scholarly journals Epigenetics in β-cell adaptation and type 2 diabetes

2020 ◽  
Vol 55 ◽  
pp. 125-131
Author(s):  
Hyunki Kim ◽  
Rohit N. Kulkarni
2009 ◽  
Vol 204 (2) ◽  
pp. 143-152 ◽  
Author(s):  
J Han ◽  
Y Q Liu

Pyruvate carboxylase (PC) activity is enhanced in the islets of obese rats, but it is reduced in the islets of type 2 diabetic rats, suggesting the importance of PC in β-cell adaptation to insulin resistance as well as the possibility that PC reduction might lead to hyperglycemia. However, the causality is currently unknown. We used obese Agouti mice (AyL) as a model to show enhanced β-cell adaptation, and type 2 diabetic db/db mice as a model to show severe β-cell failure. After comparison of the two models, a less severe type 2 diabetic Agouti-K (AyK) mouse model was used to show the changes in islet PC activity during the development of type 2 diabetes mellitus (T2DM). AyK mice were separated into two groups: mildly (AyK-M, blood glucose <250 mg/dl) and severely (AyK-S, blood glucose >250 mg/dl) hyperglycemic. Islet PC activity, but not protein level, was increased 1.7-fold in AyK-M mice; in AyK-S mice, islet PC activity and protein level were reduced. All other changes including insulin secretion and islet morphology in AyK-M mice were similar to those observed in AyL mice, but they were worse in AyK-S mice where these parameters closely matched those in db/db mice. In 2-day treated islets, PC activity was inhibited by high glucose but not by palmitate. Our findings suggest that islet PC might play a role in the development of T2DM where reduction of PC activity might be a consequence of mild hyperglycemia and a cause for severe hyperglycemia.


2015 ◽  
Vol 42 ◽  
pp. 19-41 ◽  
Author(s):  
Emilyn U. Alejandro ◽  
Brigid Gregg ◽  
Manuel Blandino-Rosano ◽  
Corentin Cras-Méneur ◽  
Ernesto Bernal-Mizrachi

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.


2020 ◽  
Vol 16 (7) ◽  
pp. 699-715 ◽  
Author(s):  
Georgios S. Papaetis

Background: Prediabetes is defined as a state of glucose metabolism between normal glucose tolerance and type 2 diabetes. Continuous β-cell failure and death are the reasons for the evolution from normal glucose tolerance to prediabetes and finally type 2 diabetes. Introduction: The necessity of new therapeutic approaches in order to prevent or delay the development of type 2 diabetes is obligatory. Liraglutide, a long-acting GLP-1 receptor agonist, has 97% homology for native GLP-1. Identification of the trophic and antiapoptotic properties of liraglutide in preclinical studies, together with evidence of sustained β-cell function longevity during its administration in type 2 diabetes individuals, indicated its earliest possible administration during this disease, or even before its development, so as to postpone or delay its onset. Methods: Pubmed and Google databases have been thoroughly searched and relevant studies were selected. Results: This paper explores the current evidence of liraglutide administration both in humans and animal models with prediabetes. Also, it investigates the safety profile of liraglutide treatment and its future role to postpone or delay the evolution of type 2 diabetes. Conclusion: Liralgutide remains a valuable tool in our therapeutic armamentarium for individuals who are overweight or obese and have prediabetes. Future well designed studies will give valuable information that will help clinicians to stratify individuals who will derive the most benefit from this agent, achieving targeted therapeutic strategies.


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

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.


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