Unique and Shared Metabolic Regulation in Clonal β-Cells and Primary Islets Derived From Rat Revealed by Metabolomics Analysis

Endocrinology ◽  
2015 ◽  
Vol 156 (6) ◽  
pp. 1995-2005 ◽  
Author(s):  
Peter Spégel ◽  
Lotta E. Andersson ◽  
Petter Storm ◽  
Vladimir Sharoyko ◽  
Isabel Göhring ◽  
...  
Keyword(s):  
Metabolic Regulation ◽  
Cell Model ◽  
Cell Metabolism ◽  
Lactate Production ◽  
Cellular Heterogeneity ◽  
Β Cells ◽  
Β Cell ◽  
Rat Islets ◽  
Altered Glucose ◽  
Elevated Glucose

Abstract As models for β-cell metabolism, rat islets are, to some extent, a, heterogeneous cell population stressed by the islet isolation procedure, whereas rat-derived clonal β-cells exhibit a tumor-like phenotype. To describe to what extent either of these models reflect normal cellular metabolism, we compared metabolite profiles and gene expression in rat islets and the INS-1 832/13 line, a widely used clonal β-cell model. We found that insulin secretion and metabolic regulation provoked by glucose were qualitatively similar in these β-cell models. However, rat islets exhibited a more pronounced glucose-provoked increase of glutamate, glycerol-3-phosphate, succinate, and lactate levels, whereas INS-1 832/13 cells showed a higher glucose-elicited increase in glucose-6-phosphate, alanine, isocitrate, and α-ketoglutarate levels. Glucose induced a decrease in levels of γ-aminobutyrate (GABA) and aspartate in rat islets and INS-1 832/13 cells, respectively. Genes with cellular functions related to proliferation and the cell cycle were more highly expressed in the INS-1 832/13 cells. Most metabolic pathways that were differentially expressed included GABA metabolism, in line with altered glucose responsiveness of GABA. Also, lactate dehydrogenase A, which is normally expressed at low levels in mature β-cells, was more abundant in rat islets than in INS-1 832/13 cells, confirming the finding of elevated glucose-provoked lactate production in the rat islets. Overall, our results suggest that metabolism in rat islets and INS-1 832/13 cells is qualitatively similar, albeit with quantitative differences. Differences may be accounted for by cellular heterogeneity of islets and proliferation of the INS-1 832/13 cells.

Time-resolved metabolomics analysis of β-cells implicates the pentose phosphate pathway in the control of insulin release

2013 ◽  
Vol 450 (3) ◽  
pp. 595-605 ◽  
Author(s):  
Peter Spégel ◽  
Vladimir V. Sharoyko ◽  
Isabel Goehring ◽  
Anders P. H. Danielsson ◽  
Siri Malmgren ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Pentose Phosphate Pathway ◽  
Metabolic Response ◽  
Cell Metabolism ◽  
Pentose Phosphate ◽  
Β Cells ◽  
Β Cell ◽  
Time Resolved ◽  
Atp Production ◽  
Rat Islets

Insulin secretion is coupled with changes in β-cell metabolism. To define this process, 195 putative metabolites, mitochondrial respiration, NADP+, NADPH and insulin secretion were measured within 15 min of stimulation of clonal INS-1 832/13 β-cells with glucose. Rapid responses in the major metabolic pathways of glucose occurred, involving several previously suggested metabolic coupling factors. The complexity of metabolite changes observed disagreed with the concept of one single metabolite controlling insulin secretion. The complex alterations in metabolite levels suggest that a coupling signal should reflect large parts of the β-cell metabolic response. This was fulfilled by the NADPH/NADP+ ratio, which was elevated (8-fold; P<0.01) at 6 min after glucose stimulation. The NADPH/NADP+ ratio paralleled an increase in ribose 5-phosphate (>2.5-fold; P<0.001). Inhibition of the pentose phosphate pathway by trans-dehydroepiandrosterone (DHEA) suppressed ribose 5-phosphate levels and production of reduced glutathione, as well as insulin secretion in INS-1 832/13 β-cells and rat islets without affecting ATP production. Metabolite profiling of rat islets confirmed the glucose-induced rise in ribose 5-phosphate, which was prevented by DHEA. These findings implicate the pentose phosphate pathway, and support a role for NADPH and glutathione, in β-cell stimulus-secretion coupling.

[Ca2+]i-reducing action of cAMP in rat pancreatic β-cells: involvement of thapsigargin-sensitive stores

1998 ◽  
Vol 274 (2) ◽  
pp. C513-C521 ◽  
Author(s):  
Kazuro Yaekura ◽  
Toshihiko Yada
Keyword(s):  
Cell Metabolism ◽  
Pyridine Nucleotide ◽  
Dependent Manner ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Concentration Dependent Manner ◽  
Elevated Glucose ◽  
Glucagon Like Peptide 1 ◽  
Pka Pathway

In the present study, we examined the ability of adenosine 3′,5′-cyclic monophosphate (cAMP) to reduce elevated levels of cytosolic Ca2+ concentration ([Ca2+]i) in pancreatic β-cells. [Ca2+]iand reduced pyridine nucleotide, NAD(P)H, were measured in rat single β-cells by fura 2 and autofluorescence microfluorometry. Sustained [Ca2+]ielevation, induced by high KCl (25 mM) at a basal glucose concentration (2.8 mM), was substantially reduced by cAMP-increasing agents, dibutyryl cAMP (DBcAMP, 5 mM), an adenylyl cyclase activator forskolin (10 μM), and an incretin glucagon-like peptide-1-(7–36) amide (10−9 M), as well as by glucose (16.7 mM). The [Ca2+]i-reducing effects of cAMP were greater at elevated glucose (8.3–16.7 mM) than at basal glucose (2.8 mM). An inhibitor of protein kinase A (PKA), H-89, counteracted [Ca2+]i-reducing effects of cAMP but not those of glucose. Okadaic acid, a phosphatase inhibitor, at 10–100 nM also reduced sustained [Ca2+]ielevation in a concentration-dependent manner. Glucose, but not DBcAMP, increased NAD(P)H in β-cells. [Ca2+]i-reducing effects of cAMP were inhibited by 0.3 μM thapsigargin, an inhibitor of the endoplasmic reticulum (ER) Ca2+ pump. In contrast, [Ca2+]i-reducing effects of cAMP were not altered by ryanodine, an ER Ca2+-release inhibitor, Na+-free conditions, or diazoxide, an ATP-sensitive K+ channel opener. In conclusion, the cAMP-PKA pathway reduces [Ca2+]ielevation by sequestering Ca2+ in thapsigargin-sensitive stores. This process does not involve, but is potentiated by, activation of β-cell metabolism. Together with the known [Ca2+]i-increasing action of cAMP, our results reveal dual regulation of β-cell [Ca2+]iby the cAMP-signaling pathway and by a physiological incretin.

scholarly journals High sensitivity of β-cell replication to the inhibitory effects of interleukin-1β: modulation by adenoviral overexpression of IGF2 in rat islets

2009 ◽  
Vol 203 (1) ◽  
pp. 55-63 ◽  
Author(s):  
Elisabet Estil.les ◽  
Noèlia Téllez ◽  
Joan Soler ◽  
Eduard Montanya
Keyword(s):  
Cell Proliferation ◽  
Cell Apoptosis ◽  
Interleukin 1Β ◽  
Complete Suppression ◽  
Cell Replication ◽  
Inhibitory Effects ◽  
Β Cells ◽  
Β Cell ◽  
Rat Islets ◽  
Induced Apoptosis

Interleukin-1β (IL1B) is an important contributor to the autoimmune destruction of β-cells in type 1 diabetes, and it has been recently related to the development of type 2 diabetes. IGF2 stimulates β-cell proliferation and survival. We have determined the effect of IL1B on β-cell replication, and the potential modulation by IGF2 and glucose. Control-uninfected and adenovirus encoding for IGF2 (Ad-IGF2)-infected rat islets were cultured at 5.5 or 22.2 mmol/l glucose with or without 1, 10, 30, and 50 U/ml of IL1B. β-Cell replication was markedly reduced by 10 U/ml of IL1B and was almost nullified with 30 or 50 U/ml of IL1B. Higher concentrations of IL1B were required to increase β-cell apoptosis. Although IGF2 overexpression had a strong mitogenic effect on β-cells, IGF2 could preserve β-cell proliferation only in islets cultured with 10 U/ml IL1B, and had no effect with 30 and 50 U/ml of IL1B. In contrast, IGF2 overexpression induced a clear protection against IL1B-induced apoptosis, and higher concentrations of the cytokine were needed to increase β-cell apoptosis in Ad-IGF2-infected islets. These results indicate that β-cell replication is highly sensitive to the deleterious effects of the IL1B as shown by the inhibition of replication by relatively low IL1B concentrations, and the almost complete suppression of β-cell replication with high IL1B concentrations. Likewise, the inhibitory effects of IL-β on β-cell replication were not modified by glucose, and were only modestly prevented by IGF2 overexpression, in contrast with the higher protection against IL1B-induced apoptosis afforded by glucose and by IGF2 overexpression.

scholarly journals Inhibition of Forkhead Box O1 Protects Pancreatic β-Cells against Dexamethasone-Induced Dysfunction

Endocrinology ◽  
2009 ◽  
Vol 150 (9) ◽  
pp. 4065-4073 ◽  
Author(s):  
Xiongfei Zhang ◽  
Wei Yong ◽  
Jinghuan Lv ◽  
Yunxia Zhu ◽  
Jingjing Zhang ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Types ◽  
Pancreatic Β Cell ◽  
Rinm5f Cells ◽  
Β Cells ◽  
Β Cell ◽  
Rat Islets ◽  
Cell Dysfunction ◽  
Forkhead Box ◽  
Glucose Stimulated Insulin Secretion

Abstract Forkhead Box O1 (FoxO1) is a key transcription regulator of insulin/IGF-I signaling pathway, and its activity can be increased by dexamethasone (DEX) in several cell types. However, the role of FoxO1 in DEX-induced pancreatic β-cell dysfunction has not been fully understood. Therefore, in this study, we investigated whether FoxO1 could mediate DEX-induced β-cell dysfunction and the possible underlying mechanisms in pancreatic β-cell line RINm5F cells and primary rat islet. We found that DEX markedly increased FoxO1 mRNA and protein expression and decreased FoxO1 phosphorylation through the Akt pathway, which resulted in an increase in active FoxO1 in RINm5F cells and isolated rat islets. Activated FoxO1 subsequently inhibited pancreatic duodenal homeobox-1 expression and induced nuclear exclusion of pancreatic duodenal homeobox-1. Knockdown of FoxO1 by RNA interference restored the expression of pancreatic duodenal homeobox-1 and prevented DEX-induced dysfunction of glucose-stimulated insulin secretion in rat islets. Together, the results of present study demonstrate that FoxO1 is integrally involved in DEX-induced inhibition of pancreatic duodenal homeobox-1 and glucose-stimulated insulin secretion dysfunction in pancreatic islet β-cells. Inhibition of FoxO1 can effectively protect β-cells against DEX-induced dysfunction.

scholarly journals Medicinal Plants for the Treatment of Mental Diseases in Pregnancy: An In Vitro Safety Assessment

Planta Medica ◽  
2021 ◽  
Author(s):  
Deborah Spiess ◽  
Moritz Winker ◽  
Antoine Chauveau ◽  
Vanessa Fabienne Abegg ◽  
Olivier Potterat ◽  
...  
Keyword(s):  
Cell Model ◽  
Lactate Production ◽  
Well Being ◽  
Placental Cell ◽  
California Poppy ◽  
Altered Glucose ◽  
Mental Diseases ◽  
Bewo B30 ◽  
In Pregnancy

AbstractPregnancy is a critical period for medical care, during which the well-being of woman and fetus must be considered. This is particularly relevant in managing non-psychotic mental disorders since treatment with central nervous system-active drugs and untreated NMDs may have negative effects. Some well-known herbal preparations (phytopharmaceuticals), including St. Johnʼs wort, California poppy, valerian, lavender, and hops, possess antidepressant, sedative, anxiolytic, or antidepressant properties and could be used to treat mental diseases such as depression, restlessness, and anxiety in pregnancy. Our goal was to assess their safety in vitro, focusing on cytotoxicity, induction of apoptosis, genotoxicity, and effects on metabolic properties and differentiation in cells widely used as a placental cell model (BeWo b30 placenta choriocarcinoma cells). The lavender essential oil was inconspicuous in all experiments and showed no detrimental effects. At low-to-high concentrations, no extract markedly affected the chosen safety parameters. At an artificially high concentration of 100 µg/mL, extracts from St. Johnʼs wort, California poppy, valerian, and hops had minimal cytotoxic effects. None of the extracts resulted in genotoxic effects or altered glucose consumption or lactate production, nor did they induce or inhibit BeWo b30 cell differentiation. This study suggests that all tested preparations from St. Johnʼs wort, California poppy, valerian, lavender, and hops, in concentrations up to 30 µg/mL, do not possess any cytotoxic or genotoxic potential and do not compromise placental cell viability, metabolic activity, and differentiation. Empirical and clinical studies during pregnancy are needed to support these in vitro data.

scholarly journals Perilipin2 down-regulation in β cells impairs insulin secretion under nutritional stress and damages mitochondria

2020 ◽  
Author(s):  
Akansha Mishra ◽  
Siming Liu ◽  
Joseph Promes ◽  
Mikako Harata ◽  
William Sivitz ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Function ◽  
Islet Cells ◽  
Cell Metabolism ◽  
Nutritional Stress ◽  
Β Cells ◽  
Β Cell ◽  
Down Regulation

Perilipin 2 (PLIN2) is the lipid droplet (LD) protein in β cells that increases under nutritional stress. Down-regulation of PLIN2 is often sufficient to reduce LD accumulation. To determine whether PLIN2 positively or negatively affects β cell function under nutritional stress, PLIN2 was down-regulated in mouse β cells, INS1 cells, and human islet cells. β cell specific deletion of PLIN2 in mice on a high fat diet reduced glucose-stimulated insulin secretion (GSIS) in vivo and in vitro. Down-regulation of PLIN2 in INS1 cells blunted GSIS after 24 h incubation with 0.2 mM palmitic acids. Down-regulation of PLIN2 in human pseudoislets cultured at 5.6 mM glucose impaired both phases of GSIS, indicating that PLIN2 is critical for GSIS. Down-regulation of PLIN2 decreased specific OXPHOS proteins in all three models and reduced oxygen consumption rates in INS1 cells and mouse islets. Moreover, we found that PLIN2 deficient INS1 cells increased the distribution of a fluorescent oleic acid analog to mitochondria and showed signs of mitochondrial stress as indicated by susceptibility to fragmentation and alterations of acyl-carnitines and glucose metabolites. Collectively, PLIN2 in β cells have an important role in preserving insulin secretion, β cell metabolism and mitochondrial function under nutritional stress.

scholarly journals Emerging role of testosterone in pancreatic β cell function and insulin secretion

2019 ◽  
Vol 240 (3) ◽  
pp. R97-R105 ◽  
Author(s):  
Weiwei Xu ◽  
Jamie Morford ◽  
Franck Mauvais-Jarvis
Keyword(s):  
Insulin Secretion ◽  
Metabolic Regulation ◽  
Cell Function ◽  
Visceral Obesity ◽  
Β Cells ◽  
Β Cell ◽  
Β Cell Function ◽  
Glucagon Like Peptide 1 ◽  
Glucose Stimulated Insulin Secretion

One of the most sexually dimorphic aspects of metabolic regulation is the bidirectional modulation of glucose homeostasis by testosterone in male and females. Severe testosterone deficiency predisposes men to type 2 diabetes (T2D), while in contrast, androgen excess predisposes women to hyperglycemia. The role of androgen deficiency and excess in promoting visceral obesity and insulin resistance in men and women respectively is well established. However, although it is established that hyperglycemia requires β cell dysfunction to develop, the role of testosterone in β cell function is less understood. This review discusses recent evidence that the androgen receptor (AR) is present in male and female β cells. In males, testosterone action on AR in β cells enhances glucose-stimulated insulin secretion by potentiating the insulinotropic action of glucagon-like peptide-1. In females, excess testosterone action via AR in β cells promotes insulin hypersecretion leading to oxidative injury, which in turn predisposes to T2D.

scholarly journals The Role of Oxidative Stress in Pancreatic β Cell Dysfunction in Diabetes

2021 ◽  
Vol 22 (4) ◽  
pp. 1509
Author(s):  
Natsuki Eguchi ◽  
Nosratola D. Vaziri ◽  
Donald C. Dafoe ◽  
Hirohito Ichii
Keyword(s):  
Oxidative Stress ◽  
Cell Function ◽  
Pancreatic Β Cell ◽  
Antioxidative Capacity ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Levels ◽  
Cell Dysfunction ◽  
Elevated Glucose ◽  
Β Cell Function

Diabetes is a chronic metabolic disorder characterized by inappropriately elevated glucose levels as a result of impaired pancreatic β cell function and insulin resistance. Extensive studies have been conducted to elucidate the mechanism involved in the development of β cell failure and death under diabetic conditions such as hyperglycemia, hyperlipidemia, and inflammation. Of the plethora of proposed mechanisms, endoplasmic reticulum (ER) stress, mitochondrial dysfunction, and oxidative stress have been shown to play a central role in promoting β cell dysfunction. It has become more evident in recent years that these 3 factors are closely interrelated and importantly aggravate each other. Oxidative stress in particular is of great interest to β cell health and survival as it has been shown that β cells exhibit lower antioxidative capacity. Therefore, this review will focus on discussing factors that contribute to the development of oxidative stress in pancreatic β cells and explore the downstream effects of oxidative stress on β cell function and health. Furthermore, antioxidative capacity of β cells to counteract these effects will be discussed along with new approaches focused on preserving β cells under oxidative conditions.

scholarly journals Metabolic regulation of insulin secretion in health and disease

2021 ◽  
Vol 43 (2) ◽  
pp. 4-8
Author(s):  
Elizabeth Haythorne ◽  
Frances M Ashcroft
Keyword(s):  
Insulin Secretion ◽  
Metabolic Regulation ◽  
Cell Function ◽  
Cell Metabolism ◽  
Neonatal Diabetes ◽  
Β Cell ◽  
Membrane Pore ◽  
Glucose Levels ◽  
Global Pandemic ◽  
Β Cell Function

Despite the current media focus, Covid-19 is not the only current pandemic. There is also a global pandemic of diabetes. It is caused by an insufficiency of the hormone insulin, which lowers blood glucose levels. Here we highlight recent work that addresses the question of how insulin is normally secreted from the β-cells of the pancreas and what goes wrong with this process in diabetes. We focus on the metabolic regulation of the ATP-sensitive potassium channel, an ATP-gated membrane pore that regulates insulin secretion. We show that when this pore is shut, insulin is released, and when it is open, insulin release is prevented. As may be expected, genetic mutations that impair the ability of ATP to close the channel cause neonatal diabetes. We also consider if a failure of β-cell metabolism to generate enough ATP to close the channel may lead to the progressive decline in β-cell function in type 2 diabetes.

scholarly journals Kinetic modelling of β-cell metabolism reveals control points in the insulin-regulating pyruvate cycling pathways

2021 ◽  
Author(s):  
Rahul Rahul ◽  
Adam Stinchcombe ◽  
Jamie Joseph ◽  
Brian P Ingalls
Keyword(s):  
Drug Targets ◽  
Kinetic Modelling ◽  
Tricarboxylic Acid Cycle ◽  
Cell Metabolism ◽  
Second Phase ◽  
Β Cells ◽  
Glucose Levels ◽  
Pyruvate Cycling ◽  
Elevated Glucose

Insulin, a key hormone in the regulation of glucose homeostasis, is secreted by pancreatic β-cells in response to elevated glucose levels. Insulin is released in a biphasic manner in response to glucose metabolism in β-cells. The first phase of insulin secretion is triggered by an increase in the ATP:ADP ratio; the second phase occurs in response to both a rise in ATP:ADP as well as other key metabolic signals, including a rise in the NADPH:NADP+ ratio. Experimental evidence indicates that pyruvate-cycling pathways play an important role in the elevation of the NADPH:NADP+ ratio in response to glucose. In this work we developed a kinetic model for the tricarboxylic acid cycle and pyruvate cycling pathways. We successfully validated our model against recent experimental observations and performed local and global sensitivity analysis to identify key regulatory interactions in the system. The model predicts that the dicarboxylate carrier (DIC) and pyruvate transporter (PYC) are the most important regulators of pyruvate cycling and NADPH production. In contrast, our analysis showed that variation in the pyruvate carboxylase (PC) flux was compensated by a response in the activity of mitochondrial isocitrate dehydrogenase (ICDm) resulting in minimal effect on overall pyruvate cycling flux. The model predictions suggest starting points for further experimental investigation, as well as potential drug targets for treatment of type 2 diabetes.

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