scholarly journals Diacylglycerol Signaling Pathway in Pancreatic β-Cells: An Essential Role of Diacylglycerol Kinase in the Regulation of Insulin Secretion

2015 ◽  
Vol 38 (5) ◽  
pp. 669-673 ◽  
Author(s):  
Yukiko K. Kaneko ◽  
Tomohisa Ishikawa
Keyword(s):  
Insulin Secretion ◽  
Signaling Pathway ◽  
Essential Role ◽  
Diacylglycerol Kinase ◽  
Β Cells ◽  
Pancreatic Β Cells

Deletion of Fas in the pancreatic β-cells leads to enhanced insulin secretion

2009 ◽  
Vol 297 (6) ◽  
pp. E1304-E1312 ◽  
Author(s):  
Diana Choi ◽  
Anna Radziszewska ◽  
Stephanie A. Schroer ◽  
Nicole Liadis ◽  
Yunfeng Liu ◽  
...  
Keyword(s):  
Cell Death ◽  
Insulin Secretion ◽  
Essential Role ◽  
Fas Ligand ◽  
Cell Mass ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Insulin Promoter

Fas/Fas ligand belongs to the tumor necrosis factor superfamily of receptors/ligands and is best known for its role in apoptosis. However, recent evidence supports its role in other cellular responses, including proliferation and survival. Although Fas has been implicated as an essential mediator of β-cell death in the pathogenesis of type 1 diabetes, the essential role of Fas specifically in pancreatic β-cells has been found to be controversial. Moreover, the role of Fas on β-cell homeostasis and function is not clear. The objective of this study is to determine the role of Fas specifically in β-cells under both physiological and diabetes models. Mice with Fas deletion specifically in the β-cells were generated using the Cre-loxP system. Cre-mediated Fas deletion was under the control of the rat insulin promoter. Absence of Fas in β-cells leads to complete protection against FasL-induced cell death. However, Fas is not essential in determining β-cell mass or susceptibility to streptozotocin- or HFD-induced diabetes. Importantly, Fas deletion in β-cells leads to increased p65 expression, enhanced glucose tolerance, and glucose-stimulated insulin secretion, with increased exocytosis as manifested by increased changes in membrane capacitance and increased expression of Syntaxin1A, VAMP2, and munc18a. Together, our study shows that Fas in the β-cells indeed plays an essential role in the canonical death receptor-mediated apoptosis but is not essential in regulating β-cell mass or diabetes development. However, β-cell Fas is critical in the regulation of glucose homeostasis through regulation of the exocytosis machinery.

scholarly journals Bimodal role of conventional protein kinase C in insulin secretion from rat pancreatic β cells

2004 ◽  
Vol 561 (1) ◽  
pp. 133-147 ◽  
Author(s):  
Hui Zhang ◽  
Masahiro Nagasawa ◽  
Satoko Yamada ◽  
Hideo Mogami ◽  
Yuko Suzuki ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Insulin Secretion ◽  
Protein Kinase ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Kinase C

scholarly journals Role of the active zone protein, ELKS, in insulin secretion from pancreatic β-cells

2019 ◽  
Vol 27 ◽  
pp. S81-S91 ◽  
Author(s):  
Mica Ohara-Imaizumi ◽  
Kyota Aoyagi ◽  
Toshihisa Ohtsuka
Keyword(s):  
Insulin Secretion ◽  
Active Zone ◽  
Β Cells ◽  
Pancreatic Β Cells

CFTR silencing in pancreatic β-cells reveals a functional impact on glucose-stimulated insulin secretion and oxidative stress response

2016 ◽  
Vol 310 (3) ◽  
pp. E200-E212 ◽  
Author(s):  
Thierry Ntimbane ◽  
Geneviève Mailhot ◽  
Schohraya Spahis ◽  
Remi Rabasa-Lhoret ◽  
Marie-Laure Kleme ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cystic Fibrosis ◽  
Insulin Secretion ◽  
Inflammatory Responses ◽  
Lipid Peroxides ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Min6 Cells ◽  
Atp Production

Cystic fibrosis (CF)-related diabetes (CFRD) has become a critical complication that seriously affects the clinical outcomes of CF patients. Although CFRD has emerged as the most common nonpulmonary complication of CF, little is known about its etiopathogenesis. Additionally, whether oxidative stress (OxS), a common feature of CF and diabetes, influences CFRD pathophysiology requires clarification. The main objective of this study was to shed light on the role of the cystic fibrosis transmembrane conductance regulator (CFTR) in combination with OxS in insulin secretion from pancreatic β-cells. CFTR silencing was accomplished in MIN6 cells by stable expression of small hairpin RNAs (shRNA), and glucose-induced insulin secretion was evaluated in the presence and absence of the valuable prooxidant system iron/ascorbate (Fe/Asc; 0.075/0.75 mM) along with or without the antioxidant Trolox (1 mM). Insulin output from CFTR-silenced MIN6 cells was significantly reduced (∼70%) at basal and at different glucose concentrations compared with control Mock cells. Furthermore, CFTR silencing rendered MIN6 cells more sensitive to OxS as evidenced by both increased lipid peroxides and weakened antioxidant defense, especially following incubation with Fe/Asc. The decreased insulin secretion in CFTR-silenced MIN6 cells was associated with high levels of NF-κB (the major participant in inflammatory responses), raised apoptosis, and diminished ATP production in response to the Fe/Asc challenge. However, these defects were alleviated by the addition of Trolox, thereby pointing out the role of OxS in aggravating the effects of CFTR deficiency. Our findings indicate that CFTR deficiency in combination with OxS may contribute to endocrine cell dysfunction and insulin secretion, which at least in part may explain the development of CFRD.

scholarly journals Nuclear Factor Y in Male Mouse pancreatic β-cells Plays a Crucial Role in Glucose Homeostasis by Regulating β-Cell Mass and Insulin Secretion

2021 ◽  
Author(s):  
Yin Liu ◽  
Siyuan He ◽  
Ruixue Zhou ◽  
Xueping Zhang ◽  
Shanshan Yang ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Insulin Secretion ◽  
Cell Mass ◽  
Physiological Role ◽  
Nuclear Factor ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Nuclear Factor Y

Pancreatic β-cell mass and insulin secretion are determined by the dynamic change of transcription factor expression levels in response to altered metabolic demand. Nuclear factor-Y (NF-Y) is an evolutionarily conserved transcription factor playing critical roles in multiple cellular processes. However, the physiological role of NF-Y in pancreatic β-cells is poorly understood. The present study was undertaken in a conditional knockout of <i>Nf-ya</i> specifically in pancreatic β-cells (<i>Nf-ya </i>βKO) to define the essential physiological role of NF-Y in β-cells. <i>Nf-ya </i>βKO mice exhibited glucose intolerance without changes in insulin sensitivity. Reduced β-cell proliferation resulting in decreased β-cell mass was observed in these mice, which was associated with disturbed actin cytoskeleton. NF-Y-deficient β-cells also exhibited impaired insulin secretion with a reduced Ca<sup>2+</sup> influx in response to glucose, which was associated an inefficient glucose uptake into β-cells due to a decreased expression of glucose transporter 2 and a reduction in ATP production resulting from the disruption of mitochondrial integrity. This study is the first to show that NF-Y is critical for pancreatic islets homeostasis and function through regulation in β-cell proliferation, glucose uptake into β-cells, and mitochondrial energy metabolism. Modulating NF-Y expression in β-cells may therefore offer an attractive approach for therapeutic intervention.

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