Toxicity Induced by Cytokines, Glucose, and Lipids Increase Apoptosis and Hamper Insulin Secretion in the 1.1E7 Beta Cell-Line

Basic research on types 1 and 2 diabetes mellitus require early stage studies using beta cells or cell lines, ideally of human origin and with preserved insulin secretion in response to glucose. The 1.1E7 cells are a hybrid cell line resulting from the electrofusion of dispersed human islets and PANC-1 cells, capable of secreting insulin in response to glucose, but their survival and function under toxic conditions remains untested. This characterization is the purpose of the present study. We treated these cells with a cytokine mix, high glucose, palmitate, and the latter two combined. Under these conditions, we measured cell viability and apoptosis (MTT, Caspase Glo and TUNEL assays, as well as caspase-8 and -9 levels by Western blotting), endoplasmic reticulum stress markers (EIF2AK3, HSPA4, EIF2a, and HSPA5) by real-time PCR, and insulin secretion with a glucose challenge. All of these stimuli (i) induce apoptosis and ER stress markers expression, (ii) reduce mRNA amounts of 2–5 components of genes involved in the insulin secretory pathway, and (iii) abrogate the insulin release capability of 1.1E7 cells in response to glucose. The most pronounced effects were observed with cytokines and with palmitate and high glucose combined. This characterization may well serve as the starting point for those choosing this cell line for future basic research on certain aspects of diabetes.

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Effects of High Glucose Levels and Glycated Serum on GIP Responsiveness in the Pancreatic Beta Cell Line HIT-T15

Journal of Diabetes Research ◽

10.1155/2015/326359 ◽

2015 ◽

Vol 2015 ◽

pp. 1-7 ◽

Cited By ~ 4

Author(s):

Alessandra Puddu ◽

Roberta Sanguineti ◽

Fabrizio Montecucco ◽

Giorgio Luciano Viviani

Keyword(s):

Insulin Secretion ◽

Beta Cell ◽

Cell Line ◽

High Glucose ◽

Intracellular Signaling ◽

Pancreatic Beta Cells ◽

Pancreatic Beta Cell ◽

Diabetic Patients ◽

Glucose Levels ◽

Beta Cell Line

Glucose-dependent insulinotropic peptide (GIP) is an incretin hormone produced in the gastrointestinal tract that stimulates glucose dependent insulin secretion. Impaired incretin response has been documented in diabetic patients and was mainly related to the inability of the pancreatic beta cells to secrete insulin in response to GIP. Advanced Glycation End Products (AGEs) have been shown to play an important role in pancreatic beta cell dysfunction. The aim of this study is to investigate whether the exposure to AGEs can induce GIP resistance in the pancreatic beta cell line HIT-T15. Cells were cultured for 5 days in low (CTR) or high glucose (HG) concentration in the presence of AGEs (GS) to evaluate the expression of GIP receptor (GIPR), the intracellular signaling activated by GIP, and secretion of insulin in response to GIP. The results showed that incubation with GS alone altered intracellular GIP signaling and decreased insulin secretion as compared to CTR. GS in combination with HG reduced the expression of GIPR and PI3K and abrogated GIP-induced AKT phosphorylation and GIP-stimulated insulin secretion. In conclusion, we showed that treatment with GS is associated with the loss of the insulinotropic effect of GIP in hyperglycemic conditions.

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Glucose induces calcium-dependent and calcium-independent insulin secretion from the pancreatic beta cell line MIN6

Acta Endocrinologica ◽

10.1530/eje.0.1330227 ◽

1995 ◽

Vol 133 (2) ◽

pp. 227-234 ◽

Cited By ~ 5

Author(s):

Nobuko Sakuma ◽

San-e Ishikawa ◽

Koji Okada ◽

Jun-ichi Miyazaki ◽

Toshikazu Saito

Keyword(s):

Insulin Secretion ◽

Beta Cell ◽

Cell Line ◽

Glucose Level ◽

High Glucose ◽

Pancreatic Beta Cell ◽

Camp Production ◽

Calcium Dependent ◽

Beta Cell Line ◽

High Glucose Level

Sakuma N, Ishikawa S, Okada K, Miyazaki J, Saito T, Glucose induces calcium-dependent and calcium-independent insulin secretion from the pancreatic beta cell line MIN6. Eur J Endocrinol 1995;133:227–34. ISSN 0804–4643 The present study was undertaken to determine whether there are Ca2+-dependent and -independent pathways of glucose-induced insulin secretion from the pancreatic beta cell line MIN6. Glucose at a concentration of 16.7 mmol/l caused marked increases in cellular free calcium [Ca2+]1) and insulin secretion, which depended on glucose metabolism. When cells were pretreated with 20 mmol/l mannoheptulose, an inhibitor of glucokinase, the 16.7 mmol/l glucose induced a rise in [Ca2+]1 and insulin secretion disappeared. Also, l-leucine and l-arginine increased [Ca2+]1 and induced insulin secretion. Under Ca2+-free conditions, insulin release was still induced, without any change in [Ca2+]1, by these three different stimulants. The cumulative values of insulin secretion were 13.7–29.3% of the control, which were significantly less than that in the presence of Ca2+. Cellular alkalinization occurred in response to all these stimulants, irrespective of the presence or absence of Ca2+. Forskolin, a diterpene activator of adenylate cyclase, produced insulin secretion independently of [Ca2+]1, which accompanied cellular alkalinization. Also, a high glucose level increased cellular cyclic AMP (cAMP) production in the presence and absence of Ca2+, and the effect was diminished by approximately 73% in Ca2+-free conditions. These results indicate that a high glucose level stimulates both Ca2+-dependent and -independent insulin secretion from pancreatic beta cells. We suggest that the cAMP production and the cellular alkalinization participate in the Ca2+-independent mechanism. Nobuko Sakuma, Division of Endocrinology and Metabolism, Department of Medicine, Jichi Medical School, 3311-1 Yakushiji Minamikawachi-machi, Tochigi 329-04, Japan

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The Role of Cytosolic Calcium in Insulin Secretion from a Hamster Beta Cell Line

Advances in Experimental Medicine and Biology - Biophysics of the Pancreatic β-Cell ◽

10.1007/978-1-4684-5314-0_27 ◽

1986 ◽

pp. 305-316

Author(s):

A. E. Boyd ◽

R. S. Hill ◽

T. Y. Nelson ◽

J. M. Oberwetter ◽

M. Berg

Keyword(s):

Insulin Secretion ◽

Beta Cell ◽

Cell Line ◽

Cytosolic Calcium ◽

Beta Cell Line

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alpha-Glycerophosphate shuttle in a clonal beta-cell line

AJP Endocrinology and Metabolism ◽

10.1152/ajpendo.1989.256.1.e173 ◽

1989 ◽

Vol 256 (1) ◽

pp. E173-E178 ◽

Cited By ~ 1

Author(s):

M. D. Meglasson ◽

K. M. Smith ◽

D. Nelson ◽

M. Erecinska

Keyword(s):

Insulin Secretion ◽

Cell Line ◽

Electron Transport Chain ◽

Direct Evidence ◽

Mitochondrial Fraction ◽

Secreting Cell ◽

Transport Chain ◽

Beta Cell Line ◽

Atp Generation ◽

Hit Cells

It has been proposed that the alpha-glycerophosphate (alpha-GOP) shuttle plays a crucial role in regulation of glycolysis in beta-cells by linking reoxidation of cytosolic NADH to formation of ATP in the electron transport chain (J. Biol. Chem. 265: 8287, 1981). Direct evidence for this suggestion is still lacking, however. In this work the operation of the alpha-GOP shuttle was investigated in the insulin-secreting cell line HIT-T15. The constituent enzymes of the pathway were found to be present in HIT cells. Flavin-linked alpha-GOP dehydrogenase was associated with the mitochondrial fraction, whereas NAD+-dependent alpha-GOP dehydrogenase was localized in the cytosol. In the presence of amobarbital (used to preserve the function of the alpha-GOP shuttle under conditions where oxidation of NADH by the respiratory chain was blocked), glucose increased insulin secretion, O2 consumption, and the cell [ATP]/[ADP] when compared with amobarbital alone. These results indicate that the alpha-GOP shuttle contributes to ATP generation in HIT cells and that its activation may be necessary for the initiation of insulin secretion by glucose.

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A comparative study of amino acid consumption by rat islet cells and the clonal beta-cell line BRIN-BD11 - the functional significance of L-alanine

Journal of Endocrinology ◽

10.1677/joe.0.1790447 ◽

2003 ◽

Vol 179 (3) ◽

pp. 447-454 ◽

Cited By ~ 50

Author(s):

G Dixon ◽

J Nolan ◽

N McClenaghan ◽

PR Flatt ◽

P Newsholme

Keyword(s):

Insulin Secretion ◽

Beta Cell ◽

Cell Line ◽

Islet Cells ◽

Beta Cell Line ◽

Acid Consumption ◽

Glutamine Consumption ◽

Order Of Magnitude ◽

Stimulus Secretion Coupling ◽

Insulinotropic Effect

Evidence has been published that L -alanine may, under appropriate conditions, promote insulin secretion in normal rodent islets and various beta cell lines. Previous results utilising the clonal beta-cell line BRIN-BD11, demonstrated that alanine dramatically elevated insulin release by a mechanism requiring oxidative metabolism. We demonstrate in this paper that addition ofL -alanine had an insulinotropic effect in dispersed primary islet cells. Addition of D -glucose increasedL -alanine consumption in both BRIN-BD11 cells and primary islet cells.L -glutamine consumption in the BRIN-BD11 cell line and primary rat islets was also determined. The consumption rate was in line with that previously reported for cells of the immune system and other glutamine-utilising cells or tIssues. However,L -alanine consumption was at least an order of magnitude higher thanL -glutamine consumption. The metabolism ofL -alanine in the beta-cell may result in stimulation of insulin secretion via generation of metabolic stimulus secretion coupling factors such asL -glutamate.

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High dose of histone deacetylase inhibitors affects insulin secretory mechanism of pancreatic beta cell line

Endocrine Regulations ◽

10.2478/enr-2018-0004 ◽

2018 ◽

Vol 52 (1) ◽

pp. 21-26 ◽

Cited By ~ 5

Author(s):

Eiji Yamato

Keyword(s):

Insulin Secretion ◽

Beta Cell ◽

Cell Line ◽

Beta Cells ◽

Pancreatic Beta Cells ◽

Pancreatic Beta Cell ◽

High Dose ◽

Min6 Cells ◽

Beta Cell Line ◽

High Doses

Abstract Objective. Histone deacytylase inhibitors (HDACis) inhibit the deacetylation of the lysine residue of proteins, including histones, and regulate the transcription of a variety of genes. Recently, HDACis have been used clinically as anti-cancer drugs and possible anti-diabetic drugs. Even though HDACis have been proven to protect the cytokine-induced damage of pancreatic beta cells, evidence also shows that high doses of HDACis are cytotoxic. In the present study, we, therefore, investigated the eff ect of HDACis on insulin secretion in a pancreatic beta cell line. Methods. Pancreatic beta cells MIN6 were treated with selected HDACis (trichostatin A, TSA; valproic acid, VPA; and sodium butyrate, NaB) in medium supplemented with 25 mM glucose and 13% heat-inactivated fetal bovine serum (FBS) for indicated time intervals. Protein expression of Pdx1 and Mafa in MIN6 cells was demonstrated by immunohistochemistry and immunocytochemistry, expression of Pdx1 and Mafa genes was measured by quantitative RT-PCR method. Insulin release from MIN6 cells and insulin cell content were estimated by ELISA kit. Superoxide production in MIN6 cells was measured using a Total ROS/Superoxide Detection System. Results. TSA, VPA, and NaB inhibited the expression of Pdx1 and Mafa genes and their products. TSA treatment led to beta cell malfunction, characterized by enhanced insulin secretion at 3 and 9 mM glucose, but impaired insulin secretion at 15 and 25 mM glucose. Th us, TSA induced dysregulation of the insulin secretion mechanism. TSA also enhanced reactive oxygen species production in pancreatic beta cells. Conclusions. Our results showed that HDACis caused failure to suppress insulin secretion at low glucose concentrations and enhance insulin secretion at high glucose concentrations. In other words, when these HDACis are used clinically, high doses of HDACis may cause hypoglycemia in the fasting state and hyperglycemia in the fed state. When using HDACis, physicians should, therefore, be aware of the capacity of these drugs to modulate the insulin secretory capacity of pancreatic beta cells.

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