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Hospodiuk-Karwowski M, Chi K, Pritchard J, Catchmark JM. Vascularized pancreas-on-a-chip device produced using a printable simulated extracellular matrix. Biomed Mater 2022; 17. [PMID: 36001993 DOI: 10.1088/1748-605x/ac8c74] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2022] [Accepted: 08/24/2022] [Indexed: 11/12/2022]
Abstract
The extracellular matrix (ECM) influences cellular behavior, function, and fate. The ECM surrounding Langerhans islets has not been investigated in detail to explain its role in the development and maturation of pancreatic β-cells. Herein, a complex combination of the simulated ECM (sECM) has been examined with a comprehensive analysis of cell response and a variety of controls. The most promising results were obtained from group containing fibrin, collagen type I, Matrigel®, hyaluronic acid, methylcellulose, and two compounds of functionalized, ionically crosslinking bacterial cellulose (sECMbc). Even though the cell viability was not significantly impacted, the performance of group of sECMbc showed 2 to 4x higher sprouting number and length, 2 to 4x higher insulin secretion in static conditions, and 2 to 10x higher gene expression of VEGF-A, Endothelin-1, and NOS3 than the control group of fibrin matrix (sECMf). Each material was tested in a hydrogel-based, perfusable, pancreas-on-a-chip device and the best group - sECMbc has been tested with the drug Sunitinib to show the extended possibilities of the device for both diabetes-like screening as well as PDAC chemotherapeutics screening for potential personal medicine approach. It proved its functionality in 7 days dynamic culture and is suitable as a physiological tissue model. Moreover, the device with the pancreatic-like spheroids was 3D bioprintable and perfusable.
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Affiliation(s)
- Monika Hospodiuk-Karwowski
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, 201 Old Main, University Park, Pennsylvania, 16802-1503, UNITED STATES
| | - Kai Chi
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, 201 Old Main, University Park, Pennsylvania, 16802-1503, UNITED STATES
| | - Justin Pritchard
- Biomedical Engineering Department, The Pennsylvania State University, 201 Old Main, University Park, Pennsylvania, 16802-1503, UNITED STATES
| | - Jeffrey M Catchmark
- Department of Agricultural and Biological Engineering, The Pennsylvania State University, 201 Old Main, University Park, Pennsylvania, 16802-1503, UNITED STATES
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Akolpoglu MB, Inceoglu Y, Bozuyuk U, Sousa AR, Oliveira MB, Mano JF, Kizilel S. Recent advances in the design of implantable insulin secreting heterocellular islet organoids. Biomaterials 2020; 269:120627. [PMID: 33401104 DOI: 10.1016/j.biomaterials.2020.120627] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 12/14/2020] [Accepted: 12/18/2020] [Indexed: 12/11/2022]
Abstract
Islet transplantation has proved one of the most remarkable transmissions from an experimental curiosity into a routine clinical application for the treatment of type I diabetes (T1D). Current efforts for taking this technology one-step further are now focusing on overcoming islet donor shortage, engraftment, prolonged islet availability, post-transplant vascularization, and coming up with new strategies to eliminate lifelong immunosuppression. To this end, insulin secreting 3D cell clusters composed of different types of cells, also referred as heterocellular islet organoids, spheroids, or pseudoislets, have been engineered to overcome the challenges encountered by the current islet transplantation protocols. β-cells or native islets are accompanied by helper cells, also referred to as accessory cells, to generate a cell cluster that is not only able to accurately secrete insulin in response to glucose, but also superior in terms of other key features (e.g. maintaining a vasculature, longer durability in vivo and not necessitating immunosuppression after transplantation). Over the past decade, numerous 3D cell culture techniques have been integrated to create an engineered heterocellular islet organoid that addresses current obstacles. Here, we first discuss the different cell types used to prepare heterocellular organoids for islet transplantation and their contribution to the organoids design. We then introduce various cell culture techniques that are incorporated to prepare a fully functional and insulin secreting organoids with select features. Finally, we discuss the challenges and present a future outlook for improving clinical outcomes of islet transplantation.
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Affiliation(s)
- M Birgul Akolpoglu
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey
| | - Yasemin Inceoglu
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey
| | - Ugur Bozuyuk
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey
| | - Ana Rita Sousa
- Department of Chemistry, CICECO - Aveiro Institute of Materials. University of Aveiro. Campus Universitário de Santiago. 3810-193 Aveiro. Portugal
| | - Mariana B Oliveira
- Department of Chemistry, CICECO - Aveiro Institute of Materials. University of Aveiro. Campus Universitário de Santiago. 3810-193 Aveiro. Portugal.
| | - João F Mano
- Department of Chemistry, CICECO - Aveiro Institute of Materials. University of Aveiro. Campus Universitário de Santiago. 3810-193 Aveiro. Portugal
| | - Seda Kizilel
- Chemical and Biological Engineering, Koc University, Sariyer, 34450, Istanbul, Turkey.
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Seo H, Son J, Park JK. Controlled 3D co-culture of beta cells and endothelial cells in a micropatterned collagen sheet for reproducible construction of an improved pancreatic pseudo-tissue. APL Bioeng 2020; 4:046103. [PMID: 33195961 PMCID: PMC7647615 DOI: 10.1063/5.0023873] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2020] [Accepted: 10/16/2020] [Indexed: 01/12/2023] Open
Abstract
The co-culture of beta cells and endothelial cells in constructing a pancreatic pseudo-tissue can provide a functional advancement for in vitro diabetic-related drug testing and biological studies or in vivo transplantation. In order to mimic the pancreatic tissue more similar to in vivo, it is necessary to control the microenvironment, including cell-cell and cell-extracellular matrix interactions. In this study, we report a geometrically controlled three-dimensional (3D) pancreatic model where MIN6 and MS1 cells are co-cultured within a micropatterned collagen sheet. In 4-10 days, depending on the cell seeding concentration, the MIN6 cells formed islet-like clusters surrounded by an endothelial MS1 cell monolayer. The MS1 cells also formed monolayers at the edge of the micropatterns connecting between the clusters, resulting in a blood vessel-like structure in which no cells were found. It was confirmed that the 3D co-culture structure was not formed in a non-patterned sheet and the structure also helped insulin secretion of MIN6 cells. By simply embedding the cell mixture and the hexagonal micropattern into the collagen sheet, we were also able to achieve the highly reproducible fabrication of a 3D pancreatic pseudo-tissue construct for in vivo and in vitro applications.
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Affiliation(s)
- Haewon Seo
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Jaejung Son
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), 291 Daehak-ro, Yuseong-gu, Daejeon 34141, Republic of Korea
| | - Je-Kyun Park
- Author to whom correspondence should be addressed:
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Wieland FC, Sthijns MMJPE, Geuens T, van Blitterswijk CA, LaPointe VLS. The Role of Alpha Cells in the Self-Assembly of Bioengineered Islets. Tissue Eng Part A 2020; 27:1055-1063. [PMID: 33076775 PMCID: PMC8392094 DOI: 10.1089/ten.tea.2020.0080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Vascularization is undoubtedly one of the greatest challenges in tissue engineering. Its importance is particularly evident when considering the transplantation of (bioengineered) pancreatic islets of Langerhans, which are highly sensitive to the delivery of oxygen and nutrients for their survival and function. Here we studied pseudoislets of Langerhans, which are three-dimensional spheroids composed of β (INS1E), α (alpha TC-1), and endothelial (HUVEC) cells, and were interested in how the location and prevalence of the different cell types affected the presence of endothelial cells in the pseudoislet. We hypothesized that alpha (α) cells play an essential role in islet self-assembly and the incorporation of endothelial cells into the pseudoislet, and are thus important to consider in tissue engineering or regenerative medicine strategies, which typically focuses on the insulin-producing beta (β) cells alone. We first determined the effect of changing the relative ratios of the cells and found the cell distribution converged on a steady state of ∼21% α cells, 74% β cells, and 5% endothelial cells after 10 days of culture regardless of their respective ratios at seeding. We also found that the incorporation of endothelial cells was related to the pseudoislet size, with more endothelial cells found in the core of larger pseudoislets following a concomitant increase of α cells and a decrease in β cells. Finally, we observed that both endothelial and β cells were found adjacent to α cells significantly more frequently than to each other. In conclusion, this study demonstrates that the self-assembly of a pseudoislet is an intrinsically cell-regulated process. The endothelial cells had preferential proximity to the α cells, and this persisted even when challenged with changing the cell ratios and numbers. This study gives insight into the rules governing the self-organization of pseudoislets and suggests an important role for α cells to promote the incorporation of endothelial cells.
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Affiliation(s)
- Fredrik C Wieland
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, Netherlands
| | - Mireille M J P E Sthijns
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, Netherlands
| | - Thomas Geuens
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, Netherlands
| | - Clemens A van Blitterswijk
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, Netherlands
| | - Vanessa L S LaPointe
- MERLN Institute for Technology-Inspired Regenerative Medicine, Maastricht University, Maastricht, Netherlands
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Drzazga A, Cichońska E, Koziołkiewicz M, Gendaszewska-Darmach E. Formation of βTC3 and MIN6 Pseudoislets Changes the Expression Pattern of Gpr40, Gpr55, and Gpr119 Receptors and Improves Lysophosphatidylcholines-Potentiated Glucose-Stimulated Insulin Secretion. Cells 2020; 9:E2062. [PMID: 32917053 PMCID: PMC7565006 DOI: 10.3390/cells9092062] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 09/01/2020] [Accepted: 09/08/2020] [Indexed: 02/06/2023] Open
Abstract
The impaired spatial arrangement and connections between cells creating islets of Langerhans as well as altered expression of G protein-coupled receptors (GPCRs) often lead to dysfunction of insulin-secreting pancreatic β cells and can significantly contribute to the development of diabetes. Differences in glucose-stimulated insulin secretion (GSIS) are noticeable not only in diabetic individuals but also in model pancreatic β cells, e.g., βTC3 and MIN6 β cell lines with impaired and normal insulin secretion, respectively. Now, we compare the ability of GPCR agonists (lysophosphatidylcholines bearing fatty acid chains of different lengths) to potentiate GSIS in βTC3 and MIN6 β cell models, cultured as adherent monolayers and in a form of pseudoislets (PIs) with pancreatic MS1 endothelial cells. Our aim was also to investigate differences in expression of the GPCRs responsive to LPCs in these experimental systems. Aggregation of β cells into islet-like structures greatly enhanced the expression of Gpr40, Gpr55, and Gpr119 receptors. In contrast, the co-culture of βTC3 cells with endothelial cells converted the GPCR expression pattern closer to the pattern observed in MIN6 cells. Additionally, the efficiencies of various LPC species in βTC3-MS1 PIs also shifted toward the MIN6 cell model.
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Affiliation(s)
- Anna Drzazga
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland; (E.C.); (M.K.)
| | | | | | - Edyta Gendaszewska-Darmach
- Institute of Molecular and Industrial Biotechnology, Faculty of Biotechnology and Food Sciences, Lodz University of Technology, Stefanowskiego 4/10, 90-924 Lodz, Poland; (E.C.); (M.K.)
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Spelios MG, Afinowicz LA, Tipon RC, Akirav EM. Human EndoC-βH1 β-cells form pseudoislets with improved glucose sensitivity and enhanced GLP-1 signaling in the presence of islet-derived endothelial cells. Am J Physiol Endocrinol Metab 2018; 314:E512-E521. [PMID: 29351476 DOI: 10.1152/ajpendo.00272.2017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Three-dimensional (3D) pseudoislets (PIs) can be used for the study of insulin-producing β-cells in free-floating islet-like structures similar to that of primary islets. Previously, we demonstrated the ability of islet-derived endothelial cells (iECs) to induce PIs using murine insulinomas, where PI formation enhanced insulin production and glucose responsiveness. In this report, we examined the ability of iECs to spontaneously induce the formation of free-floating 3D PIs using the EndoC-βH1 human β-cell line murine MS1 iEC. Within 14 days, the coculturing of both cell types produced fully humanized EndoC-βH1 PIs with little to no contaminating murine iECs. The size and shape of these PIs were similar to primary human islets. iEC-induced PIs demonstrated reduced dysregulated insulin release under low glucose levels and higher insulin secretion in response to high glucose and exendin-4 [a glucagon-like peptide-1 (GLP-1) analog] compared with monolayer cells cultured alone. Interestingly, iEC-PIs were also better at glucose sensing in the presence of extendin-4 compared with PIs generated on a low-adhesion surface plate in the absence of iECs and showed an overall improvement in cell viability. iEC-induced PIs exhibited increased expression of key genes involved in glucose transport, glucose sensing, β-cell differentiation, and insulin processing, with a concomitant decrease in glucagon mRNA expression. The enhanced responsiveness to exendin-4 was associated with increased protein expression of GLP-1 receptor and phosphokinase A. This rapid coculture system provides an unlimited number of human PIs with improved insulin secretion and GLP-1 responsiveness for the study of β-cell biology.
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Affiliation(s)
- Michael G Spelios
- Research Institute, Islet Biology, New York University Winthrop Hospital, Mineola, New York
| | - Lauren A Afinowicz
- Research Institute, Islet Biology, New York University Winthrop Hospital, Mineola, New York
| | - Regine C Tipon
- Research Institute, Islet Biology, New York University Winthrop Hospital, Mineola, New York
| | - Eitan M Akirav
- Research Institute, Islet Biology, New York University Winthrop Hospital, Mineola, New York
- Stony Brook University School of Medicine , Stony Brook, New York
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Hospodiuk M, Dey M, Ayan B, Sosnoski D, Moncal KK, Wu Y, Ozbolat IT. Sprouting angiogenesis in engineered pseudo islets. Biofabrication 2018; 10:035003. [PMID: 29451122 DOI: 10.1088/1758-5090/aab002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
Despite the recent achievements in cell-based therapies for curing type-1 diabetes (T1D), capillarization in beta (β)-cell clusters is still a major roadblock as it is essential for long-term viability and function of β-cells in vivo. In this research, we report sprouting angiogenesis in engineered pseudo islets (EPIs) made of mouse insulinoma βTC3 cells and rat heart microvascular endothelial cells (RHMVECs). Upon culturing in three-dimensional (3D) constructs under angiogenic conditions, EPIs sprouted extensive capillaries into the surrounding matrix. Ultra-morphological analysis through histological sections also revealed presence of capillarization within EPIs. EPIs cultured in 3D constructs maintained their viability and functionality over time while non-vascularized EPIs, without the presence of RHMVECs, could not retain their viability nor functionality. Here we demonstrate angiogenesis in engineered islets, where patient specific stem cell-derived human beta cells can be combined with microvascular endothelial cells in the near future for long-term graft survival in T1D patients.
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Affiliation(s)
- Monika Hospodiuk
- The Huck Institutes of the Life Sciences, Penn State University, State College, PA 16801, United States of America. Department of Agriculture and Biological Engineering, Penn State University, State College, PA 16801, United States of America
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Skrzypek K, Barrera YB, Groth T, Stamatialis D. Endothelial and beta cell composite aggregates for improved function of a bioartificial pancreas encapsulation device. Int J Artif Organs 2018; 41:152-159. [PMID: 29546813 PMCID: PMC6161570 DOI: 10.1177/0391398817752295] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
INTRODUCTION Encapsulation of pancreatic islets or beta cells is a promising strategy for treatment of type 1 diabetes by providing an immune isolated environment and allowing for transplantation in a different location than the liver. However, islets used for encapsulation often show lower functionality due to the damaging of islet endothelial cells during the isolation procedure. Factors produced by endothelial cells have great impact on beta cell insulin secretion. Therefore, mutual signaling between endothelial cells and beta cells should be considered for the development of encapsulation systems to achieve high insulin secretion and maintain beta cell viability. Here, we investigate whether co-culture of beta cells with endothelial cells could improve beta cell function within encapsulation devices. MATERIALS AND METHODS Mouse insulinoma MIN6 cells and human umbilical vein endothelial cells were used for creating composite aggregates on agarose microwell platform. The composite aggregates were encapsulated within flat poly(ether sulfone)/polyvinylpyrrolidone device. Their functionality was assessed by glucose-induced insulin secretion test and compared to non-encapsulated free-floating aggregates. RESULTS We created composite aggregates of 80-100 µm in diameter, closely mimicking pancreatic islets. Upon glucose stimulation, their insulin secretion is improved in comparison to aggregates consisting of only MIN6 cells. Moreover, the composite aggregates encapsulated within a device secrete more insulin than aggregates consisting of only MIN6 cells. CONCLUSION Composite aggregates of MIN6 cells with human umbilical vein endothelial cells have improved insulin secretion in comparison to MIN6 aggregates showing that the interaction of beta cell and endothelial cell is crucial for a functional encapsulation system.
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Affiliation(s)
- Katarzyna Skrzypek
- 1 Bioartificial Organs, Biomaterials Science and Technology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
| | - Yazmin Brito Barrera
- 2 Biomedical Materials Group and Institute of Pharmacy, Martin Luther University of Halle-Wittenberg, Halle, Germany
| | - Thomas Groth
- 2 Biomedical Materials Group and Institute of Pharmacy, Martin Luther University of Halle-Wittenberg, Halle, Germany.,3 Interdisciplinary Centre of Material Sciences, Martin Luther University of Halle-Wittenberg, Halle, Germany
| | - Dimitrios Stamatialis
- 1 Bioartificial Organs, Biomaterials Science and Technology, MIRA Institute for Biomedical Technology and Technical Medicine, University of Twente, Enschede, The Netherlands
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Tsonkova VG, Sand FW, Wolf XA, Grunnet LG, Kirstine Ringgaard A, Ingvorsen C, Winkel L, Kalisz M, Dalgaard K, Bruun C, Fels JJ, Helgstrand C, Hastrup S, Öberg FK, Vernet E, Sandrini MPB, Shaw AC, Jessen C, Grønborg M, Hald J, Willenbrock H, Madsen D, Wernersson R, Hansson L, Jensen JN, Plesner A, Alanentalo T, Petersen MBK, Grapin-Botton A, Honoré C, Ahnfelt-Rønne J, Hecksher-Sørensen J, Ravassard P, Madsen OD, Rescan C, Frogne T. The EndoC-βH1 cell line is a valid model of human beta cells and applicable for screenings to identify novel drug target candidates. Mol Metab 2018; 8:144-157. [PMID: 29307512 PMCID: PMC5985049 DOI: 10.1016/j.molmet.2017.12.007] [Citation(s) in RCA: 85] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2017] [Revised: 12/12/2017] [Accepted: 12/13/2017] [Indexed: 12/20/2022] Open
Abstract
OBJECTIVE To characterize the EndoC-βH1 cell line as a model for human beta cells and evaluate its beta cell functionality, focusing on insulin secretion, proliferation, apoptosis and ER stress, with the objective to assess its potential as a screening platform for identification of novel anti-diabetic drug candidates. METHODS EndoC-βH1 was transplanted into mice for validation of in vivo functionality. Insulin secretion was evaluated in cells cultured as monolayer and as pseudoislets, as well as in diabetic mice. Cytokine induced apoptosis, glucolipotoxicity, and ER stress responses were assessed. Beta cell relevant mRNA and protein expression were investigated by qPCR and antibody staining. Hundreds of proteins or peptides were tested for their effect on insulin secretion and proliferation. RESULTS Transplantation of EndoC-βH1 cells restored normoglycemia in streptozotocin induced diabetic mice. Both in vitro and in vivo, we observed a clear insulin response to glucose, and, in vitro, we found a significant increase in insulin secretion from EndoC-βH1 pseudoislets compared to monolayer cultures for both glucose and incretins. Apoptosis and ER stress were inducible in the cells and caspase 3/7 activity was elevated in response to cytokines, but not affected by the saturated fatty acid palmitate. By screening of various proteins and peptides, we found Bombesin (BB) receptor agonists and Pituitary Adenylate Cyclase-Activating Polypeptides (PACAP) to significantly induce insulin secretion and the proteins SerpinA6, STC1, and APOH to significantly stimulate proliferation. ER stress was readily induced by Tunicamycin and resulted in a reduction of insulin mRNA. Somatostatin (SST) was found to be expressed by 1% of the cells and manipulation of the SST receptors was found to significantly affect insulin secretion. CONCLUSIONS Overall, the EndoC-βH1 cells strongly resemble human islet beta cells in terms of glucose and incretin stimulated insulin secretion capabilities. The cell line has an active cytokine induced caspase 3/7 apoptotic pathway and is responsive to ER stress initiation factors. The cells' ability to proliferate can be further increased by already known compounds as well as by novel peptides and proteins. Based on its robust performance during the functionality assessment assays, the EndoC-βH1 cell line was successfully used as a screening platform for identification of novel anti-diabetic drug candidates.
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Affiliation(s)
- Violeta Georgieva Tsonkova
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark; University of Copenhagen, Department of Biomedical Sciences, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Fredrik Wolfhagen Sand
- Novo Nordisk A/S, Diabetes Research, GLP-1 & T2D Pharmacology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Xenia Asbæk Wolf
- Novo Nordisk A/S, Diabetes Research, GLP-1 & T2D Pharmacology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Lars Groth Grunnet
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Anna Kirstine Ringgaard
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark; University of Copenhagen, Department of Biomedical Sciences, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Camilla Ingvorsen
- Novo Nordisk A/S, Diabetes Research, Histology & Imaging, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Louise Winkel
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Mark Kalisz
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Kevin Dalgaard
- Novo Nordisk A/S, Diabetes Research, GLP-1 & T2D Pharmacology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Christine Bruun
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Johannes Josef Fels
- Novo Nordisk A/S, Discovery Biology & Technology, Research Bioanalysis, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Charlotte Helgstrand
- Novo Nordisk A/S, Protein Engineering, Expression Technologies 1, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Sven Hastrup
- Novo Nordisk A/S, Protein Engineering, Expression Technologies 1, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Fredrik Kryh Öberg
- Novo Nordisk A/S, Protein Engineering, Expression Technologies 1, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Erik Vernet
- Novo Nordisk Research Center Seattle Inc., Protein Engineering, NNRC Seattle, Inc., 530 Fairview Avenue North, 98109, Seattle, WA, USA
| | | | - Allan Christian Shaw
- Novo Nordisk A/S, Protein Engineering, Characterisation & Modelling Technology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Carsten Jessen
- Novo Nordisk A/S, Protein Engineering, Protein & Peptide Chemistry 2, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Mads Grønborg
- Novo Nordisk A/S, Discovery Biology & Technology, Discovery ADME, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Jacob Hald
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Hanni Willenbrock
- Novo Nordisk A/S, Discovery Biology & Technology, Bioinformatics, Maaloev, Denmark
| | - Dennis Madsen
- Novo Nordisk A/S, Discovery Biology & Technology, Bioinformatics, Maaloev, Denmark
| | | | - Lena Hansson
- Intomics A/S, Lottenborgvej 26, DK-2800, Lyngby, Denmark; Novo Nordisk Pharma Ltd., Research Centre Oxford, Bioinformatics, Novo Nordisk Ltd., 3 City Place Beehive Ring Road, Gatwick, RH6 0PA, West Sussex, United Kingdom
| | - Jan Nygaard Jensen
- Novo Nordisk Pharma Ltd., Research Centre Oxford, Bioinformatics, Novo Nordisk Ltd., 3 City Place Beehive Ring Road, Gatwick, RH6 0PA, West Sussex, United Kingdom
| | - Annette Plesner
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Tomas Alanentalo
- Novo Nordisk A/S, Diabetes Research, Histology & Imaging, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Maja Borup Kjær Petersen
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark; University of Copenhagen, DanStem, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Anne Grapin-Botton
- University of Copenhagen, DanStem, Blegdamsvej 3B, DK-2200, Copenhagen, Denmark
| | - Christian Honoré
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Jonas Ahnfelt-Rønne
- Novo Nordisk A/S, Diabetes Research, Histology & Imaging, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Jacob Hecksher-Sørensen
- Novo Nordisk A/S, Diabetes Research, Histology & Imaging, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Philippe Ravassard
- Institut du cerveau et de la moelle (ICM) - Hôpital Pitié-Salpêtrière, Boulevard de l'Hôpital, Sorbonne Universités, Inserm, CNRS, UPMC Univ, Paris 06, Paris, France
| | - Ole D Madsen
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Claude Rescan
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark
| | - Thomas Frogne
- Novo Nordisk A/S, Diabetes Research, Department of Islet & Stem Cell Biology, Novo Nordisk Park, 2760, Maaloev, Denmark.
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2- OMe -lysophosphatidylcholine analogues are GPR119 ligands and activate insulin secretion from βTC-3 pancreatic cells: Evaluation of structure-dependent biological activity. Biochim Biophys Acta Mol Cell Biol Lipids 2018; 1863:91-103. [DOI: 10.1016/j.bbalip.2017.10.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Revised: 10/19/2017] [Accepted: 10/22/2017] [Indexed: 01/08/2023]
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11
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Perugini V, Best M, Kumar S, Guildford AL, Bone AJ, Macfarlane WM, Santin M, Phillips GJ. Carboxybetaine-modified succinylated chitosan-based beads encourage pancreatic β-cells (Min-6) to form islet-like spheroids under in vitro conditions. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2017; 29:15. [PMID: 29290028 PMCID: PMC5748029 DOI: 10.1007/s10856-017-6018-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 12/05/2017] [Indexed: 05/13/2023]
Abstract
In vitro, pancreatic β-cells tend to reduce their ability to aggregate into islets and lose insulin-producing ability, likely due to insufficient cell-cell and cell-matrix interactions that are essential for β-cell retention, viability and functionality. In response to these needs, surfaces of succinylated chitosan-based beads (NSC) were modified with zwitterionic carboxy-betaine (CB) moieties, a compatible osmolyte known to regulate cellular hydration state, and used to promote the formation of β-cell spheroids using a conventional 2D cell culture technique. The NSC were synthesised by ionic gelation and surface-functionalised with CB using carbodiimide chemistry. Scanning electron microscopy (SEM), dynamic laser scattering (DLS) and Fourier transform infrared spectroscopy (FTIR) were employed as characterisation tools to confirm the successful modification of the succinylated chitosan material into spherical beads with rough surfaces and a diameter of 0.4 µm. NSC with and without CB were re-suspended at concentrations of 0.1, 0.3 and 0.6 mg/mL in saline medium and tested in vitro with MIN6 murine pancreatic β-cell line. Results showed that a concentration of 0.3 mg/mL, NSC-CB encouraged pancreatic MIN6 cells to proliferate and form spheroids via E-cadherin and Pdx-1 activation within 48 h in culture. These spheroids, with a size of approximately 80 µm, exhibited high cell viability and enhanced insulin protein expression and secretion when compared to cells organised by the non-modified beads.
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Affiliation(s)
- Valeria Perugini
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK
| | - Mark Best
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK
| | - Sandeep Kumar
- Cellon S.A., ZAE Robert Steichen, 16 rue Hèierchen, L-4940, Bascharage, Luxembourg
| | - Anna L Guildford
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK
| | - Adrian J Bone
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK
| | - Wendy M Macfarlane
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK
| | - Matteo Santin
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK.
| | - Gary J Phillips
- School of Pharmacy and Biomolecular Sciences, University of Brighton, Huxley Building Lewes Road, Brighton, BN2 4GJ, UK
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Shah P, Lueschen N, Ardestani A, Oberholzer J, Olerud J, Carlsson PO, Maedler K. Angiopoetin-2 Signals Do Not Mediate the Hypervascularization of Islets in Type 2 Diabetes. PLoS One 2016; 11:e0161834. [PMID: 27617438 PMCID: PMC5019443 DOI: 10.1371/journal.pone.0161834] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2015] [Accepted: 08/12/2016] [Indexed: 12/12/2022] Open
Abstract
AIMS Changes in the islet vasculature have been implicated in the regulation of β-cell survival and function during the progression to type 2 diabetes (T2D). Failure of the β-cell to compensate for the increased insulin demand in obesity eventually leads to diabetes; as a result of the complex interplay of genetic and environmental factors (e.g. ongoing inflammation within the islets) and impaired vascular function. The Angiopoietin/Tie (Ang/Tie) angiogenic system maintains vasculature and is closely related to organ inflammation and angiogenesis. In this study we aimed to identify whether the vessel area within the islets changes in diabetes and whether such changes would be triggered by the Tie-antagonist Ang-2. METHODS Immunohistochemical and qPCR analyses to follow islet vascularization and Ang/Tie levels were performed in human pancreatic autopsies and isolated human and mouse islets. The effect of Ang-2 was assessed in β-cell-specific Ang-2 overexpressing mice during high fat diet (HFD) feeding. RESULTS Islet vessel area was increased in autopsy pancreases from patients with T2D. The vessel markers Tie-1, Tie-2 and CD31 were upregulated in mouse islets upon HFD feeding from 8 to 24 weeks. Ang-2 was transiently upregulated in mouse islets at 8 weeks of HFD and under glucolipotoxic conditions (22.2 mM glucose/ 0.5 mM palmitate) in vitro in human and mouse islets, in contrast to its downregulation by cytokines (IL-1β, IFN-ɣ and TNF-α). Ang-1 on the other hand was oppositely regulated, with a significant loss under glucolipotoxic condition, a trend to reduce in islets from patients with T2D and an upregulation by cytokines. Modulation of such changes in Ang-2 by its overexpression or the inhibition of its receptor Tie-2 impaired β-cell function at basal conditions but protected islets from cytokine induced apoptosis. In vivo, β-cell-specific Ang-2 overexpression in mice induced hypervascularization under normal diet but contrastingly led to hypovascularized islets in response to HFD together with increased apoptosis and reduced β-cell mass. CONCLUSIONS Islet hypervascularization occurs in T2D. A balanced expression of the Ang1/Ang2 system is important for islet physiology. Ang-2 prevents β-cell mass and islet vascular adaptation in response to HFD feeding with no major influence on glucose homeostasis.
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Affiliation(s)
- Payal Shah
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Navina Lueschen
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Amin Ardestani
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany
| | - Jose Oberholzer
- Division of Transplantation, University of Illinois at Chicago, Chicago, Illinois, United States of America
| | - Johan Olerud
- Department of Immunology, Genetics and pathology, Uppsala University, Uppsala, Sweden
| | - Per-Ola Carlsson
- Department of Medical cell biology and Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - Kathrin Maedler
- Centre for Biomolecular Interactions, University of Bremen, Bremen, Germany,German Center for Diabetes Research (DZD) project partner, University of Bremen, Bremen, Germany,* E-mail:
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13
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Dorrell C, Schug J, Canaday PS, Russ HA, Tarlow BD, Grompe MT, Horton T, Hebrok M, Streeter PR, Kaestner KH, Grompe M. Human islets contain four distinct subtypes of β cells. Nat Commun 2016; 7:11756. [PMID: 27399229 PMCID: PMC4942571 DOI: 10.1038/ncomms11756] [Citation(s) in RCA: 253] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2016] [Accepted: 04/27/2016] [Indexed: 01/10/2023] Open
Abstract
Human pancreatic islets of Langerhans contain five distinct endocrine cell types, each producing a characteristic hormone. The dysfunction or loss of the insulin-producing β cells causes diabetes mellitus, a disease that harms millions. Until now, β cells were generally regarded as a single, homogenous cell population. Here we identify four antigenically distinct subtypes of human β cells, which we refer to as β1–4, and which are distinguished by differential expression of ST8SIA1 and CD9. These subpopulations are always present in normal adult islets and have diverse gene expression profiles and distinct basal and glucose-stimulated insulin secretion. Importantly, the β cell subtype distribution is profoundly altered in type 2 diabetes. These data suggest that this antigenically defined β cell heterogeneity is functionally and likely medically relevant. Dysfunction or loss of insulin-secreting β cells in the pancreas is a hallmark of diabetes. Here, Dorrell et al. identify four subpopulations of β cells in humans, which differ in gene expression and insulin secretion kinetics, and the abundance of which is altered in patients with type 2 diabetes.
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Affiliation(s)
- Craig Dorrell
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Jonathan Schug
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism; University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Pamela S Canaday
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Holger A Russ
- Diabetes Center, Department of Medicine, University of California San Francisco, San Francisco, California 94143, USA
| | - Branden D Tarlow
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Maria T Grompe
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Tamara Horton
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Matthias Hebrok
- Diabetes Center, Department of Medicine, University of California San Francisco, San Francisco, California 94143, USA
| | - Philip R Streeter
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
| | - Klaus H Kaestner
- Department of Genetics and Institute for Diabetes, Obesity, and Metabolism; University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania 19104, USA
| | - Markus Grompe
- Oregon Stem Cell Center, Papé Family Pediatric Research Institute, Department of Pediatrics, Oregon Health and Science University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA
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14
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Functionality and antidiabetic utility of β- and L-cell containing pseudoislets. Exp Cell Res 2016; 344:201-9. [DOI: 10.1016/j.yexcr.2016.04.007] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Revised: 04/06/2016] [Accepted: 04/07/2016] [Indexed: 12/12/2022]
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15
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Circulating Differentially Methylated Amylin DNA as a Biomarker of β-Cell Loss in Type 1 Diabetes. PLoS One 2016; 11:e0152662. [PMID: 27111653 PMCID: PMC4844136 DOI: 10.1371/journal.pone.0152662] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2015] [Accepted: 03/17/2016] [Indexed: 01/07/2023] Open
Abstract
In type 1 diabetes (T1D), β-cell loss is silent during disease progression. Methylation-sensitive quantitative real-time PCR (qPCR) of β-cell-derived DNA in the blood can serve as a biomarker of β-cell death in T1D. Amylin is highly expressed by β-cells in the islet. Here we examined whether demethylated circulating free amylin DNA (cfDNA) may serve as a biomarker of β-cell death in T1D. β cells showed unique methylation patterns within the amylin coding region that were not observed with other tissues. The design and use of methylation-specific primers yielded a strong signal for demethylated amylin in purified DNA from murine islets when compared with other tissues. Similarly, methylation-specific primers detected high levels of demethylated amylin DNA in human islets and enriched human β-cells. In vivo testing of the primers revealed an increase in demethylated amylin cfDNA in sera of non-obese diabetic (NOD) mice during T1D progression and following the development of hyperglycemia. This increase in amylin cfDNA did not mirror the increase in insulin cfDNA, suggesting that amylin cfDNA may detect β-cell loss in serum samples where insulin cfDNA is undetected. Finally, purified cfDNA from recent onset T1D patients yielded a high signal for demethylated amylin cfDNA when compared with matched healthy controls. These findings support the use of demethylated amylin cfDNA for detection of β-cell-derived DNA. When utilized in conjunction with insulin, this latest assay provides a comprehensive multi-gene approach for the detection of β-cell loss.
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16
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Spégel P, Andersson LE, Storm P, Sharoyko V, Göhring I, Rosengren AH, Mulder H. Unique and Shared Metabolic Regulation in Clonal β-Cells and Primary Islets Derived From Rat Revealed by Metabolomics Analysis. Endocrinology 2015; 156:1995-2005. [PMID: 25774549 DOI: 10.1210/en.2014-1391] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
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.
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Affiliation(s)
- Peter Spégel
- Unit of Molecular Metabolism (P.S., L.E.A., V.S., I.G., H.M.), Lund University Diabetes Centre, Clinical Research Center, Skåne University Hospital, and Lund University Diabetes Centre (P.S., A.H.R.), Clinical Research Center, Skåne University Hospital, 205 02 Malmö, Sweden
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Spelios MG, Olsen JA, Kenna LA, Akirav EM. Islet Endothelial Cells Induce Glycosylation and Increase Cell-surface Expression of Integrin β1 in β Cells. J Biol Chem 2015; 290:15250-9. [PMID: 25911095 DOI: 10.1074/jbc.m114.628784] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Indexed: 12/27/2022] Open
Abstract
The co-culturing of insulinoma and islet-derived endothelial cell (iEC) lines results in the spontaneous formation of free-floating pseudoislets (PIs). We previously showed that iEC-induced PIs display improved insulin expression and secretion in response to glucose stimulation. This improvement was associated with a de novo deposition of extracellular matrix (ECM) proteins by iECs in and around the PIs. Here, iEC-induced PIs were used to study the expression and posttranslational modification of the ECM receptor integrin β1. A wide array of integrin β subunits was detected in βTC3 and NIT-1 insulinomas as well as in primary islets, with integrin β1 mRNA and protein detected in all three cell types. Interestingly, the formation of iEC-induced PIs altered the glycosylation patterns of integrin β1, resulting in a higher molecular weight form of the receptor. This form was found in native pancreas but was completely absent in monolayer β-cells. Fluorescence-activated cell sorting analysis of monolayers and PIs revealed a higher expression of integrin β1 in PIs. Antibody-mediated blocking of integrin β1 led to alterations in β-cell morphology, reduced insulin gene expression, and enhanced glucose secretion under baseline conditions. These results suggest that iEC-induced PI formation may alter integrin β1 expression and posttranslational modification by enhancing glycosylation, thereby providing a more physiological culture system for studying integrin-ECM interactions in β cells.
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Affiliation(s)
- Michael G Spelios
- From the Research Institute, Islet Biology, Winthrop-University Hospital, Mineola, New York 11501 and
| | - John A Olsen
- From the Research Institute, Islet Biology, Winthrop-University Hospital, Mineola, New York 11501 and
| | - Lauren A Kenna
- From the Research Institute, Islet Biology, Winthrop-University Hospital, Mineola, New York 11501 and
| | - Eitan M Akirav
- From the Research Institute, Islet Biology, Winthrop-University Hospital, Mineola, New York 11501 and Stony Brook University School of Medicine, Stony Brook, New York 11794
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