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Slak Rupnik M, Hara M. Local Dialogues Between the Endocrine and Exocrine Cells in the Pancreas. Diabetes 2024; 73:533-541. [PMID: 38215069 PMCID: PMC10958587 DOI: 10.2337/db23-0760] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Accepted: 01/03/2024] [Indexed: 01/14/2024]
Abstract
For many years, it has been taught in medical textbooks that the endocrine and exocrine parts of the pancreas have separate blood supplies that do not mix. Therefore, they have been studied by different scientific communities, and patients with pancreatic disorders are treated by physicians in different medical disciplines, where endocrine and exocrine function are the focus of endocrinologists and gastroenterologists, respectively. The conventional model that every islet in each pancreatic lobule receives a dedicated arterial blood supply was first proposed in 1932, and it has been inherited to date. Recently, in vivo intravital recording of red blood cell flow in mouse islets as well as in situ structural analysis of 3D pancreatic vasculature from hundreds of islets provided evidence for preferentially integrated pancreatic blood flow in six mammalian species. The majority of islets have no association with the arteriole, and there is bidirectional blood exchange between the two segments. Such vascularization may allow an entire downstream region of islets and acinar cells to be simultaneously exposed to a topologically and temporally specific plasma content, which could underlie an adaptive sensory function as well as common pathogeneses of both portions of the organ in pancreatic diseases, including diabetes. ARTICLE HIGHLIGHTS
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Affiliation(s)
- Marjan Slak Rupnik
- Center for Physiology and Pharmacology, Medical University of Vienna, Vienna, Austria
| | - Manami Hara
- Department of Medicine, The University of Chicago, Chicago, IL
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2
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Schlünder K, Cipriano M, Zbinden A, Fuchs S, Mayr T, Schenke-Layland K, Loskill P. Microphysiological pancreas-on-chip platform with integrated sensors to model endocrine function and metabolism. LAB ON A CHIP 2024; 24:2080-2093. [PMID: 38441218 DOI: 10.1039/d3lc00838j] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/27/2024]
Abstract
Pancreatic in vitro research is of major importance to advance mechanistic understanding and development of treatment options for diseases such as diabetes mellitus. We present a thermoplastic-based microphysiological system aiming to model the complex microphysiological structure and function of the endocrine pancreas with concurrent real-time read-out capabilities. The specifically tailored platform enables self-guided trapping of single islets at defined locations: β-cells are assembled to pseudo-islets and injected into the tissue chamber using hydrostatic pressure-driven flow. The pseudo-islets can further be embedded in an ECM-like hydrogel mimicking the native microenvironment of pancreatic islets in vivo. Non-invasive real-time monitoring of the oxygen levels on-chip is realized by the integration of luminescence-based optical sensors to the platform. To monitor insulin secretion kinetics in response to glucose stimulation in a time-resolved manner, an automated cycling of different glucose conditions is implemented. The model's response to glucose stimulation can be monitored via offline analysis of insulin secretion and via specific changes in oxygen consumption due to higher metabolic activity of pseudo-islets at high glucose levels. To demonstrate applicability for drug testing, the effects of antidiabetic medications are assessed and changes in dynamic insulin secretion are observed in line with the respective mechanism of action. Finally, by integrating human pancreatic islet microtissues, we highlight the flexibility of the platform and demonstrate the preservation of long-term functionality of human endocrine pancreatic tissue.
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Affiliation(s)
- Katharina Schlünder
- Department for Microphysiological Systems, Institute of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany.
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
| | - Madalena Cipriano
- Department for Microphysiological Systems, Institute of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany.
| | - Aline Zbinden
- Department for Medical Technologies and Regenerative Medicine, Institute of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Stefanie Fuchs
- Institute for Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz, Austria
| | - Torsten Mayr
- Institute for Analytical Chemistry and Food Chemistry, Graz University of Technology, Graz, Austria
| | - Katja Schenke-Layland
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
- Department for Medical Technologies and Regenerative Medicine, Institute of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Peter Loskill
- Department for Microphysiological Systems, Institute of Biomedical Engineering, Eberhard Karls University Tübingen, Tübingen, Germany.
- NMI Natural and Medical Sciences Institute at the University of Tübingen, Reutlingen, Germany
- 3R-Center for In vitro Models and Alternatives to Animal Testing, Eberhard Karls University Tübingen, Tübingen, Germany
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3
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Regeenes R, Rocheleau JV. Twenty years of islet-on-a-chip: microfluidic tools for dissecting islet metabolism and function. LAB ON A CHIP 2024; 24:1327-1350. [PMID: 38277011 DOI: 10.1039/d3lc00696d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2024]
Abstract
Pancreatic islets are metabolically active micron-sized tissues responsible for controlling blood glucose through the secretion of insulin and glucagon. A loss of functional islet mass results in type 1 and 2 diabetes. Islet-on-a-chip devices are powerful microfluidic tools used to trap and study living ex vivo human and murine pancreatic islets and potentially stem cell-derived islet organoids. Devices developed over the past twenty years offer the ability to treat islets with controlled and dynamic microenvironments to mimic in vivo conditions and facilitate diabetes research. In this review, we explore the various islet-on-a-chip devices used to immobilize islets, regulate the microenvironment, and dynamically detect islet metabolism and insulin secretion. We first describe and assess the various methods used to immobilize islets including chambers, dam-walls, and hydrodynamic traps. We subsequently describe the surrounding methods used to create glucose gradients, enhance the reaggregation of dispersed islets, and control the microenvironment of stem cell-derived islet organoids. We focus on the various methods used to measure insulin secretion including capillary electrophoresis, droplet microfluidics, off-chip ELISAs, and on-chip fluorescence anisotropy immunoassays. Additionally, we delve into the various multiparametric readouts (NAD(P)H, Ca2+-activity, and O2-consumption rate) achieved primarily by adopting a microscopy-compatible optical window into the devices. By critical assessment of these advancements, we aim to inspire the development of new devices by the microfluidics community and accelerate the adoption of islet-on-a-chip devices by the wider diabetes research and clinical communities.
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Affiliation(s)
- Romario Regeenes
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Jonathan V Rocheleau
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
- Departments of Medicine and Physiology, University of Toronto, ON, Canada
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4
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Wang Y, Regeenes R, Memon M, Rocheleau JV. Insulin C-peptide secretion on-a-chip to measure the dynamics of secretion and metabolism from individual islets. CELL REPORTS METHODS 2023; 3:100602. [PMID: 37820726 PMCID: PMC10626205 DOI: 10.1016/j.crmeth.2023.100602] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2023] [Revised: 08/16/2023] [Accepted: 09/15/2023] [Indexed: 10/13/2023]
Abstract
First-phase glucose-stimulated insulin secretion is mechanistically linked to type 2 diabetes, yet the underlying metabolism is difficult to discern due to significant islet-to-islet variability. Here, we miniaturize a fluorescence anisotropy immunoassay onto a microfluidic device to measure C-peptide secretion from individual islets as a surrogate for insulin (InsC-chip). This method measures secretion from up to four islets at a time with ∼7 s resolution while providing an optical window for real-time live-cell imaging. Using the InsC-chip, we reveal two glucose-dependent peaks of insulin secretion (i.e., a double peak) within the classically defined 1st phase (<10 min). By combining real-time secretion and live-cell imaging, we show islets transition from glycolytic to oxidative phosphorylation (OxPhos)-driven metabolism at the nadir of the peaks. Overall, these data validate the InsC-chip to measure glucose-stimulated insulin secretion while revealing new dynamics in secretion defined by a shift in glucose metabolism.
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Affiliation(s)
- Yufeng Wang
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Romario Regeenes
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Mahnoor Memon
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada
| | - Jonathan V Rocheleau
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON M5G 1L7, Canada; Institute of Biomedical Engineering, University of Toronto, Toronto, ON M5S 3G9, Canada; Departments of Medicine and Physiology, University of Toronto, Toronto, ON M5S 1A8, Canada.
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5
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Mohandas S, Gayatri V, Kumaran K, Gopinath V, Paulmurugan R, Ramkumar KM. New Frontiers in Three-Dimensional Culture Platforms to Improve Diabetes Research. Pharmaceutics 2023; 15:pharmaceutics15030725. [PMID: 36986591 PMCID: PMC10056755 DOI: 10.3390/pharmaceutics15030725] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/13/2023] [Accepted: 02/16/2023] [Indexed: 02/25/2023] Open
Abstract
Diabetes mellitus is associated with defects in islet β-cell functioning and consequent hyperglycemia resulting in multi-organ damage. Physiologically relevant models that mimic human diabetic progression are urgently needed to identify new drug targets. Three-dimensional (3D) cell-culture systems are gaining a considerable interest in diabetic disease modelling and are being utilized as platforms for diabetic drug discovery and pancreatic tissue engineering. Three-dimensional models offer a marked advantage in obtaining physiologically relevant information and improve drug selectivity over conventional 2D (two-dimensional) cultures and rodent models. Indeed, recent evidence persuasively supports the adoption of appropriate 3D cell technology in β-cell cultivation. This review article provides a considerably updated view of the benefits of employing 3D models in the experimental workflow compared to conventional animal and 2D models. We compile the latest innovations in this field and discuss the various strategies used to generate 3D culture models in diabetic research. We also critically review the advantages and the limitations of each 3D technology, with particular attention to the maintenance of β-cell morphology, functionality, and intercellular crosstalk. Furthermore, we emphasize the scope of improvement needed in the 3D culture systems employed in diabetes research and the promises they hold as excellent research platforms in managing diabetes.
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Affiliation(s)
- Sundhar Mohandas
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - Vijaya Gayatri
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - Kriya Kumaran
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
| | - Vipin Gopinath
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Centre for Cancer Early Detection, Bio-X Program, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Molecular Oncology Division, Malabar Cancer Centre, Moozhikkara P.O, Thalassery 670103, Kerala, India
| | - Ramasamy Paulmurugan
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Centre for Cancer Early Detection, Bio-X Program, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Correspondence: (R.P.); (K.M.R.)
| | - Kunka Mohanram Ramkumar
- Department of Biotechnology, School of Bioengineering, SRM Institute of Science and Technology, Kattankulathur 603203, Tamil Nadu, India
- Department of Radiology, Molecular Imaging Program at Stanford, Canary Centre for Cancer Early Detection, Bio-X Program, Stanford University School of Medicine, Palo Alto, CA 94304, USA
- Correspondence: (R.P.); (K.M.R.)
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6
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Shinde A, Illath K, Kasiviswanathan U, Nagabooshanam S, Gupta P, Dey K, Chakrabarty P, Nagai M, Rao S, Kar S, Santra TS. Recent Advances of Biosensor-Integrated Organ-on-a-Chip Technologies for Diagnostics and Therapeutics. Anal Chem 2023; 95:3121-3146. [PMID: 36716428 DOI: 10.1021/acs.analchem.2c05036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- Ashwini Shinde
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Kavitha Illath
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Uvanesh Kasiviswanathan
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Shalini Nagabooshanam
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Pallavi Gupta
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Koyel Dey
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Pulasta Chakrabarty
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Moeto Nagai
- Department of Mechanical Engineering, Toyohashi University of Technology, Toyohashi 441-8580, Japan
| | - Suresh Rao
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
| | - Srabani Kar
- Department of Physics, Indian Institute of Science Education and Research (IISER), Tirupati, Andhra Pradesh 517507, India
| | - Tuhin Subhra Santra
- Department of Engineering Design, Indian Institute of Technology Madras, Chennai 600036, India
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Rodrigues Oliveira SM, Rebocho A, Ahmadpour E, Nissapatorn V, de Lourdes Pereira M. Type 1 Diabetes Mellitus: A Review on Advances and Challenges in Creating Insulin Producing Devices. MICROMACHINES 2023; 14:151. [PMID: 36677212 PMCID: PMC9867263 DOI: 10.3390/mi14010151] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 12/25/2022] [Accepted: 12/30/2022] [Indexed: 06/17/2023]
Abstract
Type 1 diabetes mellitus (T1DM) is the most common autoimmune chronic disease in young patients. It is caused by the destruction of pancreatic endocrine β-cells that produce insulin in specific areas of the pancreas, known as islets of Langerhans. As a result, the body becomes insulin deficient and hyperglycemic. Complications associated with diabetes are life-threatening and the current standard of care for T1DM consists still of insulin injections. Lifesaving, exogenous insulin replacement is a chronic and costly burden of care for diabetic patients. Alternative therapeutic options have been the focus in these fields. Advances in molecular biology technologies and in microfabrication have enabled promising new therapeutic options. For example, islet transplantation has emerged as an effective treatment to restore the normal regulation of blood glucose in patients with T1DM. However, this technique has been hampered by obstacles, such as limited islet availability, extensive islet apoptosis, and poor islet vascular engraftment. Many of these unsolved issues need to be addressed before a potential cure for T1DM can be a possibility. New technologies like organ-on-a-chip platforms (OoC), multiplexed assessment tools and emergent stem cell approaches promise to enhance therapeutic outcomes. This review will introduce the disorder of type 1 diabetes mellitus, an overview of advances and challenges in the areas of microfluidic devices, monitoring tools, and prominent use of stem cells, and how they can be linked together to create a viable model for the T1DM treatment. Microfluidic devices like OoC platforms can establish a crucial platform for pathophysiological and pharmacological studies as they recreate the pancreatic environment. Stem cell use opens the possibility to hypothetically generate a limitless number of functional pancreatic cells. Additionally, the integration of stem cells into OoC models may allow personalized or patient-specific therapies.
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Affiliation(s)
- Sonia M. Rodrigues Oliveira
- HMRI-Hunter Medical Research Institute, New Lambton, NSW 2305, Australia
- CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
| | - António Rebocho
- Department of Biology, University of Aveiro, 3810-193 Aveiro, Portugal
| | - Ehsan Ahmadpour
- Drug Applied Research Center, Department of Parasitology and Mycology, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
- Department of Parasitology and Mycology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz 5166/15731, Iran
| | - Veeranoot Nissapatorn
- Department of Medical Technology, School of Allied Health Sciences, Walailak University, Nakhon Si Thammarat 80160, Thailand
- School of Allied Health Sciences, Southeast Asia Water Team (SEAWater Team), World Union for Herbal Drug Discovery (WUHeDD), Research Excellence Center for Innovation and Health Products, Walailak University, Nakhon Si Thammarat 80160, Thailand
| | - Maria de Lourdes Pereira
- CICECO-Aveiro Institute of Materials, University of Aveiro, 3810-193 Aveiro, Portugal
- Department of Medical Sciences, University of Aveiro, 3810-193 Aveiro, Portugal
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8
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Goswami I, de Klerk E, Carnese P, Hebrok M, Healy KE. Multiplexed microfluidic platform for stem-cell derived pancreatic islet β cells. LAB ON A CHIP 2022; 22:4430-4442. [PMID: 36305868 PMCID: PMC9642094 DOI: 10.1039/d2lc00468b] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2022] [Accepted: 10/06/2022] [Indexed: 06/16/2023]
Abstract
Stem cell-derived β cells offer an alternative to primary islets for biomedical discoveries as well as a potential surrogate for islet transplantation. The expense and challenge of obtaining and maintaining functional stem cell-derived β cells calls for a need to develop better high-content and high-throughput culture systems. Microphysiological systems (MPS) are promising high-content in vitro platforms, but scaling for high-throughput screening and discoveries remain a challenge. Traditionally, simultaneous multiplexing of liquid handling and cell loading poses a challenge in the design of high-throughput MPS. Furthermore, although MPS for islet β culture/testing have been developed, studies on multi-day culture of stem-cell derived β cells in MPS have been limited. We present a scalable, multiplexed islet β MPS device that incorporates microfluidic gradient generators to parallelize fluid handling for culture and test conditions. We demonstrated the viability and functionality of the stem cell-derived enriched β clusters (eBCs) for a week, as assessed by the ∼2 fold insulin release by the clusters to glucose challenge. To show the scalable multiplexing for drug testing, we demonstrated the loss of stimulation index after long-term exposure to logarithmic concentration range of glybenclamide. The MPS cultured eBCs also confirmed a glycolytic bottleneck as inferred by insulin secretion responses to metabolites methyl succinate and glyceric acid. Thus, we present an innovative culture platform for eBCs with a balance of high-content and high-throughput characteristics.
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Affiliation(s)
- Ishan Goswami
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California Berkeley, Berkeley, CA 94720, USA.
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720, USA
| | - Eleonora de Klerk
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Phichitpol Carnese
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Matthias Hebrok
- Diabetes Center, University of California San Francisco, San Francisco, CA 94143, USA
| | - Kevin E Healy
- Department of Bioengineering and California Institute for Quantitative Biosciences (QB3), University of California Berkeley, Berkeley, CA 94720, USA.
- Department of Materials Science and Engineering, University of California Berkeley, Berkeley, CA 94720, USA
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9
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Microfluidic Technology for Evaluating and Preserving Islet Function for Islet Transplant in Type 1 Diabetes. CURRENT TRANSPLANTATION REPORTS 2022. [DOI: 10.1007/s40472-022-00377-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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10
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Rafiei N, Moghadam MG, Au A, Regeenes R, Chidambaram S, Liang T, Wang Y, Yip CM, Gaisano H, Rocheleau JV. Design of a versatile microfluidic device for imaging precision-cut-tissue slices. Biofabrication 2022; 14. [PMID: 35793653 DOI: 10.1088/1758-5090/ac7eea] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 07/06/2022] [Indexed: 11/12/2022]
Abstract
Precision-cut-tissues (PCTs), which preserve many aspects of a tissue's microenvironment, are typically imaged using conventional sample dishes and chambers. These can require large amounts of reagent and, when used for flow-through experiments, the shear forces applied on the tissues are often ill-defined. Their physical design also makes it difficult to image large volumes and repetitively image smaller regions of interest in the living slice. We report here on the design of a versatile microfluidic device capable of holding mouse or human pancreas PCTs for 3D fluorescence imaging using confocal and selective plane illumination microscopy (SPIM). Our design positions PCTs within a 5 × 5 mm × 140µm deep chamber fitted with 150µm tall channels to facilitate media exchange. Shear stress in the device is localized to small regions on the surface of the tissue and can be easily controlled. This design allows for media exchange at flowrates ∼10-fold lower than those required for conventional chambers. Finally, this design allows for imaging the same immunofluorescently labeled PCT with high resolution on a confocal and with large field of view on a SPIM, without adversely affecting image quality.
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Affiliation(s)
- Nafiseh Rafiei
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada
| | - Mohammadamir G Moghadam
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Aaron Au
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada
| | - Romario Regeenes
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | | | - Tao Liang
- Department of Medicine, University of Toronto, Toronto, ON, Canada
| | - Yufeng Wang
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada
| | - Christopher M Yip
- Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,Donnelly Centre for Cellular and Biomolecular Research, University of Toronto, Toronto, ON, Canada.,Department of Chemical Engineering and Applied Chemistry, University of Toronto, Toronto, ON, Canada.,Department of Biochemistry, University of Toronto, Toronto, ON, Canada
| | - Herbert Gaisano
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada.,Department of Medicine, University of Toronto, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
| | - Jonathan V Rocheleau
- Advanced Diagnostics, Toronto General Hospital Research Institute, Toronto, ON, Canada.,Institute of Biomedical Engineering, University of Toronto, Toronto, ON, Canada.,Department of Medicine, University of Toronto, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
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11
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D’Angelo CV, West HL, Whitticar NB, Corbin KL, Donovan LM, Stiadle BI, Nunemaker CS. Similarities in Calcium Oscillations Between Neonatal Mouse Islets and Mature Islets Exposed to Chronic Hyperglycemia. Endocrinology 2022; 163:6585503. [PMID: 35551371 PMCID: PMC9186310 DOI: 10.1210/endocr/bqac066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2022] [Indexed: 11/19/2022]
Abstract
Pulsatility is important to islet function. As islets mature into fully developed insulin-secreting micro-organs, their ability to produce oscillatory intracellular calcium ([Ca2+]i) patterns in response to glucose also matures. In this study, we measured [Ca2+]i using fluorescence imaging to characterize oscillations from neonatal mice on postnatal (PN) days 0, 4, and 12 in comparison to adult islets. Under substimulatory (3-mM) glucose levels, [Ca2+]i was low and quiescent for adult islets as expected, as well as for PN day 12 islets. In contrast, one-third of islets on PN day 0 and 4 displayed robust [Ca2+]i oscillations in low glucose. In stimulatory glucose (11 mM) conditions, oscillations were present on all neonatal days but differed from patterns in adults. By PN day 12, [Ca2+]i oscillations were approaching characteristics of fully developed islets. The immature response pattern of neonatal islets was due, at least in part, to differences in adenosine 5'-triphosphate (ATP)-sensitive K+-channel activity estimated by [Ca2+]i responses to KATP channel agents diazoxide and tolbutamide. Neonatal [Ca2+]i patterns were also strikingly similar to patterns observed in mature islets exposed to hyperglycemic conditions (20 mM glucose for 48 hours): elevated [Ca2+]i and oscillations in low glucose along with reduced pulse mass in high glucose. Since a hallmark of diabetic islets is dedifferentiation, we propose that diabetic islets display features of "reverse maturation," demonstrating similar [Ca2+]i dynamics as neonatal islets. Pulsatility is thus an important emergent feature of neonatal islets. Our findings may provide insight into reversing β-cell dedifferentiation and to producing better functioning β cells from pluripotent stem cells.
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Affiliation(s)
- Cathleen V D’Angelo
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
| | - Hannah L West
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
- Honors Tutorial College, Ohio University, Athens, Ohio 45701, USA
| | - Nicholas B Whitticar
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
- Translational Biomedical Sciences Program, Graduate College, Ohio University, Athens, Ohio 45701, USA
| | - Kathryn L Corbin
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
- Diabetes Institute, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
| | - Lauren M Donovan
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
| | - Benjamin I Stiadle
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University, Athens, Ohio 45701, USA
| | - Craig S Nunemaker
- Correspondence: Craig S. Nunemaker, PhD, Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, 1 Ohio University, Athens, OH 45701, USA.
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12
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Donati V, Peres C, Nardin C, Scavizzi F, Raspa M, Ciubotaru CD, Bortolozzi M, Pedersen MG, Mammano F. Calcium Signaling in the Photodamaged Skin: In Vivo Experiments and Mathematical Modeling. FUNCTION 2021; 3:zqab064. [PMID: 35330924 PMCID: PMC8788836 DOI: 10.1093/function/zqab064] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2021] [Revised: 11/23/2021] [Accepted: 11/23/2021] [Indexed: 01/07/2023] Open
Abstract
The epidermis forms an essential barrier against a variety of insults. The overall goal of this study was to shed light not only on the effects of accidental epidermal injury, but also on the mechanisms that support laser skin resurfacing with intra-epidermal focal laser-induced photodamage, a widespread medical practice used to treat a range of skin conditions. To this end, we selectively photodamaged a single keratinocyte with intense, focused and pulsed laser radiation, triggering Ca2+ waves in the epidermis of live anesthetized mice with ubiquitous expression of a genetically encoded Ca2+ indicator. Waves expanded radially and rapidly, reaching up to eight orders of bystander cells that remained activated for tens of minutes, without displaying oscillations of the cytosolic free Ca2+ concentration ([Formula: see text]). By combining in vivo pharmacological dissection with mathematical modeling, we demonstrate that Ca2+ wave propagation depended primarily on the release of ATP, a prime damage-associated molecular patterns (DAMPs), from the hit cell. Increments of the [Formula: see text] in bystander cells were chiefly due to Ca2+ release from the endoplasmic reticulum (ER), downstream of ATP binding to P2Y purinoceptors. ATP-dependent ATP release though connexin hemichannels (HCs) affected wave propagation at larger distances, where the extracellular ATP concentration was reduced by the combined effect of passive diffusion and hydrolysis due to the action of ectonucleotidases, whereas pannexin channels had no role. Bifurcation analysis suggests basal keratinocytes have too few P2Y receptors (P2YRs) and/or phospholipase C (PLC) to transduce elevated extracellular ATP levels into inositol trisphosphate (IP3) production rates sufficiently large to sustain [Formula: see text] oscillations.
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Affiliation(s)
- Viola Donati
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Chiara Peres
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Chiara Nardin
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Ferdinando Scavizzi
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | - Marcello Raspa
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
| | | | - Mario Bortolozzi
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
- Foundation for Advanced Biomedical Research, Veneto Institute of Molecular Medicine (VIMM), 35129 Padova (PD), Italy
| | - Morten Gram Pedersen
- Department of Information Engineering, University of Padova, 35131 Padova (PD), Italy
- Department of Mathematics “Tullio Levi-Civita”, University of Padova, 35121 Padova (PD), Italy
| | - Fabio Mammano
- Department of Physics and Astronomy “G. Galilei”, University of Padova, 35131 Padova, Italy
- Institute of Biochemistry and Cell Biology (IBBC)-CNR, 00015 Monterotondo (RM), Italy
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13
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Ng XW, Chung YH, Piston DW. Intercellular Communication in the Islet of Langerhans in Health and Disease. Compr Physiol 2021; 11:2191-2225. [PMID: 34190340 DOI: 10.1002/cphy.c200026] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Blood glucose homeostasis requires proper function of pancreatic islets, which secrete insulin, glucagon, and somatostatin from the β-, α-, and δ-cells, respectively. Each islet cell type is equipped with intrinsic mechanisms for glucose sensing and secretory actions, but these intrinsic mechanisms alone cannot explain the observed secretory profiles from intact islets. Regulation of secretion involves interconnected mechanisms among and between islet cell types. Islet cells lose their normal functional signatures and secretory behaviors upon dispersal as compared to intact islets and in vivo. In dispersed islet cells, the glucose response of insulin secretion is attenuated from that seen from whole islets, coordinated oscillations in membrane potential and intracellular Ca2+ activity, as well as the two-phase insulin secretion profile, are missing, and glucagon secretion displays higher basal secretion profile and a reverse glucose-dependent response from that of intact islets. These observations highlight the critical roles of intercellular communication within the pancreatic islet, and how these communication pathways are crucial for proper hormonal and nonhormonal secretion and glucose homeostasis. Further, misregulated secretions of islet secretory products that arise from defective intercellular islet communication are implicated in diabetes. Intercellular communication within the islet environment comprises multiple mechanisms, including electrical synapses from gap junctional coupling, paracrine interactions among neighboring cells, and direct cell-to-cell contacts in the form of juxtacrine signaling. In this article, we describe the various mechanisms that contribute to proper islet function for each islet cell type and how intercellular islet communications are coordinated among the same and different islet cell types. © 2021 American Physiological Society. Compr Physiol 11:2191-2225, 2021.
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Affiliation(s)
- Xue W Ng
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| | - Yong H Chung
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
| | - David W Piston
- Department of Cell Biology and Physiology, Washington University, St Louis, Missouri, USA
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14
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Scialla S, Loppini A, Patriarca M, Heinsalu E. Hubs, diversity, and synchronization in FitzHugh-Nagumo oscillator networks: Resonance effects and biophysical implications. Phys Rev E 2021; 103:052211. [PMID: 34134340 DOI: 10.1103/physreve.103.052211] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Accepted: 05/03/2021] [Indexed: 11/06/2022]
Abstract
Using the FitzHugh-Nagumo equations to represent the oscillatory electrical behavior of β-cells, we develop a coupled oscillator network model with cubic lattice topology, showing that the emergence of pacemakers or hubs in the system can be viewed as a natural consequence of oscillator population diversity. The optimal hub to nonhub ratio is determined by the position of the diversity-induced resonance maximum for a given set of FitzHugh-Nagumo equation parameters and is predicted by the model to be in a range that is fully consistent with experimental observations. The model also suggests that hubs in a β-cell network should have the ability to "switch on" and "off" their pacemaker function. As a consequence, their relative amount in the population can vary in order to ensure an optimal oscillatory performance of the network in response to environmental changes, such as variations of an external stimulus.
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Affiliation(s)
- Stefano Scialla
- Department of Engineering, Università Campus Bio-Medico di Roma, Via Á. del Portillo 21, 00128 Rome, Italy
| | - Alessandro Loppini
- Department of Engineering, Università Campus Bio-Medico di Roma, Via Á. del Portillo 21, 00128 Rome, Italy
| | - Marco Patriarca
- National Institute of Chemical Physics and Biophysics, Rävala 10, Tallinn 15042, Estonia
| | - Els Heinsalu
- National Institute of Chemical Physics and Biophysics, Rävala 10, Tallinn 15042, Estonia
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15
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Wu Jin P, Rousset N, Hierlemann A, Misun PM. A Microfluidic Hanging-Drop-Based Islet Perifusion System for Studying Glucose-Stimulated Insulin Secretion From Multiple Individual Pancreatic Islets. Front Bioeng Biotechnol 2021; 9:674431. [PMID: 34055765 PMCID: PMC8149801 DOI: 10.3389/fbioe.2021.674431] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2021] [Accepted: 04/12/2021] [Indexed: 01/09/2023] Open
Abstract
Islet perifusion systems can be used to monitor the highly dynamic insulin release of pancreatic islets in glucose-stimulated insulin secretion (GSIS) assays. Here, we present a new generation of the microfluidic hanging-drop-based islet perifusion platform that was developed to study the alterations in insulin secretion dynamics from single pancreatic islet microtissues at high temporal resolution. The platform was completely redesigned to increase experimental throughput and to reduce operational complexity. The experimental throughput was increased fourfold by implementing a network of interconnected hanging drops, which allows for performing GSIS assays with four individual islet microtissues in parallel with a sampling interval of 30 s. We introduced a self-regulating drop-height mechanism that enables continuous flow and maintains a constant liquid volume in the chip, which enables simple and robust operation. Upon glucose stimulation, reproducible biphasic insulin release was simultaneously observed from all islets in the system. The measured insulin concentrations showed low sample-to-sample variation as a consequence of precise liquid handling with stable drop volumes, equal flow rates in the channels, and accurately controlled sampling volumes in all four drops. The presented device will be a valuable tool in islet and diabetes research for studying dynamic insulin secretion from individual pancreatic islets.
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Affiliation(s)
| | | | - Andreas Hierlemann
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
| | - Patrick M. Misun
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Basel, Switzerland
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16
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Glieberman AL, Pope BD, Melton DA, Parker KK. Building Biomimetic Potency Tests for Islet Transplantation. Diabetes 2021; 70:347-363. [PMID: 33472944 PMCID: PMC7881865 DOI: 10.2337/db20-0297] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2020] [Accepted: 11/12/2020] [Indexed: 12/12/2022]
Abstract
Diabetes is a disease of insulin insufficiency, requiring many to rely on exogenous insulin with constant monitoring to avoid a fatal outcome. Islet transplantation is a recent therapy that can provide insulin independence, but the procedure is still limited by both the availability of human islets and reliable tests to assess their function. While stem cell technologies are poised to fill the shortage of transplantable cells, better methods are still needed for predicting transplantation outcome. To ensure islet quality, we propose that the next generation of islet potency tests should be biomimetic systems that match glucose stimulation dynamics and cell microenvironmental preferences and rapidly assess conditional and continuous insulin secretion with minimal manual handing. Here, we review the current approaches for islet potency testing and outline technologies and methods that can be used to arrive at a more predictive potency test that tracks islet secretory capacity in a relevant context. With the development of potency tests that can report on islet secretion dynamics in a context relevant to their intended function, islet transplantation can expand into a more widely accessible and reliable treatment option for individuals with diabetes.
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Affiliation(s)
- Aaron L Glieberman
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA
| | - Benjamin D Pope
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA
| | - Douglas A Melton
- Harvard Department of Stem Cell and Regenerative Biology, Cambridge, MA
- Harvard Stem Cell Institute, Cambridge, MA
| | - Kevin Kit Parker
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA
- Harvard Stem Cell Institute, Cambridge, MA
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17
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Weitz J, Menegaz D, Caicedo A. Deciphering the Complex Communication Networks That Orchestrate Pancreatic Islet Function. Diabetes 2021; 70:17-26. [PMID: 33355306 PMCID: PMC7881851 DOI: 10.2337/dbi19-0033] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Accepted: 10/01/2020] [Indexed: 12/27/2022]
Abstract
Pancreatic islets are clusters of hormone-secreting endocrine cells that rely on intricate cell-cell communication mechanisms for proper function. The importance of multicellular cooperation in islet cell physiology was first noted nearly 30 years ago in seminal studies showing that hormone secretion from endocrine cell types is diminished when these cells are dispersed. These studies showed that reestablishing cellular contacts in so-called pseudoislets caused endocrine cells to regain hormone secretory function. This not only demonstrated that cooperation between islet cells is highly synergistic but also gave birth to the field of pancreatic islet organoids. Here we review recent advances related to the mechanisms of islet cell cross talk. We first describe new developments that revise current notions about purinergic and GABA signaling in islets. Then we comment on novel multicellular imaging studies that are revealing emergent properties of islet communication networks. We finish by highlighting and discussing recent synthetic approaches that use islet organoids of varied cellular composition to interrogate intraislet signaling mechanisms. This reverse engineering of islets not only will shed light on the mechanisms of intraislet signaling and define communication networks but also may guide efforts aimed at restoring islet function and β-cell mass in diabetes.
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Affiliation(s)
- Jonathan Weitz
- Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL
| | - Danusa Menegaz
- Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL
| | - Alejandro Caicedo
- Department of Medicine, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Diabetes Research Institute, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Department of Physiology and Biophysics, University of Miami Leonard M. Miller School of Medicine, Miami, FL
- Program in Neuroscience, University of Miami Leonard M. Miller School of Medicine, Miami, FL
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18
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Abadpour S, Aizenshtadt A, Olsen PA, Shoji K, Wilson SR, Krauss S, Scholz H. Pancreas-on-a-Chip Technology for Transplantation Applications. Curr Diab Rep 2020; 20:72. [PMID: 33206261 PMCID: PMC7674381 DOI: 10.1007/s11892-020-01357-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 10/26/2020] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW Human pancreas-on-a-chip (PoC) technology is quickly advancing as a platform for complex in vitro modeling of islet physiology. This review summarizes the current progress and evaluates the possibility of using this technology for clinical islet transplantation. RECENT FINDINGS PoC microfluidic platforms have mainly shown proof of principle for long-term culturing of islets to study islet function in a standardized format. Advancement in microfluidic design by using imaging-compatible biomaterials and biosensor technology might provide a novel future tool for predicting islet transplantation outcome. Progress in combining islets with other tissue types gives a possibility to study diabetic interventions in a minimal equivalent in vitro environment. Although the field of PoC is still in its infancy, considerable progress in the development of functional systems has brought the technology on the verge of a general applicable tool that may be used to study islet quality and to replace animal testing in the development of diabetes interventions.
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Affiliation(s)
- Shadab Abadpour
- Department of Transplant Medicine and Institute for Surgical Research, Oslo University Hospital, Post Box 4950, Nydalen, N-0424 Oslo, Norway
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Aleksandra Aizenshtadt
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Petter Angell Olsen
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Kayoko Shoji
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
| | - Steven Ray Wilson
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Department of Chemistry, University of Oslo, Oslo, Norway
| | - Stefan Krauss
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
- Institute of Immunology, Oslo University Hospital, Oslo, Norway
| | - Hanne Scholz
- Department of Transplant Medicine and Institute for Surgical Research, Oslo University Hospital, Post Box 4950, Nydalen, N-0424 Oslo, Norway
- Hybrid Technology Hub-Centre of Excellence, Institute of Basic Medical Sciences, University of Oslo, Oslo, Norway
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19
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Tran R, Moraes C, Hoesli CA. Developmentally-Inspired Biomimetic Culture Models to Produce Functional Islet-Like Cells From Pluripotent Precursors. Front Bioeng Biotechnol 2020; 8:583970. [PMID: 33117786 PMCID: PMC7576674 DOI: 10.3389/fbioe.2020.583970] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2020] [Accepted: 09/08/2020] [Indexed: 12/28/2022] Open
Abstract
Insulin-producing beta cells sourced from pluripotent stem cells hold great potential as a virtually unlimited cell source to treat diabetes. Directed pancreatic differentiation protocols aim to mimic various stimuli present during embryonic development through sequential changes of in vitro culture conditions. This is commonly accomplished by the timed addition of soluble signaling factors, in conjunction with cell-handling steps such as the formation of 3D cell aggregates. Interestingly, when stem cells at the pancreatic progenitor stage are transplanted, they form functional insulin-producing cells, suggesting that in vivo microenvironmental cues promote beta cell specification. Among these cues, biophysical stimuli have only recently emerged in the context of optimizing pancreatic differentiation protocols. This review focuses on studies of cell–microenvironment interactions and their impact on differentiating pancreatic cells when considering cell signaling, cell–cell and cell–ECM interactions. We highlight the development of in vitro cell culture models that allow systematic studies of pancreatic cell mechanobiology in response to extracellular matrix proteins, biomechanical effects, soluble factor modulation of biomechanics, substrate stiffness, fluid flow and topography. Finally, we explore how these new mechanical insights could lead to novel pancreatic differentiation protocols that improve efficiency, maturity, and throughput.
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Affiliation(s)
- Raymond Tran
- Department of Chemical Engineering, McGill University, Montreal, QC, Canada
| | - Christopher Moraes
- Department of Chemical Engineering, McGill University, Montreal, QC, Canada.,Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
| | - Corinne A Hoesli
- Department of Chemical Engineering, McGill University, Montreal, QC, Canada.,Department of Biomedical Engineering, McGill University, Montreal, QC, Canada
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20
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Horowitz LF, Rodriguez AD, Dereli-Korkut Z, Lin R, Castro K, Mikheev AM, Monnat RJ, Folch A, Rostomily RC. Multiplexed drug testing of tumor slices using a microfluidic platform. NPJ Precis Oncol 2020; 4:12. [PMID: 32435696 PMCID: PMC7237421 DOI: 10.1038/s41698-020-0117-y] [Citation(s) in RCA: 25] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2019] [Accepted: 03/25/2020] [Indexed: 12/11/2022] Open
Abstract
Current methods to assess the drug response of individual human cancers are often inaccurate, costly, or slow. Functional approaches that rapidly and directly assess the response of patient cancer tissue to drugs or small molecules offer a promising way to improve drug testing, and have the potential to identify the best therapy for individual patients. We developed a digitally manufactured microfluidic platform for multiplexed drug testing of intact cancer slice cultures, and demonstrate the use of this platform to evaluate drug responses in slice cultures from human glioma xenografts and patient tumor biopsies. This approach retains much of the tissue microenvironment and can provide results rapidly enough, within days of surgery, to guide the choice of effective initial therapies. Our results establish a useful preclinical platform for cancer drug testing and development with the potential to improve cancer personalized medicine.
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Affiliation(s)
- L. F. Horowitz
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
- Department of Neurosurgery, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Pathology, University of Washington, Seattle, WA 98195 USA
| | - A. D. Rodriguez
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - Z. Dereli-Korkut
- Department of Neurosurgery, Houston Methodist Hospital and Research Institute, Houston, TX USA
| | - R. Lin
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - K. Castro
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - A. M. Mikheev
- Department of Neurosurgery, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Neurosurgery, Houston Methodist Hospital and Research Institute, Houston, TX USA
| | - R. J. Monnat
- Department of Pathology, University of Washington, Seattle, WA 98195 USA
- Department of Genome Sciences, University of Washington, Seattle, WA 98195 USA
| | - A. Folch
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - R. C. Rostomily
- Department of Neurosurgery, Institute for Stem Cell and Regenerative Medicine, University of Washington, Seattle, WA 98195 USA
- Department of Neurosurgery, Houston Methodist Hospital and Research Institute, Houston, TX USA
- Weill Cornell School of Medicine, Department of Neurosurgery, New York, NY USA
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21
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L-Glucose: Another Path to Cancer Cells. Cancers (Basel) 2020; 12:cancers12040850. [PMID: 32244695 PMCID: PMC7225996 DOI: 10.3390/cancers12040850] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2020] [Revised: 03/24/2020] [Accepted: 03/30/2020] [Indexed: 01/31/2023] Open
Abstract
Cancerous tumors comprise cells showing metabolic heterogeneity. Among numerous efforts to understand this property, little attention has been paid to the possibility that cancer cells take up and utilize otherwise unusable substrates as fuel. Here we discuss this issue by focusing on l-glucose, the mirror image isomer of naturally occurring d-glucose; l-glucose is an unmetabolizable sugar except in some bacteria. By combining relatively small fluorophores with l-glucose, we generated fluorescence-emitting l-glucose tracers (fLGs). To our surprise, 2-NBDLG, one of these fLGs, which we thought to be merely a control substrate for the fluorescent d-glucose tracer 2-NBDG, was specifically taken up into tumor cell aggregates (spheroids) that exhibited nuclear heterogeneity, a major cytological feature of malignancy in cancer diagnosis. Changes in mitochondrial activity were also associated with the spheroids taking up fLG. To better understand these phenomena, we review here the Warburg effect as well as key studies regarding glucose uptake. We also discuss tumor heterogeneity involving aberrant uptake of glucose and mitochondrial changes based on the data obtained by fLG. We then consider the use of fLGs as novel markers for visualization and characterization of malignant tumor cells.
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22
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Misun PM, Yesildag B, Forschler F, Neelakandhan A, Rousset N, Biernath A, Hierlemann A, Frey O. In Vitro Platform for Studying Human Insulin Release Dynamics of Single Pancreatic Islet Microtissues at High Resolution. ADVANCED BIOSYSTEMS 2020; 4:e1900291. [PMID: 32293140 PMCID: PMC7610574 DOI: 10.1002/adbi.201900291] [Citation(s) in RCA: 39] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/10/2019] [Indexed: 01/18/2023]
Abstract
Insulin is released from pancreatic islets in a biphasic and pulsatile manner in response to elevated glucose levels. This highly dynamic insulin release can be studied in vitro with islet perifusion assays. Herein, a novel platform to perform glucose-stimulated insulin secretion (GSIS) assays with single islets is presented for studying the dynamics of insulin release at high temporal resolution. A standardized human islet model is developed and a microfluidic hanging-drop-based perifusion system is engineered, which facilitates rapid glucose switching, minimal sample dilution, low analyte dispersion, and short sampling intervals. Human islet microtissues feature robust and long-term glucose responsiveness and demonstrate reproducible dynamic GSIS with a prominent first phase and a sustained, pulsatile second phase. Perifusion of single islet microtissues produces a higher peak secretion rate, higher secretion during the first and second phases of insulin release, as well as more defined pulsations during the second phase in comparison to perifusion of pooled islets. The developed platform enables to study compound effects on both phases of insulin secretion as shown with two classes of insulin secretagogs. It provides a new tool for studying physiologically relevant dynamic insulin secretion at comparably low sample-to-sample variation and high temporal resolution.
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Affiliation(s)
- Patrick M. Misun
- Bio Engineering Laboratory Department of Biosystems Science and Engineering ETH Zürich Mattenstrasse 26, 4058 Basel, Switzerland
| | | | - Felix Forschler
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | | | - Nassim Rousset
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | | | - Andreas Hierlemann
- Bio Engineering Laboratory, Department of Biosystems Science and Engineering, ETH Zürich, Mattenstrasse 26, 4058 Basel, Switzerland
| | - Olivier Frey
- InSphero AG Wagistrasse 27, 8952 Schlieren, Switzerland
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23
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Idevall-Hagren O, Tengholm A. Metabolic regulation of calcium signaling in beta cells. Semin Cell Dev Biol 2020; 103:20-30. [PMID: 32085965 DOI: 10.1016/j.semcdb.2020.01.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2019] [Revised: 01/10/2020] [Accepted: 01/28/2020] [Indexed: 12/22/2022]
Abstract
The cytoplasmic Ca2+ concentration ([Ca2+]cyt) regulates a vast number of cellular functions, including insulin secretion from beta cells. The major physiological insulin secretagogue, glucose, triggers [Ca2+]cyt oscillations in beta cells. Synchronization of the oscillations among the beta cells within an islet underlies the generation of pulsatile insulin secretion. This review describes the mechanisms generating [Ca2+]cyt oscillations, the interactions between [Ca2+]cyt and cell metabolism, as well as the contribution of various organelles to the shaping of [Ca2+]cyt signals and insulin secretion. It also discusses how Ca2+ signals are coordinated and spread throughout the islets and data indicating that altered Ca2+ signaling is associated with beta cell dysfunction and development of type 2 diabetes.
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Affiliation(s)
- Olof Idevall-Hagren
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23 Uppsala, Sweden
| | - Anders Tengholm
- Department of Medical Cell Biology, Uppsala University, Biomedical Centre, Box 571, SE-751 23 Uppsala, Sweden.
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24
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Horowitz LF, Rodriguez AD, Ray T, Folch A. Microfluidics for interrogating live intact tissues. MICROSYSTEMS & NANOENGINEERING 2020; 6:69. [PMID: 32879734 PMCID: PMC7443437 DOI: 10.1038/s41378-020-0164-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 03/10/2020] [Accepted: 03/12/2020] [Indexed: 05/08/2023]
Abstract
The intricate microarchitecture of tissues - the "tissue microenvironment" - is a strong determinant of tissue function. Microfluidics offers an invaluable tool to precisely stimulate, manipulate, and analyze the tissue microenvironment in live tissues and engineer mass transport around and into small tissue volumes. Such control is critical in clinical studies, especially where tissue samples are scarce, in analytical sensors, where testing smaller amounts of analytes results in faster, more portable sensors, and in biological experiments, where accurate control of the cellular microenvironment is needed. Microfluidics also provides inexpensive multiplexing strategies to address the pressing need to test large quantities of drugs and reagents on a single biopsy specimen, increasing testing accuracy, relevance, and speed while reducing overall diagnostic cost. Here, we review the use of microfluidics to study the physiology and pathophysiology of intact live tissues at sub-millimeter scales. We categorize uses as either in vitro studies - where a piece of an organism must be excised and introduced into the microfluidic device - or in vivo studies - where whole organisms are small enough to be introduced into microchannels or where a microfluidic device is interfaced with a live tissue surface (e.g. the skin or inside an internal organ or tumor) that forms part of an animal larger than the device. These microfluidic systems promise to deliver functional measurements obtained directly on intact tissue - such as the response of tissue to drugs or the analysis of tissue secretions - that cannot be obtained otherwise.
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Affiliation(s)
- Lisa F. Horowitz
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - Adán D. Rodriguez
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
| | - Tyler Ray
- Department of Mechanical Engineering, University of Hawaiʻi at Mānoa, Honolulu, HI 96822 USA
| | - Albert Folch
- Department of Bioengineering, University of Washington, Seattle, WA 98195 USA
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25
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26
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Glieberman AL, Pope BD, Zimmerman JF, Liu Q, Ferrier JP, Kenty JHR, Schrell AM, Mukhitov N, Shores KL, Tepole AB, Melton DA, Roper MG, Parker KK. Synchronized stimulation and continuous insulin sensing in a microfluidic human Islet on a Chip designed for scalable manufacturing. LAB ON A CHIP 2019; 19:2993-3010. [PMID: 31464325 PMCID: PMC6814249 DOI: 10.1039/c9lc00253g] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
Pancreatic β cell function is compromised in diabetes and is typically assessed by measuring insulin secretion during glucose stimulation. Traditionally, measurement of glucose-stimulated insulin secretion involves manual liquid handling, heterogeneous stimulus delivery, and enzyme-linked immunosorbent assays that require large numbers of islets and processing time. Though microfluidic devices have been developed to address some of these limitations, traditional methods for islet testing remain the most common due to the learning curve for adopting microfluidic devices and the incompatibility of most device materials with large-scale manufacturing. We designed and built a thermoplastic, microfluidic-based Islet on a Chip compatible with commercial fabrication methods, that automates islet loading, stimulation, and insulin sensing. Inspired by the perfusion of native islets by designated arterioles and capillaries, the chip delivers synchronized glucose pulses to islets positioned in parallel channels. By flowing suspensions of human cadaveric islets onto the chip, we confirmed automatic capture of islets. Fluorescent glucose tracking demonstrated that stimulus delivery was synchronized within a two-minute window independent of the presence or size of captured islets. Insulin secretion was continuously sensed by an automated, on-chip immunoassay and quantified by fluorescence anisotropy. By integrating scalable manufacturing materials, on-line, continuous insulin measurement, and precise spatiotemporal stimulation into an easy-to-use design, the Islet on a Chip should accelerate efforts to study and develop effective treatments for diabetes.
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Affiliation(s)
- Aaron L Glieberman
- Disease Biophysics Group, Wyss Institute for Biologically Inspired Engineering, Harvard John A. Paulson School of Engineering and Applied Sciences, Harvard University, Pierce Hall, 29 Oxford Street, Cambridge, MA 02138, USA.
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27
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Loppini A, Chiodo L. Biophysical modeling of β-cells networks: Realistic architectures and heterogeneity effects. Biophys Chem 2019; 254:106247. [PMID: 31472460 DOI: 10.1016/j.bpc.2019.106247] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2019] [Revised: 08/06/2019] [Accepted: 08/06/2019] [Indexed: 11/29/2022]
Abstract
The β-cells dynamics is the regulator of insulin secretion in the pancreas, and its investigation is a central aspect in designing effective treatment strategies for diabetes. Despite great efforts, much is still unknown about the complex organization of such endocrine cells and realistic mathematical modeling represents a useful tool to elucidate key aspects of glucose control in humans. In this contribution, we study the human β-cells collective behaviour, by modeling their electric and metabolic coupling in a cluster, of size and architecture similar to human islets of Langerhans. We focus on the effect of coupling on various dynamics regimes observed in the islets, that are spiking and bursting on multiple timescales. In particular, we test the effect of hubs, that are highly glucose-sensitive β-cells, on the overall network dynamics, observing different modulation depending on the timescale of the dynamics. By properly taking into account the role of cells heterogeneity, recently emerged, our model effectively describes the effect of hubs on the synchronization of the islet response and the correlation of β-cells activity.
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Affiliation(s)
- A Loppini
- Department of Engineering, University Campus Bio-Medico of Rome, Via Á. del Portillo 21, 00128 Rome, Italy.
| | - L Chiodo
- Department of Engineering, University Campus Bio-Medico of Rome, Via Á. del Portillo 21, 00128 Rome, Italy
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28
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Lee SH, Hong S, Song J, Cho B, Han EJ, Kondapavulur S, Kim D, Lee LP. Microphysiological Analysis Platform of Pancreatic Islet β-Cell Spheroids. Adv Healthc Mater 2018; 7. [PMID: 29283208 DOI: 10.1002/adhm.201701111] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2017] [Revised: 10/27/2017] [Indexed: 02/06/2023]
Abstract
The hallmarks of diabetics are insufficient secretion of insulin and dysregulation of glucagon. It is critical to understand release mechanisms of insulin, glucagon, and other hormones from the islets of Langerhans. In spite of remarkable advancements in diabetes research and practice, robust and reproducible models that can measure pancreatic β-cell function are lacking. Here, a microphysiological analysis platform (MAP) that allows the uniform 3D spheroid formation of pancreatic β-cell islets, large-scale morphological phenotyping, and gene expression mapping of chronic glycemia and lipidemia development is reported. The MAP enables the scaffold-free formation of densely packed β-cell spheroids (i.e., multiple array of 110 bioreactors) surrounded with a perfusion flow network inspired by physiologically relevant microenvironment. The MAP permits dynamic perturbations on the β-cell spheroids and the precise controls of glycemia and lipidemia, which allow us to confirm that cellular apoptosis in the β-cell spheroid under hyperglycemia and hyperlipidemia is mostly dependent to a reactive oxygen species-induced caspase-mediated pathway. The β-cells' MAP might provide a potential new map in the pathophysiological mechanisms of β cells.
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Affiliation(s)
- Sang Hun Lee
- Department of Bioengineering; University of California, Berkeley; Berkeley CA 94720 USA
- Berkeley Sensor and Actuator Center; University of California, Berkeley; Berkeley CA 94720 USA
| | - SoonGweon Hong
- Department of Bioengineering; University of California, Berkeley; Berkeley CA 94720 USA
- Berkeley Sensor and Actuator Center; University of California, Berkeley; Berkeley CA 94720 USA
| | - Jihwan Song
- Department of Mechanical Engineering; Hanbat National University; Daejeon 34158 South Korea
- Berkeley Sensor and Actuator Center; University of California, Berkeley; Berkeley CA 94720 USA
| | - Byungrae Cho
- Berkeley Sensor and Actuator Center; University of California, Berkeley; Berkeley CA 94720 USA
- UC Berkeley and UCSF Joint Graduate Program in Bioengineering; Berkeley/San Francisco CA 94720 USA
| | - Esther J. Han
- Department of Chemistry; University of California, Berkeley; Berkeley CA 94720 USA
| | - Sravani Kondapavulur
- Department of Bioengineering; University of California, Berkeley; Berkeley CA 94720 USA
| | - Dongchoul Kim
- Department of Mechanical Engineering; Sogang University; Seoul 04107 South Korea
| | - Luke P. Lee
- Department of Bioengineering; University of California, Berkeley; Berkeley CA 94720 USA
- Berkeley Sensor and Actuator Center; University of California, Berkeley; Berkeley CA 94720 USA
- Department of Electrical Engineering and Computer Science; University of California, Berkeley; Berkeley CA 94720 USA
- Biophysics Graduate Program; University of California, Berkeley; Berkeley CA 94720 USA
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29
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Westacott MJ, Ludin NWF, Benninger RKP. Spatially Organized β-Cell Subpopulations Control Electrical Dynamics across Islets of Langerhans. Biophys J 2017; 113:1093-1108. [PMID: 28877492 DOI: 10.1016/j.bpj.2017.07.021] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2017] [Revised: 07/21/2017] [Accepted: 07/31/2017] [Indexed: 10/18/2022] Open
Abstract
Understanding how heterogeneous cells within a multicellular system interact and affect overall function is difficult without a means of perturbing individual cells or subpopulations. Here we apply optogenetics to understand how subpopulations of β-cells control the overall [Ca2+]i response and insulin secretion dynamics of the islets of Langerhans. We spatiotemporally perturbed electrical activity in β-cells of channelrhodopsin2-expressing islets, mapped the [Ca2+]i response, and correlated this with the cellular metabolic activity and an in silico electrophysiology model. We discovered organized regions of metabolic activity across the islet, and these affect the way in which β-cells electrically interact. Specific regions acted as pacemakers by initiating calcium wave propagation. Our findings reveal the functional architecture of the islet, and show how distinct subpopulations of cells can disproportionality affect function. These results also suggest ways in which other neuroendocrine systems can be regulated, and demonstrate how optogenetic tools can discern their functional architecture.
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Affiliation(s)
| | - Nurin W F Ludin
- Department of Bioengineering, University of Colorado, Aurora, Colorado
| | - Richard K P Benninger
- Department of Bioengineering, University of Colorado, Aurora, Colorado; Barbara Davis Center for Diabetes, University of Colorado, Aurora, Colorado.
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30
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Loppini A, Pedersen MG, Braun M, Filippi S. Gap-junction coupling and ATP-sensitive potassium channels in human β-cell clusters: Effects on emergent dynamics. Phys Rev E 2017; 96:032403. [PMID: 29346932 DOI: 10.1103/physreve.96.032403] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Indexed: 11/07/2022]
Abstract
The importance of gap-junction coupling between β cells in pancreatic islets is well established in mouse. Such ultrastructural connections synchronize cellular activity, confine biological heterogeneity, and enhance insulin pulsatility. Dysfunction of coupling has been associated with diabetes and altered β-cell function. However, the role of gap junctions between human β cells is still largely unexplored. By using patch-clamp recordings of β cells from human donors, we previously estimated electrical properties of these channels by mathematical modeling of pairs of human β cells. In this work we revise our estimate by modeling triplet configurations and larger heterogeneous clusters. We find that a coupling conductance in the range 0.005-0.020 nS/pF can reproduce experiments in almost all the simulated arrangements. We finally explore the consequence of gap-junction coupling of this magnitude between β cells with mutant variants of the ATP-sensitive potassium channels involved in some metabolic disorders and diabetic conditions, translating studies performed on rodents to the human case. Our results are finally discussed from the perspective of therapeutic strategies. In summary, modeling of more realistic clusters with more than two β cells slightly lowers our previous estimate of gap-junction conductance and gives rise to patterns that more closely resemble experimental traces.
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Affiliation(s)
- A Loppini
- Nonlinear Physics and Mathematical Modeling Laboratory, Campus Bio-Medico University of Rome, I-00128 Rome, Italy
| | - M G Pedersen
- Department of Information Engineering, University of Padua, I-35131 Padua, Italy
| | - M Braun
- Alberta Diabetes Institute, Department of Pharmacology, University of Alberta, Edmonton, T6G 2H7 Alberta, Canada
| | - S Filippi
- Nonlinear Physics and Mathematical Modeling Laboratory, Campus Bio-Medico University of Rome, I-00128 Rome, Italy
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31
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Xing Y, Nourmohammadzadeh M, Elias JEM, Chan M, Chen Z, McGarrigle JJ, Oberholzer J, Wang Y. A pumpless microfluidic device driven by surface tension for pancreatic islet analysis. Biomed Microdevices 2017; 18:80. [PMID: 27534648 DOI: 10.1007/s10544-016-0109-4] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
We present a novel pumpless microfluidic array driven by surface tension for studying the physiology of pancreatic islets of Langerhans. Efficient fluid flow in the array is achieved by surface tension-generated pressure as a result of inlet and outlet size differences. Flow properties are characterized in numerical simulation and further confirmed by experimental measurements. Using this device, we perform a set of biological assays, which include real-time fluorescent imaging and insulin secretion kinetics for both mouse and human islets. Our results demonstrate that this system not only drastically simplifies previously published experimental protocols for islet study by eliminating the need for external pumps/tubing and reducing the volume of solution consumption, but it also achieves a higher analytical spatiotemporal resolution due to efficient flow exchanges and the extremely small volume of solutions required. Overall, the microfluidic platform presented can be used as a potential powerful tool for understanding islet physiology, antidiabetic drug development, and islet transplantation.
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Affiliation(s)
- Yuan Xing
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60115, USA
| | - Mohammad Nourmohammadzadeh
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60115, USA
| | - Joshua E Mendoza Elias
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60115, USA
| | - Manwai Chan
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA.,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60115, USA
| | - Zequn Chen
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA
| | - James J McGarrigle
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA
| | - José Oberholzer
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA. .,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60115, USA.
| | - Yong Wang
- Department of Surgery/Transplant, University of Illinois at Chicago, 840 S. Wood St, Rm 502, Chicago, IL, 60612, USA. .,Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60115, USA.
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32
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Bae CY, Son J, Kim H, Park JK. Demonstration of Interposed Modular Hydrogel Sheet for Multicellular Analysis in a Microfluidic Assembly Platform. Sci Rep 2017; 7:1289. [PMID: 28465532 PMCID: PMC5430983 DOI: 10.1038/s41598-017-01363-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Accepted: 03/29/2017] [Indexed: 12/29/2022] Open
Abstract
Hydrogel sheets have emerged as a promising biomaterial scaffold for the encapsulation and transfer of multicellular structures. Although the improvement of the chemical interactions and the design of micro-scaled geometry have contributed to the development of multipurpose hydrogel scaffolds, the application of hydrogel sheets to assess multicellular structures is still challenging. To expand the technical applicability of hydrogel sheets, we here demonstrate that a single layer of the hydrogel sheet can be integrated as an interposed module in a microfluidic device for multicellular analysis. As a cell culture unit, encapsulated pancreatic insulinoma (MIN6) cells in the hydrogel sheet were labeled and examined via multiple microchannels. After obtaining simultaneously multi-labeled cells in the hydrogel sheet that had been incorporated into the microfluidic device, each modular hydrogel sheet was also recoverable and re-cultured without any distortion. The modular hydrogel sheet can be simply manipulated and conserved as a multicellular module in a three-dimensional (3D) in vitro culture platform. Using the modular concept of hydrogel sheets capable of cell culture and/or assay, an integrated multicellular analysis in the microfluidic device is expected to improve accessibility, scalability, and practicality for end users.
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Affiliation(s)
- Chae Yun Bae
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Jaejung Son
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Hail Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea
| | - Je-Kyun Park
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology (KAIST), Daejeon, 34141, Republic of Korea.
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33
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Lenguito G, Chaimov D, Weitz JR, Rodriguez-Diaz R, Rawal SAK, Tamayo-Garcia A, Caicedo A, Stabler CL, Buchwald P, Agarwal A. Resealable, optically accessible, PDMS-free fluidic platform for ex vivo interrogation of pancreatic islets. LAB ON A CHIP 2017; 17:772-781. [PMID: 28157238 PMCID: PMC5330806 DOI: 10.1039/c6lc01504b] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
We report the design and fabrication of a robust fluidic platform built out of inert plastic materials and micromachined features that promote optimized convective fluid transport. The platform is tested for perfusion interrogation of rodent and human pancreatic islets, dynamic secretion of hormones, concomitant live-cell imaging, and optogenetic stimulation of genetically engineered islets. A coupled quantitative fluid dynamics computational model of glucose stimulated insulin secretion and fluid dynamics was first utilized to design device geometries that are optimal for complete perfusion of three-dimensional islets, effective collection of secreted insulin, and minimization of system volumes and associated delays. Fluidic devices were then fabricated through rapid prototyping techniques, such as micromilling and laser engraving, as two interlocking parts from materials that are non-absorbent and inert. Finally, the assembly was tested for performance using both rodent and human islets with multiple assays conducted in parallel, such as dynamic perfusion, staining and optogenetics on standard microscopes, as well as for integration with commercial perfusion machines. The optimized design of convective fluid flows, use of bio-inert and non-absorbent materials, reversible assembly, manual access for loading and unloading of islets, and straightforward integration with commercial imaging and fluid handling systems proved to be critical for perfusion assay, and particularly suited for time-resolved optogenetics studies.
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Affiliation(s)
- Giovanni Lenguito
- Department of Biomedical Engineering, Department of Pathology & Laboratory Medicine, University of Miami, Miami, FL 33136, USA.
| | - Deborah Chaimov
- Department of Biomedical Engineering, University of Florida, USA
| | | | | | - Siddarth A K Rawal
- Department of Biomedical Engineering, Department of Pathology & Laboratory Medicine, University of Miami, Miami, FL 33136, USA.
| | | | | | - Cherie L Stabler
- Department of Biomedical Engineering, University of Florida, USA
| | - Peter Buchwald
- Diabetes Research Institute, University of Miami, USA and Department of Molecular and Cellular Pharmacology, University of Miami, USA
| | - Ashutosh Agarwal
- Department of Biomedical Engineering, Department of Pathology & Laboratory Medicine, University of Miami, Miami, FL 33136, USA. and Diabetes Research Institute, University of Miami, USA
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34
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Li X, Brooks JC, Hu J, Ford KI, Easley CJ. 3D-templated, fully automated microfluidic input/output multiplexer for endocrine tissue culture and secretion sampling. LAB ON A CHIP 2017; 17:341-349. [PMID: 27990542 PMCID: PMC5293597 DOI: 10.1039/c6lc01201a] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
A fully automated, 16-channel microfluidic input/output multiplexer (μMUX) has been developed for interfacing to primary cells and to improve understanding of the dynamics of endocrine tissue function. The device utilizes pressure driven push-up valves for precise manipulation of nutrient input and hormone output dynamics, allowing time resolved interrogation of the cells. The ability to alternate any of the 16 channels from input to output, and vice versa, provides for high experimental flexibility without the need to alter microchannel designs. 3D-printed interface templates were custom designed to sculpt the above-channel polydimethylsiloxane (PDMS) in microdevices, creating millimeter scale reservoirs and confinement chambers to interface primary murine islets and adipose tissue explants to the μMUX sampling channels. This μMUX device and control system was first programmed for dynamic studies of pancreatic islet function to collect ∼90 minute insulin secretion profiles from groups of ∼10 islets. The automated system was also operated in temporal stimulation and cell imaging mode. Adipose tissue explants were exposed to a temporal mimic of post-prandial insulin and glucose levels, while simultaneous switching between labeled and unlabeled free fatty acid permitted fluorescent imaging of fatty acid uptake dynamics in real time over a ∼2.5 hour period. Application with varying stimulation and sampling modes on multiple murine tissue types highlights the inherent flexibility of this novel, 3D-templated μMUX device. The tissue culture reservoirs and μMUX control components presented herein should be adaptable as individual modules in other microfluidic systems, such as organ-on-a-chip devices, and should be translatable to different tissues such as liver, heart, skeletal muscle, and others.
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Affiliation(s)
- Xiangpeng Li
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
| | - Jessica C Brooks
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
| | - Juan Hu
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
| | - Katarena I Ford
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
| | - Christopher J Easley
- Department of Chemistry and Biochemistry, Auburn University, Auburn, AL 36849, USA.
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35
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Hwang PTJ, Shah DK, Garcia JA, Bae CY, Lim DJ, Huiszoon RC, Alexander GC, Jun HW. Progress and challenges of the bioartificial pancreas. NANO CONVERGENCE 2016; 3:28. [PMID: 28191438 PMCID: PMC5271153 DOI: 10.1186/s40580-016-0088-4] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 10/07/2016] [Indexed: 05/14/2023]
Abstract
Pancreatic islet transplantation has been validated as a treatment for type 1 diabetes since it maintains consistent and sustained type 1 diabetes reversal. However, one of the major challenges in pancreatic islet transplantation is the body's natural immune response to the implanted islets. Immunosuppressive drug treatment is the most popular immunomodulatory approach for islet graft survival. However, administration of immunosuppressive drugs gives rise to negative side effects, and long-term effects are not clearly understood. A bioartificial pancreas is a therapeutic approach to enable pancreatic islet transplantation without or with minimal immune suppression. The bioartificial pancreas encapsulates the pancreatic islets in a semi-permeable environment which protects islets from the body's immune responses, while allowing the permeation of insulin, oxygen, nutrients, and waste. Many groups have developed various types of the bioartificial pancreas and tested their efficacy in animal models. However, the clinical application of the bioartificial pancreas still requires further investigation. In this review, we discuss several types of bioartificial pancreases and address their advantages and limitations. We also discuss recent advances in bioartificial pancreas applications with microfluidic or micropatterning technology.
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Affiliation(s)
- Patrick T. J. Hwang
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Dishant K. Shah
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Jacob A. Garcia
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Chae Yun Bae
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Dong-Jin Lim
- Department of Otolaryngology, University of Alabama at Birmingham, Boshell, 1720 2nd Avenue South, Birmingham, AL 35294 USA
| | - Ryan C. Huiszoon
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Grant C. Alexander
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
| | - Ho-Wook Jun
- Department of Biomedical Engineering, University of Alabama at Birmingham, Birmingham, AL 35294 USA
- 806 Shelby, 1825 University Boulevard, Birmingham, AL USA
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36
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Silva PN, Atto Z, Regeenes R, Tufa U, Chen YY, Chan WCW, Volchuk A, Kilkenny DM, Rocheleau JV. Highly efficient adenoviral transduction of pancreatic islets using a microfluidic device. LAB ON A CHIP 2016; 16:2921-2934. [PMID: 27378588 DOI: 10.1039/c6lc00345a] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Tissues are challenging to genetically manipulate due to limited penetration of viral particles resulting in low transduction efficiency. We are particularly interested in expressing genetically-encoded sensors in ex vivo pancreatic islets to measure glucose-stimulated metabolism, however poor viral penetration biases these measurements to only a subset of cells at the periphery. To increase mass transfer of viral particles, we designed a microfluidic device that holds islets in parallel hydrodynamic traps connected by an expanding by-pass channel. We modeled viral particle flow into the tissue using fluorescently-labelled gold nanoparticles of varying sizes and showed a penetration threshold of only ∼5 nm. To increase this threshold, we used EDTA to transiently reduce cell-cell adhesion and expand intercellular space. Ultimately, a combination of media flow and ETDA treatment significantly increased adenoviral transduction to the core of the islet. As proof-of-principle, we used this protocol to transduce an ER-targeted redox sensitive sensor (eroGFP), and revealed significantly greater ER redox capacity at core islet cells. Overall, these data demonstrate a robust method to enhance transduction efficiency of islets, and potentially other tissues, by using a combination of microfluidic flow and transient tissue expansion.
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Affiliation(s)
- Pamuditha N Silva
- Institute of Biomaterials and Biomedical Engineering, University of Toronto, 164 College St., Toronto, Ontario M5S 3G9, Canada.
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37
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Nourmohammadzadeh M, Xing Y, Lee JW, Bochenek MA, Mendoza-Elias JE, McGarrigle JJ, Marchese E, Chun-Chieh Y, Eddington DT, Oberholzer J, Wang Y. A microfluidic array for real-time live-cell imaging of human and rodent pancreatic islets. LAB ON A CHIP 2016; 16:1466-72. [PMID: 26999734 PMCID: PMC6286192 DOI: 10.1039/c5lc01173f] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/07/2023]
Abstract
In this study, we present a microfluidic array for high-resolution imaging of individual pancreatic islets. The device is based on hydrodynamic trapping principle and enables real-time analysis of islet cellular responses to insulin secretagogues. This device has significant advantages over our previously published perifusion chamber device including significantly increased analytical power and assay sensitivity, as well as improved spatiotemporal resolution. The islet array, with live-cell multiparametric imaging integration, provides a better tool to understand the physiological and pathophysiological changes of pancreatic islets through the analysis of single islet responses. This platform demonstrates the feasibility of array-based islet cellular analysis and opens up a new modality to conduct informative and quantitive evaluation of islets and cell-based screening for new diabetes treatments.
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Affiliation(s)
- Mohammad Nourmohammadzadeh
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA. and Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
| | - Yuan Xing
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA. and Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
| | - Jin Wuk Lee
- Department of Electroengineering, Northern Illinois University, Chicago, IL, 60115 USA
| | - Matthew A Bochenek
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA. and Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
| | - Joshua E Mendoza-Elias
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA. and Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
| | - James J McGarrigle
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA.
| | - Enza Marchese
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA.
| | - Yeh Chun-Chieh
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA.
| | - David T Eddington
- Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
| | - José Oberholzer
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA. and Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
| | - Yong Wang
- Department of Surgery/Transplant, University of Illinois at Chicago, Chicago, IL, 60612 USA. and Department of Bioengineering, University of Illinois at Chicago, Chicago, IL, 60607 USA
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38
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Castiello FR, Heileman K, Tabrizian M. Microfluidic perfusion systems for secretion fingerprint analysis of pancreatic islets: applications, challenges and opportunities. LAB ON A CHIP 2016; 16:409-31. [PMID: 26732665 DOI: 10.1039/c5lc01046b] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/08/2023]
Abstract
A secretome signature is a heterogeneous profile of secretions present in a single cell type. From the secretome signature a smaller panel of proteins, namely a secretion fingerprint, can be chosen to feasibly monitor specific cellular activity. Based on a thorough appraisal of the literature, this review explores the possibility of defining and using a secretion fingerprint to gauge the functionality of pancreatic islets of Langerhans. It covers the state of the art regarding microfluidic perfusion systems used in pancreatic islet research. Candidate analytical tools to be integrated within microfluidic perfusion systems for dynamic secretory fingerprint monitoring were identified. These analytical tools include patch clamp, amperometry/voltametry, impedance spectroscopy, field effect transistors and surface plasmon resonance. Coupled with these tools, microfluidic devices can ultimately find applications in determining islet quality for transplantation, islet regeneration and drug screening of therapeutic agents for the treatment of diabetes.
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Affiliation(s)
- F Rafael Castiello
- Biomedical Engineering Department, McGill University, Montreal, QC H3A 2B4, Canada.
| | - Khalil Heileman
- Biomedical Engineering Department, McGill University, Montreal, QC H3A 2B4, Canada.
| | - Maryam Tabrizian
- Biomedical Engineering Department, McGill University, Montreal, QC H3A 2B4, Canada.
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Cherubini C, Filippi S, Gizzi A, Loppini A. Role of topology in complex functional networks of beta cells. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2015; 92:042702. [PMID: 26565267 DOI: 10.1103/physreve.92.042702] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2015] [Indexed: 06/05/2023]
Abstract
The activity of pancreatic β cells can be described by biological networks of coupled nonlinear oscillators that, via electrochemical synchronization, release insulin in response to augmented glucose levels. In this work, we analyze the emergent behavior of regular and percolated β-cells clusters through a stochastic mathematical model where "functional" networks arise. We show that the emergence and robustness of the synchronized dynamics depend both on intrinsic and extrinsic parameters. In particular, cellular noise level, glucose concentration, network spatial architecture, and cell-to-cell coupling strength are the key factors for the generation of a rhythmic and robust activity. Their role in the functional network topology associated with β-cells clusters is analyzed and discussed.
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Affiliation(s)
- Christian Cherubini
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, I-00128, Rome, Italy
- International Center for Relativistic Astrophysics Network-I.C.R.A.Net, University Campus Bio-Medico of Rome, I-00128, Rome, Italy
| | - Simonetta Filippi
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, I-00128, Rome, Italy
- International Center for Relativistic Astrophysics Network-I.C.R.A.Net, University Campus Bio-Medico of Rome, I-00128, Rome, Italy
| | - Alessio Gizzi
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, I-00128, Rome, Italy
| | - Alessandro Loppini
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico of Rome, I-00128, Rome, Italy
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Loppini A, Braun M, Filippi S, Pedersen MG. Mathematical modeling of gap junction coupling and electrical activity in human β-cells. Phys Biol 2015; 12:066002. [PMID: 26403477 DOI: 10.1088/1478-3975/12/6/066002] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Coordinated insulin secretion is controlled by electrical coupling of pancreatic β-cells due to connexin-36 gap junctions. Gap junction coupling not only synchronizes the heterogeneous β-cell population, but can also modify the electrical behavior of the cells. These phenomena have been widely studied with mathematical models based on data from mouse β-cells. However, it is now known that human β-cell electrophysiology shows important differences to its rodent counterpart, and although human pancreatic islets express connexin-36 and show evidence of β-cell coupling, these aspects have been little investigated in human β-cells. Here we investigate theoretically, the gap junction coupling strength required for synchronizing electrical activity in a small cluster of cells simulated with a recent mathematical model of human β-cell electrophysiology. We find a lower limit for the coupling strength of approximately 20 pS (i.e., normalized to cell size, ∼2 pS pF(-1)) below which spiking electrical activity is asynchronous. To confront this theoretical lower bound with data, we use our model to estimate from an experimental patch clamp recording that the coupling strength is approximately 100-200 pS (10-20 pS pF(-1)), similar to previous estimates in mouse β-cells. We then investigate the role of gap junction coupling in synchronizing and modifying other forms of electrical activity in human β-cell clusters. We find that electrical coupling can prolong the period of rapid bursting electrical activity, and synchronize metabolically driven slow bursting, in particular when the metabolic oscillators are in phase. Our results show that realistic coupling conductances are sufficient to promote synchrony in small clusters of human β-cells as observed experimentally, and provide motivation for further detailed studies of electrical coupling in human pancreatic islets.
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Affiliation(s)
- Alessandro Loppini
- Nonlinear Physics and Mathematical Modeling Laboratory, University Campus Bio-Medico, I-00128, Rome, Italy
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Heileman K, Daoud J, Hasilo C, Gasparrini M, Paraskevas S, Tabrizian M. Microfluidic platform for assessing pancreatic islet functionality through dielectric spectroscopy. BIOMICROFLUIDICS 2015; 9:044125. [PMID: 26339324 PMCID: PMC4552695 DOI: 10.1063/1.4929652] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 08/14/2015] [Indexed: 05/07/2023]
Abstract
Human pancreatic islets are seldom assessed for dynamic responses to external stimuli. Thus, the elucidation of human islet functionality would provide insights into the progression of diabetes mellitus, evaluation of preparations for clinical transplantation, as well as for the development of novel therapeutics. The objective of this study was to develop a microfluidic platform for in vitro islet culture, allowing the multi-parametric investigation of islet response to chemical and biochemical stimuli. This was accomplished through the fabrication and implementation of a microfluidic platform that allowed the perifusion of islet culture while integrating real-time monitoring using impedance spectroscopy, through microfabricated, interdigitated electrodes located along the microchamber arrays. Real-time impedance measurements provide important dielectric parameters, such as cell membrane capacitance and cytoplasmic conductivity, representing proliferation, differentiation, viability, and functionality. The perifusion of varying glucose concentrations and monitoring of the resulting impedance of pancreatic islets were performed as proof-of-concept validation of the lab-on-chip platform. This novel technique to elucidate the underlying mechanisms that dictate islet functionality is presented, providing new information regarding islet function that could improve the evaluation of islet preparations for transplantation. In addition, it will lead to a better understanding of fundamental diabetes-related islet dysfunction and the development of therapeutics through evaluation of potential drug effects.
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Affiliation(s)
- K Heileman
- Biomedical Engineering Department, McGill University , Montreal, Quebec H3A 2B4, Canada
| | - J Daoud
- Biomedical Engineering Department, McGill University , Montreal, Quebec H3A 2B4, Canada
| | - C Hasilo
- Department of Surgery, McGill University , Montreal, Quebec H3A 0G4, Canada
| | - M Gasparrini
- Department of Surgery, McGill University , Montreal, Quebec H3A 0G4, Canada
| | - S Paraskevas
- Department of Surgery, McGill University , Montreal, Quebec H3A 0G4, Canada
| | - M Tabrizian
- Biomedical Engineering Department, McGill University , Montreal, Quebec H3A 2B4, Canada
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Yasotharan S, Pinto S, Sled JG, Bolz SS, Günther A. Artery-on-a-chip platform for automated, multimodal assessment of cerebral blood vessel structure and function. LAB ON A CHIP 2015; 15:2660-9. [PMID: 25990299 DOI: 10.1039/c5lc00021a] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/10/2023]
Abstract
We present a compact microfluidic platform for the automated, multimodal assessment of intact small blood vessels. Mouse olfactory artery segments were reversibly loaded onto a microfluidic device and kept under physiological (i.e., close to in vivo) environmental conditions. For immunohistochemical endpoint protein analysis, automated on chip fixation and staining of the artery eliminated the need for any subsequent tissue sectioning or processing outside the chip. In a first case study, we demonstrate the blood vessel abluminal structure based on the positions of smooth muscle cell nuclei, actin filaments and voltage gated calcium channels. In a second case study we incubated smooth muscle cells (SMCs) with a calcium-sensitive dye to simultaneously assess time-dependent, agonist-induced calcium and diameter changes of pressurized resistance arteries. We expect the presented microfluidic platform to promote routine on-chip staining and quantitative fluorescence imaging of intact blood vessels from different vascular beds, tissue engineered vascular constructs and vascularized microtissues. The at least tenfold reduction in required aliquot volumes for functional assessment and staining was achieved by on-board fluid manipulation of the syringe-pump free platform and may promote its applications for screening of newly synthesized compounds.
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Affiliation(s)
- Sanjesh Yasotharan
- Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario M5S3G8, Canada.
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Wall ML, Pound LD, Trenary I, O'Brien RM, Young JD. Novel stable isotope analyses demonstrate significant rates of glucose cycling in mouse pancreatic islets. Diabetes 2015; 64:2129-37. [PMID: 25552595 PMCID: PMC4439557 DOI: 10.2337/db14-0745] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2014] [Accepted: 12/20/2014] [Indexed: 11/20/2022]
Abstract
A polymorphism located in the G6PC2 gene, which encodes an islet-specific glucose-6-phosphatase catalytic subunit, is the most important common determinant of variations in fasting blood glucose (FBG) levels in humans. Studies of G6pc2 knockout (KO) mice suggest that G6pc2 represents a negative regulator of basal glucose-stimulated insulin secretion (GSIS) that acts by hydrolyzing glucose-6-phosphate (G6P), thereby reducing glycolytic flux. However, this conclusion conflicts with the very low estimates for the rate of glucose cycling in pancreatic islets, as assessed using radioisotopes. We have reassessed the rate of glucose cycling in pancreatic islets using a novel stable isotope method. The data show much higher levels of glucose cycling than previously reported. In 5 mmol/L glucose, islets from C57BL/6J chow-fed mice cycled ∼16% of net glucose uptake. The cycling rate was further increased at 11 mmol/L glucose. Similar cycling rates were observed using islets from high fat-fed mice. Importantly, glucose cycling was abolished in G6pc2 KO mouse islets, confirming that G6pc2 opposes the action of the glucose sensor glucokinase by hydrolyzing G6P. The demonstration of high rates of glucose cycling in pancreatic islets explains why G6pc2 deletion enhances GSIS and why variants in G6PC2 affect FBG in humans.
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Affiliation(s)
- Martha L Wall
- Department of Chemical and Biomolecular Engineering, Vanderbilt School of Engineering, Nashville, TN
| | - Lynley D Pound
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, TN
| | - Irina Trenary
- Department of Chemical and Biomolecular Engineering, Vanderbilt School of Engineering, Nashville, TN
| | - Richard M O'Brien
- Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, TN
| | - Jamey D Young
- Department of Chemical and Biomolecular Engineering, Vanderbilt School of Engineering, Nashville, TN Department of Molecular Physiology and Biophysics, Vanderbilt University Medical School, Nashville, TN
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Yi L, Wang X, Dhumpa R, Schrell AM, Mukhitov N, Roper MG. Integrated perfusion and separation systems for entrainment of insulin secretion from islets of Langerhans. LAB ON A CHIP 2015; 15:823-32. [PMID: 25474044 PMCID: PMC4304979 DOI: 10.1039/c4lc01360c] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
A microfluidic system was developed to investigate the entrainment of insulin secretion from islets of Langerhans to oscillatory glucose levels. A gravity-driven perfusion system was integrated with a microfluidic system to deliver sinusoidal glucose waveforms to the islet chamber. Automated manipulation of the height of the perfusion syringes allowed precise control of the ratio of two perfusion solutions into a chamber containing 1-10 islets. Insulin levels in the perfusate were measured using an online competitive electrophoretic immunoassay with a sampling period of 10 s. The insulin immunoassay had a detection limit of 3 nM with RSDs of calibration points ranging from 2-8%. At 11 mM glucose, insulin secretion from single islets was oscillatory with a period ranging from 3-6 min. Application of a small amplitude sinusoidal wave of glucose with a period of 5 or 10 min, shifted the period of the insulin oscillations to this forcing period. Exposing groups of 6-10 islets to a sinusoidal glucose wave synchronized their behavior, producing a coherent pulsatile insulin response from the population. These results demonstrate the feasibility of the developed system for the study of oscillatory insulin secretion and can be easily modified for investigating the dynamic nature of other hormones released from different cell types.
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Affiliation(s)
- Lian Yi
- Department of Chemistry and Biochemistry, Florida State University, 95 Chieftain Way, Tallahassee, FL 32306, USA.
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Elliott AD, Ustione A, Piston DW. Somatostatin and insulin mediate glucose-inhibited glucagon secretion in the pancreatic α-cell by lowering cAMP. Am J Physiol Endocrinol Metab 2015; 308:E130-43. [PMID: 25406263 PMCID: PMC4297778 DOI: 10.1152/ajpendo.00344.2014] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
The dysregulation of glucose-inhibited glucagon secretion from the pancreatic islet α-cell is a critical component of diabetes pathology and metabolic disease. We show a previously uncharacterized [Ca(2+)]i-independent mechanism of glucagon suppression in human and murine pancreatic islets whereby cAMP and PKA signaling are decreased. This decrease is driven by the combination of somatostatin, which inhibits adenylyl cyclase production of cAMP via the Gαi subunit of the SSTR2, and insulin, which acts via its receptor to activate phosphodiesterase 3B and degrade cytosolic cAMP. Our data indicate that both somatostatin and insulin signaling are required to suppress cAMP/PKA and glucagon secretion from both human and murine α-cells, and the combination of these two signaling mechanisms is sufficient to reduce glucagon secretion from isolated α-cells as well as islets. Thus, we conclude that somatostatin and insulin together are critical paracrine mediators of glucose-inhibited glucagon secretion and function by lowering cAMP/PKA signaling with increasing glucose.
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Affiliation(s)
- Amicia D Elliott
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - Alessandro Ustione
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
| | - David W Piston
- Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee
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46
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Benninger RKP, Hutchens T, Head WS, McCaughey MJ, Zhang M, Le Marchand SJ, Satin LS, Piston DW. Intrinsic islet heterogeneity and gap junction coupling determine spatiotemporal Ca²⁺ wave dynamics. Biophys J 2014; 107:2723-33. [PMID: 25468351 DOI: 10.1016/j.bpj.2014.10.048] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2014] [Revised: 09/09/2014] [Accepted: 10/08/2014] [Indexed: 10/24/2022] Open
Abstract
Insulin is released from the islets of Langerhans in discrete pulses that are linked to synchronized oscillations of intracellular free calcium ([Ca(2+)]i). Associated with each synchronized oscillation is a propagating calcium wave mediated by Connexin36 (Cx36) gap junctions. A computational islet model predicted that waves emerge due to heterogeneity in β-cell function throughout the islet. To test this, we applied defined patterns of glucose stimulation across the islet using a microfluidic device and measured how these perturbations affect calcium wave propagation. We further investigated how gap junction coupling regulates spatiotemporal [Ca(2+)]i dynamics in the face of heterogeneous glucose stimulation. Calcium waves were found to originate in regions of the islet having elevated excitability, and this heterogeneity is an intrinsic property of islet β-cells. The extent of [Ca(2+)]i elevation across the islet in the presence of heterogeneity is gap-junction dependent, which reveals a glucose dependence of gap junction coupling. To better describe these observations, we had to modify the computational islet model to consider the electrochemical gradient between neighboring β-cells. These results reveal how the spatiotemporal [Ca(2+)]i dynamics of the islet depend on β-cell heterogeneity and cell-cell coupling, and are important for understanding the regulation of coordinated insulin release across the islet.
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Affiliation(s)
- Richard K P Benninger
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee; Department of Bioengineering, University of Colorado, Aurora, Colorado; Barbara Davis Center, University of Colorado, Aurora, Colorado.
| | - Troy Hutchens
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee
| | - W Steven Head
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee
| | - Michael J McCaughey
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee
| | - Min Zhang
- Department of Pharmacology, Virginia Commonwealth University, Richmond, Virginia
| | - Sylvain J Le Marchand
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee
| | - Leslie S Satin
- Department of Pharmacology, Virginia Commonwealth University, Richmond, Virginia; Department of Pharmacology, University of Michigan, Ann Arbor, Michigan; Brehm Diabetes Center, University of Michigan, Ann Arbor, Michigan
| | - David W Piston
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, Tennessee.
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Barnes TM, Otero YF, Elliott AD, Locke AD, Malabanan CM, Coldren AG, Brissova M, Piston DW, McGuinness OP. Interleukin-6 amplifies glucagon secretion: coordinated control via the brain and pancreas. Am J Physiol Endocrinol Metab 2014; 307:E896-905. [PMID: 25205821 PMCID: PMC4233256 DOI: 10.1152/ajpendo.00343.2014] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Inappropriate glucagon secretion contributes to hyperglycemia in inflammatory disease. Previous work implicates the proinflammatory cytokine interleukin-6 (IL-6) in glucagon secretion. IL-6-KO mice have a blunted glucagon response to lipopolysaccharide (LPS) that is restored by intravenous replacement of IL-6. Given that IL-6 has previously been demonstrated to have a transcriptional (i.e., slow) effect on glucagon secretion from islets, we hypothesized that the rapid increase in glucagon following LPS occurred by a faster mechanism, such as by action within the brain. Using chronically catheterized conscious mice, we have demonstrated that central IL-6 stimulates glucagon secretion uniquely in the presence of an accompanying stressor (hypoglycemia or LPS). Contrary to our hypothesis, however, we found that IL-6 amplifies glucagon secretion in two ways; IL-6 not only stimulates glucagon secretion via the brain but also by direct action on islets. Interestingly, IL-6 augments glucagon secretion from both sites only in the presence of an accompanying stressor (such as epinephrine). Given that both adrenergic tone and plasma IL-6 are elevated in multiple inflammatory diseases, the interactions of the IL-6 and catecholaminergic signaling pathways in regulating GCG secretion may contribute to our present understanding of these diseases.
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Affiliation(s)
- Tammy M Barnes
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Yolanda F Otero
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Amicia D Elliott
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Alicia D Locke
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Carlo M Malabanan
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Anastasia G Coldren
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Marcela Brissova
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - David W Piston
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Owen P McGuinness
- Department of Molecular Physiology and Biophysics, Vanderbilt University School of Medicine, Nashville, Tennessee
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Hraha TH, Westacott MJ, Pozzoli M, Notary AM, McClatchey PM, Benninger RKP. Phase transitions in the multi-cellular regulatory behavior of pancreatic islet excitability. PLoS Comput Biol 2014; 10:e1003819. [PMID: 25188228 PMCID: PMC4154652 DOI: 10.1371/journal.pcbi.1003819] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Accepted: 07/16/2014] [Indexed: 12/23/2022] Open
Abstract
The pancreatic islets of Langerhans are multicellular micro-organs integral to maintaining glucose homeostasis through secretion of the hormone insulin. β-cells within the islet exist as a highly coupled electrical network which coordinates electrical activity and insulin release at high glucose, but leads to global suppression at basal glucose. Despite its importance, how network dynamics generate this emergent binary on/off behavior remains to be elucidated. Previous work has suggested that a small threshold of quiescent cells is able to suppress the entire network. By modeling the islet as a Boolean network, we predicted a phase-transition between globally active and inactive states would emerge near this threshold number of cells, indicative of critical behavior. This was tested using islets with an inducible-expression mutation which renders defined numbers of cells electrically inactive, together with pharmacological modulation of electrical activity. This was combined with real-time imaging of intracellular free-calcium activity [Ca2+]i and measurement of physiological parameters in mice. As the number of inexcitable cells was increased beyond ∼15%, a phase-transition in islet activity occurred, switching from globally active wild-type behavior to global quiescence. This phase-transition was also seen in insulin secretion and blood glucose, indicating physiological impact. This behavior was reproduced in a multicellular dynamical model suggesting critical behavior in the islet may obey general properties of coupled heterogeneous networks. This study represents the first detailed explanation for how the islet facilitates inhibitory activity in spite of a heterogeneous cell population, as well as the role this plays in diabetes and its reversal. We further explain how islets utilize this critical behavior to leverage cellular heterogeneity and coordinate a robust insulin response with high dynamic range. These findings also give new insight into emergent multicellular dynamics in general which are applicable to many coupled physiological systems, specifically where inhibitory dynamics result from coupled networks. As science has successfully broken down the elements of many biological systems, the network dynamics of large-scale cellular interactions has emerged as a new frontier. One way to understand how dynamical elements within large networks behave collectively is via mathematical modeling. Diabetes, which is of increasing international concern, is commonly caused by a deterioration of these complex dynamics in a highly coupled micro-organ called the islet of Langerhans. Therefore, if we are to understand diabetes and how to treat it, we must understand how coupling affects ensemble dynamics. While the role of network connectivity in islet excitation under stimulatory conditions has been well studied, how connectivity also suppresses activity under fasting conditions remains to be elucidated. Here we use two network models of islet connectivity to investigate this process. Using genetically altered islets and pharmacological treatments, we show how suppression of islet activity is solely dependent on a threshold number of inactive cells. We found that the islet exhibits critical behavior in the threshold region, rapidly transitioning from global activity to inactivity. We therefore propose how the islet and multicellular systems in general can generate a robust stimulated response from a heterogeneous cell population.
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Affiliation(s)
- Thomas H. Hraha
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Matthew J. Westacott
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Marina Pozzoli
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Aleena M. Notary
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - P. Mason McClatchey
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Richard K. P. Benninger
- Department of Bioengineering, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- Barbara Davis Center for Childhood Diabetes, University of Colorado, Anschutz Medical Campus, Aurora, Colorado, United States of America
- * E-mail:
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Benninger RKP, Piston DW. Cellular communication and heterogeneity in pancreatic islet insulin secretion dynamics. Trends Endocrinol Metab 2014; 25:399-406. [PMID: 24679927 PMCID: PMC4112137 DOI: 10.1016/j.tem.2014.02.005] [Citation(s) in RCA: 98] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Revised: 02/21/2014] [Accepted: 02/25/2014] [Indexed: 11/20/2022]
Abstract
Coordinated pulses of electrical activity and insulin secretion are a hallmark of the islet of Langerhans. These coordinated behaviors are lost when β cells are dissociated, which also leads to increased insulin secretion at low glucose levels. Islets without gap junctions exhibit asynchronous electrical activity similar to dispersed cells, but their secretion at low glucose levels is still clamped off, putatively by a juxtacrine mechanism. Mice lacking β cell gap junctions have near-normal average insulin levels, but are glucose intolerant due to reduced first-phase and pulsatile insulin secretion, illustrating the importance of temporal dynamics. Here, we review the quantitative data on islet synchronization and the current mathematical models that have been developed to explain these behaviors and generate greater understanding of the underlying mechanisms.
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Affiliation(s)
- Richard K P Benninger
- Department of Bioengineering and Barbara Davis Center, University of Colorado Anschutz Medical campus, Aurora, CO, USA.
| | - David W Piston
- Department of Molecular Physiology & Biophysics, Vanderbilt University, Nashville, TN, USA.
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50
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Rutter GA, Hodson DJ. Minireview: intraislet regulation of insulin secretion in humans. Mol Endocrinol 2013; 27:1984-95. [PMID: 24243488 PMCID: PMC5426601 DOI: 10.1210/me.2013-1278] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Accepted: 10/23/2013] [Indexed: 12/25/2022] Open
Abstract
The higher organization of β-cells into spheroid structures termed islets of Langerhans is critical for the proper regulation of insulin secretion. Thus, rodent β-cells form a functional syncytium that integrates and propagates information encoded by secretagogues, producing a "gain-of-function" in hormone release through the generation of coordinated cell-cell activity. By contrast, human islets possess divergent topology, and this may have repercussions for the cell-cell communication pathways that mediate the population dynamics underlying the intraislet regulation of insulin secretion. This is pertinent for type 2 diabetes mellitus pathogenesis, and its study in rodent models, because environmental and genetic factors may converge on these processes in a species-specific manner to precipitate the defective insulin secretion associated with glucose intolerance. The aim of the present minireview is therefore to discuss the structural and functional underpinnings that influence insulin secretion from human islets, and the possibility that dyscoordination between individual β-cells may play an important role in some forms of type 2 diabetes mellitus.
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Affiliation(s)
- Guy A Rutter
- Section Cell Biology, Department of Medicine, Imperial College London, London SW7 2AZ, United Kingdom. ; or Professor Guy A. Rutter, Section of Cell Biology, Department of Medicine, Imperial College London, London SW7 2AZ, United Kingdom. E-mail:
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