scholarly journals Photolysis of cell-permeant caged inositol pyrophosphates controls oscillations of cytosolic calcium in a β-cell line

2019 ◽  
Vol 10 (9) ◽  
pp. 2687-2692 ◽  
Author(s):  
S. Hauke ◽  
A. K. Dutta ◽  
V. B. Eisenbeis ◽  
D. Bezold ◽  
T. Bittner ◽  
...  
Keyword(s):  
Cell Line ◽  
Cytosolic Calcium ◽  
Β Cells ◽  
Β Cell ◽  
Inositol Pyrophosphate ◽  
Inositol Pyrophosphates ◽  
Line P

β-Cells respond directly to the intracellular photochemical release of caged inositol pyrophosphate isomers with modulations of oscillations in cytosolic Ca2+.

scholarly journals Differentiation of Sendai Virus-Reprogrammed iPSC into β Cells, Compared with Human Pancreatic Islets and Immortalized β Cell Line

2018 ◽  
Vol 27 (10) ◽  
pp. 1548-1560 ◽  
Author(s):  
Silvia Pellegrini ◽  
Fabio Manenti ◽  
Raniero Chimienti ◽  
Rita Nano ◽  
Linda Ottoboni ◽  
...  
Keyword(s):  
Gene Expression ◽  
Pancreatic Islets ◽  
Cell Line ◽  
Expression Profile ◽  
Sendai Virus ◽  
Secretory Function ◽  
Β Cells ◽  
Β Cell ◽  
Insulin Producing Cells ◽  
Gene And Protein Expression

Background: New sources of insulin-secreting cells are strongly in demand for treatment of diabetes. Induced pluripotent stem cells (iPSCs) have the potential to generate insulin-producing cells (iβ). However, the gene expression profile and secretory function of iβ still need to be validated in comparison with native β cells. Methods: Two clones of human iPSCs, reprogrammed from adult fibroblasts through integration-free Sendai virus, were differentiated into iβ and compared with donor pancreatic islets and EndoC-βH1, an immortalized human β cell line. Results: Both clones of iPSCs differentiated into insulin+ cells with high efficiency (up to 20%). iβ were negative for pluripotency markers (Oct4, Sox2, Ssea4) and positive for Pdx1, Nkx6.1, Chromogranin A, PC1/3, insulin, glucagon and somatostatin. iβ basally secreted C-peptide, glucagon and ghrelin and released insulin in response either to increasing concentration of glucose or a depolarizing stimulus. The comparison revealed that iβ are remarkably similar to donor derived islets in terms of gene and protein expression profile and similar level of heterogeneity. The ability of iβ to respond to glucose instead was more related to that of EndoC-βH1. Discussion: We demonstrated that insulin-producing cells generated from iPSCs recapitulate fundamental gene expression profiles and secretory function of native human β cells.

scholarly journals XPR1 mediates the pancreatic β-cell phosphate flush

2020 ◽  
Author(s):  
Ada Admin ◽  
Christopher J. Barker ◽  
Fernando Henrique Galvão Tessaro ◽  
Sabrina de Souza Ferreira ◽  
Rafael Simas ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Inorganic Phosphate ◽  
Blood Glucose Concentration ◽  
Cell Types ◽  
Pancreatic Β Cell ◽  
Β Cell ◽  
Inositol Pyrophosphate ◽  
Inositol Pyrophosphates ◽  
Potential Impact ◽  
Glucose Stimulated Insulin Secretion

Glucose-stimulated insulin secretion is the hallmark of the pancreatic β-cell, a critical player in the regulation of blood glucose concentration. In 1974 Dawson, Freinkel and co-workers made the remarkable observation that an efflux of intracellular inorganic phosphate (P<sub>i</sub>) accompanied the events of stimulated insulin secretion. The mechanism behind this ‘phosphate flush’, its association with insulin secretion and its regulation have since then remained a mystery. We recapitulated the phosphate flush in the MIN6m9 β-cell line and pseudoislets. We demonstrated that knockdown of XPR1, a phosphate transporter present in MIN6m9 cells and pancreatic islets, prevented this flush. Concomitantly, XPR1 silencing led to intracellular P<sub>i</sub> accumulation and a potential impact on Ca<sup>2+</sup> signaling. XPR1 knockdown slightly blunted first phase glucose-stimulated insulin secretion in MIN6m9 cells, but had no significant impact on pseudoislet secretion. In keeping with other cell types, basal P<sub>i</sub> efflux was stimulated by inositol pyrophosphates and basal intracellular P<sub>i</sub> accumulated following knockdown of inositol hexakisphosphate kinases. However, the glucose-driven phosphate flush occurred despite inositol pyrophosphate depletion. Finally, whilst it is unlikely that XPR1 directly affects exocytosis, it may protect Ca<sup>2+ </sup>signaling. Thus we have revealed XPR1 as the missing mediator of the phosphate flush, shedding light on a 45-year-old mystery.

scholarly journals Insulin and secretagogues differentially regulate fluid-phase pinocytosis in insulin-secreting β-cells

1996 ◽  
Vol 318 (2) ◽  
pp. 623-629 ◽  
Author(s):  
Gang XU ◽  
Jennie HOWLAND ◽  
Paul L ROTHENBERG
Keyword(s):  
T Cells ◽  
Cell Surface ◽  
Insulin Receptor ◽  
Cell Line ◽  
Chinese Hamster Ovary Cells ◽  
Insulin Receptors ◽  
Fluid Phase ◽  
Β Cells ◽  
Β Cell ◽  
Basal Rate

The physiological role of the β-cell insulin receptor is unknown. To evaluate a candidate function, the insulin regulation of fluid-phase pinocytosis was investigated in a clonal insulinoma cell line (βTC6-F7) and, for comparison, also in Chinese hamster ovary cells transfected with the human insulin receptor (CHO-T cells). In CHO-T cells, the net rate of fluid-phase pinocytosis was rapidly increased 3–4-fold over the basal rate by 100 nM insulin, with half-maximal stimulation at 2 nM insulin, as assayed by cellular uptake of horseradish peroxidase from the medium. Wortmannin, an inhibitor of phosphatidylinositol (PI)-3-kinase, blocked insulin-stimulated pinocytosis with an IC50 of 7.5 nM without affecting the basal rate of pinocytosis. In insulin-secreting βTC6-F7 cells, the secretagogues glucose and carbachol (at maximally effective concentrations of 15 mM and 0.5 mM respectively) augmented fluid-phase pinocytosis 1.65-fold over the basal rate. Wortmannin also inhibited secretagogue-stimulated pinocytosis in these β-cells with an IC50 of 7 nM but did not affect the basal rate of pinocytosis measured in the absence of secretagogues. Wortmannin did not influence either basal or secretagogue-induced insulin secretion. Although these βTC6-F7 cells have cell-surface insulin receptors, adding exogenous insulin or insulin-like growth factor 1 did not affect their rate of fluid-phase pinocytosis, either in the absence or presence of secretagogues. From these observations, we conclude that: (1) in both insulin-secreting β-cells and in conventional, insulin-responsive CHO-T cells, a common, wortmannin-sensitive reaction, which probably involves PI-3-kinase, regulates fluid-phase pinocytosis; (2) the insulin-receptor signal transduction pathway is dissociated from the regulation of fluid-phase pinocytosis in the insulin-secreting β-cell line we studied; and (3) the enhancement of fluid-phase pinocytosis associated with secretagogue-induced insulin release in βTC6-F7 cells is not attributable to autocrine activation of β-cell surface insulin receptors.

scholarly journals CRISPR/Cas9-Mediated α-ENaC Knockout in a Murine Pancreatic β-Cell Line

2021 ◽  
Vol 12 ◽  
Author(s):  
Xue Zhang ◽  
Lihua Zhao ◽  
Runbing Jin ◽  
Min Li ◽  
Mei-Shuang Li ◽  
...  
Keyword(s):  
Cell Line ◽  
Gene Knockout ◽  
Pancreatic Tissue ◽  
Pancreatic Β Cell ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
Min6 Cells ◽  
Insulin Synthesis ◽  
Guide Rna

Many ion channels participate in controlling insulin synthesis and secretion of pancreatic β-cells. Epithelial sodium channel (ENaC) expressed in human pancreatic tissue, but the biological role of ENaC in pancreatic β-cells is still unclear. Here, we applied the CRISPR/Cas9 gene editing technique to knockout α-ENaC gene in a murine pancreatic β-cell line (MIN6 cell). Four single-guide RNA (sgRNA) sites were designed for the exons of α-ENaC. The sgRNA1 and sgRNA3 with the higher activity were constructed and co-transfected into MIN6 cells. Through processing a series of experiment flow included drug screening, cloning, and sequencing, the α-ENaC gene-knockout (α-ENaC−/−) in MIN6 cells were obtained. Compared with the wild-type MIN6 cells, the cell viability and insulin content were significantly increased in α-ENaC−/− MIN6 cells. Therefore, α-ENaC−/− MIN6 cells generated by CRISPR/Cas9 technology added an effective tool to study the biological function of α-ENaC in pancreatic β-cells.

scholarly journals Characterization of the secretome, transcriptome and proteome of human β cell line EndoC-βH1

2021 ◽  
Author(s):  
Maria Ryaboshapkina ◽  
Kevin Saitoski ◽  
Ghaith M. Hamza ◽  
Andrew F. Jarnuczak ◽  
Claire Berthault ◽  
...  
Keyword(s):  
Cell Line ◽  
Bioactive Peptides ◽  
Cell Model ◽  
Future Research ◽  
List Type ◽  
Diabetes Research ◽  
Β Cells ◽  
Β Cell ◽  
Early Diabetes ◽  
Major Mode

ABSTRACTEarly diabetes research is hampered by limited availability, variable quality and instability of human pancreatic islets in culture. Little is known about the human β cell secretome, and recent studies question translatability of rodent β cell secretory profiles. Here, we verify representativeness of EndoC-βH1, one of the most widely used human β cell lines, as a translational human β cell model based on omics and characterize the EndoC-βH1 secretome. We profiled EndoC-βH1 cells using RNA-seq, Data Independent Acquisition (DIA) and Tandem Mass Tag proteomics of cell lysate. Omics profiles of EndoC-βH1 cells were compared to human β cells and insulinomas. Secretome composition was assessed by DIA proteomics. Agreement between EndoC-βH1 cells and primary adult human β cells was ~90% for global omics profiles as well as for β cell markers, transcription factors and enzymes. Discrepancies in expression were due to elevated proliferation rate of EndoC-βH1 cells compared to adult β cells. Consistently, similarity was slightly higher with benign non-metastatic insulinomas. EndoC-βH1 secreted 671 proteins in untreated baseline state and 3,278 proteins when stressed with non-targeting control siRNA, including known β cell hormones INS, IAPP, and IGF2. Further, EndoC-βH1 secreted proteins known to generate bioactive peptides such as granins and enzymes required for production of bioactive peptides. Unexpectedly, exosomes appeared to be a major mode of secretion in EndoC-βH1 cells. We believe that secretion of exosomes and bioactive peptides warrant further investigation with specialized proteomics workflows in future studies.Graphical abstractHighlightsWe validate EndoC-βH1 as a translational human β cell model using omics.We present the first unbiased proteomics composition of human β cell line secretome.The secretome of human β cells is more extensive than previously thought.Untreated cells secreted 671 proteins and stressed cells secreted 3,278 proteins.Secretion of exosomes and bioactive peptides constitute directions of future research.

scholarly journals Perilipin Is Present in Islets of Langerhans and Protects against Lipotoxicity When Overexpressed in the β-Cell Line INS-1

Endocrinology ◽  
2009 ◽  
Vol 150 (7) ◽  
pp. 3049-3057 ◽  
Author(s):  
Jörgen Borg ◽  
Cecilia Klint ◽  
Nils Wierup ◽  
Kristoffer Ström ◽  
Sara Larsson ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Line ◽  
Islets Of Langerhans ◽  
Prolonged Exposure ◽  
Human Islets ◽  
Lipid Storage ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Stimulated Insulin Secretion ◽  
In Cells

Lipids have been shown to play a dual role in pancreatic β-cells: a lipid-derived signal appears to be necessary for glucose-stimulated insulin secretion, whereas lipid accumulation causes impaired insulin secretion and apoptosis. The ability of the protein perilipin to regulate lipolysis prompted an investigation of the presence of perilipin in the islets of Langerhans. In this study evidence is presented for perilipin expression in rat, mouse, and human islets of Langerhans as well as the rat clonal β-cell line INS-1. In rat and mouse islets, perilipin was verified to be present in β-cells. To examine whether the development of lipotoxicity could be prevented by manipulating the conditions for lipid storage in the β-cell, INS-1 cells with adenoviral-mediated overexpression of perilipin were exposed to lipotoxic conditions for 72 h. In cells exposed to palmitate, perilipin overexpression caused increased accumulation of triacylglycerols and decreased lipolysis compared with control cells. Whereas glucose-stimulated insulin secretion was retained after palmitate exposure in cells overexpressing perilipin, it was completely abolished in control β-cells. Thus, overexpression of perilipin appears to confer protection against the development of β-cell dysfunction after prolonged exposure to palmitate by promoting lipid storage and limiting lipolysis.

GLP-1(28–36) improves β-cell mass and glucose disposal in streptozotocin-induced diabetic mice and activates cAMP/PKA/β-catenin signaling in β-cells in vitro

2013 ◽  
Vol 304 (12) ◽  
pp. E1263-E1272 ◽  
Author(s):  
Weijuan Shao ◽  
Zhaoxia Wang ◽  
Wilfred Ip ◽  
Yu-Ting Chiang ◽  
Xiaoquan Xiong ◽  
...  
Keyword(s):  
Cyclin D1 ◽  
Cell Line ◽  
Cell Mass ◽  
Glucose Disposal ◽  
Β Cells ◽  
Β Cell ◽  
Pancreatic Β Cells ◽  
In Vitro Investigation

Recent studies have demonstrated that the COOH-terminal fragment of the incretin hormone glucagon-like peptide-1 (GLP-1), a nonapeptide GLP-1(28–36)amide, attenuates diabetes and hepatic steatosis in diet-induced obese mice. However, the effect of this nonapeptide in pancreatic β-cells remains largely unknown. Here, we show that in a streptozotocin-induced mouse diabetes model, GLP-1(28–36)amide improved glucose disposal and increased pancreatic β-cell mass and β-cell proliferation. An in vitro investigation revealed that GLP-1(28–36)amide stimulates β-catenin (β-cat) Ser675 phosphorylation in both the clonal INS-1 cell line and rat primary pancreatic islet cells. In INS-1 cells, the stimulation was accompanied by increased nuclear β-cat content. GLP-1(28–36)amide was also shown to increase cellular cAMP levels, PKA enzymatic activity, and cAMP response element-binding protein (CREB) and cyclic AMP-dependent transcription factor-1 (ATF-1) phosphorylation. Furthermore, GLP-1(28–36)amide treatment enhanced islet insulin secretion and increased the growth of INS-1 cells, which was associated with increased cyclin D1 expression. Finally, PKA inhibition attenuated the effect of GLP-1(28–36)amide on β-cat Ser675 phosphorylation and cyclin D1 expression in the INS-1 cell line. We have thus revealed the beneficial effect of GLP-1(28–36)amide in pancreatic β-cells in vitro and in vivo. Our observations suggest that GLP-1(28–36)amide may exert its effect through the PKA/β-catenin signaling pathway.

scholarly journals Pancreatic β Cells Inhibit Glucagon Secretion from α Cells: An In Vitro Demonstration of α–β Cell Interaction

Nutrients ◽  
2021 ◽  
Vol 13 (7) ◽  
pp. 2281
Author(s):  
Wenqian Gu ◽  
Camilla Christine Bundgaard Anker ◽  
Christine Bodelund Christiansen ◽  
Tilo Moede ◽  
Per-Olof Berggren ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Hormone Secretion ◽  
Glucagon Secretion ◽  
Cell Contact ◽  
Β Cells ◽  
Β Cell ◽  
Gene Expressions ◽  
The Impact

Interactions between endocrine α and β cells are critical to their secretory function in vivo. The interactions are highly regulated, although yet to be fully understood. In this study, we aim to assess the impact of α and β cell co-culture on hormone secretion. Mouse clonal cell lines α-TC6-1 (α cell line) and MIN-6 (β cell line) were cultured independently or in combination in a medium containing 5.5, 11.1, or 25 mM glucose, respectively. After 72 h, hormone release was measured using insulin and glucagon secretion assays, the cell distribution was visualized by inverted microscopy and an immunocytochemistry assay, and changes in gene expressions were assessed using the RT-PCR technique. The co-culture of the two cell lines caused a decrease in glucagon secretion from α-TC1-6 cells, while no effect on insulin secretion from MIN-6 cells was revealed. Both types of cells were randomly scattered throughout the culture flask, unlike in mice islets in vivo where β cells cluster in the core and α cells are localized at the periphery. During the α–β cell co-culture, the gene expression of glucagon (Gcg) decreased significantly. We conclude that islet β cells suppress glucagon secretion from α cells, apparently via direct cell-to-cell contact, of which the molecular mechanism needs further verification.

scholarly journals Establishment of a long-term stable β-cell line and its application to analyze the effect of Gcg expression on insulin secretion

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Satsuki Miyazaki ◽  
Fumi Tashiro ◽  
Takashi Tsuchiya ◽  
Kazuki Sasaki ◽  
Jun-ichi Miyazaki
Keyword(s):  
Insulin Secretion ◽  
Cell Line ◽  
Cell Function ◽  
T Antigen ◽  
Β Cells ◽  
Β Cell ◽  
Β Cell Function ◽  
Vitro Analysis

AbstractA pancreatic β-cell line MIN6 was previously established in our lab from an insulinoma developed in an IT6 transgenic mouse expressing the SV40 T antigen in β-cells. This cell line has been widely used for in vitro analysis of β-cell function, but tends to lose the mature β-cell features, including glucose-stimulated insulin secretion (GSIS), in long-term culture. The aim of this study was to develop a stable β-cell line that retains the characteristics of mature β-cells. Considering that mice derived from a cross between C3H and C57BL/6 strains are known to exhibit higher insulin secretory capacity than C57BL/6 mice, an IT6 male mouse of this hybrid background was used to isolate insulinomas, which were independently cultured. After 7 months of continuous culturing, we obtained the MIN6-CB4 β-cell line, which stably maintains its GSIS. It has been noted that β-cell lines express the glucagon (Gcg) gene at certain levels. MIN6-CB4 cells were utilized to assess the effects of differential Gcg expression on β-cell function. Our data show the functional importance of Gcg expression and resulting basal activation of the GLP-1 receptor in β-cells. MIN6-CB4 cells can serve as an invaluable tool for studying the regulatory mechanisms of insulin secretion, such as the GLP-1/cAMP signaling, in β-cells.

Sign in / Sign up

Export Citation Format

Share Document