scholarly journals Noninvasive Evaluation of GPR119 Agonist Effects on β-Cell Mass in Diabetic Male Mice Using 111In-Exendin-4 SPECT/CT

Endocrinology ◽  
2019 ◽  
Vol 160 (12) ◽  
pp. 2959-2968 ◽  
Author(s):  
Takaaki Murakami ◽  
Hiroyuki Fujimoto ◽  
Naotaka Fujita ◽  
Keita Hamamatsu ◽  
Koji Matsumoto ◽  
...  

Abstract Longitudinal observation of pancreatic β-cell mass (BCM) remains challenging because noninvasive techniques for determining BCM in vivo have not been established. Such observations would be useful for the monitoring of type 2 diabetes mellitus, a progressive disease involving loss of pancreatic BCM and function. An indium 111 (111In)–labeled exendin-4 derivative ([Lys12(111In-BnDTPA-Ahx)]exendin-4) targeting the glucagon-like peptide-1 receptor has been developed recently as a promising probe for quantifying the BCM noninvasively. In the present study, we used the 111In-exendin-4 single-photon emission CT/CT (SPECT/CT) technique to investigate the efficacy of DS-8500a, a novel G protein–coupled receptor-119 agonist currently under investigation for type 2 diabetes mellitus treatment in prediabetic db/db mice under dietary restriction. During the 8-week study, the treatment of mice with DS-8500a delayed and attenuated the progression of glucose intolerance compared with mice under dietary restriction alone. 111In-exendin-4 SPECT/CT of db/db mice revealed continuously decreasing radioactive isotope (RI) intensity in the pancreas during the 8-week intervention. DS-8500a attenuated this decrease and preserved pancreatic RI accumulation compared with dietary restriction alone at the end of the observation period. This result was corroborated not only by ex vivo pancreatic analysis using the [Lys12(111In-BnDTPA-Ahx)]exendin-4 probe but also by conventional histological BCM analysis. These results indicate that DS-8500a attenuates the progression of BCM loss beyond that of dietary restriction alone in prediabetic db/db mice. These results have shown that 111In-exendin-4 SPECT/CT will be useful for noninvasive longitudinal investigation of BCM in vivo.

2010 ◽  
Vol 31 (2) ◽  
pp. 261-261
Author(s):  
Alexander M. Owyang ◽  
Kathrin Maedler ◽  
Lisa Gross ◽  
Johnny Yin ◽  
Lin Esposito ◽  
...  

ABSTRACT Recent evidence suggests that IL-1β-mediated glucotoxicity plays a critical role in type 2 diabetes mellitus. Although previous work has shown that inhibiting IL-1β can lead to improvements in glucose control and β-cell function, we hypothesized that more efficient targeting of IL-1β with a novel monoclonal antibody, XOMA 052, would reveal an effect on additional parameters affecting metabolic disease. In the diet-induced obesity model, XOMA 052 was administered to mice fed either normal or high-fat diet (HFD) for up to 19 wk. XOMA 052 was administered as a prophylactic treatment or as a therapy. Mice were analyzed for glucose tolerance, insulin tolerance, insulin secretion, and lipid profile. In addition, the pancreata were analyzed for β-cell apoptosis, proliferation, and β-cell mass. Mice on HFD exhibited elevated glucose and glycated hemoglobin levels, impaired glucose tolerance and insulin secretion, and elevated lipid profile, which were prevented by XOMA 052. XOMA 052 also reduced β-cell apoptosis and increased β-cell proliferation. XOMA 052 maintained the HFDinduced compensatory increase in β-cell mass, while also preventing the loss in β-cell mass seen with extended HFD feeding. Analysis of fasting insulin and glucose levels suggests that XOMA 052 prevented HFD-induced insulin resistance. These studies provide new evidence that targeting IL-1β in vivo could improve insulin sensitivity and lead to β-cell sparing. This is in addition to previously reported benefits on glycemic control. Taken together, the data presented suggest that XOMA 052 could be effective for treating many aspects of type 2 diabetes mellitus.


2021 ◽  
Vol 12 ◽  
Author(s):  
Takaaki Murakami ◽  
Hiroyuki Fujimoto ◽  
Nobuya Inagaki

Pancreatic beta (β)-cell dysfunction and reduced mass play a central role in the development and progression of diabetes mellitus. Conventional histological β-cell mass (BCM) analysis is invasive and limited to cross-sectional observations in a restricted sampling area. However, the non-invasive evaluation of BCM remains elusive, and practical in vivo and clinical techniques for β-cell-specific imaging are yet to be established. The lack of such techniques hampers a deeper understanding of the pathophysiological role of BCM in diabetes, the implementation of personalized BCM-based diabetes management, and the development of antidiabetic therapies targeting BCM preservation and restoration. Nuclear medical techniques have recently triggered a major leap in this field. In particular, radioisotope-labeled probes using exendin peptides that include glucagon-like peptide-1 receptor (GLP-1R) agonist and antagonist have been employed in positron emission tomography and single-photon emission computed tomography. These probes have demonstrated high specificity to β cells and provide clear images accurately showing uptake in the pancreas and transplanted islets in preclinical in vivo and clinical studies. One of these probes, 111indium-labeled exendin-4 derivative ([Lys12(111In-BnDTPA-Ahx)]exendin-4), has captured the longitudinal changes in BCM during the development and progression of diabetes and under antidiabetic therapies in various mouse models of type 1 and type 2 diabetes mellitus. GLP-1R-targeted imaging is therefore a promising tool for non-invasive BCM evaluation. This review focuses on recent advances in non-invasive in vivo β-cell imaging for BCM evaluation in the field of diabetes; in particular, the exendin-based GLP-1R-targeted nuclear medicine techniques.


Vaccines ◽  
2020 ◽  
Vol 8 (1) ◽  
pp. 116 ◽  
Author(s):  
Elisa S. Roesti ◽  
Christina N. Boyle ◽  
Daniel T. Zeman ◽  
Marcos Sande-Melon ◽  
Federico Storni ◽  
...  

Type 2 diabetes mellitus (T2DM) is a chronic progressive disease characterized by insulin resistance and insufficient insulin secretion to maintain normoglycemia. The majority of T2DM patients bear amyloid deposits mainly composed of islet amyloid polypeptide (IAPP) in their pancreatic islets. These—originally β-cell secretory products—extracellular aggregates are cytotoxic for insulin-producing β-cells and are associated with β-cell loss and inflammation in T2DM advanced stages. Due to the absence of T2DM preventive medicaments and the presence of only symptomatic drugs acting towards increasing hormone secretion and action, we aimed at establishing a novel disease-modifying therapy targeting the cytotoxic IAPP deposits in order to prevent the development of T2DM. We generated a vaccine based on virus-like particles (VLPs), devoid of genomic material, coupled to IAPP peptides inducing specific antibodies against aggregated, but not monomeric IAPP. Using a mouse model of islet amyloidosis, we demonstrate in vivo that our vaccine induced a potent antibody response against aggregated, but not soluble IAPP, strikingly preventing IAPP depositions, delaying onset of hyperglycemia and the induction of the associated pro-inflammatory cytokine Interleukin 1β (IL-1β). We offer the first cost-effective and safe disease-modifying approach targeting islet dysfunction in T2DM, preventing pathogenic aggregates without disturbing physiological IAPP function.


2020 ◽  
Vol 21 (5) ◽  
pp. 1770
Author(s):  
Nadia Rachdaoui

Insulin, a hormone produced by pancreatic β-cells, has a primary function of maintaining glucose homeostasis. Deficiencies in β-cell insulin secretion result in the development of type 1 and type 2 diabetes, metabolic disorders characterized by high levels of blood glucose. Type 2 diabetes mellitus (T2DM) is characterized by the presence of peripheral insulin resistance in tissues such as skeletal muscle, adipose tissue and liver and develops when β-cells fail to compensate for the peripheral insulin resistance. Insulin resistance triggers a rise in insulin demand and leads to β-cell compensation by increasing both β-cell mass and insulin secretion and leads to the development of hyperinsulinemia. In a vicious cycle, hyperinsulinemia exacerbates the metabolic dysregulations that lead to β-cell failure and the development of T2DM. Insulin and IGF-1 signaling pathways play critical roles in maintaining the differentiated phenotype of β-cells. The autocrine actions of secreted insulin on β-cells is still controversial; work by us and others has shown positive and negative actions by insulin on β-cells. We discuss findings that support the concept of an autocrine action of secreted insulin on β-cells. The hypothesis of whether, during the development of T2DM, secreted insulin initially acts as a friend and contributes to β-cell compensation and then, at a later stage, becomes a foe and contributes to β-cell decompensation will be discussed.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Patlada Suthamwong ◽  
Manabu Minami ◽  
Toshiaki Okada ◽  
Nonomi Shiwaku ◽  
Mai Uesugi ◽  
...  

Endocrinology ◽  
2010 ◽  
Vol 151 (6) ◽  
pp. 2515-2527 ◽  
Author(s):  
Alexander M. Owyang ◽  
Kathrin Maedler ◽  
Lisa Gross ◽  
Johnny Yin ◽  
Lin Esposito ◽  
...  

Recent evidence suggests that IL-1β-mediated glucotoxicity plays a critical role in type 2 diabetes mellitus. Although previous work has shown that inhibiting IL-1β can lead to improvements in glucose control and β-cell function, we hypothesized that more efficient targeting of IL-1β with a novel monoclonal antibody, XOMA 052, would reveal an effect on additional parameters affecting metabolic disease. In the diet-induced obesity model, XOMA 052 was administered to mice fed either normal or high-fat diet (HFD) for up to 19 wk. XOMA 052 was administered as a prophylactic treatment or as a therapy. Mice were analyzed for glucose tolerance, insulin tolerance, insulin secretion, and lipid profile. In addition, the pancreata were analyzed for β-cell apoptosis, proliferation, and β-cell mass. Mice on HFD exhibited elevated glucose and glycated hemoglobin levels, impaired glucose tolerance and insulin secretion, and elevated lipid profile, which were prevented by XOMA 052. XOMA 052 also reduced β-cell apoptosis and increased β-cell proliferation. XOMA 052 maintained the HFD-induced compensatory increase in β-cell mass, while also preventing the loss in β-cell mass seen with extended HFD feeding. Analysis of fasting insulin and glucose levels suggests that XOMA 052 prevented HFD-induced insulin resistance. These studies provide new evidence that targeting IL-1β in vivo could improve insulin sensitivity and lead to β-cell sparing. This is in addition to previously reported benefits on glycemic control. Taken together, the data presented suggest that XOMA 052 could be effective for treating many aspects of type 2 diabetes mellitus.


2015 ◽  
Vol 112 (20) ◽  
pp. E2611-E2619 ◽  
Author(s):  
Karin Åvall ◽  
Yusuf Ali ◽  
Ingo B. Leibiger ◽  
Barbara Leibiger ◽  
Tilo Moede ◽  
...  

Insulin resistance and β-cell failure are the major defects in type 2 diabetes mellitus. However, the molecular mechanisms linking these two defects remain unknown. Elevated levels of apolipoprotein CIII (apoCIII) are associated not only with insulin resistance but also with cardiovascular disorders and inflammation. We now demonstrate that local apoCIII production is connected to pancreatic islet insulin resistance and β-cell failure. An increase in islet apoCIII causes promotion of a local inflammatory milieu, increased mitochondrial metabolism, deranged regulation of β-cell cytoplasmic free Ca2+ concentration ([Ca2+]i) and apoptosis. Decreasing apoCIII in vivo results in improved glucose tolerance, and pancreatic apoCIII knockout islets transplanted into diabetic mice, with high systemic levels of the apolipoprotein, demonstrate a normal [Ca2+]i response pattern and no hallmarks of inflammation. Hence, under conditions of islet insulin resistance, locally produced apoCIII is an important diabetogenic factor involved in impairment of β-cell function and may thus constitute a novel target for the treatment of type 2 diabetes mellitus.


2008 ◽  
Vol 93 (10) ◽  
pp. 3703-3716 ◽  
Author(s):  
Chee W. Chia ◽  
Josephine M. Egan

Context: Glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide are incretins secreted from enteroendocrine cells postprandially in part to regulate glucose homeostasis. Dysregulation of these hormones is evident in type 2 diabetes mellitus (T2DM). Two new drugs, exenatide (GLP-1 mimetic) and sitagliptin [dipeptidyl peptidase (DPP) 4 inhibitor], have been approved by regulatory agencies for treating T2DM. Liraglutide (GLP-1 mimetic) and vildagliptin (DPP 4 inhibitor) are expected to arrive on the market soon. Evidence Acquisition: The background of incretin-based therapy and selected clinical trials of these four drugs are reviewed. A MEDLINE search was conducted for published articles using the key words incretin, glucose-dependent insulinotropic polypeptide, GLP-1, exendin-4, exenatide, DPP 4, liraglutide, sitagliptin, and vildagliptin. Evidence Synthesis: Exenatide and liraglutide are injection based. Three-year follow-up data on exenatide showed a sustained weight loss and glycosylated hemoglobin (HbA1c) reduction of 1%. Nausea and vomiting are common. Results from phase 3 studies are pending on liraglutide. Sitagliptin and vildagliptin are orally active. In 24-wk studies, sitagliptin reduces HbA1c by 0.6–0.8% as monotherapy, 1.8% as initial combination therapy with metformin, and 0.7% as add-on therapy to metformin. Vildagliptin monotherapy lowered HbA1c by 1.0–1.4% after 24 wk. Their major side effects are urinary tract and nasopharyngeal infections and headaches. Exenatide and liraglutide cause weight loss, whereas sitagliptin and vildagliptin do not. Conclusions: The availability of GLP-1 mimetics and DPP 4 inhibitors has increased our armamentarium for treating T2DM. Unresolved issues such as the effects of GLP-1 mimetics and DPP 4 inhibitors on β-cell mass, the mechanism by which GLP-1 mimetics lowers glucagon levels, and exactly how DPP 4 inhibitors lead to a decline in plasma glucose levels without an increase in insulin secretion, need further research.


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