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 Promotion of β-Cell Differentiation in Pancreatic Precursor Cells by Adult Islet Cells

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 570-579 ◽  
Author(s):  
Wei Chen ◽  
Salma Begum ◽  
Lynn Opare-Addo ◽  
Justin Garyu ◽  
Thomas F. Gibson ◽  
...  
Keyword(s):  
Cell Differentiation ◽  
Glucose Transporter ◽  
Islet Cells ◽  
Precursor Cells ◽  
Cell Contact ◽  
Β Cells ◽  
Β Cell ◽  
Glucose Transporter 2 ◽  
Adult Islet

It is thought that differentiation of β-cell precursors into mature cells is largely autonomous, but under certain conditions differentiation can be modified by external factors. The factors that modify β-cell differentiation have not been identified. In this study, we tested whether adult islet cells can affect the differentiation process in mouse and human pancreatic anlage cells. We assessed β-cell proliferation and differentiation in mouse and human pancreatic anlage cells cocultured with adult islet cells or βTC3 cells using cellular, molecular, and immunohistochemical methods. Differentiation of murine anlage cells into β-cells was induced by mature islet cells. It was specific for β-cells and not a general feature of endodermal derived cells. β-Cell differentiation required cell-cell contact. The induced cells acquired features of mature β-cells including increased expression of β-cell transcription factors and surface expression of receptor for stromal cell-derived factor 1 and glucose transporter-2 (GLUT-2). They secreted insulin in response to glucose and could correct hyperglycemia in vivo when cotransplanted with vascular cells. Human pancreatic anlage cells responded in a similar manner and showed increased expression of pancreatic duodenal homeobox 1 and v-maf musculoaponeurotic fibrosarcoma oncogene homolog A and increased production of proinsulin when cocultured with adult islets. We conclude that mature β-cells can modify the differentiation of precursor cells and suggest a mechanism whereby changes in differentiation of β-cells can be affected by other β-cells. Mature β cells affect differentiation of pancreatic anlage cells into functional β cells. The differentiated cells respond to glucose and ameliorate diabetes.

Cell type-specific activation of metabolism reveals that β-cell secretion suppresses glucagon release from α-cells in rat pancreatic islets

2006 ◽  
Vol 290 (2) ◽  
pp. E308-E316 ◽  
Author(s):  
Rui Takahashi ◽  
Hisamitsu Ishihara ◽  
Akira Tamura ◽  
Suguru Yamaguchi ◽  
Takahiro Yamada ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Pancreatic Islets ◽  
Cell Activation ◽  
Tricarboxylic Acid Cycle ◽  
Expression System ◽  
Hormone Secretion ◽  
Glucagon Secretion ◽  
Glucagon Release ◽  
Β Cells ◽  
Β Cell

Abnormal glucagon secretion is often associated with diabetes mellitus. However, the mechanisms by which nutrients modulate glucagon secretion remain poorly understood. Paracrine modulation by β- or δ-cells is among the postulated mechanisms. Herein we present further evidence of the paracrine mechanism. First, to activate cellular metabolism and thus hormone secretion in response to specific secretagogues, we engineered insulinoma INS-1E cells using an adenovirus-mediated expression system. Expression of the Na+-dependent dicarboxylate transporter (NaDC)-1 resulted in 2.5- to 4.6-fold ( P < 0.01) increases in insulin secretion in response to various tricarboxylic acid cycle intermediates. Similarly, expression of glycerol kinase (GlyK) increased insulin secretion 3.8- or 4.2-fold ( P < 0.01) in response to glycerol or dihydroxyacetone, respectively. This cell engineering method was then modified, using the Cre- loxP switching system, to activate β-cells and non-β-cells separately in rat islets. NaDC-1 expression only in non-β-cells, among which α-cells are predominant, caused an increase (by 1.8-fold, P < 0.05) in glucagon secretion in response to malate or succinate. However, the increase in glucagon release was prevented when NaDC-1 was expressed in whole islets, i.e., both β-cells and non-β-cells. Similarly, an increase in glucagon release with glycerol was observed when GlyK was expressed only in non-β-cells but not when it was expressed in whole islets. Furthermore, dicarboxylates suppressed basal glucagon secretion by 30% ( P < 0.05) when NaDC-1 was expressed only in β-cells. These data demonstrate that glucagon secretion from rat α-cells depends on β-cell activation and provide insights into the coordinated mechanisms underlying hormone secretion from pancreatic islets.

scholarly journals β-Cell Differentiation from a Human Pancreatic Cell Line in Vitro and in Vivo

2001 ◽  
Vol 15 (3) ◽  
pp. 476-483 ◽  
Author(s):  
Dominique Dufayet de la Tour ◽  
Tanya Halvorsen ◽  
Carla Demeterco ◽  
Björn Tyrberg ◽  
Pamela Itkin-Ansari ◽  
...  
Keyword(s):  
Insulin Secretion ◽  
Cell Differentiation ◽  
Cell Transplantation ◽  
Cell Lines ◽  
Β Cells ◽  
Β Cell ◽  
Cell Transplantation Therapy ◽  
Transplantation Therapy

Abstract Cell transplantation therapy for diabetes is limited by an inadequate supply of cells exhibiting glucose-responsive insulin secretion. To generate an unlimited supply of human β-cells, inducibly transformed pancreatic β-cell lines have been created by expression of dominant oncogenes. The cell lines grow indefinitely but lose differentiated function. Induction of β-cell differentiation was achieved by stimulating the signaling pathways downstream of the transcription factor PDX-1, cell-cell contact, and the glucagon-like peptide (GLP-1) receptor. Synergistic activation of those pathways resulted in differentiation into functional β-cells exhibiting glucose-responsive insulin secretion in vitro. Both oncogene-expressing and oncogene-deleted cells were transplanted into nude mice and found to exhibit glucose-responsive insulin secretion in vivo. The ability to grow unlimited quantities of human β-cells is a major step toward developing a cell transplantation therapy for diabetes.

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.

The two major glucokinase isoforms show conserved functionality in β-cells despite different subcellular distribution

2018 ◽  
Vol 399 (6) ◽  
pp. 565-576 ◽  
Author(s):  
Brian Lu ◽  
Miguel Munoz-Gomez ◽  
Yasuhiro Ikeda
Keyword(s):  
Cell Proliferation ◽  
Subcellular Distribution ◽  
Normal Diet ◽  
Β Cells ◽  
Β Cell ◽  
Functional Conservation ◽  
Exon 1 ◽  
The Impact

Abstract Glucokinase (GCK) is crucial to regulating glucose metabolism in the liver and in pancreatic β-cells. There are two major GCK isoforms, hepatic and pancreatic GCKs, which differ only in exon 1. However, the functional differences between the two GCK isoforms remain poorly understood. Here, we used a β-cell-targeted gene transfer vector to determine the impact of isoform-specific GCK overexpression on β-cells in vitro and in vivo. We showed that pancreatic GCK had a nuclear localization signal unique to the pancreatic isoform, facilitating its nuclear distribution in β-cells. Despite the difference in subcellular distribution, overexpression of GCK isoforms similarly enhanced glucose uptake and β-cell proliferation in vitro. Overexpression of hepatic or pancreatic GCK also similarly enhanced β-cell proliferation in normal diet mice without affecting fasting glucose and intraperitoneal glucose tolerance tests (IPGTT). Our further study on human GCK sequences identified disproportional GCK amino acid variants in exon 1, while mutations linked to maturity onset diabetes of the young type 2 (MODY2) were disproportionally found in exons 2 through 10. Our results therefore indicate functional conservation between the two major GCK isoforms despite their distinct subcellular distribution.

scholarly journals 3D Models of the NCI60 Cell Lines for Screening Oncology Compounds

2017 ◽  
Vol 22 (5) ◽  
pp. 473-483 ◽  
Author(s):  
Mike Selby ◽  
Rene Delosh ◽  
Julie Laudeman ◽  
Chad Ogle ◽  
Russell Reinhart ◽  
...  
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Predictive Accuracy ◽  
3D Culture ◽  
Human Tumor ◽  
3D Models ◽  
Cell Contact ◽  
Cell Line Panel ◽  
Nci60 Cell Line

The NCI60 cell line panel screen includes 60 human tumor cell lines derived from nine tumor types that has been used over the past 20+ years to screen small molecules, biologics, and natural products for activity. Cells in monolayer culture in 96-well plates are exposed to compounds for 48 h, and Sulforhodamine B is used to determine cell viability. Data analysis tools such as COMPARE allow classification of compounds based on the pattern of cell line response. However, many compounds highly active in monolayer cell culture fail to show efficacy in vivo. Therefore, we explored 3D culture of the NCI60 panel as a strategy to improve the predictive accuracy of the screen. 3D cultures more closely resemble tumors than monolayer cultures with tighter cell-cell contact and nutrient and oxygen gradients between the periphery and the center. We optimized the NCI60 cell line panel for generating 3D spheroids of a prespecified diameter (300–500 µm) in ultra-low attachment (ULA) plates. Spheroids were classified into four categories based on imaging, and concentration response of select agents in 2D and 3D models is presented.

scholarly journals The efficiency of insulin production and its content in insulin-expressing model β-cells correlate with their Zn 2+ levels

Open Biology ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 200137
Author(s):  
Petra Dzianová ◽  
Seiya Asai ◽  
Martina Chrudinová ◽  
Lucie Kosinová ◽  
Pavlo Potalitsyn ◽  
...  
Keyword(s):  
Cell Lines ◽  
Secretory Granules ◽  
Zinc Content ◽  
Zinc Homeostasis ◽  
Insulin Production ◽  
Β Cells ◽  
Β Cell ◽  
Impaired Insulin ◽  
The Impact ◽  
And Storage

Insulin is produced and stored inside the pancreatic β-cell secretory granules, where it is assumed to form Zn 2+ -stabilized oligomers. However, the actual storage forms of this hormone and the impact of zinc ions on insulin production in vivo are not known. Our initial X-ray fluorescence experiment on granules from native Langerhans islets and insulinoma-derived INS-1E cells revealed a considerable difference in the zinc content. This led our further investigation to evaluate the impact of the intra-granular Zn 2+ levels on the production and storage of insulin in different model β-cells. Here, we systematically compared zinc and insulin contents in the permanent INS-1E and BRIN-BD11 β-cells and in the native rat pancreatic islets by flow cytometry, confocal microscopy, immunoblotting, specific messenger RNA (mRNA) and total insulin analysis. These studies revealed an impaired insulin production in the permanent β-cell lines with the diminished intracellular zinc content. The drop in insulin and Zn 2+ levels was paralleled by a lower expression of ZnT8 zinc transporter mRNA and hampered proinsulin processing/folding in both permanent cell lines. To summarize, we showed that the disruption of zinc homeostasis in the model β-cells correlated with their impaired insulin and ZnT8 production. This indicates a need for in-depth fundamental research about the role of zinc in insulin production and storage.

Cytotoxicity of chitosan ultrafine nanoshuttles on MCF-7 cell line as surrogate model for breast cancer

2020 ◽  
Vol 17 ◽  
Author(s):  
Tarek Faris ◽  
Gamaleldin I. Harisa ◽  
Fars K. Alanazi ◽  
Mohamed M. Badran ◽  
Afraa Mohammad Alotaibi ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Factorial Design ◽  
Cell Line ◽  
Cell Lines ◽  
Blood Cells ◽  
Sodium Tripolyphosphate ◽  
Physicochemical Characterization ◽  
Spherical Shape ◽  
Mcf 7

Aim: This study aimed to explore an affordable technique for the fabrication of Chitosan Nanoshuttles (CSNS) at the ultrafine nanoscale less than 100 nm with improved physicochemical properties, and cytotoxicity on the MCF-7 cell line. Background: Despite several studies reported that the antitumor effect of CS and CSNS could achieve intracellular compartment target ability, no enough available about this issue and further studies are required to address this assumption. Objectives: The objective of the current study was to investigate the potential processing variables for the production of ultrafine CSNS (> 100 nm) using Box-Benhken Design factorial design (BBD). This was achieved through a study of the effects of processing factors, such as CS concentration, CS/TPP ratio, and pH of the CS solution, on PS, PDI, and ZP. Moreover, the obtained CSNS was evaluated for physicochemical characteristics, morphology Also, hemocompatibility, and cytotoxicity using Red Blood Cells (RBCs) and MCF-7 cell lines were investigated. Methods: Box-Benhken Design factorial design (BBD) was used in the analysis of different selected variables. The effects of CS concentration, sodium tripolyphosphate (TPP) ratio, and pH on particle size, Polydispersity Index (PDI), and Zeta Potential (ZP) were measured. Subsequently, the prepared CS nanoshuttles were exposed to stability studies, physicochemical characterization, hemocompatibility, and cytotoxicity using red blood cells and MCF-7 cell lines as surrogate models for in vivo study. Result: The present results revealed that the optimized CSNS have ultrafine nanosize, (78.3±0.22 nm), homogenous with PDI (0.131±0.11), and ZP (31.9±0.25 mV). Moreover, CSNS have a spherical shape, amorphous in structure, and physically stable. Also, CSNS has biological safety as indicated by a gentle effect on red blood cell hemolysis, besides, the obtained nanoshuttles decrease MCF-7 viability. Conclusion: The present findings concluded that the developed ultrafine CSNS has unique properties with enhanced cytotoxicity. thus promising for use in intracellular organelles drug delivery.

scholarly journals Transformation-associated alterations in interactions between pre-B cells and fibronectin

Blood ◽  
1990 ◽  
Vol 76 (11) ◽  
pp. 2311-2320 ◽  
Author(s):  
FM Lemoine ◽  
S Dedhar ◽  
GM Lima ◽  
CJ Eaves
Keyword(s):  
B Cells ◽  
B Cell ◽  
Cell Line ◽  
Cell Lines ◽  
Stromal Cells ◽  
Stromal Cell ◽  
Cell Attachment ◽  
Attachment Site ◽  
Receptor Antibodies

Abstract Marrow stromal elements produce as yet uncharacterized soluble growth factors that can stimulate the proliferation of murine pre-B cells, although close contact between these two cell types appears to ensure a better pre-B cell response. We have now shown that freshly isolated normal pre-B cells (ie, the B220+, surface mu- fraction of adult mouse bone marrow) adhere to fibronectin (FN) via an RGD cell-attachment site, as shown in a serum-free adherence assay, and they lose this functional ability on differentiation in vivo into B cells (ie, the B220+, surface mu+ fraction). Similarly, cells from an immortalized but stromal cell-dependent and nontumorigenic murine pre-B cell line originally derived from a Whitlock-Witte culture were also found to adhere to fibronectin (FN) via an RGD cell-attachment site. Moreover, in the presence of anti-FN receptor antibodies, the ability of this immortalized pre-B cell line to proliferate when co-cultured with a supportive stromal cell line (M2–10B4 cells) was markedly reduced (down to 30% of control). This suggests that pre-B cell attachment to FN on stromal cells may be an important component of the mechanism by which stromal cells stimulate normal pre-B cell proliferation and one that is no longer operative to control their more differentiated progeny. Two differently transformed pre-B cell lines, both of which are autocrine, stromal-independent, tumorigenic in vivo, and partially or completely differentiation-arrested at a very early stage of pre-B cell development, did not bind to FN. In addition, anti-FN receptor antibodies were much less effective in diminishing the ability of these tumorigenic pre-B cells to respond to M2–10B4 cell stimulation, which could still be demonstrated when the tumorigenic pre-B cells were co- cultured with M2–10B4 cells at a sufficiently low cell density. Analysis of cell surface molecules immunoprecipitated from both the nontumorigenic and tumorigenic pre-B cell lines by an anti-FN receptor antibody showed an increase in very late antigen (VLA) alpha chain(s) in both tumorigenic pre-B cell lines and a decrease in the beta 1 chain in one. Interestingly, all of the pre-B cell lines expressed similar amounts of messenger RNA for the beta 1 chain of the FN receptor. These results suggest that alteration of FN receptor expression on pre-B cells may represent a mechanism contributing to the outgrowth of leukemic pre-B cells with an autocrine phenotype and capable of stromal cell-independent, autonomous growth.

scholarly journals Probing the Intracellular Bio-Nano Interface in Different Cell Lines with Gold Nanostars

Nanomaterials ◽  
2021 ◽  
Vol 11 (5) ◽  
pp. 1183
Author(s):  
Cecilia Spedalieri ◽  
Gergo Péter Szekeres ◽  
Stephan Werner ◽  
Peter Guttmann ◽  
Janina Kneipp
Keyword(s):  
Cell Line ◽  
Cell Lines ◽  
Early Stage ◽  
Protein Corona ◽  
Fibroblast Cell ◽  
Ultrastructural Level ◽  
Epithelial Cell Line ◽  
Animal Cells ◽  
Gold Nanostars

Gold nanostars are a versatile plasmonic nanomaterial with many applications in bioanalysis. Their interactions with animal cells of three different cell lines are studied here at the molecular and ultrastructural level at an early stage of endolysosomal processing. Using the gold nanostars themselves as substrate for surface-enhanced Raman scattering, their protein corona and the molecules in the endolysosomal environment were characterized. Localization, morphology, and size of the nanostar aggregates in the endolysosomal compartment of the cells were probed by cryo soft-X-ray nanotomography. The processing of the nanostars by macrophages of cell line J774 differed greatly from that in the fibroblast cell line 3T3 and in the epithelial cell line HCT-116, and the structure and composition of the biomolecular corona was found to resemble that of spherical gold nanoparticles in the same cells. Data obtained with gold nanostars of varied morphology indicate that the biomolecular interactions at the surface in vivo are influenced by the spike length, with increased interaction with hydrophobic groups of proteins and lipids for longer spike lengths, and independent of the cell line. The results will support optimized nanostar synthesis and delivery for sensing, imaging, and theranostics.

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