AMPK α1 mediates the protective effect of adiponectin against insulin resistance in INS‐1 pancreatic β cells

2019 ◽  
Vol 37 (8) ◽  
pp. 625-632 ◽  
Author(s):  
Yan Wang ◽  
Yan Li ◽  
Jing Qiao ◽  
Na Li ◽  
Shun Qiao
Keyword(s):  
Insulin Resistance ◽  
Protective Effect ◽  
Β Cells ◽  
Pancreatic Β Cells

scholarly journals Autocrine IGF2 programmes β-cell plasticity under conditions of increased metabolic demand

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ionel Sandovici ◽  
Constanze M. Hammerle ◽  
Sam Virtue ◽  
Yurena Vivas-Garcia ◽  
Adriana Izquierdo-Lahuerta ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Glucose Homeostasis ◽  
Association Studies ◽  
Susceptibility Gene ◽  
Chow Diet ◽  
Genome Wide Association Studies ◽  
Cell Plasticity ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells

AbstractWhen exposed to nutrient excess and insulin resistance, pancreatic β-cells undergo adaptive changes in order to maintain glucose homeostasis. The role that growth control genes, highly expressed in early pancreas development, might exert in programming β-cell plasticity in later life is a poorly studied area. The imprinted Igf2 (insulin-like growth factor 2) gene is highly transcribed during early life and has been identified in recent genome-wide association studies as a type 2 diabetes susceptibility gene in humans. Hence, here we investigate the long-term phenotypic metabolic consequences of conditional Igf2 deletion in pancreatic β-cells (Igf2βKO) in mice. We show that autocrine actions of IGF2 are not critical for β-cell development, or for the early post-natal wave of β-cell remodelling. Additionally, adult Igf2βKO mice maintain glucose homeostasis when fed a chow diet. However, pregnant Igf2βKO females become hyperglycemic and hyperinsulinemic, and their conceptuses exhibit hyperinsulinemia and placentomegalia. Insulin resistance induced by congenital leptin deficiency also renders Igf2βKO females more hyperglycaemic compared to leptin-deficient controls. Upon high-fat diet feeding, Igf2βKO females are less susceptible to develop insulin resistance. Based on these findings, we conclude that in female mice, autocrine actions of β-cell IGF2 during early development determine their adaptive capacity in adult life.

Specific Deletion of CASK in Pancreatic β Cells Affects Glucose Homeostasis and Improves Insulin Sensitivity in Obese Mice by Reducing Hyperinsulinemia Running Title: β Cell CASK Deletion Reduces Hyperinsulinemia

2021 ◽  
Author(s):  
Xingjing Liu ◽  
Peng Sun ◽  
Qingzhao Yuan ◽  
Jinyang Xie ◽  
Ting Xiao ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Insulin Secretion ◽  
Insulin Sensitivity ◽  
Glucose Homeostasis ◽  
Chow Diet ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Calcium Calmodulin Dependent ◽  
Normal Chow

Calcium/calmodulin-dependent serine protein kinase (CASK) is involved in the secretion of insulin vesicles in pancreatic β-cells. The present study revealed a new <i>in vivo </i>role of CASK in glucose homeostasis during the progression of type 2 diabetes mellitus (T2DM). A Cre-loxP system was used to specifically delete the <i>Cask </i>gene in mouse β-cells (βCASKKO), and the glucose metabolism was evaluated in <a>βCASKKO</a> mice fed a normal chow diet (ND) or a high-fat diet (HFD). ND-fed mice exhibited impaired insulin secretion in response to glucose stimulation. Transmission electron microscopy showed significantly reduced numbers of insulin granules at or near the cell membrane in the islets of βCASKKO mice. By contrast, HFD-fed βCASKKO mice showed reduced blood glucose and a partial relief of hyperinsulinemia and insulin resistance when compared to HFD-fed wildtype mice. The IRS1/PI3K/AKT signaling pathway was upregulated in the adipose tissue of HFD-βCASKKO mice. These results indicated that knockout of the <i>Cask</i> gene in β cells had a diverse effect on glucose homeostasis: reduced insulin secretion in ND-fed mice, but improves insulin sensitivity in HFD-fed mice. Therefore, CASK appears to function in the insulin secretion and contributes to hyperinsulinemia and insulin resistance during the development of obesity-related T2DM.

scholarly journals Selenoprotein P as a significant regulator of pancreatic β cell function

2019 ◽  
Author(s):  
Yoshiro Saito
Keyword(s):  
Insulin Resistance ◽  
Type 2 Diabetes ◽  
Molecular Mechanisms ◽  
Cell Function ◽  
Insulin Signalling ◽  
Selenoprotein P ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Β Cell Function

Abstract Selenoprotein P (SeP; encoded by SELENOP) is selenium (Se)-rich plasma protein that is mainly produced in the liver. SeP functions as a Se-transport protein to deliver Se from the liver to other tissues, such as the brain and testis. The protein plays a pivotal role in Se metabolism and antioxidative defense, and it has been identified as a ‘hepatokine’ that causes insulin resistance in type 2 diabetes. SeP levels are increased in type 2 diabetes patients, and excess SeP impairs insulin signalling, promoting insulin resistance. Furthermore, increased levels of SeP disturb the functioning of pancreatic β cells and inhibit insulin secretion. This review focuses on the biological function of SeP and the molecular mechanisms associated with the adverse effects of excess SeP on pancreatic β cells’ function, particularly with respect to redox reactions. Interactions between the liver and pancreas are also discussed.

Bile acid-polymer-probucol microparticles: protective effect on pancreatic β-cells and decrease in type 1 diabetes development in a murine model

2019 ◽  
Vol 24 (10) ◽  
pp. 1272-1277 ◽  
Author(s):  
Armin Mooranian ◽  
Nassim Zamani ◽  
Giuseppe Luna ◽  
Hesham Al-Sallami ◽  
Momir Mikov ◽  
...  
Keyword(s):  
Type 1 Diabetes ◽  
Bile Acid ◽  
Protective Effect ◽  
Murine Model ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Diabetes Development

Bach1 deficiency protects pancreatic β-cells from oxidative stress injury

2013 ◽  
Vol 305 (5) ◽  
pp. E641-E648 ◽  
Author(s):  
Keiichi Kondo ◽  
Yasushi Ishigaki ◽  
Junhong Gao ◽  
Tetsuya Yamada ◽  
Junta Imai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Insulin Resistance ◽  
Pancreatic Islets ◽  
Antioxidative Enzymes ◽  
Heme Oxygenase 1 ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Stress Injury ◽  
Induced Apoptosis ◽  
Deficient Mice

BTB and CNC homology 1 (Bach1) is a transcriptional repressor of antioxidative enzymes, such as heme oxygenase-1 (HO-1). Oxidative stress is reportedly involved in insulin secretion impairment and obesity-associated insulin resistance. However, the role of Bach1 in the development of diabetes is unclear. HO-1 expression in the liver, white adipose tissue, and pancreatic islets was markedly upregulated in Bach1-deficient mice. Unexpectedly, glucose and insulin tolerance tests showed no differences in obese wild-type (WT) and obese Bach1-deficient mice after high-fat diet loading for 6 wk, suggesting minimal roles of Bach1 in the development of insulin resistance. In contrast, Bach1 deficiency significantly suppressed alloxan-induced pancreatic insulin content reduction and the resultant glucose elevation. Furthermore, TUNEL-positive cells in pancreatic islets of Bach1-deficient mice were markedly decreased, by 60%, compared with those in WT mice. HO-1 expression in islets was significantly upregulated in alloxan-injected Bach1-deficient mice, whereas expression of other antioxidative enzymes, e.g., catalase, superoxide dismutase, and glutathione peroxidase, was not changed by either alloxan administration or Bach1 deficiency. Our results suggest that Bach1 deficiency protects pancreatic β-cells from oxidative stress-induced apoptosis and that the enhancement of HO-1 expression plays an important role in this protection.

scholarly journals Hyperinsulinemia promotes HMGB1 release leading to inflammation induced systemic insulin resistance: An interplay between pancreatic beta-cell and peripheral organs

2019 ◽  
Author(s):  
Abhinav Choubey ◽  
Aditya K Kar ◽  
Khyati Girdhar ◽  
Tandrika Chattopadhyay ◽  
Surbhi Dogra ◽  
...  
Keyword(s):  
Insulin Resistance ◽  
Pancreatic Beta Cell ◽  
Underlying Mechanism ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Extracellular Milieu ◽  
Peripheral Organs ◽  
Systemic Insulin Resistance

SummaryInsulin resistance results from several pathophysiologic mechanisms, including chronic tissue inflammation and defective insulin signaling. Pancreatic β-cells hypersecretion (hyperinsulinemia), is a central hallmark of peripheral insulin resistance. However, the underlying mechanism by which hyperinsulinemia perpetuates towards the development of insulin resistance remains unclear and is still a bigger therapeutic challenge. Here, we found hyperinsulinemia triggers inflammation and insulin resistance by stimulating TLR4-driven inflammatory cascades. We show that hyperinsulinemia activates the TLR4 signaling through HMGB1, an endogenous TLR4 ligand emanating from hyperinsulinemia exposed immune cells and peripheral organs like adipose tissue and liver. Further, our observation suggests hyperinsulinemia ensuring hyperacetylation, nuclear-to-cytoplasmic shuttling and release of HMGB1 into the extracellular space. HMGB1 was also found to be elevated in serum of T2DM patients. We found that extracellular HMGB1 plays a crucial role to promote proinflammatory responses and provokes systemic insulin resistance. Importantly, in-vitro and in-vivo treatment with naltrexone, a TLR4 antagonist led to an anti-inflammatory phenotype with protection from hyperinsulinemia mediated insulin resistance. In-vitro treatment with naltrexone directly enhanced SIRT1 activity, blocked the release of HMGB1 into extracellular milieu, suppressed release of proinflammatory cytokines and ultimately led to insulin-sensitizing effects. These observations elucidate a regulatory network between pancreatic β-cells, macrophage and hepatocytes and assign an unexpected role of TLR4 - HMGB1 signaling axis in hyperinsulinemia mediated systemic insulin resistance.Graphical Abstract

scholarly journals Protective Effect of Siegesbeckia orientalis on Pancreatic β-Cells under High Glucose-Induced Glucotoxicity

2021 ◽  
Vol 11 (22) ◽  
pp. 10963
Author(s):  
Chi-Chang Chang ◽  
Jer-Yiing Houng ◽  
Shih-Wei Wang ◽  
Chin-Feng Hsuan ◽  
Yung-Chuan Lu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Enzymes ◽  
Insulin Secretion ◽  
Protective Effect ◽  
Normal Level ◽  
High Glucose ◽  
Glucose Concentration ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Siegesbeckia Orientalis

The glucotoxicity caused by long-term exposure of β-cells to high glucose (HG) conditions may lead to the generation of more reactive oxygen species (ROS), reduce the activity of antioxidant enzymes, cause cell damage and apoptosis, and induce insulin secretion dysfunction. Siegesbeckia orientalis linne is a traditional folk herbal medicine used to treat snake bites, rheumatoid arthritis, allergies, and immune deficiencies. In this study, we evaluated the protective effect of S. orientalis ethanol extract (SOE) on cell death and oxidative stress in RIN-m5f pancreatic β-cells stimulated by two HG concentrations (50–100 mM). In the cell viability assay, SOE could significantly increase the survival rate of pancreatic β-cells under HG-induced conditions. For the oxidative stress induced by HG condition, the treatment of SOE effectively reduced the ROS formation, increased the content of intracellular glutathione, and up-regulated the expression of antioxidant enzymes, catalase, superoxide dismutase, and glutathione peroxidase. As a result, the SOE treatment could decrease the glucotoxicity-mediated oxidative damage on RIN-m5F β-cells. Moreover, SOE had the function of regulating insulin secretion in pancreatic β-cells under different HG-mediated conditions. It could decrease the increasing intracellular insulin secretion under the low glucose concentration to normal level; while increase the decreasing intracellular insulin secretion under the relatively high glucose concentration to normal level. Taken together, this study suggests that SOE has a protective effect on pancreatic β-cells under the HG-stimulated glucotoxic environment.

scholarly journals Protective effect of pancreatic β -cells MIN6 by some medicinal plants in the Mekong Delta

2018 ◽  
Vol 56 (5) ◽  
pp. 637-641
Author(s):  
Le Thi Bach ◽  
Le Tien Dung ◽  
Nguyen Trong Tuan ◽  
Nguyen Thanh Phuong ◽  
Patrick Kestemont ◽  
...  
Keyword(s):  
Medicinal Plants ◽  
Protective Effect ◽  
Mekong Delta ◽  
Β Cells ◽  
Pancreatic Β Cells

Natural Products Modulating Autophagy Pathway Against the Pathogenesis of Diabetes Mellitus

2018 ◽  
Vol 20 (1) ◽  
pp. 96-110 ◽  
Author(s):  
Linghuan Li ◽  
Jiameng Qi ◽  
Hanbing Li
Keyword(s):  
Diabetes Mellitus ◽  
Insulin Resistance ◽  
Natural Products ◽  
Potential Drug ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Drug Candidates ◽  
Peripheral Insulin Resistance ◽  
Treatment Of Diabetes ◽  
Autophagy Pathway

Autophagy is a conserved, regulated cellular process for the degradation of abnormal proteins and disrupted organelles. Literature has described that dysregulation of autophagy is closely related to the pathogenesis of diabetes mellitus in processes such as impaired pancreatic β cells function, peripheral insulin resistance and diabetic complications. Emerging evidence indicates that natural products may possess anti-diabetic activity via regulation of autophagy. In this review, we summarize natural products targeting the pathogenesis of diabetes mellitus through the regulation of autophagy and underline possible mechanisms, providing potential drug candidates or therapies for the treatment of diabetes mellitus.

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