scholarly journals Elevated Neuropeptide Y1 Receptor Signaling Contributes to β-cell Dysfunction and Failure in Type 2 Diabetes

2021 ◽  
Author(s):  
Chieh-Hsin Yang ◽  
Danise Ann-Onda ◽  
Xuzhu Lin ◽  
Stacey Fynch ◽  
Shaktypreya Nadarajah ◽  
...  

Loss of functional β-cell mass is a key factor contributing to the poor glycaemic control in type 2 diabetes. However, therapies that directly target these underlying processes remains lacking. Here we demonstrate that gene expression of neuropeptide Y1 receptor and its ligand, neuropeptide Y, was significantly upregulated in human islets from subjects with type 2 diabetes. Importantly, the reduced insulin secretion in type 2 diabetes was associated with increased neuropeptide Y and Y1 receptor expression in human islets. Consistently, pharmacological inhibition of Y1 receptors by BIBO3304 significantly protected β-cells from dysfunction and death under multiple diabetogenic conditions in islets. In a preclinical study, Y1 receptor antagonist BIBO3304 treatment improved β-cell function and preserved functional β-cell mass, thereby resulting in better glycaemic control in both high-fat-diet/multiple low dose streptozotocin- and db/db type 2 diabetic mice. Collectively, our results uncovered a novel causal link of increased islet NPY-Y1 receptor signaling to β-cell dysfunction and failure in human type 2 diabetes. These results further demonstrate that inhibition of Y1 receptor by BIBO3304 represents a novel and effective β-cell protective therapy for improving functional β-cell mass and glycaemic control in type 2 diabetes.

Metabolites ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 58 ◽  
Author(s):  
Michael D. Schaid ◽  
Yanlong Zhu ◽  
Nicole E. Richardson ◽  
Chinmai Patibandla ◽  
Irene M. Ong ◽  
...  

The transition from β-cell compensation to β-cell failure is not well understood. Previous works by our group and others have demonstrated a role for Prostaglandin EP3 receptor (EP3), encoded by the Ptger3 gene, in the loss of functional β-cell mass in Type 2 diabetes (T2D). The primary endogenous EP3 ligand is the arachidonic acid metabolite prostaglandin E2 (PGE2). Expression of the pancreatic islet EP3 and PGE2 synthetic enzymes and/or PGE2 excretion itself have all been shown to be upregulated in primary mouse and human islets isolated from animals or human organ donors with established T2D compared to nondiabetic controls. In this study, we took advantage of a rare and fleeting phenotype in which a subset of Black and Tan BRachyury (BTBR) mice homozygous for the Leptinob/ob mutation—a strong genetic model of T2D—were entirely protected from fasting hyperglycemia even with equal obesity and insulin resistance as their hyperglycemic littermates. Utilizing this model, we found numerous alterations in full-body metabolic parameters in T2D-protected mice (e.g., gut microbiome composition, circulating pancreatic and incretin hormones, and markers of systemic inflammation) that correlate with improvements in EP3-mediated β-cell dysfunction.


2007 ◽  
Vol 292 (6) ◽  
pp. E1694-E1701 ◽  
Author(s):  
Jane J. Kim ◽  
Yoshiaki Kido ◽  
Philipp E. Scherer ◽  
Morris F. White ◽  
Domenico Accili

Type 2 diabetes results from impaired insulin action and β-cell dysfunction. There are at least two components to β-cell dysfunction: impaired insulin secretion and decreased β-cell mass. To analyze how these two variables contribute to the progressive deterioration of metabolic control seen in diabetes, we asked whether mice with impaired β-cell growth due to Irs2 ablation would be able to mount a compensatory response in the background of insulin resistance caused by Insr haploinsufficiency. As previously reported, ∼70% of mice with combined Insr and Irs2 mutations developed diabetes as a consequence of markedly decreased β-cell mass. In the initial phases of the disease, we observed a robust increase in circulating insulin levels, even as β-cell mass gradually declined, indicating that replication-defective β-cells compensate for insulin resistance by increasing insulin secretion. These data provide further evidence for a heterogeneous β-cell response to insulin resistance, in which compensation can be temporarily achieved by increasing function when mass is limited. The eventual failure of compensatory insulin secretion suggests that a comprehensive treatment of β-cell dysfunction in type 2 diabetes should positively affect both aspects of β-cell physiology.


2016 ◽  
Vol 229 (3) ◽  
pp. 343-356 ◽  
Author(s):  
Kaiyuan Yang ◽  
Jonathan Gotzmann ◽  
Sharee Kuny ◽  
Hui Huang ◽  
Yves Sauvé ◽  
...  

We compared the evolution of insulin resistance, hyperglycemia, and pancreatic β-cell dysfunction in the Nile rat (Arvicanthis niloticus), a diurnal rodent model of spontaneous type 2 diabetes (T2D), when maintained on regular laboratory chow versus a high-fiber diet. Chow-fed Nile rats already displayed symptoms characteristic of insulin resistance at 2 months (increased fat/lean mass ratio and hyperinsulinemia). Hyperglycemia was first detected at 6 months, with increased incidence at 12 months. By this age, pancreatic islet structure was disrupted (increased α-cell area), insulin secretion was impaired (reduced insulin secretion and content) in isolated islets, insulin processing was compromised (accumulation of proinsulin and C-peptide inside islets), and endoplasmic reticulum (ER) chaperone protein ERp44 was upregulated in insulin-producing β-cells. By contrast, high-fiber-fed Nile rats had normoglycemia with compensatory increase in β-cell mass resulting in maintained pancreatic function. Fasting glucose levels were predicted by the α/β-cell ratios. Our results show that Nile rats fed chow recapitulate the five stages of progression of T2D as occurs in human disease, including insulin-resistant hyperglycemia and pancreatic islet β-cell dysfunction associated with ER stress. Modification of diet alone permits long-term β-cell compensation and prevents T2D.


Author(s):  
Hironobu Sasaki ◽  
Yoshifumi Saisho ◽  
Jun Inaishi ◽  
Hiroshi Itoh

Abstract Type 2 diabetes (T2DM) is characterized by insulin resistance and β-cell dysfunction. Since patients with T2DM have inadequate beta cell mass (BCM), and β-cell dysfunction worsens glycemic control and makes treatment difficult, therapeutic strategies to preserve and restore BCM are needed.In rodent models, obesity increases BCM about 3-fold, but the increase in BCM in humans is limited. Besides, obesity-induced changes in BCM may show racial differences between East Asians and Caucasians. Recently, the Developmental Origins of Health and Disease hypothesis, which states that the risk of developing non-communicable diseases including T2DM is influenced by the fetal environment, has been proposed. It is known in rodents that animals with low birthweight have reduced BCM through epigenetic modifications, making them more susceptible to diabetes in the future. Similarly, in humans, we revealed that individuals born with low birthweight have lower BCM in adulthood. Since β-cell replication is more frequently observed in the five years after birth, and β-cells are found to be more plastic in that period, a history of childhood obesity increases BCM. BCM in patients with T2DM is reduced by 20-65% compared with that in individuals without T2DM. However, since BCM starts to decrease from the stage of borderline diabetes, early intervention is essential for β-cell protection. In this review, we summarize the current knowledge on regulatory factors of human β-cell mass in health and diabetes, and propose the β-cell centric concept of diabetes to enhance a more pathophysiology-based treatment approach for T2DM.


2021 ◽  
Author(s):  
Hung Tae Kim ◽  
Arnaldo H. de Souza ◽  
Heidi Umhoefer ◽  
JeeYoung Han ◽  
Lucille Anzia ◽  
...  

AbstractLoss of functional pancreatic β-cell mass and increased β-cell apoptosis are fundamental to the pathophysiology of both type 1 and type 2 diabetes. Pancreatic islet transplantation has the potential to cure type 1 diabetes but is often ineffective due to the death of the islet graft within the first few years after transplant. Therapeutic strategies to directly target pancreatic β-cell survival are needed to prevent and treat diabetes and to improve islet transplant outcomes. Reducing β-cell apoptosis is also a therapeutic strategy for type 2 diabetes. Cholecystokinin (CCK) is a peptide hormone typically produced in the gut after food intake, with positive effects on obesity and glucose metabolism in mouse models and human subjects. We have previously shown that pancreatic islets also produce CCK. The production of CCK within the islet promotes β-cell survival in rodent models of diabetes and aging. Now, we demonstrate a direct effect of CCK to reduce cytokine-mediated apoptosis in a β-cell line and in isolated mouse islets in a receptor-dependent manner. However, whether CCK can protect human β-cells was previously unknown. Here, we report that CCK can also reduce cytokine-mediated apoptosis in isolated human islets and CCK treatment in vivo decreases β-cell apoptosis in human islets transplanted into the kidney capsule of diabetic NOD/SCID mice. Collectively, these data identify CCK as a novel therapy that can directly promote β-cell survival in human islets and has therapeutic potential to preserve β-cell mass in diabetes and as an adjunct therapy after transplant.One Sentence SummaryCholecystokinin ameliorates pancreatic β-cell death under models of stress and after transplant of human islets.


1998 ◽  
Vol 275 (3) ◽  
pp. E457-E462 ◽  
Author(s):  
Jack L. Leahy ◽  
Mark S. Fineman

We have proposed that a hyperstimulated insulin secretion causing β-cell degranulation is the basis for the impaired glucose-potentiated insulin secretion in type 2 diabetes (“overworked β-cell”). To confirm this idea, we previously investigated tolbutamide-infused euglycemic rats. Two novel kinds of β-cell dysfunction were observed: altered phasic glucose-potentiated insulin secretion with preferential sparing of the first phase and a raised secreted ratio of amylin to insulin. The current study tested these parameters in 90% (intact β-cell insulin stores) and 95% (markedly lowered insulin stores) pancreatectomized (Px) diabetic rats. Rats underwent pancreas perfusion 5–6 wk postsurgery. Controls showed nonchanging insulin secretion during a 20-min perfusion of 16.7 mM glucose + 10 mM arginine. In contrast, both Px groups showed an altered phasic pattern, with the first phase being supernormal (for the β-cell mass) but the second phase reduced in tandem with the insulin content. Amylin secretion from control and 90% Px rats paralleled the insulin output, so that the amylin-to-insulin ratio averaged 0.12 ± 0.03% in the controls and 0.16 ± 0.01% in the 90% Px rats over the two secretory phases. In contrast, the amylin-to-insulin ratio in 95% Px rats equaled that of controls during the first phase (0.12 ± 0.1%) but was twice normal during the second phase (0.32 ± 0.4%). These results confirm the validity of the overworked β-cell schema by showing identical β-cell functional defects in Px rats and tolbutamide-infused normoglycemic rats.


2020 ◽  
Vol 12 (2) ◽  
Author(s):  
Stephen Hanley

While the prevalence of maternal While the prevalence of diabetes mellitus reaches epidemic proportions, most available treatments still focus on the symptoms of the disease, rather than the underlying pathology. Types 1 and 2 diabetes have in common a deficit in β-cell mass. In type 1 diabetes, auto-immune β-cell destruction leads to an absolute deficit in β-cells, while in type 2 diabetes, insulin resistance and β-cell dysfunction cause a functional deficit. More recently, however, it has been suggested that type 2 diabetes is also marked by an absolute deficit in β-cell mass, although a causal relationship has not yet been established. Overall β-cell mass reflects the balance between the dynamic processes of β-cell expansion, through proliferation and neogenesis, and β-cell loss via apoptosis. Given that β-cell mass can be modified significantly by altering the rate of any of these mechanisms, therapies that modulate β-cell expansion and loss have garnered recent interest. We review herein the current therapeutics under investigation as modulators of β-cell mass dynamics, and the basic research that supports these novel therapeutic targets.


2011 ◽  
pp. 5-10
Author(s):  
Huu Dang Tran

The incretins are peptide hormones secreted from the gut in response to food. They increase the secretion of insulin. The incretin response is reduced in patients with type 2 diabetes so drugs acting on incretins may improve glycaemic control. Incretins are metabolised by dipeptidyl peptidase, so selectively inhibiting this enzyme increases the concentration of circulating incretins. A similar effect results from giving an incretin analogue that cannot be cleaved by dipeptidyl peptidase. Studies have identified other actions including improvement in pancreatic β cell glucose sensitivity and, in animal studies, promotion of pancreatic β cell proliferation and reduction in β cell apoptosis.


Author(s):  
Froylan David Martínez-Sánchez ◽  
Valerie Paola Vargas-Abonce ◽  
Andrea Rocha-Haro ◽  
Romina Flores-Cardenas ◽  
Milagros Fernández-Barrio ◽  
...  

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