problems for these new drugs at the so-called fourth (cost-effectiveness) hurdle. In the light of these findings, the implications for generating credible fit-for-purpose cost-effectiveness an

Topics: Cost-Benefit Analysis; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Economics, Pharmaceutical; Exenatide; Humans; Hypoglycemic Agents; Insulin; Insulin Detemir; Insulin, Long-Acting; Peptides; Prediabetic State; Venoms

Insulin is not the only hormone that regulates plasma glucose levels. Glucagon-like peptide 1 (GLP-1), produced in the small intestine, and amylin, produced by beta cells in the pancreas, also have glucose-lowering effects. Synthetic analogues of these hormones are now available for clinical use.

Topics: Amyloid; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Peptides; Venoms

Topics: Blood Glucose; Cell Differentiation; Cell Division; Diabetes Mellitus, Type 1; Exenatide; Genetic Therapy; Glucagon; Glucagon-Like Peptide 1; Homeostasis; Humans; Immunotherapy; Islets of Langerhans; Islets of Langerhans Transplantation; Peptide Fragments; Peptides; Protein Precursors; Stem Cells; Venoms

Amylin Pharmaceuticals Inc and Eli Lilly & Co are co-developing exenatide (AC-2993; synthetic exendin-4), a 39-amino acid, glucagon-like peptide-1 agonist derived from the venom of the Gila monster lizard (Heloderma suspectum) as a potential injectable treatment for type 2 diabetes. The first phase III trial (exenatide as a monotherapy) was initiated in December 2001. In January 2002 the second phase III trial, of exenatide in conjunction with sulfonylureas, was initiated and in March 2002, Amylin initiated the third phase III trial, of exenatide in combination with metformin and sulfonylureas.

Topics: Animals; Anti-Obesity Agents; Clinical Trials, Phase I as Topic; Clinical Trials, Phase II as Topic; Clinical Trials, Phase III as Topic; Contraindications; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Humans; Hypoglycemic Agents; Obesity; Peptides; Structure-Activity Relationship; Venoms

Recent availability of expanded treatment options for both type 1 and type 2 diabetes has not translated into easier and significantly better glycemic and metabolic management. Patients with type 1 diabetes continue to experience increased risk of hypoglycemic episodes and progressive weight gain resulting from intensive insulin treatment, despite the recent availability of a variety of insulin analog. Given the progressive nature of the disease, most patients with type 2 diabetes inevitably proceed from oral agent monotherapy to combination therapy and, ultimately, require exogenous insulin replacement. Insulin therapy in type 2 diabetes is also accompanied by untoward weight gain. Both type 1 and type 2 diabetes continue to be characterized by marked postprandial hyperglycemia. Two hormones still in development are candidates for pharmacologic intervention, have novel modes of action (some centrally mediated), and show great promise in addressing some of the unmet needs of current diabetes management. Pramlintide acetate, an analog of the beta cell hormone amylin and the first non-insulin related therapeutic modality for type 1 and type 2 diabetic patients with severe beta cell failure, may be useful as adjunctive therapy to insulin. The principal anti-diabetic effects of pramlintide arise from interactions via its cognate receptors located in the central nervous system resulting in postprandial glucagon suppression, modulation of nutrient absorption rate, and reduction of food intake. Another polypeptide hormone, exendin-4, exerts at least some of its pharmacologic actions as an agonist at the glucagon-like peptide-1 (GLP-1) receptor. GLP-1 and related compounds exhibit multiple modes of action, the most notable being a glucose-dependent insulinotropic effects and the potential to preserve or improve the beta-cell function. The latter effect could potentially halt or delay the progressive deterioration of the diabetic state associated with type 2 diabetes. Physiologically, both amylin and glucagon-like peptide (GLP)-1, along with insulin, are involved in a coordinated and concerted interplay between hormones acting both centrally and peripherally to provide meticulous control over the rate of appearance of exogenous and endogenous glucose and to match that rate to the rate of glucose disappearance. Both hormones are deficient in diabetes. Therapies directed at restoring this complex physiology have the potential to facilitate glucose control and thus m

Topics: Amyloid; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Drug Design; Exenatide; Glucagon; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Peptide Fragments; Peptides; Postprandial Period; Protein Precursors; Venoms

To evaluate the efficacy of the short-acting glucagon-like peptide-1 receptor agonist, exenatide, added to insulin therapy in type 1 diabetes on bone mineral density and bone turnover markers.. In a randomized, double-blinded, parallel-group trial, 108 individuals with type 1 diabetes aged 18 years or older on basal-bolus therapy with HbA1c 59-88 mmol/mol (7.5%-10.0%) and body mass index of more than 22.0 kg/m. Exenatide elicited a body weight reduction of 4.4 kg compared with placebo, but no between-group differences in bone mineral density, as assessed by whole-body, hip, lumbar, and forearm dual-energy X-ray absorptiometry following 26 weeks of treatment, were observed. Fasting plasma levels of C-terminal telopeptides of type I collagen, a marker of bone resorption, and amino-terminal propeptide of type I procollagen, a marker of bone formation, were unchanged by exenatide compared with placebo after 26 weeks.. Despite an exenatide-induced body weight reduction, no changes in bone metabolism were observed with exenatide added to insulin therapy in type 1 diabetes after 26 weeks.

Topics: Adolescent; Blood Glucose; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Venoms

To investigate the effect of adding the short-acting glucagon-like peptide 1 receptor agonist (GLP-1RA) exenatide to insulin treatment on markers of cardiovascular risk in type 1 diabetes.. Exenatide changed total fat mass by -2.6 kg (95% confidence interval [CI] -3.6; -1.6; P < 0.0001) and lean body mass by -1.1 kg (95% CI -1.9; -0.4; P = 0.01) compared with placebo, as assessed by dual-energy X-ray absorptiometry. Fat mass reductions were similar for central and peripheral fat mass. Exenatide did not change levels of interleukin-2 or -6; tumour necrosis factor-α; C-reactive protein; N-terminal prohormone of brain natriuretic peptide; or 8-oxo-7,8-dihydroguanosine (RNA oxidation marker) and 8-oxo-7,8-dihydro-2'-deoxyguanosine (DNA oxidation marker).. Exenatide added to insulin therapy in type 1 diabetes for 26 weeks resulted in body weight loss primarily from fat mass reduction, but had no effect on biomarkers of cardiovascular disease risk.

Topics: Adolescent; Adult; Biomarkers; Cardiovascular Diseases; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Double-Blind Method; Exenatide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Venoms

To test whether a long-acting GLP-1 receptor agonist would improve glucose control in patients with type 1 diabetes (T1D) and to determine whether the presence of residual beta cell function would affect the response. In addition, we sought to determine whether the drug would affect beta cell function.. We performed a randomized placebo-controlled trial of exenatide extended release (ER) in participants with T1D with and without detectable levels of C-peptide. Seventy-nine participants were randomized to exenatide ER 2 mcg weekly, or placebo, stratified by the presence or absence of detectable C-peptide levels. The primary outcome was the difference in glycated haemoglobin (HbA1c) levels at 24 weeks. Participants were followed for another 6 months off study drug.. At week 24, the time of the primary outcome, the least squares (LS) mean HbA1c level was 7.76% (95% confidence interval [CI] 7.42, 8.10) in the exenatide ER group versus 8.0% (95% CI 7.64, 8.35) in the placebo group (P = 0.08). At week 12 the LS mean HbA1c levels were 7.71% (95% CI 7.37, 8.05) in the exenatide ER group versus 8.05% (95% CI 7.7, 8.4) in the placebo group (P = 0.01). The improvement at week 12 was driven mainly by those with detectable levels of C-peptide. Those treated with exenatide ER lost weight at 12 and 24 weeks compared to those treated with placebo (P <0.001 and P = 0.007). The total insulin dose was lower, but not when corrected for body weight, and was not affected by residual insulin production. Adverse events were more frequent with exenatide ER, but hypoglycaemia was not increased.. Treatment with exenatide ER may have short-term benefits in some individuals with T1D who are overweight or who have detectable levels of C-peptide, but short-term improvements were not sustained.

Topics: Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Insulin; Venoms

To investigate the effect of add-on exenatide to insulin on glycemic excursion and the counter-regulatory hormone in response to hypoglycemia in patients with type 1 diabetes mellitus (T1DM).. 30 patients with T1DM were recruited and randomly assigned to exenatide + insulin-treated group (group 1, n = 15) or insulin-only-treated group (group 2, n = 15) for 4 weeks. All patients had continuous glucose monitor system (CGMS) applied at before (week-0) and after (week-4) treatment to evaluate the glycemic variability. All patients had an arginine-stimulated test at before and after treatment. Six patients from each group also had hypoglycemic clamp test to assess counter-regulatory hormone level.. Patients in the exenatide group had significant reductions in body weight, body mass index (BMI), total insulin dose, bolus insulin dose, fructosamine, and glycemic excursion after 4 weeks' treatment. Compared with patients in group 2, the mean amplitude of glycemic excursion (MAGE) and coefficient of variation (CV) of exenatide group decreased significantly. Similarly, a significant decrease of glucagon (GLC) in the arginine-stimulated test was found in group 1. No significant changes of GLC, growth hormone (GH), cortisol (COR), epinephrine (E), and norepinephrine (NE) were found in both groups during hypoglycemia clamp test. However, patients who had residual islet function in group 1 showed an upward trend of basic C-peptide (C-P) and GLC during the hypoglycemia period.. Although exenatide could inhibit glucagon secretion during euglycemia or hyperglycemia in patients with T1DM, it has no effect on GLC and counter-regulatory hormones during hypoglycemia clamp in patients with no functional residual islet test.

Topics: Adolescent; Adult; Biomarkers; Blood Glucose; Case-Control Studies; Diabetes Mellitus, Type 1; Drug Therapy, Combination; Exenatide; Female; Follow-Up Studies; Glucagon; Glycated Hemoglobin; Glycemic Index; Humans; Hypoglycemia; Hypoglycemic Agents; Incidence; Insulin; Male; Middle Aged; Peptides; Prognosis; Venoms; Young Adult

Persons with type 1 diabetes require intensive insulin therapy to achieve glycaemic control, but side effects, including hypoglycaemia and weight gain, may reduce treatment compliance. We hypothesise that add-on treatment of the short-acting glucagon-like peptide-1 receptor agonist, exenatide, to insulin therapy in persons with type 1 diabetes will reduce insulin requirements, glycaemic excursions and body weight and improve glycaemic control without increasing the risk of hypoglycaemia. The present article describes a protocol developed to test this hypothesis.. One-hundred adult persons with type 1 diabetes for more than 1 year, insufficient glycaemic control (glycated haemoglobin A1c (HbA1c) between 58 and 86 mmol/mol) and body mass index >22.0 kg/m. The study is approved by the Danish Medicines Agency, the Regional Scientific Ethics Committee of the Capital Region of Denmark and the Data Protection Agency. The study will be carried out under the surveillance and guidance of the good clinical practice (GCP) unit at Copenhagen University Hospital Bispebjerg in accordance with the ICH-GCP guidelines and the Helsinki Declaration. Positive, negative as well as inconclusive results will be sought disseminated at scientific meetings and in international peer-reviewed scientific journals.. NCT03017352.

Topics: Blood Glucose Self-Monitoring; Denmark; Diabetes Mellitus, Type 1; Double-Blind Method; Drug Administration Schedule; Drug Therapy, Combination; Exenatide; Female; Glycated Hemoglobin; Humans; Hypoglycemia; Hypoglycemic Agents; Insulin; Male; Meals; Overweight; Quality of Life; Randomized Controlled Trials as Topic

OBJECTIVE Glucagon-like peptide 1 (GLP-1) is an incretin hormone that is released from the gastrointestinal tract. Treatment with GLP-1 analogs has proven to be of clinical use for patients with type 2 diabetes. Patients with type 1 diabetes, particularly those with residual β-cell function, may also respond to treatment, but the acute metabolic effects of GLP-1 analogs on these patients in reaction to both oral and intravenous glucose challenges are not well understood. RESEARCH DESIGN AND METHODS Seventeen patients with type 1 diabetes, half of whom had residual insulin production, underwent two mixed-meal tolerance tests (MMTTs) and two intravenous glucose tolerance tests (IVGTTs), with and without pretreatment with exenatide. No exogenous bolus insulin was administered for the studies. Glucose excursions, insulin secretion rates (ISRs), and levels of glucagon, endogenous GLP-1, and gastric inhibitory polypeptide were measured after the meal or glucose loads. RESULTS During the MMTT, glucose levels were suppressed with exenatide in patients with or without residual insulin production (P = 0.0003). Exenatide treatment did not change the absolute ISR, but the ISR to glucose levels were increased (P = 0.0078). Gastric emptying was delayed (P = 0.0017), and glucagon was suppressed (P = 0.0015). None of these hormonal or glucose changes were detected during the IVGTT with exenatide administration. CONCLUSIONS Exenatide showed a significant antidiabetogenic effect prior to an oral meal in patients with type 1 diabetes involving glucagon suppression and gastric emptying, while preserving increased insulin secretion. GLP-1 analogs may be useful as an adjunctive treatment in type 1 diabetes.

Topics: Administration, Intravenous; Administration, Oral; Adolescent; Adult; Diabetes Mellitus, Type 1; Exenatide; Female; Gastric Emptying; Gastric Inhibitory Polypeptide; Glucagon; Glucagon-Like Peptide 1; Glucose; Glucose Tolerance Test; Humans; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Male; Middle Aged; Peptides; Venoms; Young Adult

Exenatide treatment improves glycemia in adults with type 2 diabetes and has been shown to reduce postprandial hyperglycemia in adolescents with type 1 diabetes. We studied the effects of exenatide on glucose homeostasis in adults with long-standing type 1 diabetes.. Fourteen patients with type 1 diabetes participated in a crossover study of 6 months' duration on exenatide (10 μg four times a day) and 6 months off exenatide. We assessed changes in fasting and postprandial blood glucose and changes in insulin sensitivity before and after each study period.. High-dose exenatide therapy reduced postprandial blood glucose but was associated with higher fasting glucose concentrations without net changes in hemoglobin A1c. Exenatide increased insulin sensitivity beyond the effects expected as a result of weight reduction.. Exenatide is a promising adjunctive agent to insulin therapy because of its beneficial effects on postprandial blood glucose and insulin sensitivity in patients with type 1 diabetes.

Topics: Adult; Blood Glucose; Body Weight; Cross-Over Studies; Diabetes Mellitus, Type 1; Drug Administration Schedule; Exenatide; Fasting; Female; Glycated Hemoglobin; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin Resistance; Male; Middle Aged; Peptides; Postprandial Period; Venoms

Postprandial hyperglycemia due to paradoxical hyperglucagonemia is a major challenge of diabetes treatment despite the use of the artificial pancreas. We postulated that adjunctive therapy with pramlintide or exenatide would attenuate hyperglycemia in the postprandial phase through glucagon suppression, thereby optimizing the functioning of the closed-loop (CL) system. Subjects with type 1 diabetes (T1DM) on insulin pump therapy were recruited to participate in a 27-hour hospitalized admission on 3 occasions (2-4 weeks apart) and placed on the insulin delivery via CL system in random order to receive (1) insulin alone (control), (2) exenatide 2.5 µg + insulin, (3) pramlintide 30 µg + insulin. Medications were given prior to lunch and dinner, which was a standardized meal of 60 grams of carbohydrates. Insulin delivery was as per the ePID algorithm via the Medtronic CL system and continuous subcutaneous glucose monitoring via Medtronic Sof-sensors. Ten subjects age 23 ± 1 years with a HbA1c of 7.29 ± 0.3% (56 ± 1 mmol/mol) and duration of T1DM 10.6 ± 2.0 years participated in the 3-part study. Exenatide was found to be significantly better in attenuating postprandial hyperglycemia as compared to insulin monotherapy (P < .03) and pramlintide (P > .05). Glucagon suppression was statistically significant with exenatide (P < .03) as compared to pramlintide. Insulin requirements were lower with adjunctive therapy, but statistically insignificant. Insulin monotherapy results in postprandial hyperglycemia in T1DM in the CL setting and adjunctive therapy with exenatide reduces postprandial hyperglycemia effectively and should be considered as adjunctive therapy in T1DM.

Topics: Adolescent; Adult; Algorithms; Blood Glucose; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Infusion Systems; Islet Amyloid Polypeptide; Male; Pancreas, Artificial; Peptides; Venoms; Young Adult

Incretin based therapies are known to have pleotropic benefits in type 2 diabetes but have not been studied in new onset type 1 diabetes. In this randomized, open label study, we investigated the effect of the addition of exenatide or sitagliptin to insulin in patients with new onset type 1 diabetes. Our data suggest that the addition of exenatide and sitagliptin decreases insulin requirements without increasing endogenous insulin production and hypoglycemic events.

Topics: Adult; Diabetes Mellitus, Type 1; Exenatide; Female; Humans; Insulin; Male; Peptides; Pyrazines; Sitagliptin Phosphate; Treatment Outcome; Triazoles; Venoms; Young Adult

Exenatide improves postprandial glycemic excursions in type 2 diabetes. Exenatide could benefit type 1 diabetes as well. We aimed to determine an effective and safe glucose-lowering adjuvant exenatide dose in adolescents with type 1 diabetes.. Eight subjects completed a three-part double-blinded randomized controlled study of premeal exenatide. Two doses of exenatide (1.25 and 2.5 microg) were compared with insulin monotherapy. Prandial insulin dose was reduced by 20%. Gastric emptying and hormones were analyzed for 300 min postmeal.. Treatment with both doses of exenatide versus insulin monotherapy significantly reduced glucose excursions over 300 min (P < 0.0001). Exenatide administration failed to suppress glucagon but delayed gastric emptying (P < 0.004).. Adjunctive exenatide therapy reduces postprandial hyperglycemia in adolescents with type 1 diabetes. This reduction in glucose excursion occurs despite reduction in insulin dose. We suggest that exenatide has therapeutic potential as adjunctive therapy in type 1 diabetes.

Topics: Adolescent; Adult; Blood Glucose; Child; Diabetes Mellitus, Type 1; Double-Blind Method; Drug Administration Schedule; Exenatide; Female; Humans; Hypoglycemic Agents; Male; Peptides; Postprandial Period; Venoms; Young Adult

Glucagon-like peptide-1 (GLP-1) is a potent insulinotropic peptide expressed in the gut and brain, which is secreted in response to food intake. The levels of GLP-1 within the brain have been related to the activity of the hypothalamic-pituitary-adrenal (HPA) axis, and hence, this peptide might mediate some responses to stress. Nevertheless, there is little information regarding the effects of circulating GLP-1 on the neuroendocrine control of HPA activity. Here, we have studied the response of corticoadrenal steroids to the peripheral administration of GLP-1 (7-36)-amide and related peptides [exendin (Ex)-3, Ex-4, and Ex-4(3-39)] in rats, mice, and humans. GLP-1 increases circulating corticosterone levels in a time-dependent manner, both in conscious and anaesthetized rats, and it has also increased aldosterone levels. Moreover, GLP-1 augmented cortisol levels in healthy subjects and diabetes mellitus (DM)-1 patients. The effects of GLP-1/Ex-4 on the HPA axis are very consistent after distinct means of administration (intracerebroventricular, iv, and ip), irrespective of the metabolic state of the animals (fasting or fed ad libitum), and they were reproduced by different peptides in this family, independent of glycaemic changes and their insulinotropic properties. Indeed, these effects were also observed in diabetic subjects (DM-1 patients) and in the DM-1 streptozotocin-rat or DM-2 muscle IGF-I receptor-lysine-arginine transgenic mouse animal models. The mechanisms whereby circulating GLP-1 activates the HPA axis remain to be elucidated, although an increase in ACTH after Ex-4 and GLP-1 administration implicates the central nervous system or a direct effect on the pituitary. Together, these findings suggest that GLP-1 may play an important role in regulating the HPA axis.

Topics: Adrenocorticotropic Hormone; Adult; Animals; Corticosterone; Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide 1; Humans; Hypothalamo-Hypophyseal System; Injections, Intraperitoneal; Injections, Intravenous; Male; Mice; Mice, Transgenic; Peptides; Pituitary-Adrenal System; Rats; Rats, Sprague-Dawley; Venoms; Young Adult

In patients with long-standing type 1 diabetes, we investigated whether improved beta-cell function can be achieved by combining intensive insulin therapy with agents that may 1) promote beta-cell growth and/or limit beta-cell apoptosis and 2) weaken the anti-beta-cell autoimmunity.. For this study, 20 individuals (mean age 39.5 +/- 11.1 years) with long-standing type 1 diabetes (21.3 +/- 10.7 years) were enrolled in this prospective open-label crossover trial. After achieving optimal blood glucose control, 16 subjects were randomized to exenatide with or without daclizumab. Endogenous insulin production was determined by repeatedly measuring serum C-peptide.. In 85% of individuals with long-standing type 1 diabetes who were screened for participation in this trial, C-peptide levels >or=0.05 ng/ml (0.02 nmol/l) were found. Residual beta-cells responded to physiological (mixed-meal) and pharmacological (arginine) stimuli. During exenatide treatment, patients lost 4.1 +/- 2.9 kg body wt and insulin requirements declined significantly (total daily dose on exenatide 0.48 +/- 0.11 vs. 0.55 +/- 0.13 units x kg(-1) x day(-1) without exenatide; P = 0.0062). No signs of further activation of the underlying autoimmune disease were observed. Exenatide delayed gastric emptying, suppressed endogenous incretin levels, but did not increase C-peptide secretion.. In long-standing type 1 diabetes, which remains an active autoimmune disease even decades after its onset, surviving beta-cells secrete insulin in a physiologically regulated manner. However, the combination of intensified insulin therapy, exenatide, and daclizumab did not induce improved function of these remaining beta-cells.

Topics: Adult; Age of Onset; Antibodies, Monoclonal; Antibodies, Monoclonal, Humanized; Autoimmunity; Cross-Over Studies; Daclizumab; Diabetes Mellitus, Type 1; Drug Therapy, Combination; Exenatide; Female; Glycated Hemoglobin; HLA-DR Antigens; HLA-DRB1 Chains; Humans; Hypoglycemic Agents; Immunoglobulin G; Immunosuppressive Agents; Insulin; Insulin-Secreting Cells; Male; Peptides; Research Design; Surveys and Questionnaires; United States; Venoms; Young Adult

The initial success of islet transplantation (ITx) is followed by graft dysfunction (GDF) and insulin reintroduction. Exenatide, a GLP-1 agonist, increases insulin and decreases glucagon secretion and has potential for beta-cell regeneration. To improve functional islet mass, exenatide treatment was given to ITx recipients with GDF. The objective of this study was to assess metabolic and hormonal effects of exenatide in GDF. In this prospective, single-arm, nonrandomized study, 11 type 1 diabetes recipients of ITx with GDF had HbA1c, weight, insulin requirements, and 5-h mixed meal tolerance test (MMTT; with/without exenatide given before test) at baseline, 3, 6, and 12 months after initiating exenatide treatment. Baseline MMTT showed postprandial hyperglycemia and hyperglucagonemia. Daily exenatide treatment resulted in improved glucose, increased amylin/insulin ratio, and decreased proinsulin/insulin ratio as assessed by MMTT. Glucagon responses remained unchanged. Exenatide administration 1 h before MMTT showed decreased glucagon and glucose at 0 min and attenuation in their postprandial rise. Time-to-peak glucose was delayed, followed by insulin, proinsulin, amylin, and C-peptide, indicating glucose-driven insulin secretion. Five subjects completed 12-month follow-up. Glucose and glucagon suppression responses after MMTT with exenatide were no longer observed. Retrospective 3-month analysis of these subjects revealed higher and sustained glucagon levels that did not suppress as profoundly with exenatide administration, associated with higher glucose levels and increased C-peptide responses. In conclusion, Exenatide suppresses the abnormal postprandial hyperglucagonemia and hyperglycemia observed in GDF. Changes in amylin and proinsulin secretion may reflect more efficient insulin processing. Different degrees of responsiveness to exenatide were identified. These may help guide the clinical management of ITx recipients.

Topics: Adult; Amyloid; Area Under Curve; C-Peptide; Demography; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon; Glucose; Humans; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin Secretion; Islet Amyloid Polypeptide; Islets of Langerhans; Islets of Langerhans Transplantation; Male; Middle Aged; Peptides; Primary Graft Dysfunction; Prospective Studies; Transplantation, Homologous; Venoms

This prospective phase 1/2 trial investigated the safety and reproducibility of allogeneic islet transplantation (Tx) in type I diabetic (T1DM) patients and tested a strategy to achieve insulin-independence with lower islet mass. Ten C-peptide negative T1DM subjects with hypoglycemic unawareness received 1-3 intraportal allogeneic islet Tx and were followed for 15 months. Four subjects (Group 1) received the Edmonton immunosuppression regimen (daclizumab, sirolimus, tacrolimus). Six subjects (Group 2) received the University of Illinois protocol (etanercept, exenatide and the Edmonton regimen). All subjects became insulin- independent. Group 1 received a mean total number of islets (EIN) of 1460 080 +/- 418 330 in 2 (n = 2) or 3 (n = 2) Tx, whereas Group 2 became insulin- independent after 1 Tx (537 495 +/- 190 968 EIN, p = 0.028). All Group 1 subjects remained insulin free through the follow-up. Two Group 2 subjects resumed insulin: one after immunosuppression reduction during an infectious complication, the other with exenatide intolerance. HbA1c reached normal range in both groups (6.5 +/- 0.6 at baseline to 5.6 +/- 0.5 after 2-3 Tx in Group 1 vs. 7.8 +/- 1.1 to 5.8 +/- 0.3 after 1 Tx in Group 2). HYPO scores markedly decreased in both groups. Combined treatment of etanercept and exenatide improves islet graft function and facilitates achievement of insulin-independence with less islets.

Topics: Clinical Protocols; Diabetes Mellitus, Type 1; Etanercept; Exenatide; Humans; Hypoglycemic Agents; Immunoglobulin G; Immunosuppressive Agents; Islets of Langerhans Transplantation; Peptides; Prospective Studies; Receptors, Tumor Necrosis Factor; Venoms

Islet transplantation can reduce or eliminate the need for insulin in patients with type 1 diabetes. Exenatide is a long acting analogue of Glucagon-like peptide-1 (GLP-1) that augments glucose induced insulin secretion, and may increase beta cell mass. We evaluated the effect of exenatide on insulin secretion after islet transplantation.. Eleven C-peptide positive islet cell recipients with elevated glucose levels were treated with exenatide for three months. Response was assessed by insulin requirements, meal tolerance tests, and hyperglycemic glucose clamps.. Ten patients responded to exenatide. Two patients who had not restarted insulin achieved good glycemic control and one patient who had received 5500 IE/kg in first islet infusion was able to stop insulin. Seven other patients decreased their insulin dose by 39% on exenatide. Hyperglycemic clamp studies showed a rise in second phase insulin release (before exenatide: 246+/-88 pM; during exenatide: 644+/-294 pM, P<0.01). Meal tolerance studies before and one month after stopping exenatide did not show a difference in glucose or C-peptide values. Nausea and vomiting were the major side effects.. Exenatide stimulates insulin secretion in islet transplant recipients. It reduces insulin dose in some patients and may delay the need to resume insulin in others. We did not find any evidence of a trophic effect on islets.

Topics: Adult; Blood Glucose; Diabetes Mellitus, Type 1; Dose-Response Relationship, Drug; Exenatide; Female; Glucose Clamp Technique; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin; Islets of Langerhans Transplantation; Male; Middle Aged; Peptides; Venoms

Exendin-4 is a reptilian peptide that activates the mammalian receptor for truncated glucagon-like peptide 1 (tGLP-1) with relatively prolonged actions. Exendin-4 and tGLP-1 can reduce blood glucose levels by stimulating insulin secretion, inhibiting glucagon secretion, and delaying gastric emptying. We tested a range of doses of exendin-4 on postcibal glycemic excursions in nine volunteers with type 1 diabetes, all with negligible endogenous insulin secretion, in paired comparisons with vehicle in at least six volunteers with each of six doses. We established a side effect-free dose and an appropriate antecibal time for sc administration of exendin-4. Subsequently, exendin-4 was administered 15 min before breakfast, with usual insulin, to eight of the volunteers. Acetaminophen was ingested with the meal as an indicator of gastric emptying. The mean plasma glucose excursion was reduced by 90%, falling into the normal range, after breakfast, whereas plasma pancreatic polypeptide, glucagon, and acetaminophen levels were reduced, and insulin levels were not affected. Thus, normalization of postcibal glycemia was associated with delayed gastric emptying and suppression of glucagon secretion, without increased secretion or blood levels of insulin. We suggest that tGLP-1 agonists have therapeutic potential as congeners with insulin in C-peptide-negative type 1 diabetes.

Topics: Adult; Aged; Analysis of Variance; Area Under Curve; Blood Glucose; Diabetes Mellitus, Type 1; Drug Administration Schedule; Exenatide; Female; Gastric Emptying; Glucagon; Humans; Injections, Subcutaneous; Insulin; Insulin Secretion; Male; Middle Aged; Peptides; Postprandial Period; Time Factors; Venoms

Intrahepatic transplantation of islets of Langerhans (ITx) is a treatment option for individuals with complicated type 1 diabetes and profoundly unstable glycemic control, but its therapeutic success is hampered by deterioration of graft function over time. To improve ITx strategies, technologies to noninvasively monitor the fate and survival of transplanted islets over time are of great potential value. We used [68Ga]Ga-NODAGA-exendin-4 (68Ga-exendin) positron emission tomography (PET)/computed tomography (CT) imaging to demonstrate the feasibility of quantifying β-cell mass in intrahepatic islet grafts in 13 individuals with type 1 diabetes, nine after ITx with functional islet grafts and four control patients not treated with ITx. β-Cell function was measured by mixed-meal tolerance test. With dynamic 68Ga-exendin PET/CT images, we determined tracer accumulation in hepatic hotspots, and intrahepatic fat was assessed using MRI and spectroscopy. Quantification of hepatic hotspots showed a significantly higher uptake of 68Ga-exendin in the ITx group compared with the control group (median 0.55 [interquartile range 0.51-0.63] vs. 0.43 [0.42-0.45]). GLP-1 receptor expression was found in transplanted islets by immunohistochemistry. Intrahepatic fat was not detected in a majority of the individuals. Our study provides the first clinical evidence that radiolabeled exendin imaging can be used to monitor viable transplanted islets after intraportal ITx.. This clinical study researched the potential of radiolabeled exendin to follow the fate and survival of intrahepatic islet grafts. Is it feasible to quantitatively detect intrahepatic islet transplants with [68Ga]Ga-NODAGA-exendin-4 (68Ga-exendin) positron emission tomography (PET) imaging? Our study findings indicate that the imaging technique 68Ga-exendin PET can be used to monitor viable islet mass after intrahepatic islet transplantation in humans. Alongside functional measures, 68Ga-exendin PET imaging could significantly aid in the evaluation of strategies designed to improve islet engraftment, survival, and function.

Topics: Cell Survival; Diabetes Mellitus, Type 1; Exenatide; Humans; Islets of Langerhans Transplantation; Positron Emission Tomography Computed Tomography; Positron-Emission Tomography

Neonatal porcine pancreatic cell clusters (NPCCs) have been proposed as an alternative source of β cells for islet transplantation because of their low cost and growth potential after transplantation. However, the delayed glucose lowering effect due to the immaturity of NPCCs and immunologic rejection remain as a barrier to NPCC's clinical application. Here, we demonstrate accelerated differentiation and immune-tolerant NPCCs by in vitro chemical treatment and microencapsulation.. NPCCs isolated from 3-day-old piglets were cultured in F-10 media and then microencapsulated with alginate on day 5. Differentiation of NPCCs is facilitated by media supplemented with activin receptor-like kinase 5 inhibitor II, triiodothyronine and exendin-4 for 2 weeks. Marginal number of microencapsulated NPCCs to cure diabetes with and without differentiation were transplanted into diabetic mice and observed for 8 weeks.. The proportion of insulin-positive cells and insulin mRNA levels of NPCCs were significantly increased in vitro in the differentiated group compared with the undifferentiated group. Blood glucose levels decreased eventually after transplantation of microencapsulated NPCCs in diabetic mice and normalized after 7 weeks in the differentiated group. In addition, the differentiated group showed nearly normal glucose tolerance at 8 weeks after transplantation. In contrast, neither blood glucose levels nor glucose tolerance were improved in the undifferentiated group. Retrieved graft in the differentiated group showed greater insulin response to high glucose compared with the undifferentiated group.. in vitro differentiation of microencapsulated immature NPCCs increased the proportion of insulin-positive cells and improved transplant efficacy in diabetic mice without immune rejection.

Topics: Alginates; Animals; Animals, Newborn; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Exenatide; Insulin; Islets of Langerhans; Mice; Receptor, Transforming Growth Factor-beta Type I; RNA, Messenger; Swine; Transplantation, Heterologous; Triiodothyronine

Exenatide is a stable analogue of glucagon-like peptide 1 that can reduce postprandial hyperglycemia and has been utilized as adjunctive therapy for type 1 diabetes mellitus (T1DM). The human umbilical cord is a rich source of MSCs, and human umbilical cord mesenchymal stem cells (hUCMSCs) also show potential to enhance insulin secretion. Here, we aimed to explore the effects of hUCMSCs carrying exenatide in T1DM and further identify the possible mechanisms involved.. hUCMSCs were isolated from human umbilical cord tissues, identified, and transduced with recombinant lentivirus carrying exenatide to obtain exenatide-carrying hUCMSCs (hUCMSCs@Ex-4).. The results showed that hUCMSCs@Ex-4 restored the blood glucose levels and body weight of NOD mice, and repressed immune cell infiltration and islet tissue changes. Additionally, in T1DM mice, treatment with hUCMSCs@Ex-4 reduced the blood glucose levels and promoted repair of islet tissue damage. Moreover, hUCMSCs@Ex-4 attenuated renal tissue lesions in T1DM mice. Applying bioinformatic analysis, the effects of hUCMSCs@Ex-4 were suggested to correlate with decreased abundance of pro-inflammatory intestinal bacteria and increased abundance of anti-inflammatory intestinal bacteria.. Overall, the study indicated that hUCMSCs carrying exenatide might improve beneficial intestinal microflora abundance and promote islet tissue damage repair, thereby alleviating T1DM.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 1; Exenatide; Gastrointestinal Microbiome; Humans; Mesenchymal Stem Cells; Mice; Mice, Inbred NOD

The oral delivery of bioactive peptides and proteins is prevented by the intestinal epithelial barrier, in which intercellular tight junction complexes block the uptake of macromolecules. Here we show that anionic nanoparticles induce tight junction relaxation, increasing intestinal permeability and enabling the oral delivery of proteins. This permeation-enhancing effect is a function of nanoparticle size and charge, with smaller (≤ 200 nm) and more negative particles (such as silica) conferring enhanced permeability. In healthy mice, silica nanoparticles enabled the oral delivery of insulin and exenatide, with 10 U kg

Topics: Administration, Oral; Animals; Cell Line; Cell Membrane Permeability; Diabetes Mellitus, Type 1; Drug Delivery Systems; Exenatide; Insulin; Intestinal Mucosa; Mice, Inbred C57BL; Nanoparticles; Particle Size; Silicon Dioxide; Tight Junctions

Topics: Blood Glucose; Diabetes Mellitus, Type 1; Double-Blind Method; Exenatide; Glucagon-Like Peptide-1 Receptor; Humans; Hypoglycemic Agents

Nrf2 is an essential part of the defense mechanism of vertebrates and protects them from surrounding stress via participation in stimulated expression of detoxification as well as antioxidant enzymes. It also exerts a role in defending hosts from different stress in the environment, including reactive oxygen species. Our study investigates the role of exendin-4 on Nrf2 pathway as well as cell death in pancreatic β-cell and in non-obese diabetic mice. Result of study indicates exendin-4 mediates activation of Keap1-Nrf2-ARE pathway and may serve as a potential agent to treat type I diabetes mellitus. In our research, we observed excessive reactive oxygen species production, low level of cell death, and PKC phosphorylation on exendine-4 treatment. Nrf2 knockdown led to suppression of reactive oxygen species generation as well as increasing apoptosis. Moreover, siRNA-mediated Nrf2 down-regulation attenuated the suppressive effect of exendin-4 in pancreatic β-cell viability, via modulating apoptosis promoting- and counteracting-proteins, Bax, and Bcl-2.

Topics: Animals; Apoptosis; Cell Line; Diabetes Mellitus, Type 1; Exenatide; Kelch-Like ECH-Associated Protein 1; Mice; Mice, Inbred NOD; NF-E2-Related Factor 2; Phosphorylation; Protein Kinase C; Rats; Reactive Oxygen Species; RNA Interference; Signal Transduction

Topics: Adult; Biopsy, Needle; Diabetes Mellitus, Type 1; Diagnosis, Differential; Drug Eruptions; Exenatide; Female; Humans; Hypoglycemic Agents; Immunohistochemistry; Injections, Subcutaneous; Microspheres; Panniculitis; Staining and Labeling

A defining characteristic of type 1 diabetes mellitus (T1DM) pathophysiology is pancreatic β-cell death and dysfunction, resulting in insufficient insulin secretion to properly control blood glucose levels. Treatments that promote β-cell replication and survival, thus reversing the loss of β-cell mass, while also preserving β-cell function, could lead to a real cure for T1DM. The α-subunit of the heterotrimeric Gz protein, Gαz, is a tonic negative regulator of adenylate cyclase and downstream cAMP production. cAMP is one of a few identified signaling molecules that can simultaneously have a positive impact on pancreatic islet β-cell proliferation, survival, and function. The purpose of our study was to determine whether mice lacking Gαz might be protected, at least partially, from β-cell loss and dysfunction after streptozotocin treatment. We also aimed to determine whether Gαz might act in concert with an activator of the cAMP-stimulatory glucagon-like peptide 1 receptor, exendin-4 (Ex4). Without Ex4 treatment, Gαz-null mice still developed hyperglycemia, albeit delayed. The same finding held true for wild-type mice treated with Ex4. With Ex4 treatment, Gαz-null mice were protected from developing severe hyperglycemia. Immunohistological studies performed on pancreas sections and in vitro apoptosis, cytotoxicity, and survival assays demonstrated a clear effect of Gαz signaling on pancreatic β-cell replication and death; β-cell function was also improved in Gαz-null islets. These data support our hypothesis that a combination of therapies targeting both stimulatory and inhibitory pathways will be more effective than either alone at protecting, preserving, and possibly regenerating β-cell mass and function in T1DM.

Topics: Adenylyl Cyclases; Animals; Blood Glucose; Cell Line, Tumor; Cell Proliferation; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide 1; Glucose; Hyperglycemia; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Mice, Knockout; Pancreas; Peptides; Rats; Signal Transduction; Streptozocin; Venoms

Topics: Allografts; C-Peptide; Diabetes Mellitus, Type 1; Everolimus; Exenatide; Glycated Hemoglobin; Graft Survival; Humans; Hypoglycemic Agents; Immunosuppressive Agents; Islets of Langerhans Transplantation; Peptides; Pilot Projects; Time Factors; Treatment Outcome; Venoms

The use of once-weekly exenatide in type 2 diabetes mellitus is well supported, but little is known about its effectiveness in type 1 diabetes. The objective of this study was to determine the clinical efficacy of once-weekly exenatide on glycemic control in patients with type 1 diabetes when added to basal-bolus insulin therapy.. For this retrospective study, patients with type 1 diabetes, aged 18 years and older, receiving continuous subcutaneous insulin infusion, using a continuous glucose monitoring device or regularly measuring blood glucose levels and receiving 2 mg of exenatide once weekly for at least 3 months were included. Demographic information, glycated hemoglobin (A1C), body weight, body mass index, systolic and diastolic blood pressures, total daily insulin dose, basal and bolus insulin doses, 28-day continuous subcutaneous insulin infusion glucose average and incidence of hypoglycemia were collected at baseline and 3 months after beginning therapy with once-weekly exenatide.. An electronic medical record search identified 11 patients with type 1 diabetes who met the inclusion criteria. Comparing baseline and 3 months after initiation of once-weekly exenatide revealed reductions of 0.6% in A1C (p=0.013), 3.7% in body weight (p=0.008), 1.7 kg/m(2) in body mass index (p=0.003), 13% in total daily insulin dose (p=0.011) and 9.3 units in bolus insulin dose (p=0.015).. This study revealed that the addition of once-weekly exenatide to insulin therapy for type 1 diabetes patients leads to significant improvements in A1C, body weight, body mass index and insulin doses.

Topics: Adult; Body Mass Index; Diabetes Mellitus, Type 1; Exenatide; Humans; Hypoglycemic Agents; Insulin; Insulin Infusion Systems; Peptides; Retrospective Studies; Venoms

Diabetes is the fastest growing metabolic disease that fails to utilize glucose properly due to insulin deficiency or insulin resistance. Although several limited studies demonstrated non-invasive means of protein delivery, major hurdles for commercial success such as short half-life, enzymatic degradation and low bioavailability still remain to overcome. Methylcellulose (MC), a hydrophobically-modified cellulose derivative, forms temperature reversible gel in aqueous solution. However, as the gelling temperature of MC is higher than body temperature, it should be lowered to below body temperature for practical clinical application. In order to decrease gelling temperature and increase bio-compatibility and bio-elimination of MC, the molecular weight of MC was decreased using enzymatic degradation method and confirmed by gel permeation chromatography. Bio-elimination of low molecular weight (LMw) MC was confirmed with non-invasive live image and ex vivo experiment. The exenatide and FGF 21 were physically loaded 100% into LMwMC-based thermo-reversible gel and slowly released from gel with no initial bursts. Exenatide-loaded LMwMC gel showed reduction of blood glucose level for a week in type 1 diabetic animal model. FGF 21-loaded LMwMC gel reduced glucose level to normal condition and maintained over 10 days in type 2 diabetic animal model. LMwMC-based thermo-reversible and injectable hydrogel provides a strong potential to be efficient protein drug delivery system for the treatment of type 1 and type 2 diabetes.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Fibroblast Growth Factors; Gels; Hypoglycemic Agents; Male; Methylcellulose; Mice; Mice, Inbred BALB C; Molecular Weight; Peptides; Pharmaceutic Aids; Thermodynamics; Tissue Distribution; Venoms

This study proposed that microencapsulation of exendin-4 gene transduced islets using alginate, poly-L-lysine, and polyethylene glycol could lead to increased viability and functionality of islets in a rat to mouse xenograft model. The stability of the microcapsules was determined using an osmotic pressure test and a rotational stress test. Exendin-4 gene was transduced into pancreatic islets using lenti-viral vectors and the transduced islets were encapsulated using multi-component microcapsules mentioned above. Both viability and functionality of microencapsulated islets were evaluated in both in vitro and in vivo xenograft model. The viabilities of the unmodified islets (control) and the exendin-4 transduced islets (test) on 14th day were 18.6 ± 11.1 and 49.2 ± 13.4%, respectively (p < 0.05). The stimulation index of the control and the test groups was 2.3 ± 1.7 and 3.0 ± 1.6, respectively. The mean survival times (MST) of the control and the test groups were 20.2 ± 8.0 and 35.2 ± 10.0 days, respectively (p < 0.05). Significant differences in MST suggested that transduction of exendin-4 gene had a great potential to increase the function of encapsulated islets. In conclusion, exendin-4 gene transduced islets encapsulated by poly(ethylene glycol) conjugated alginate/PLL microcapsules significantly improved both viability and functionality of encapsulated islets.

Topics: Alginates; Animals; Capsules; Diabetes Mellitus, Type 1; Drug Carriers; Exenatide; Glucose; Glucuronic Acid; Hexuronic Acids; Insulin; Insulin Secretion; Islets of Langerhans; Male; Mice; Microspheres; Peptides; Polyethylene Glycols; Polylysine; Rats; Rats, Sprague-Dawley; Static Electricity; Tissue Survival; Transduction, Genetic; Transplantation, Heterologous; Venoms

This study focuses on the impact of aliskiren and (or) glucagon-like peptide-1 analogue on the binding affinity/regulation of endothelin-1 (ET-1) to its receptor subtypes A (ETAR) and B (ETBR) at the level of the coronary endothelium and the cardiomyocytes in a type-1 diabetic rat model. Seven groups were used: (i) normal rats, (ii) rats with induced diabetes, (iii) rats with induced diabetes that were treated with insulin, (iv) rats with induced diabetes that were treated with exendin-4, (v) rats with induced diabetes that were treated with aliskiren, (vi) rats with induced diabetes that were co-treated with insulin plus aliskiren, and (vii) rats with induced diabetes that were co-treated with exendin-4 plus aliskiren. Heart perfusion with [(125)I]-ET-1 was employed to estimate ET-1 binding affinity (τ = 1/K-n) to ETAR and ETBR at the level of the coronary endothelium and the cardiomyocytes. Plasma ET-1 levels were measured using enzyme immunoassay, whereas densities of ETAR and ETBR were detected using Western blot. No significance differences were detected in the τ of ETAR and ETBR between normal and diabetic in cardiomyocytes and the coronary endothelium. Exendin-4 normalized the τ value for ETAR and ETBR on coronary endothelium, while aliskiren normalized it on cardiomyocytes. Furthermore, ETAR and ETBR densities were normalized with monotreatments of aliskiren and exendin-4, compared with up-regulated ETAR and down-regulated ETBR band densities in the diabetic animals. Our data indicate that aliskiren alleviates diabetes-associated hypertrophy in type 1 diabetes mellitus.

Topics: Amides; Animals; Cardiomegaly; Coronary Vessels; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Endothelin-1; Endothelium, Vascular; Exenatide; Fumarates; Hypoglycemic Agents; Insulin; Male; Myocytes, Cardiac; Peptides; Rats; Rats, Sprague-Dawley; Receptor, Endothelin A; Receptor, Endothelin B; Streptozocin; Time Factors; Venoms

Topics: Automobile Driving; Blood Glucose; Device Approval; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Dose-Response Relationship, Drug; Exenatide; Female; Glucagon-Like Peptide 1; Humans; Hypoglycemia; Hypoglycemic Agents; Licensure; Liraglutide; Male; Middle Aged; Peptides; United Kingdom; Venoms

Like insulin, glucagon-like peptide 1 (GLP-1) may have direct trophic actions on the nervous system, but its potential role in supporting diabetic sensory neurons is uncertain. We identified wide expression of GLP-1 receptors on dorsal root ganglia sensory neurons of diabetic and nondiabetic mice. Exendin-4, a GLP-1 agonist, increased neurite outgrowth of adult sensory neurons in vitro. To determine the effects ofexendin-4 in comparison with continuous low- or high-dose insulin in vivo, we evaluated parallel cohorts of type 1 (streptozotocin-induced) and type 2 (db/db) mice of 2 months' diabetes duration with established neuropathy during an additional month of treatment. High-dose insulin alone reversed hyperglycemia in type 1 diabetic mice, partly reversed thermal sensory loss, improved epidermal innervation but failed to reverse electrophysiological abnormalities. Exendin-4 improved both sensory electrophysiology and behavioral sensory loss. Low-dose insulin was ineffective. In type 2 diabetes, hyperglycemia was uncorrected, and neither insulin nor exendin-4 reversed sensory electrophysiology, sensory behavior, or loss of epidermal axons. However, exendin-4 alone improved motor electrophysiology. Receptor for advanced glycosylated end products and nuclear factor-κB neuronal expression were not significantly altered by diabetes or treatment. Taken together, these results suggest that although GLP-1 agonists and insulin alone are insufficient to reverse all features of diabetic neuropathy, in combination, they might benefit some aspects of established diabetic neuropathy.

Topics: Animals; Axons; Blood Glucose; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Diabetic Neuropathies; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Glycated Hemoglobin; Immunohistochemistry; Insulin; Male; Mice; Motor Neurons; Neural Conduction; Peptides; Peripheral Nerves; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Sensory Receptor Cells; Signal Transduction; Venoms

Viral infection is one of the important factors for the pathogenesis of type 1 diabetes. Particularly, in fulminant type 1 diabetes, rapid β-cell destruction is suggested to be triggered by viral infection. Recently, glucagon-like peptide 1 (GLP-1) receptor agonists have been reported to have direct beneficial effects on β-cells, such as anti-apoptotic effect, increasing β-cell mass, and improvement of β-cell function. However, their effects on β-cell destruction induced by viral infections have not been elucidated. In this study, we used an encephalomyocarditis virus (EMCV)-induced diabetic model mouse to show that a GLP-1 receptor agonist, exendin-4, prevents β-cell destruction. Nine-week-old male DBA/2 mice were intraperitoneally injected with EMCV (200 plaque forming units (PFU)mouse(-1)). Low (20 nmolkg(-1)d(-1)) or high (40 nmolkg(-1)d(-1)) doses of exendin-4 were administered for 10d, starting from 2d before the infection, and the rate of diabetic onset was evaluated. In addition, the number of infiltrating macrophage per islet and the ratio of β-cell area to islet area were determined. The effects of exendin-4 on infected β-cells and macrophages were investigated by using MIN6 and RAW264 mouse macrophages. The incidence of diabetes was significantly lower in the high-dose exendin-4-treated group than in the control group. Furthermore, the β-cell area was significantly more preserved in the high-dose exendin-4-treated group than in the control. In addition, the number of macrophages infiltrating into the islets was significantly less in the high-dose exendin-4-treated group than in the control group. In vitro, exendin-4 reduced β-cell apoptosis, and tumor necrosis factor α (TNFα), interleukin β (IL-β), and inducible nitric oxide synthase (iNOS) production of infected or lipopolysaccharide (LPS)-stimulated macrophages. These results suggested that exendin-4 limits β-cell destruction by protecting β cells and reducing the inflammatory response of macrophages.

Topics: Animals; Apoptosis; Cardiovirus Infections; Diabetes Mellitus, Type 1; Disease Models, Animal; Encephalomyocarditis virus; Exenatide; Glucagon-Like Peptide-1 Receptor; Insulin-Secreting Cells; Macrophages; Male; Mice; Peptides; Receptors, Glucagon; Venoms

Glucagon-like peptide-1 (GLP-1) has various extra-pancreatic actions, in addition to its enhancement of insulin secretion from pancreatic beta cells. The GLP-1 receptor is produced in kidney tissue. However, the direct effect of GLP-1 on diabetic nephropathy remains unclear. Here we demonstrate that a GLP-1 receptor agonist, exendin-4, exerts renoprotective effects through its anti-inflammatory action via the GLP-1 receptor without lowering blood glucose.. We administered exendin-4 at 10 μg/kg body weight daily for 8 weeks to a streptozotocin-induced rat model of type 1 diabetes and evaluated their urinary albumin excretion, metabolic data, histology and morphometry. We also examined the direct effects of exendin-4 on glomerular endothelial cells and macrophages in vitro.. Exendin-4 ameliorated albuminuria, glomerular hyperfiltration, glomerular hypertrophy and mesangial matrix expansion in the diabetic rats without changing blood pressure or body weight. Exendin-4 also prevented macrophage infiltration, and decreased protein levels of intercellular adhesion molecule-1 (ICAM-1) and type IV collagen, as well as decreasing oxidative stress and nuclear factor-κB activation in kidney tissue. In addition, we found that the GLP-1 receptor was produced on monocytes/macrophages and glomerular endothelial cells. We demonstrated that in vitro exendin-4 acted directly on the GLP-1 receptor, and attenuated release of pro-inflammatory cytokines from macrophages and ICAM-1 production on glomerular endothelial cells.. These results indicate that GLP-1 receptor agonists may prevent disease progression in the early stage of diabetic nephropathy through direct effects on the GLP-1 receptor in kidney tissue.

Topics: Animals; Blood Glucose; Blotting, Western; Cell Line; Cell Line, Tumor; Collagen Type IV; Diabetes Mellitus, Type 1; Diabetic Nephropathies; Exenatide; Fluorescent Antibody Technique; Glucagon-Like Peptide-1 Receptor; Humans; Intercellular Adhesion Molecule-1; Male; NF-kappa B; Peptides; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Reverse Transcriptase Polymerase Chain Reaction; Tumor Necrosis Factor-alpha; Venoms

Glucagon-like peptide-1 (GLP-1) is an incretin hormone secreted from intestinal L cells upon nutrients ingestion, and is currently used for treating diabetes mellitus. It plays an important role in receptor modulation and cross talk with insulin at the coronary endothelium (CE) and cardiomyocytes (CM) in diabetic type 1 rat heart model. We studied the effects of insulin, GLP-1 analogues (exendin-4), and dipeptidyl peptidase-IV (DPP-IV) inhibitor on GLP-1 cardiac receptor modulation. The binding affinity of GLP-1 to its receptor on CE and CM was calculated using a rat heart perfusion model with [(125)I]-GLP-1(7-36). Tissue samples from the heart were used for immunostaining and Western blot analyses. GLP-1 systemic blood levels were measured using ELISA. GLP-1 binding affinity (τ) increased on the CE (0.33 ± 0.01 vs. 0.25 ± 0.01 min; p < 0.001) and decreased on the CM (0.29 ± 0.02 vs. 0.43 ± 0.02 min; p < 0.001) in the diabetic non-treated rats when compared to normal. There was normalization of τ back to baseline on the CE and CM levels with insulin and DPP-IV inhibitor treatment, respectively. Histological sections and immunofluorescence showed receptor up-regulation in diabetic rats with significant decrease and even normalization with the different treatment strategies. Systemic GLP-1 levels increased after 14 days of diabetes induction (10 ± 3.7 vs. 103 ± 58 pM; p = 0.0005). In conclusion, there is a significant GLP-1 receptor affinity modulation on the CE and CM levels in rats with diabetes type 1, and a cross talk with GLP-1 analogues in early prevention of cardiac remodeling.

Topics: Animals; Blood Glucose; Diabetes Mellitus, Type 1; Dipeptidyl-Peptidase IV Inhibitors; Endothelium, Vascular; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Insulin; Male; Myocytes, Cardiac; Peptides; Protein Binding; Rats; Rats, Sprague-Dawley; Receptor Cross-Talk; Receptors, Glucagon; Venoms; Ventricular Remodeling

This study focuses on the effects of long-term renin-angiotensin system suppression and/or incretin mimetic therapies on the regulation and binding affinity of GLP-1 to its receptor in the coronary endothelium (CE) and cardiomyocytes (CMs) of type 1 diabetic male Sprague-Dawley rats. The groups assessed are normal (N), streptozotocin-induced diabetic (D), Insulin treated (DI), Exendin-4 treated (DE), Aliskiren treated (DA), cotreated with Insulin and Aliskiren (DIA) and cotreated with exendin-4 and Aliskiren (DEA). Heart perfusion with (125)I-GLP-1 was performed to estimate GLP-1 binding affinity (τ = 1/k-n) to its receptor in the heart. Western Blotting was assessed to determine the expression variation of GLP-1 receptor in the heart. Plasma GLP-1 levels were measured using Enzyme-Linked Immunosorbent Assay (ELISA). Diabetes decreased the τ value on CE and increased it on CMs compared to normal. The combination of Exendin-4 with Aliskiren showed a normalizing effect on the binding affinity of GLP-1 at the coronary endothelium, while at the cardiomyocyte level Exendin-4 treatment alone was the most effective.

Topics: Amides; Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Drug Evaluation, Preclinical; Exenatide; Fumarates; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Heart; Hypoglycemic Agents; Male; Myocardium; Peptides; Protein Binding; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Renin; Streptozocin; Venoms

The hallmark of type 1 diabetes is autoimmune destruction of the insulin-producing β-cells of the pancreatic islets. Autoimmune diabetes has been difficult to study or treat because it is not usually diagnosed until substantial β-cell loss has already occurred. Imaging agents that permit noninvasive visualization of changes in β-cell mass remain a high-priority goal. We report on the development and testing of a near-infrared fluorescent β-cell imaging agent. Based on the amino acid sequence of exendin-4, we created a neopeptide via introduction of an unnatural amino acid at the K(12) position, which could subsequently be conjugated to fluorophores via bioorthogonal copper-catalyzed click-chemistry. Cell assays confirmed that the resulting fluorescent probe (E4(×12)-VT750) had a high binding affinity (~3 nM). Its in vivo properties were evaluated using high-resolution intravital imaging, histology, whole-pancreas visualization, and endoscopic imaging. According to intravital microscopy, the probe rapidly bound to β-cells and, as demonstrated by confocal microscopy, it was internalized. Histology of the whole pancreas showed a close correspondence between fluorescence and insulin staining, and there was an excellent correlation between imaging signals and β-cell mass in mice treated with streptozotocin, a β-cell toxin. Individual islets could also be visualized by endoscopic imaging. In short, E4(×12)-VT750 showed strong and selective binding to glucose-like peptide-1 receptors and permitted accurate measurement of β-cell mass in both diabetic and nondiabetic mice. This near-infrared imaging probe, as well as future radioisotope-labeled versions of it, should prove to be important tools for monitoring diabetes, progression, and treatment in both experimental and clinical contexts.

Topics: Amino Acid Sequence; Animals; Binding Sites; Cell Line, Tumor; Diabetes Mellitus, Type 1; Exenatide; Fluorescent Dyes; Glucagon-Like Peptide-1 Receptor; Green Fluorescent Proteins; HEK293 Cells; Humans; Insulin-Secreting Cells; Laparoscopy; Lysine; Mice; Mice, Inbred C57BL; Mice, Transgenic; Microscopy, Confocal; Microscopy, Fluorescence; Molecular Sequence Data; NIH 3T3 Cells; Pancreas; Peptides; Receptors, Glucagon; Streptozocin; Venoms

In autoimmune type 1 diabetes mellitus, proinflammatory cytokine-mediated apoptosis of beta-cells has been considered to be the first event directly responsible for beta-cell mass reduction. In the Bio-Breeding (BB) rat, an in vivo model used in the study of autoimmune diabetes, beta-cell apoptosis is observed from 9 wk of age and takes place after an insulitis period that begins at an earlier age. Previous studies by our group have shown an antiproliferative effect of proinflammatory cytokines on cultured beta-cells in Wistar rats, an effect that was partially reversed by Exendin-4, an analogue of glucagon-like peptide-1. In the current study, the changes in beta-cell apoptosis and proliferation during insulitis stage were also determined in pancreatic tissue sections in normal and thymectomized BB rats, as well as in Wistar rats of 5, 7, 9, and 11 wk of age. Although stable beta-cell proliferation in Wistar and thymectomized BB rats was observed along the course of the study, a decrease in beta-cell proliferation and beta-cell mass from the age of 5 wk, and prior to the commencement of apoptosis, was noted in BB rats. Exendin-4, in combination with anti-interferon-gamma antibody, induced a near-total recovery of beta-cell proliferation during the initial stages of insulitis. This highlights the importance of early intervention and, as well, the possibilities of new therapeutic approaches in preventing autoimmune diabetes by acting, initially, in the insulitis stage and, subsequently, on beta-cell regeneration and on beta-cell apoptosis.

Topics: Animals; Antibodies; Apoptosis; Cell Proliferation; Diabetes Mellitus, Type 1; Disease Models, Animal; Exenatide; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hypoglycemic Agents; Immunohistochemistry; Insulin-Secreting Cells; Interferon-gamma; Peptides; Random Allocation; Rats; Rats, Wistar; Venoms

Incretin-based compounds, including glucagon-like peptide-1 receptor agonists and dipeptidyl-peptidase-4 inhibitors, have emerged as a new class of agents for the treatment of type 2 diabetes. In this article, the potential and supporting evidence for extending their use to early type 1 diabetes are reviewed. The rationale relies on the assumption that these drugs, in addition to their action on insulin secretion and glucose regulation, may be effective in preserving and even expanding the beta-cell mass. This assumption is based on data from in vitro and animal studies, with no clear demonstrations in humans. This class of drugs may represent an entirely new approach to the treatment of type 1 diabetes, focused on protection and preservation of beta-cells, an ideal complement to immune interventions inhibiting or modulating the pathogenetic autoimmune process. The ideal candidates for this treatment are patients at the time of clinical onset of type 1 diabetes or individuals with preclinical type 1 diabetes who still have a significant viable beta-cell mass.

Topics: Antibodies, Monoclonal; Cell Proliferation; Diabetes Mellitus, Type 1; Dipeptidyl-Peptidase IV Inhibitors; Exenatide; Gastric Inhibitory Polypeptide; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Incretins; Insulin-Secreting Cells; Interleukin-2 Receptor alpha Subunit; Peptides; Venoms

Topics: Animals; Combined Modality Therapy; Diabetes Mellitus, Type 1; Disease Models, Animal; Drug Therapy; Drug Therapy, Combination; Exenatide; Humans; Hypoglycemic Agents; Immunologic Factors; Immunotherapy, Active; Peptides; Venoms

Immunotherapy with Complete Freund's adjuvant (CFA) is effective in ameliorating autoimmunity in diabetic nonobese diabetic (NOD) mice. We investigated whether CFA treatment up-regulates CD4+CD25+Foxp3+ regulatory T cells and increases transforming growth factor (TGF)-beta1 production in diabetic NOD mice.. New-onset diabetic NOD mice were treated with CFA and exendin-4, a potent analog of glucagon-like peptide-1. Reversal of diabetes was determined by monitoring blood glucose level. Ameliorating autoimmunity through immunoregulation was assessed by adoptive transfer. Regulatory T cells in the peripheral blood, spleen, thymus, and pancreatic nodes were measured. TGF-beta1 in plasma and the insulin content in the pancreas were also measured. Immunostainings for insulin and BrdU were performed.. New-onset diabetes could be reversed in 38% of NOD mice treated with CFA alone and in 86% of NOD mice treated with both CFA and exendin-4. Diabetes adoptive transfer by splenocytes from CFA-treated NOD mice was delayed. The percentage of CD4+CD25+Foxp3+ regulatory T cells in the pancreatic lymph nodes of CFA-treated NOD mice was significantly increased at 1, 5, and 15 to 17 weeks after treatment. TGF-beta1 in the plasma of CFA-treated NOD mice was also significantly increased. Combining CFA with exendin-4 treatment significantly increased the insulin content and the numbers of insulin and BrdU double-labeled beta cells in the islets.. Our results demonstrated that CFA treatment ameliorates autoimmunity in diabetic NOD mice by up-regulating CD4=CD25+Foxp3+ regulatory T cells and increasing TGF-beta1 production. Exendin-4 enhanced the effect of CFA on reversing diabetes in NOD mice by stimulating beta-cell replication.

Topics: Adjuvants, Immunologic; Adoptive Transfer; Animals; Autoimmunity; Blood Glucose; CD4-Positive T-Lymphocytes; Cell Proliferation; Diabetes Mellitus, Type 1; Disease Models, Animal; Drug Therapy, Combination; Exenatide; Female; Forkhead Transcription Factors; Freund's Adjuvant; Hypoglycemic Agents; Insulin; Insulin-Secreting Cells; Interleukin-2 Receptor alpha Subunit; Lymph Nodes; Male; Mice; Mice, Inbred NOD; Mice, SCID; Pancreas; Peptides; T-Lymphocytes, Regulatory; Time Factors; Transforming Growth Factor beta1; Up-Regulation; Venoms

Exenatide is an incretin mimetic licensed for treatment of Type 2 diabetes poorly controlled despite maximally tolerated doses of oral therapy. Similar in structure to the natural incretin hormone glucagon-like peptide 1 (GLP-1), it helps restore underlying pathophysiological abnormalities.. We report the successful use of exenatide, combined with insulin, in a 66-year-old woman initially diagnosed with Type 2 diabetes in 1989 but now exhibiting a Type 1 phenotype. Diet, lifestyle advice and oral glucose-lowering agents were commenced but persisting poor control necessitated insulin therapy in 2005. She later presented twice in diabetic ketoacidosis, suggesting conversion to a Type 1 phenotype (postprandial C-peptide < 94 pmol/l). Despite differing insulin regimens, control remained poor with frequent hyperglycaemic and hypoglycaemic excursions, severely impairing quality of life. Whilst an inpatient in 2007 [glycated haemoglobin (HbA(1c)) 10.2%, body mass index (BMI) 31.5 kg/m(2)] exenatide was commenced in an attempt to stabilize glycaemic control. Dramatic improvements were seen and continued. Eight months later, HbA(1c) had fallen by 2% with an 8-kg weight loss and 10-unit reduction in daily insulin dose. Quality of life dramatically improved. C-peptide remains undetectable.. This patient with features of both Type 1 and Type 2 diabetes benefited greatly from exenatide with insulin therapy. The improvement seen in glycaemic control could not be attributable to enhanced insulin secretion but could be as a result of a combination of the other incretin effects (postprandial glucagon suppression, delayed gastric emptying and weight loss secondary to increased satiety) all improving insulin sensitivity, reducing insulin dose and smoothing control.

Topics: Aged; C-Peptide; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Female; Humans; Hypoglycemic Agents; Overweight; Peptides; Treatment Outcome; Venoms

A current limitation of islet transplantation is reduced long-term graft function. The glucagon-like peptide-1 receptor agonist, exenatide (Byetta, Amylin Pharmaceuticals, CA) has properties that could improve existing islet function, prevent further loss of islet mass and possibly even stimulate islet regeneration.. This prospective study evaluated the safety, efficacy, and metabolic effects of exenatide in subjects with type 1 diabetes mellitus and islet allograft dysfunction requiring exogenous insulin.. Sixteen subjects commenced exenatide, 12 continue (follow-up 214+/-57 days; range 108-287), four (25%) discontinued medication because of side effects. At 6 months, exogenous insulin was significantly reduced with stable glycemic control (0.15+/-0.02 vs. 0.11+/-0.025 U/kg per day; P<0.0001); three subjects discontinued insulin from 4, 5, and 9 U/day, respectively, two sustained insulin independence with A1c reduction below graft dysfunction criteria. Postprandial capillary blood glucose was significantly decreased (129.4+/-3.8 vs. 118.7+/-4.6 mg/dL; P<0.001), C-peptide and C-peptide-to-glucose ratio increased significantly by 5th and 6th months of treatment (ratio, 1.09+/-0.15 vs. 1.52+/-0.18; P<0.05). Weight loss more than 3 kg occurred in 8 of 12 (67%) subjects. Stimulation testing demonstrated improved glucose disposal and C-peptide secretion (glucose area under the curve 52,332+/-3,219 vs. 42,072+/-1,965; P=0.002 mg x min x dL, mixed meal stimulation index 0.50+/-0.06 vs. 0.66+/-0.09; P=0.03 pmol x mL), with marked suppression of glucagon secretion and progressive increase in amylin secretion. Side effects were more frequent and severe compared with published reports in type 2 diabetes, tolerated doses were lower.. Exenatide was tolerated in this patient population after appropriate dose titration and there appeared to be gradual but sustained positive effects on glycemic control and islet graft function.

Topics: Adult; Amyloid; Blood Glucose; C-Peptide; Diabetes Mellitus, Type 1; Exenatide; Feasibility Studies; Glucagon; Graft Rejection; Graft Survival; Humans; Hypoglycemic Agents; Immunosuppressive Agents; Insulin; Islet Amyloid Polypeptide; Islets of Langerhans Transplantation; Middle Aged; Peptides; Prospective Studies; Time Factors; Transplantation, Homologous; Treatment Outcome; Venoms

Health related quality of life (HRQoL) is one of the most important outcomes to measure effectiveness of an intervention, especially for islet transplantation in which benefits should outweigh risks of long-term immunosuppression. This study aimed to evaluate long-term effects of islet transplantation and to outline possible influential factors.. Forty islet transplant recipients who completed 344 Health Status Questionnaires (HSQ 2.0) and 384 Diabetes Quality of Life Questionnaires (DQoL) between 2000 and 2007 were retrospectively reviewed. Assessments were analyzed in pretransplantation period, then every 3 months after the first infusion for 18 months and every 6 months thereafter. The mean follow-up posttransplantation was 40.8+/-21.9 months (9-72 months).. Sustained improvement in DQoL-impact score was observed at all time-points posttransplantation. Similarly, worry and satisfaction scales were significantly better than pretransplant evaluation for most time-points. Four of eight HSQ 2.0 scales demonstrated a significant improvement at some time-points. Longitudinal analysis, after adjustments for potential confounding factors, showed significantly sustained improvement in impact scale up to 72 months. Longer diabetes duration, higher insulin dosage, and occurrence of adverse events had negative effects on HRQoL. Single islet infusion or islet after kidney transplant recipients showed the lowest values in HSQ 2.0. In contrast, subjects on exenatide therapy had significantly higher HSQ 2.0 scores.. Islet transplantation is associated with long-term improvement in HRQoL. Exenatide usage had a positive effect whereas single islet infusion, islet after kidney transplantation, longer diabetes duration, higher insulin dosage, and adverse events had a negative impact on HRQoL scores.

Topics: Adult; Diabetes Mellitus, Type 1; Dose-Response Relationship, Drug; Exenatide; Female; Follow-Up Studies; Health Status; Humans; Hypoglycemic Agents; Insulin; Islets of Langerhans Transplantation; Kidney Transplantation; Longitudinal Studies; Male; Middle Aged; Peptides; Quality of Life; Retrospective Studies; Venoms

Topics: Adamantane; Animals; Diabetes Mellitus, Type 1; Exenatide; Humans; Insulin-Secreting Cells; Islets of Langerhans; Islets of Langerhans Transplantation; Mice; Nitriles; Peptides; Pyrazines; Pyrrolidines; Regeneration; Sitagliptin Phosphate; Stem Cell Transplantation; Transplantation, Heterologous; Triazoles; Venoms; Vildagliptin

Recent studies, albeit controversial, have suggested that the incretin exendin-4 (Ex-4) is capable of inducing beta cell proliferation in vivo. Furthermore, this compound has been shown to enhance the ability of other agents (e.g., anti-CD3, antilymphocyte serum) to reverse type 1 diabetes (T1D) in NOD mice. However, the mechanisms underlying this beneficial action for disease reversal remain largely unclear. Herein, we tested the hypothesis that Ex-4 therapy may act as a stimulator of regulatory T cells (Tregs). We evaluated the effect of Ex-4 (Byetta; 0.2 microg/mouse/day for 30 days) treatment on the frequency and function of Tregs and changes in the cytokine profile of NOD mice with recently diagnosed T1D. In comparison to that of saline-treated control NOD mice, the frequency of Tregs was increased in Ex-4-treated mice. Suppression assays demonstrated a trend towards increased Treg suppression after administration of Ex-4, but were limited by small sample size. Lastly, Ex-4 treatment induced production of IL-10, indicating a possible shift towards a more Th2-like phenotype. Taken collectively, these data suggest that in addition to its potential effects on beta cell proliferation, Ex-4 may also act as a regulator of the immune response.

Topics: Animals; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Drug Evaluation, Preclinical; Exenatide; Female; Hypoglycemic Agents; Interferon-gamma; Interleukin-10; Interleukin-2; Interleukin-4; Lymphocyte Count; Mice; Mice, Inbred NOD; Peptides; T-Lymphocytes, Regulatory; Tumor Necrosis Factor-alpha; Venoms

To investigate whether changes of nutritional status and behavior are associated with islet transplantation (ITx) and to assess their possible mechanisms.. In this observational study, 52 subjects with type 1 diabetes, 30 of whom received ITx, underwent nutritional assessments. The study consisted of questionnaires complemented by a dietary intake recording, anthropometric measurements, and body composition analysis. Laboratory tests were also reviewed as part of the follow up.. After ITx, significant reductions in body weight (3.7 kg; P<0.0001), body mass index (1.39 kg/m2; P<0.0001), waist circumference (3.96 cm; P=0.006), and fat weight (3.28 kg; P<0.01) were observed. The average consumption of carbohydrate and protein were also lower than pretransplant, together with some micronutrients (vitamins B12 and B6, zinc, and phosphorus). Insulin administration and changes in A1C were not associated with a significant change in anthropometric measurements. Subjects on exenatide after ITx showed significantly lower weight and body mass index than those not taking exenatide.. ITx is associated with modifications in nutritional behavior and status. Drugs and health conditions are likely to be at least in part responsible for these changes, but a voluntary modification of eating habits by the patients also plays a role. Strict monitoring of nutritional parameters, counseling by experts in nutrition, and multivitamin/mineral supplement after ITx could be of benefit to the patients.

Topics: Adult; Body Mass Index; Bone Marrow Transplantation; Diabetes Mellitus, Type 1; Diet, Diabetic; Energy Intake; Exenatide; Follow-Up Studies; Humans; Hypoglycemic Agents; Insulin; Interviews as Topic; Islets of Langerhans Transplantation; Kidney Transplantation; Nutritional Status; Peptides; Perception; Surveys and Questionnaires; Venoms

Topics: Adult; Bezoars; Diabetes Mellitus, Type 1; Endoscopy, Gastrointestinal; Exenatide; Female; Gastroparesis; Glucagon-Like Peptide 1; Humans; Hypoglycemic Agents; Islets of Langerhans Transplantation; Kidney Transplantation; Peptides; Venoms

Oxyntomodulin (OXM), a postprandially released intestinal hormone, inhibits food intake via the glucagon-like peptide-1 receptor (GLP-1R). Although OXM may have clinical value in treating obesity, the cardiovascular effects of OXM are not well understood. Using telemetry to measure heart rate (HR), body temperature (Tb), and activity in conscious and freely moving mice, we tested 1) whether OXM affects HR and 2) whether this effect is mediated by the GLP-1R. We found that peripherally administered OXM significantly increased HR in wild-type mice, raising HR by >200 beats/min to a maximum of 728 +/- 11 beats/min. To determine the extent to which the sympathetic nervous system mediates the tachycardia of OXM, we delivered this hormone to mice deficient in dopamine-beta-hydroxylase [Dbh(-/-) mice], littermate controls [Dbh(+/-) mice], and autonomically blocked C57Bl mice. OXM increased HR equally in all groups (192 +/- 13, 197 +/- 21, and 216 +/- 11 beats/min, respectively), indicating that OXM elevated intrinsic HR. Intrinsic HR was also vigorously elevated by OXM in Glp-1R(-/-) mice (200 +/- 28 beats/min). In addition, peripherally administered OXM inhibited food intake and activity levels in wild-type mice and lowered Tb in autonomically blocked mice. None of these effects were observed in Glp-1R(-/-) mice. These data suggest multiple modes of action of OXM: 1) it directly elevates murine intrinsic HR through a GLP-1R-independent mechanism, perhaps via the glucagon receptor or an unidentified OXM receptor, and 2) it lowers food intake, activity, and Tb in a GLP-1R-dependent fashion.

Topics: Animals; Autonomic Nervous System; Blood Pressure; Body Temperature; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Dopamine beta-Hydroxylase; Dose-Response Relationship, Drug; Eating; Electrocardiography; Epinephrine; Exenatide; Female; Glucagon; Glucagon-Like Peptide-1 Receptor; Heart; Heart Rate; Mice; Mice, Inbred C57BL; Mice, Knockout; Motor Activity; Norepinephrine; Oxyntomodulin; Peptides; Rats; Rats, Sprague-Dawley; Receptors, Glucagon; Telemetry; Venoms

Glucagon-like peptide 1 (GLP-1) and its analogue exendin-4 (Ex4) have displayed potent glucose homeostasis-modulating characteristics in type 2 diabetes (T2D). However, there are few reports of effectiveness in type 1 diabetes (T1D) therapy, where there is massive loss of beta cells. We previously described a novel GLP-1 analogue consisting of the fusion of active GLP-1 and IgG heavy chain constant regions (GLP-1/IgG-Fc), and showed that in vivo expression of the protein, via electroporation-enhanced intramuscular plasmid-based gene transfer, normalized blood glucose levels in T2D-prone db/db mice. In the present study, GLP-1/IgG-Fc and Ex4/IgG-Fc were independently tested in multiple low-dose streptozotocin-induced T1D. Both GLP-1/IgG-Fc and Ex4/IgG-Fc effectively reduced fed blood glucose levels in treated mice and ameliorated diabetes symptoms, where as control IgG-Fc had no effect. Treatment with GLP-1/IgG-Fc or Ex4/IgG-Fc improved glucose tolerance and increased circulating insulin and GLP-1 levels. It also significantly enhanced islet beta-cell mass, which is likely a major factor in the amelioration of diabetes. This suggests that GLP-1/IgG-Fc gene therapy may be applicable to diseases where there is either acute or chronic beta-cell injury.

Topics: Animals; Blood Glucose; Cell Size; Diabetes Mellitus, Experimental; Diabetes Mellitus, Type 1; Electroporation; Exenatide; Gene Expression; Genetic Therapy; Glucagon-Like Peptide 1; Glucose Tolerance Test; Immunoglobulin Fc Fragments; Immunoglobulin G; Injections, Intramuscular; Insulin; Insulin-Secreting Cells; Mice; Mice, Inbred Strains; Peptides; Recombinant Fusion Proteins; Venoms

The American Diabetes Association currently recommends an A1C goal of less than 7 percent. However, many patients are unable to achieve this goal by using oral drug combinations or diet and exercise, leaving insulin as the only treatment option. In most cases, insulin is initiated later in therapy because of its inconvenience and adverse effects (e.g., weight gain, hypoglycemia, possible role in atherogenesis). Although insulin effectively helps patients attain glucose goals, the search for new agents continues. Two injectable agents, pramlintide and exenatide, were approved in 2005 for the treatment of diabetes. Pramlintide, indicated for use in patients with type 1 and 2 diabetes, is a synthetic analogue of human amylin that acts in conjunction with insulin to delay gastric emptying and inhibit the release of glucagon. Exenatide, a glucagon-like peptide-1 mimetic, has multiple mechanisms for lowering glucose levels, including the enhancement of insulin secretion, and is indicated for use in patients with type 2 diabetes. Clinical trials have shown that both agents reduce, by a statistically significant degree, A1C levels (0.3 to 0.7 percent more than placebo), fasting plasma glucose levels, and body weight (3 to 5 lb [1.4 to 2.3 kg]). No studies have examined their effects on diabetic complications, cardiovascular disease, or overall mortality. Pramlintide and exenatide may help make glycemic goals more attainable.

Topics: Amyloid; Diabetes Mellitus; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; Glycated Hemoglobin; Humans; Hypoglycemic Agents; Islet Amyloid Polypeptide; Peptides; Venoms

Immune modulators can arrest loss of insulin secretion in type 1 diabetes mellitus (T1DM), but they have not caused permanent disease remission or restored normal insulin secretion. We tested whether exendin-4, a glucagon-like peptide-1 receptor agonist, would enhance remission of T1DM in NOD mice treated with anti-CD3 monoclonal antibody (mAb) and studied the effects of exendin-4 treatment on cellular and metabolic responses of beta-cells. Diabetic NOD mice treated with anti-CD3 mAb and exendin-4 had a higher rate of remission (44%) than mice treated with anti-CD3 mAb alone (37%) or exendin-4 (0%) or insulin or IgG alone (0%) (P < 0.01). The effect of exendin-4 on reversal of diabetes after anti-CD3 mAb was greatest in mice with a glucose level of less than 350 mg/dl at diagnosis (63 vs. 39%, P < 0.05). Exendin-4 did not affect beta-cell area, replication, or apoptosis or reduce the frequency of diabetogenic or regulatory T cells or modulate the antigenicity of islet cells. Reversal of T1DM with anti-CD3 mAb was associated with recovery of insulin in glucose transporter-2(+)/insulin(-) islet cells that were identified at diagnosis. Glucose tolerance and insulin responses improved in mice treated with combination therapy, and exendin-4 increased insulin content and insulin release from beta-cells. We conclude that treatment with glucagon-like peptide-1 receptor agonist enhances remission of T1DM in NOD mice treated with anti-CD3 mAb by enhancing the recovery of the residual islets. This combinatorial approach may be useful in treatment of patients with new-onset T1DM.

Topics: Animals; Antibodies, Monoclonal; CD3 Complex; Cells, Cultured; Combined Modality Therapy; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon-Like Peptide-1 Receptor; Immunotherapy; Insulin-Secreting Cells; Mice; Mice, Inbred NOD; Mice, SCID; Peptides; Receptors, Glucagon; Remission Induction; Venoms

Exenatide is an incretin mimetic indicated for the treatment of type 2 diabetes mellitus in combination with a sulfonylurea, a thiazolidinedione, metformin, or metformin plus a sulfonylurea or thiazolidinedione. Exenatide lowers postprandial blood glucose levels by stimulating glucose-dependent insulin secretion, inhibiting glucagon secretion, slowing gastric emptying, and increasing satiety. Therapy with exenatide often results in weight loss, which further assists in decreasing insulin resistance. This feature makes the drug an attractive therapeutic option for obese patients. We report the successful off-label use of exenatide in an obese, 40-year-old man with type 1 diabetes and human immunodeficiency virus (HIV) infection who had gastrointestinal intolerance to pramlintide. The patient had experienced a dramatic weight gain secondary to his antiretroviral drugs. This weight gain led to insulin resistance and the development of type 2 diabetes; thus he had characteristics of both types 1 and 2 diabetes, or double diabetes. Before the start of exenatide therapy, he weighed 123 kg, had a body mass index of 42.3 kg/m(2), and had a suboptimal hemoglobin A(1c) value of 8.7%. After 11 months of therapy, the patient lost 24 kg (19.5% of his body weight) and achieved a hemoglobin A(1c) value of 7.3%. His basal insulin requirement was reduced by 25%, and his use of short-acting insulin before breakfast and before dinner was discontinued. In addition, the patient's quality of life substantially improved, as he was able to return to work and exercise after being nearly incapacitated by his weight. To our knowledge, this is the first published case report of the use of exenatide in a patient with type 1 diabetes mellitus or human immunodeficiency virus infection. Given this experience, exenatide may prove to be a useful alternative in selected patients with type 1 diabetes.

Topics: Adult; Diabetes Mellitus, Type 1; Diabetes Mellitus, Type 2; Exenatide; HIV Infections; Humans; Hypoglycemic Agents; Injections, Subcutaneous; Insulin Resistance; Male; Obesity; Peptides; Pioglitazone; Quality of Life; Thiazolidinediones; Treatment Outcome; Venoms; Weight Gain

Topics: Animals; Antibodies; CD3 Complex; Combined Modality Therapy; Diabetes Mellitus, Type 1; Exenatide; Glucagon-Like Peptide 1; Glucagon-Like Peptide-1 Receptor; Immunotherapy; Mice; Mice, Inbred NOD; Models, Biological; Peptides; Receptors, Glucagon; Treatment Outcome; Venoms

Type 1 diabetes mellitus (T1DM) is an autoimmune disease leading to near complete pancreatic beta-cell destruction. New evidence suggests that beta-cell regeneration is possible, but ongoing autoimmune damage prevents restoration of beta-cell mass. We tested the hypothesis that simultaneously blocking autoimmune cytokine damage and supplying a growth-promoting stimulus for beta-cells would provide a novel approach to reverse T1DM. Therefore, in this study we combined lisofylline to suppress autoimmunity and exendin-4 to enhance beta-cell proliferation for treating autoimmune-mediated diabetes in the non-obese diabetic (NOD) mouse model. We found that this combined therapy effectively reversed new-onset diabetes within a week of therapy, and even maintained euglycemia up to 145 days after treatment withdrawal. The therapeutic effect of this regimen was associated with improved beta-cell metabolism and insulin secretion, while reducing beta-cell apoptosis. It is possible that such combined therapy could become a new strategy to defeat T1DM in humans.

Topics: Animals; Diabetes Mellitus, Type 1; Drug Combinations; Exenatide; Insulin-Secreting Cells; Mice; Mice, Inbred C57BL; Pentoxifylline; Peptides; Treatment Outcome; Venoms

Treatment of overtly diabetic NOD mice with anti-lymphocyte serum (ALS), a polyclonal anti-T-cell antibody, abrogates autoimmunity and achieves partial clinical remission. Here we investigated whether the addition of exendin-4, a hormone that stimulates insulin secretion and beta-cell replication and differentiation, improves induction of remission by ALS. Transient treatment of overtly diabetic NOD mice with ALS and exendin-4 achieved complete remission in 23 of 26 mice (88%) within 75 days, accompanied by progressive normalization of glucose tolerance, improved islet histology, increased insulin content in the pancreas, and insulin release in response to a glucose challenge. Syngeneic islets transplanted into mice cured by treatment with ALS plus exendin-4 remained intact, and cotransfer of lymphocytes from cured mice delayed diabetes induction by adoptive transfer, suggesting the long-lasting presence of autoimmune regulatory cells. Although ALS alone also achieved reversal of diabetes, the frequency of remission was low (40%). No treatment or exendin-4 alone failed to produce remission. These results show that exendin-4 synergistically augments the remission-inducing effect of ALS. The addition of beta-cell growth factors, such as exendin-4, to immunotherapy protocols with anti-T-cell antibodies presents a potential novel approach to the cure of patients with new-onset type 1 diabetes.

Topics: Adoptive Transfer; Animals; Antilymphocyte Serum; Blood Glucose; Diabetes Mellitus, Type 1; Drug Administration Schedule; Drug Synergism; Drug Therapy, Combination; Exenatide; Female; Hyperglycemia; Immunosuppressive Agents; Insulin; Insulin Secretion; Mice; Mice, Inbred NOD; Mice, SCID; Pancreas; Pancreas Transplantation; Peptides; Venoms

Glucagon-like peptide-1 ameliorates the symptoms of diabetes through stimulation of insulin secretion and enhancement of beta-cell mass. We have therefore investigated the effects of glucagon-like peptide-1 on the development of diabetes, using db/db mice as a model of Type II diabetes.. The potent glucagon-like peptide-1 analogue Exendin-4 or vehicle (control) was administered (i.p.; 1 nmol/kg) to obese 6-week old db/db mice daily for 14 days ( n=10).. By 8 weeks of age, control db/db mice developed hyperglycaemia (fasting: 10.4+/-0.5 mmol/l), hyperinsulinaemia and impaired glucose tolerance. However, Exendin-4 treatment prevented hyperglycaemia (fasting: 6.1+/-1.0 mmol/l, p<0.01), with reduced plasma insulin concentrations ( p<0.001) and improved glucose tolerance ( p<0.05). Peripheral insulin sensitivity was not affected. However, insulin release in vivo and in vitro from the perfused pancreas was improved by Exendin-4, as were pancreatic insulin concentrations (0.54+/-0.02 vs 0.32+/-0.01 micro g/mg protein, p<0.05). These changes occurred in conjunction with increased beta-cell mass (3.01+/-0.31 vs 2.22+/-0.22 mg, p<0.05) and proliferation (BrdU(+) beta-cells: 1.08+/-0.20 vs 0.47+/-0.11%, p<0.05), as well as decreased apoptosis (Tunel (+) beta-cells: 0.37+/-0.06 vs 1.20+/-0.21%). Western blot demonstrated increased expression of Akt1 (by fivefold, p<0.01) and p44 MAP kinase (by sixfold, p<0.01), and decreased activation of caspase-3 (by 30%, p<0.05).. Our results suggest that Ex4 treatment delays the onset of diabetes in 6-8 week old db/db mice, through a mechanism involving Akt1 and expansion of the functional beta-cell mass.

Topics: Animals; Apoptosis; Blood Glucose; Cell Division; Diabetes Mellitus; Diabetes Mellitus, Type 1; Exenatide; Female; Glucagon; Glucagon-Like Peptide 1; Glucose Tolerance Test; Hyperglycemia; Insulin; Islets of Langerhans; Mice; Mice, Inbred C57BL; Mice, Inbred Strains; Peptide Fragments; Peptides; Protein Precursors; Venoms