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Bränström R, van Krieken PP, Fröbom R, Juhlin CC, Shabo I, Leibiger B, Leibiger IB, Berggren PO, Aspinwall CA. Transplantation and Noninvasive Longitudinal In Vivo Imaging of Parathyroid Cells: A Proof-of-Concept Study. Cell Transplant 2024; 33:9636897241241995. [PMID: 38554052 PMCID: PMC10981846 DOI: 10.1177/09636897241241995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2023] [Revised: 03/05/2024] [Accepted: 03/06/2024] [Indexed: 04/01/2024] Open
Abstract
The parathyroid cell is a vital regulator of extracellular calcium levels, operating through the secretion of parathyroid hormone (PTH). Despite its importance, the regulation of PTH secretion remains complex and not fully understood, representing a unique interplay between extracellular and intracellular calcium, and hormone secretion. One significant challenge in parathyroid research has been the difficulty in maintaining cells ex vivo for in-depth cellular investigations. To address this issue, we introduce a novel platform for parathyroid cell transplantation and noninvasive in vivo imaging using the anterior chamber of the eye as a transplantation site. We found that parathyroid adenoma tissue transplanted into the mouse eye engrafted onto the iris, became vascularized, and retained cellular composition. Transplanted animals exhibited elevated PTH levels, indicating a functional graft. With in vivo confocal microscopy, we were able to repetitively monitor parathyroid graft morphology and vascularization. In summary, there is a pressing need for new methods to study complex cellular processes in parathyroid cells. Our study provides a novel approach for noninvasive in vivo investigations that can be applied to understand parathyroid physiology and pathology under physiological and pathological conditions. This innovative strategy can deepen our knowledge on parathyroid function and disease.
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Affiliation(s)
- Robert Bränström
- Endocrine and Sarcoma Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Breast, Endocrine and Sarcoma, Karolinska University Hospital, Stockholm, Sweden
| | - Pim P. van Krieken
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Robin Fröbom
- Endocrine and Sarcoma Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
| | - C. Christofer Juhlin
- Department of Oncology-Pathology, Karolinska Institutet, Stockholm, Sweden
- Department of Pathology and Cancer Diagnostics, Karolinska University Hospital, Stockholm, Sweden
| | - Ivan Shabo
- Endocrine and Sarcoma Surgery Unit, Department of Molecular Medicine and Surgery, Karolinska Institutet, Stockholm, Sweden
- Department of Breast, Endocrine and Sarcoma, Karolinska University Hospital, Stockholm, Sweden
| | - Barbara Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Ingo B. Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Craig A. Aspinwall
- Departments of Chemistry & Biochemistry and Biomedical Engineering, and BIO5 Institute, University of Arizona, Tucson, AZ, USA
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2
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Kavand H, Visa M, Köhler M, van der Wijngaart W, Berggren PO, Herland A. 3D-Printed Biohybrid Microstructures Enable Transplantation and Vascularization of Microtissues in the Anterior Chamber of the Eye. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2024; 36:e2306686. [PMID: 37815325 DOI: 10.1002/adma.202306686] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2023] [Revised: 09/14/2023] [Indexed: 10/11/2023]
Abstract
Hybridizing biological cells with man-made sensors enable the detection of a wide range of weak physiological responses with high specificity. The anterior chamber of the eye (ACE) is an ideal transplantation site due to its ocular immune privilege and optical transparency, which enable superior noninvasive longitudinal analyses of cells and microtissues. Engraftment of biohybrid microstructures in the ACE may, however, be affected by the pupillary response and dynamics. Here, sutureless transplantation of biohybrid microstructures, 3D printed in IP-Visio photoresin, containing a precisely localized pancreatic islet to the ACE of mice is presented. The biohybrid microstructures allow mechanical fixation in the ACE, independent of iris dynamics. After transplantation, islets in the microstructures successfully sustain their functionality for over 20 weeks and become vascularized despite physical separation from the vessel source (iris) and immersion in a low-viscous liquid (aqueous humor) with continuous circulation and clearance. This approach opens new perspectives in biohybrid microtissue transplantation in the ACE, advancing monitoring of microtissue-host interactions, disease modeling, treatment outcomes, and vascularization in engineered tissues.
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Affiliation(s)
- Hanie Kavand
- Division of Micro- and Nanosystems, Department of Intelligent Systems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, SE-10044, Sweden
- Division of Nanobiotechnology, Department of Protein Science, KTH Royal Institute of Technology, Tomtebodavägen 23a, Stockholm, SE-17165, Sweden
| | - Montse Visa
- The Rolf Luft Research center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, SE-17176, Sweden
| | - Martin Köhler
- The Rolf Luft Research center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, SE-17176, Sweden
| | - Wouter van der Wijngaart
- Division of Micro- and Nanosystems, Department of Intelligent Systems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, SE-10044, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, SE-17176, Sweden
| | - Anna Herland
- Division of Micro- and Nanosystems, Department of Intelligent Systems, KTH Royal Institute of Technology, Malvinas Väg 10 pl 5, Stockholm, SE-10044, Sweden
- Division of Nanobiotechnology, Department of Protein Science, KTH Royal Institute of Technology, Tomtebodavägen 23a, Stockholm, SE-17165, Sweden
- AIMES, Center for the Advancement of Integrated Medical and Engineering Sciences, Department of Neuroscience, Karolinska Institutet, Solnavägen 9/B8, Stockholm, SE-17165, Sweden
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3
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Park WY, Kim J, Le H, Kim B, Berggren PO, Kim KH. Longitudinal monitoring of pancreatic islet damage in streptozotocin-treated mice with optical coherence microscopy. BIOMEDICAL OPTICS EXPRESS 2023; 14:54-64. [PMID: 36698658 PMCID: PMC9841987 DOI: 10.1364/boe.470188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/05/2022] [Revised: 11/24/2022] [Accepted: 11/27/2022] [Indexed: 06/17/2023]
Abstract
Pancreatic islets regulate glucose homeostasis in the body, and their dysfunction is closely related to diabetes. Islet transplantation into the anterior chamber of the eye (ACE) was recently developed for both in vivo islet study and diabetes treatment. Optical coherence microscopy (OCM) was previously used to monitor ACE transplanted islets in non-obese diabetic (NOD) mice for detecting autoimmune attack. In this study, OCM was applied to streptozotocin (STZ)-induced diabetic mouse models for the early detection of islet damage. A custom extended-focus OCM (xfOCM) was used to image islet grafts in the ACE longitudinally during STZ-induced beta cell destruction together with conventional bright-field (BF) imaging and invasive glucose level measurement. xfOCM detected local structural changes and vascular degradation during the islet damage which was confirmed by confocal imaging of extracted islet grafts. xfOCM detection of islet damage was more sensitive than BF imaging and glucose measurement. Longitudinal xfOCM images of islet grafts were quantitatively analyzed. All these results showed that xfOCM could be used as a non-invasive and sensitive monitoring method for the early detection of deficient islet grafts in the ACE with potential applications to human subjects.
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Affiliation(s)
- Won Yeong Park
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Jaeyoon Kim
- Division of Integrative Biosciences & Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Hoan Le
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Bumju Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
| | - Per-Olof Berggren
- Division of Integrative Biosciences & Biotechnology, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-17 76 Stockholm, Sweden
| | - Ki Hean Kim
- Department of Mechanical Engineering, Pohang University of Science and Technology, 77 Cheongam-ro, Nam-gu, Pohang, Gyeongbuk 37673, Republic of Korea
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4
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Burgos-Gamez X, Morales-Castillo P, Fernandez-Mejia C. Maternal adaptations of the pancreas and glucose homeostasis in lactation and after lactation. Mol Cell Endocrinol 2023; 559:111778. [PMID: 36162635 DOI: 10.1016/j.mce.2022.111778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/01/2022] [Revised: 09/04/2022] [Accepted: 09/13/2022] [Indexed: 02/03/2023]
Abstract
During lactation, the maternal physiology adapts to bear the nutritional requirements of the offspring. The exocrine and endocrine pancreas are central to nutrient handling, promoting digestion and metabolism. In concert with prolactin, insulin is a determinant factor for milk synthesis. The investigation of the pancreas during lactation has been scattered over several periods. The investigations that laid the foundation of lactating pancreatic physiology and glucose homeostasis were conducted in the decades of 1970-1980. With the development of molecular biology, newer studies have revealed the molecular mechanisms involved in the endocrine pancreas during breastfeeding. There has been a surge of information recently about unexpected changes in the pancreas at the end of the lactation period and after weaning. In this review, we aim to gather information on the changes in the pancreas and glucose homeostasis during and after lactation and discuss the outcomes derived from the current discoveries.
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Affiliation(s)
- Xadeni Burgos-Gamez
- Unidad de Genética de la Nutrición. Instituto de Investigaciones Biomédicas. Universidad Nacional Autónoma de México/ Instituto Nacional de Pediatría. Avenida del Iman#1, 4th floor, Mexico City, 04500, Mexico
| | - Paulina Morales-Castillo
- Unidad de Genética de la Nutrición. Instituto de Investigaciones Biomédicas. Universidad Nacional Autónoma de México/ Instituto Nacional de Pediatría. Avenida del Iman#1, 4th floor, Mexico City, 04500, Mexico
| | - Cristina Fernandez-Mejia
- Unidad de Genética de la Nutrición. Instituto de Investigaciones Biomédicas. Universidad Nacional Autónoma de México/ Instituto Nacional de Pediatría. Avenida del Iman#1, 4th floor, Mexico City, 04500, Mexico.
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5
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Uncommon Transplantation Sites: Transplantation of Islets and Islet Organoids in the Anterior Chamber of the Eye of Rodents and Monkeys. Methods Mol Biol 2022; 2592:21-36. [PMID: 36507983 DOI: 10.1007/978-1-0716-2807-2_2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The anterior chamber of the eye is a highly vascularized and innervated location that is also particularly rich in oxygen and immune privileged. This uncommon transplantation site offers unique possibilities for the observation of the transplanted material as well as for local pharmacological intervention. Transplantation of islets and islet organoids to the anterior chamber of the eye of mice and monkeys facilitates a multitude of new approaches for research into islet physiology and pathophysiology and for the treatment of diabetes. We now present a short overview of the experimental possibilities and describe an updated protocol for transplantation of islets and islet organoids into mice and monkeys.
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6
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Hahn M, Nord C, van Krieken PP, Berggren PO, Ilegems E, Cheddad A, Ahlgren U. Quantitative 3D OPT and LSFM datasets of pancreata from mice with streptozotocin-induced diabetes. Sci Data 2022; 9:558. [PMID: 36088402 PMCID: PMC9464185 DOI: 10.1038/s41597-022-01546-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
Mouse models for streptozotocin (STZ) induced diabetes probably represent the most widely used systems for preclinical diabetes research, owing to the compound’s toxic effect on pancreatic β-cells. However, a comprehensive view of pancreatic β-cell mass distribution subject to STZ administration is lacking. Previous assessments have largely relied on the extrapolation of stereological sections, which provide limited 3D-spatial and quantitative information. This data descriptor presents multiple ex vivo tomographic optical image datasets of the full β-cell mass distribution in mice subject to single high and multiple low doses of STZ administration, and in glycaemia recovered mice. The data further include information about structural features, such as individual islet β-cell volumes, spatial coordinates, and shape as well as signal intensities for both insulin and GLUT2. Together, they provide the most comprehensive anatomical record of the effects of STZ administration on the islet of Langerhans in mice. As such, this data descriptor may serve as reference material to facilitate the planning, use and (re)interpretation of this widely used disease model. Measurement(s) | Fluorescent antibody staining of Insulin and GLUT2 in whole mouse pancreata | Technology Type(s) | Optical Projection Tomography • Light Sheet Fluorescence Microscopy (Ultramicroscope) | Factor Type(s) | mouse genotype • Streptozotocin dosage | Sample Characteristic - Organism | Mus musculus |
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7
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Ilegems E, Bryzgalova G, Correia J, Yesildag B, Berra E, Ruas JL, Pereira TS, Berggren PO. HIF-1α inhibitor PX-478 preserves pancreatic β cell function in diabetes. Sci Transl Med 2022; 14:eaba9112. [PMID: 35353540 DOI: 10.1126/scitranslmed.aba9112] [Citation(s) in RCA: 20] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
During progression of type 2 diabetes, pancreatic β cells are subjected to sustained metabolic overload. We postulated that this state mediates a hypoxic phenotype driven by hypoxia-inducible factor-1α (HIF-1α) and that treatment with the HIF-1α inhibitor PX-478 would improve β cell function. Our studies showed that the HIF-1α protein was present in pancreatic β cells of diabetic mouse models. In mouse islets with high glucose metabolism, the emergence of intracellular Ca2+ oscillations at low glucose concentration and the abnormally high basal release of insulin were suppressed by treatment with the HIF-1α inhibitor PX-478, indicating improvement of β cell function. Treatment of db/db mice with PX-478 prevented the rise of glycemia and diabetes progression by maintenance of elevated plasma insulin concentration. In streptozotocin-induced diabetic mice, PX-478 improved the recovery of glucose homeostasis. Islets isolated from these mice showed hallmarks of improved β cell function including elevation of insulin content, increased expression of genes involved in β cell function and maturity, inhibition of dedifferentiation markers, and formation of mature insulin granules. In response to PX-478 treatment, human islet organoids chronically exposed to high glucose presented improved stimulation index of glucose-induced insulin secretion. These results suggest that the HIF-1α inhibitor PX-478 has the potential to act as an antidiabetic therapeutic agent that preserves β cell function under metabolic overload.
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Affiliation(s)
- Erwin Ilegems
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Galyna Bryzgalova
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Jorge Correia
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | | | - Edurne Berra
- Centro de Investigación Cooperativa en Biociencias CIC bioGUNE, 48160 Derio, Spain
| | - Jorge L Ruas
- Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Teresa S Pereira
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.,Department of Physiology and Pharmacology, Molecular and Cellular Exercise Physiology, Karolinska Institutet, SE-171 77 Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, SE-171 76 Stockholm, Sweden.,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.,Lee Kong Chian School of Medicine, Nanyang Technological University, Novena Campus, 308232 Singapore, Singapore.,School of Biomedical Sciences, Ulster University, BT52 1SA Coleraine, Northern Ireland, UK
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8
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Zhao K, Shi Y, Yu J, Yu L, Mael A, Li Y, Kolton A, Joyce T, Odorico J, Berggren PO, Yang SN. Intracameral Microimaging of Maturation of Human iPSC Derivatives into Islet Endocrine Cells. Cell Transplant 2022; 31:9636897211066508. [PMID: 35156411 PMCID: PMC8848082 DOI: 10.1177/09636897211066508] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
We exploited the anterior chamber of the eye (ACE) of immunodeficient mice as an ectopic site for both transplantation and microimaging of engineered surrogate islets from human induced pluripotent stem cells (hiPSC-SIs). These islets contained a majority of insulin-expressing cells, positive or negative for PDX1 and NKX6.1, and a minority of glucagon- or somatostatin-positive cells. Single, non-aggregated hiPSC-SIs were satisfactorily engrafted onto the iris. They underwent gradual vascularization and progressively increased their light scattering signals, reflecting the abundance of zinc-insulin crystal packaged inside mature insulin secretory granules. Intracameral hiPSC-SIs retrieved from recipients showed enhanced insulin immunofluorescence in correlation with the parallel increase in overall vascularization and light backscattering during the post-transplantation period. This approach enables longitudinal, nondestructive and intravital microimaging of cell fates, engraftment, vascularization and mature insulin secretory granules of single hiPSC-SI grafts, and may offer a feasible and reliable means to screen compounds for promoting in vivo hiPSC-SI maturation.
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Affiliation(s)
- Kaixuan Zhao
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Yue Shi
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Jia Yu
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Lina Yu
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Amber Mael
- Regenerative Medical Solutions, Inc., Madison, WI, USA
| | - Yuxin Li
- National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
| | | | - Thomas Joyce
- Regenerative Medical Solutions, Inc., Madison, WI, USA
| | - Jon Odorico
- Regenerative Medical Solutions, Inc., Madison, WI, USA
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden
| | - Shao-Nian Yang
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, Stockholm, Sweden.,National Engineering Laboratory for Druggable Gene and Protein Screening, Northeast Normal University, Changchun, China
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9
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Ferri G, Pesce L, Tesi M, Marchetti P, Cardarelli F. β-Cell Pathophysiology: A Review of Advanced Optical Microscopy Applications. Int J Mol Sci 2021; 22:ijms222312820. [PMID: 34884624 PMCID: PMC8657725 DOI: 10.3390/ijms222312820] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Revised: 11/24/2021] [Accepted: 11/24/2021] [Indexed: 11/30/2022] Open
Abstract
β-cells convert glucose (input) resulting in the controlled release of insulin (output), which in turn has the role to maintain glucose homeostasis. β-cell function is regulated by a complex interplay between the metabolic processing of the input, its transformation into second-messenger signals, and final mobilization of insulin-containing granules towards secretion of the output. Failure at any level in this process marks β-cell dysfunction in diabetes, thus making β-cells obvious potential targets for therapeutic purposes. Addressing quantitatively β-cell (dys)function at the molecular level in living samples requires probing simultaneously the spatial and temporal dimensions at the proper resolution. To this aim, an increasing amount of research efforts are exploiting the potentiality of biophysical techniques. In particular, using excitation light in the visible/infrared range, a number of optical-microscopy-based approaches have been tailored to the study of β-cell-(dys)function at the molecular level, either in label-free mode (i.e., exploiting intrinsic autofluorescence of cells) or by the use of organic/genetically-encoded fluorescent probes. Here, relevant examples from the literature are reviewed and discussed. Based on this, new potential lines of development in the field are drawn.
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Affiliation(s)
- Gianmarco Ferri
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (G.F.); (L.P.)
| | - Luca Pesce
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (G.F.); (L.P.)
| | - Marta Tesi
- Islet Cell Laboratory, Department of Clinical and Experimental Medicine, University of Pisa, 56127 Pisa, Italy; (M.T.); (P.M.)
| | - Piero Marchetti
- Islet Cell Laboratory, Department of Clinical and Experimental Medicine, University of Pisa, 56127 Pisa, Italy; (M.T.); (P.M.)
| | - Francesco Cardarelli
- NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, Italy; (G.F.); (L.P.)
- Correspondence:
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Weitz JR, Tiriac H, Hurtado de Mendoza T, Wascher A, Lowy AM. Using Organotypic Tissue Slices to Investigate the Microenvironment of Pancreatic Cancer: Pharmacotyping and Beyond. Cancers (Basel) 2021; 13:cancers13194991. [PMID: 34638476 PMCID: PMC8507648 DOI: 10.3390/cancers13194991] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2021] [Revised: 09/29/2021] [Accepted: 10/01/2021] [Indexed: 01/04/2023] Open
Abstract
Simple Summary Pancreatic ductal adenocarcinoma (PDAC) has the highest mortality rate of all major cancers and, disappointingly, neither immune- nor stroma-directed therapies are found to improve upon the current standard of care. Among the most challenging aspects of PDAC biology which impede clinical success are the physiological features of the pancreatic cancer microenvironment (TME), including the presence of a highly fibrotic extracellular matrix marked by perineural invasion and an immunosuppressive milieu. Many current strategies for PDAC therapy are focused on altering these features to improve therapeutic efficacy. This review discusses the recent investigations using organotypic tumor slices as a model system to study cellular and extracellular interactions of the pancreatic TME. Future studies utilizing such models may provide new insights into the TME by identifying mechanisms of communication between multiple cell types and investigating novel therapeutic approaches for personalized cancer therapy. Abstract Organotypic tissue slices prepared from patient tumors are a semi-intact ex vivo preparation that recapitulates many aspects of the tumor microenvironment (TME). While connections to the vasculature and nervous system are severed, the integral functional elements of the tumor remain intact for many days during the slice culture. During this window of time, the slice platforms offer a suite of molecular, biomechanical and functional tools to investigate PDAC biology. In this review, we first briefly discuss the development of pancreatic tissue slices as a model system. Next, we touch upon using slices as an orthogonal approach to study the TME as compared to other established 3D models, such as organoids. Distinct from most other models, the pancreatic slices contain autologous immune and other stromal cells. Taking advantage of the existing immune cells within the slices, we will discuss the breakthrough studies which investigate the immune compartment in the pancreas slices. These studies will provide an important framework for future investigations seeking to exploit or reprogram the TME for cancer therapy.
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Affiliation(s)
- Jonathan Robert Weitz
- Department of Surgery, Division of Surgical Oncology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA; (J.R.W.); (H.T.); (T.H.d.M.); (A.W.)
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | - Herve Tiriac
- Department of Surgery, Division of Surgical Oncology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA; (J.R.W.); (H.T.); (T.H.d.M.); (A.W.)
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | - Tatiana Hurtado de Mendoza
- Department of Surgery, Division of Surgical Oncology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA; (J.R.W.); (H.T.); (T.H.d.M.); (A.W.)
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | - Alexis Wascher
- Department of Surgery, Division of Surgical Oncology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA; (J.R.W.); (H.T.); (T.H.d.M.); (A.W.)
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
| | - Andrew M. Lowy
- Department of Surgery, Division of Surgical Oncology, Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA; (J.R.W.); (H.T.); (T.H.d.M.); (A.W.)
- Moores Cancer Center, University of California, San Diego, La Jolla, CA 92037, USA
- Correspondence: ; Tel.: +1-858-822-2124
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11
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Siehler J, Blöchinger AK, Meier M, Lickert H. Engineering islets from stem cells for advanced therapies of diabetes. Nat Rev Drug Discov 2021; 20:920-940. [PMID: 34376833 DOI: 10.1038/s41573-021-00262-w] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/22/2021] [Indexed: 12/20/2022]
Abstract
Diabetes mellitus is a metabolic disorder that affects more than 460 million people worldwide. Type 1 diabetes (T1D) is caused by autoimmune destruction of β-cells, whereas type 2 diabetes (T2D) is caused by a hostile metabolic environment that leads to β-cell exhaustion and dysfunction. Currently, first-line medications treat the symptomatic insulin resistance and hyperglycaemia, but do not prevent the progressive decline of β-cell mass and function. Thus, advanced therapies need to be developed that either protect or regenerate endogenous β-cell mass early in disease progression or replace lost β-cells with stem cell-derived β-like cells or engineered islet-like clusters. In this Review, we discuss the state of the art of stem cell differentiation and islet engineering, reflect on current and future challenges in the area and highlight the potential for cell replacement therapies, disease modelling and drug development using these cells. These efforts in stem cell and regenerative medicine will lay the foundations for future biomedical breakthroughs and potentially curative treatments for diabetes.
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Affiliation(s)
- Johanna Siehler
- Institute of Stem Cell Research, Helmholtz Zentrum München, Neuherberg, Germany.,Technical University of Munich, Medical Faculty, Munich, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany
| | - Anna Karolina Blöchinger
- Technical University of Munich, Medical Faculty, Munich, Germany.,German Center for Diabetes Research (DZD), Neuherberg, Germany.,Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Matthias Meier
- Technical University of Munich, Medical Faculty, Munich, Germany.,Helmholtz Pioneer Campus, Helmholtz Zentrum München, Neuherberg, Germany
| | - Heiko Lickert
- Institute of Stem Cell Research, Helmholtz Zentrum München, Neuherberg, Germany. .,Technical University of Munich, Medical Faculty, Munich, Germany. .,German Center for Diabetes Research (DZD), Neuherberg, Germany. .,Institute of Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany.
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12
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Accelerating cryoprotectant diffusion kinetics improves cryopreservation of pancreatic islets. Sci Rep 2021; 11:10418. [PMID: 34001961 PMCID: PMC8129116 DOI: 10.1038/s41598-021-89853-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2021] [Accepted: 04/22/2021] [Indexed: 12/21/2022] Open
Abstract
Cryopreservation offers the potential to increase the availability of pancreatic islets for treatment of diabetic patients. However, current protocols, which use dimethyl sulfoxide (DMSO), lead to poor cryosurvival of islets. We demonstrate that equilibration of mouse islets with small molecules in aqueous solutions can be accelerated from > 24 to 6 h by increasing incubation temperature to 37 °C. We utilize this finding to demonstrate that current viability staining protocols are inaccurate and to develop a novel cryopreservation method combining DMSO with trehalose pre-incubation to achieve improved cryosurvival. This protocol resulted in improved ATP/ADP ratios and peptide secretion from β-cells, preserved cAMP response, and a gene expression profile consistent with improved cryoprotection. Our findings have potential to increase the availability of islets for transplantation and to inform the design of cryopreservation protocols for other multicellular aggregates, including organoids and bioengineered tissues.
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13
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Alanentalo T, Hahn M, Willekens SMA, Ahlgren U. Mesoscopic Optical Imaging of the Pancreas-Revisiting Pancreatic Anatomy and Pathophysiology. Front Endocrinol (Lausanne) 2021; 12:633063. [PMID: 33746904 PMCID: PMC7969990 DOI: 10.3389/fendo.2021.633063] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 01/07/2021] [Indexed: 11/24/2022] Open
Abstract
The exocrine-endocrine multipart organization of the pancreas makes it an exceedingly challenging organ to analyze, quantitatively and spatially. Both in rodents and humans, estimates of the pancreatic cellular composition, including beta-cell mass, has been largely relying on the extrapolation of 2D stereological data originating from limited sample volumes. Alternatively, they have been obtained by low resolution non-invasive imaging techniques providing little detail regarding the anatomical organization of the pancreas and its cellular and/or molecular make up. In this mini-review, the state of the art and the future potential of currently existing and emerging high-resolution optical imaging techniques working in the mm-cm range with μm resolution, here referred to as mesoscopic imaging approaches, will be discussed regarding their contribution toward a better understanding of pancreatic anatomy both in normal conditions and in the diabetic setting. In particular, optical projection tomography (OPT) and light sheet fluorescence microscopy (LSFM) imaging of the pancreas and their associated tissue processing and computational analysis protocols will be discussed in the light of their current capabilities and future potential to obtain more detailed 3D-spatial, quantitative, and molecular information of the pancreas.
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14
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Ilegems E, Berggren PO. The Eye as a Transplantation Site to Monitor Pancreatic Islet Cell Plasticity. Front Endocrinol (Lausanne) 2021; 12:652853. [PMID: 33967961 PMCID: PMC8104082 DOI: 10.3389/fendo.2021.652853] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 03/26/2021] [Indexed: 02/05/2023] Open
Abstract
The endocrine cells confined in the islets of Langerhans are responsible for the maintenance of blood glucose homeostasis. In particular, beta cells produce and secrete insulin, an essential hormone regulating glucose uptake and metabolism. An insufficient amount of beta cells or defects in the molecular mechanisms leading to glucose-induced insulin secretion trigger the development of diabetes, a severe disease with epidemic spreading throughout the world. A comprehensive appreciation of the diverse adaptive procedures regulating beta cell mass and function is thus of paramount importance for the understanding of diabetes pathogenesis and for the development of effective therapeutic strategies. While significant findings were obtained by the use of islets isolated from the pancreas, in vitro studies are inherently limited since they lack the many factors influencing pancreatic islet cell function in vivo and do not allow for longitudinal monitoring of islet cell plasticity in the living organism. In this respect a number of imaging methodologies have been developed over the years for the study of islets in situ in the pancreas, a challenging task due to the relatively small size of the islets and their location, scattered throughout the organ. To increase imaging resolution and allow for longitudinal studies in individual islets, another strategy is based on the transplantation of islets into other sites that are more accessible for imaging. In this review we present the anterior chamber of the eye as a transplantation and imaging site for the study of pancreatic islet cell plasticity, and summarize the major research outcomes facilitated by this technological platform.
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Affiliation(s)
- Erwin Ilegems
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institute, Stockholm, Sweden
- *Correspondence: Erwin Ilegems, ; Per-Olof Berggren,
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institute, Stockholm, Sweden
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL, United States
- Lee Kong Chian School of Medicine, Nanyang Technological University, Singapore, Singapore
- Center for Diabetes and Metabolism Research, Department of Endocrinology and Metabolism, West China Hospital, Sichuan University, Chengdu, China
- School of Biomedical Sciences, Ulster University, Coleraine, United Kingdom
- *Correspondence: Erwin Ilegems, ; Per-Olof Berggren,
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15
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Xiong Y, Scerbo MJ, Seelig A, Volta F, O'Brien N, Dicker A, Padula D, Lickert H, Gerdes JM, Berggren PO. Islet vascularization is regulated by primary endothelial cilia via VEGF-A-dependent signaling. eLife 2020; 9:56914. [PMID: 33200981 PMCID: PMC7695455 DOI: 10.7554/elife.56914] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Accepted: 11/16/2020] [Indexed: 12/31/2022] Open
Abstract
Islet vascularization is essential for intact islet function and glucose homeostasis. We have previously shown that primary cilia directly regulate insulin secretion. However, it remains unclear whether they are also implicated in islet vascularization. At eight weeks, murine Bbs4-/-islets show significantly lower intra-islet capillary density with enlarged diameters. Transplanted Bbs4-/- islets exhibit delayed re-vascularization and reduced vascular fenestration after engraftment, partially impairing vascular permeability and glucose delivery to β-cells. We identified primary cilia on endothelial cells as the underlying cause of this regulation, via the vascular endothelial growth factor-A (VEGF-A)/VEGF receptor 2 (VEGFR2) pathway. In vitro silencing of ciliary genes in endothelial cells disrupts VEGF-A/VEGFR2 internalization and downstream signaling. Consequently, key features of angiogenesis including proliferation and migration are attenuated in human BBS4 silenced endothelial cells. We conclude that endothelial cell primary cilia regulate islet vascularization and vascular barrier function via the VEGF-A/VEGFR2 signaling pathway.
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Affiliation(s)
- Yan Xiong
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska University Hospital L1, Stockholm, Sweden
| | - M Julia Scerbo
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Anett Seelig
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Francesco Volta
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany.,Technical University Munich, Munich, Germany
| | - Nils O'Brien
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Andrea Dicker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska University Hospital L1, Stockholm, Sweden
| | - Daniela Padula
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany
| | - Heiko Lickert
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany.,Technical University Munich, Munich, Germany.,Deutsches Zentrum für Diabetesforschung, DZD, Munich, Germany
| | - Jantje Mareike Gerdes
- Institute for Diabetes and Regeneration Research, Helmholtz Zentrum München, Neuherberg, Germany.,Deutsches Zentrum für Diabetesforschung, DZD, Munich, Germany
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska University Hospital L1, Stockholm, Sweden
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16
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Topologically selective islet vulnerability and self-sustained downregulation of markers for β-cell maturity in streptozotocin-induced diabetes. Commun Biol 2020; 3:541. [PMID: 32999405 PMCID: PMC7527346 DOI: 10.1038/s42003-020-01243-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2019] [Accepted: 08/07/2020] [Indexed: 12/15/2022] Open
Abstract
Mouse models of Streptozotocin (STZ) induced diabetes represent the most widely used preclinical diabetes research systems. We applied state of the art optical imaging schemes, spanning from single islet resolution to the whole organ, providing a first longitudinal, 3D-spatial and quantitative account of β-cell mass (BCM) dynamics and islet longevity in STZ-treated mice. We demonstrate that STZ-induced β-cell destruction predominantly affects large islets in the pancreatic core. Further, we show that hyperglycemic STZ-treated mice still harbor a large pool of remaining β-cells but display pancreas-wide downregulation of glucose transporter type 2 (GLUT2). Islet gene expression studies confirmed this downregulation and revealed impaired β-cell maturity. Reversing hyperglycemia by islet transplantation partially restored the expression of markers for islet function, but not BCM. Jointly our results indicate that STZ-induced hyperglycemia results from β-cell dysfunction rather than β-cell ablation and that hyperglycemia in itself sustains a negative feedback loop restraining islet function recovery. Hahn, van Krieken et al. provide a quantitative account of β-cell mass dynamics and islet longevity in mice treated with Streptozotocin (STZ). They find that STZ-induced hyperglycemia primarily results from β-cell dysfunction rather than its ablation. This study provides insights into how the most widely used preclinical diabetes model works.
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17
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Cohrs CM, Chen C, Speier S. Transplantation of Islets of Langerhans into the Anterior Chamber of the Eye for Longitudinal In Vivo Imaging. Methods Mol Biol 2020; 2128:149-157. [PMID: 32180192 DOI: 10.1007/978-1-0716-0385-7_11] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Noninvasive in vivo imaging techniques are attractive tools to longitudinally study various aspects of islet of Langerhans physiology and pathophysiology. Unfortunately, most imaging modalities currently applicable for clinical use do not allow the comprehensive investigation of islet cell biology due to limitations in resolution and/or sensitivity, while high-resolution imaging technologies like laser scanning microscopy (LSM) lack the penetration depth to assess islets of Langerhans within the pancreas. Significant progress in this area was made by the combination of LSM with the anterior chamber of the mouse eye platform, utilizing the cornea as a natural body window to study cell physiology of transplanted islets of Langerhans. We here describe the transplantation and longitudinal in vivo imaging of islets of Langerhans in the anterior chamber of the mouse eye as a versatile tool to study different features of islet physiology in health and disease.
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Affiliation(s)
- Christian M Cohrs
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Physiology, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Chunguang Chen
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Physiology, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany
| | - Stephan Speier
- Paul Langerhans Institute Dresden (PLID) of the Helmholtz Zentrum München at the University Clinic Carl Gustav Carus of Technische Universität Dresden, Helmholtz Zentrum München, Neuherberg, Germany.
- Institute of Physiology, Faculty of Medicine, Technische Universität Dresden, Dresden, Germany.
- German Center for Diabetes Research (DZD), München-Neuherberg, Germany.
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18
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Mateus Gonçalves L, Almaça J. Functional Characterization of the Human Islet Microvasculature Using Living Pancreas Slices. Front Endocrinol (Lausanne) 2020; 11:602519. [PMID: 33519711 PMCID: PMC7843926 DOI: 10.3389/fendo.2020.602519] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/03/2020] [Accepted: 11/23/2020] [Indexed: 12/14/2022] Open
Abstract
Pancreatic islets are clusters of endocrine cells that secrete different hormones to regulate blood glucose levels. Efficient hormone secretion requires a close interaction of endocrine cells with their vascular system. Islets receive blood through feeding arteriole(s) that branch into capillaries made of endothelial cells covered by pericytes. While a lot is known about rodent islet blood vessels, the structure and function of the human islet microvasculature has been less investigated. In this study, we used living pancreas slices from non-diabetic human donors to examine the function of human islet blood vessels. Living human pancreas slices were incubated with a membrane permeant calcium indicator and pericytes/smooth muscle cells were visualized with a fluorescent antibody against the mural cell marker NG2 proteoglycan. By confocal microscopy, we simultaneously recorded changes in the diameter of lectin-labeled blood vessels and cytosolic calcium levels in mural cells in islets. We tested several stimuli with vasoactive properties, such as norepinephrine, endothelin-1 and adenosine and compared human vascular responses with those previously published for mouse islet blood vessels. Norepinephrine and endothelin-1 significantly constricted human islet feeding arterioles, while adenosine dilated them. Islet capillaries were less responsive and only 15-20% of the mouse and human islet capillary network showed vasomotion. Nevertheless, in these responsive regions, norepinephrine and endothelin-1 decreased both mouse and human islet capillary diameter. Changes in islet blood vessel diameter were coupled to changes in cytosolic calcium levels in adjacent mouse and human islet mural cells. Our study shows that mural cells in islets are the targets of different regulatory mechanisms of islet blood perfusion. Several alterations of the human islet microvasculature occur during diabetes progression. Elucidating their functional consequences in future studies will be critical for our understanding of disease pathogenesis.
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19
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Noninvasive intravital high-resolution imaging of pancreatic neuroendocrine tumours. Sci Rep 2019; 9:14636. [PMID: 31601958 PMCID: PMC6787246 DOI: 10.1038/s41598-019-51093-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2019] [Accepted: 09/24/2019] [Indexed: 01/20/2023] Open
Abstract
Preclinical trials of cancer drugs in animal models are important for drug development. The Rip1Tag2 (RT2) transgenic mouse, a model of pancreatic neuroendocrine tumours (PNET), has provided immense knowledge about PNET biology, although tumour progression occurs in a location inaccessible for real-time monitoring. To overcome this hurdle we have developed a novel platform for intravital 3D imaging of RT2 tumours to facilitate real-time studies of cancer progression. Pre-oncogenic islets retrieved from RT2 mice were implanted into the anterior chamber of the eye (ACE) of host mice, where they engrafted on the iris, recruited blood vessels and showed continuous growth. Noninvasive confocal and two-photon laser-scanning microscopy through the transparent cornea facilitated high-resolution imaging of tumour growth and angiogenesis. RT2 tumours in the ACE expanded up to 8-fold in size and shared hallmarks with tumours developing in situ in the pancreas. Genetically encoded fluorescent reporters enabled high-resolution imaging of stromal cells and tumour cell migration. Sunitinib treatment impaired RT2 tumour angiogenesis and growth, while overexpression of the vascular endothelial growth factor (VEGF)-B increased tumour angiogenesis though tumour growth was impaired. In conclusion, we present a novel platform for intravital high-resolution and 3D imaging of PNET biology and cancer drug assessment.
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20
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Abdulreda MH, Molano RD, Faleo G, Lopez-Cabezas M, Shishido A, Ulissi U, Fotino C, Hernandez LF, Tschiggfrie A, Aldrich VR, Tamayo-Garcia A, Bayer AS, Ricordi C, Caicedo A, Buchwald P, Pileggi A, Berggren PO. In vivo imaging of type 1 diabetes immunopathology using eye-transplanted islets in NOD mice. Diabetologia 2019; 62:1237-1250. [PMID: 31087105 PMCID: PMC6561836 DOI: 10.1007/s00125-019-4879-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/14/2019] [Accepted: 03/22/2019] [Indexed: 12/31/2022]
Abstract
AIMS/HYPOTHESIS Autoimmune attack against the insulin-producing beta cells in the pancreatic islets results in type 1 diabetes. However, despite considerable research, details of the type 1 diabetes immunopathology in situ are not fully understood mainly because of difficult access to the pancreatic islets in vivo. METHODS Here, we used direct non-invasive confocal imaging of islets transplanted in the anterior chamber of the eye (ACE) to investigate the anti-islet autoimmunity in NOD mice before, during and after diabetes onset. ACE-transplanted islets allowed longitudinal studies of the autoimmune attack against islets and revealed the infiltration kinetics and in situ motility dynamics of fluorescence-labelled autoreactive T cells during diabetes development. Ex vivo immunostaining was also used to compare immune cell infiltrations into islet grafts in the eye and kidney as well as in pancreatic islets of the same diabetic NOD mice. RESULTS We found similar immune infiltration in native pancreatic and ACE-transplanted islets, which established the ACE-transplanted islets as reliable reporters of the autoimmune response. Longitudinal studies in ACE-transplanted islets identified in vivo hallmarks of islet inflammation that concurred with early immune infiltration of the islets and preceded their collapse and hyperglycaemia onset. A model incorporating data on ACE-transplanted islet degranulation and swelling allowed early prediction of the autoimmune attack in the pancreas and prompted treatments to intercept type 1 diabetes. CONCLUSIONS/INTERPRETATION The current findings highlight the value of ACE-transplanted islets in studying early type 1 diabetes pathogenesis in vivo and underscore the need for timely intervention to halt disease progression.
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Affiliation(s)
- Midhat H Abdulreda
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA.
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Ophthalmology, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - R Damaris Molano
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Gaetano Faleo
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Maite Lopez-Cabezas
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Alexander Shishido
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Ulisse Ulissi
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Carmen Fotino
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Luis F Hernandez
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Ashley Tschiggfrie
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Virginia R Aldrich
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
| | - Alejandro Tamayo-Garcia
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Allison S Bayer
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Camillo Ricordi
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA
- Diabetes Research Institute Federation, Hollywood, FL, USA
| | - Alejandro Caicedo
- Department of Medicine, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Peter Buchwald
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA.
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Antonello Pileggi
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA.
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Microbiology and Immunology, University of Miami Miller School of Medicine, Miami, FL, USA.
- Department of Biomedical Engineering, University of Miami, Coral Gables, FL, USA.
- Center for Scientific Review, National Institutes of Health, 6701 Rockledge Drive, Bethesda, MD, 20892, USA.
| | - Per-Olof Berggren
- Diabetes Research Institute and Cell Transplant Center, University of Miami Miller School of Medicine, 1450 NW 10th Ave, Miami, FL, 33136, USA.
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
- Diabetes Research Institute Federation, Hollywood, FL, USA.
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital L1, SE-17176, Stockholm, Sweden.
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21
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van Krieken PP, Voznesenskaya A, Dicker A, Xiong Y, Park JH, Lee JI, Ilegems E, Berggren PO. Translational assessment of a genetic engineering methodology to improve islet function for transplantation. EBioMedicine 2019; 45:529-541. [PMID: 31262716 PMCID: PMC6642289 DOI: 10.1016/j.ebiom.2019.06.045] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2018] [Revised: 06/17/2019] [Accepted: 06/21/2019] [Indexed: 11/05/2022] Open
Abstract
Background The functional quality of insulin-secreting islet beta cells is a major factor determining the outcome of clinical transplantations for diabetes. It is therefore of importance to develop methodological strategies aiming at optimizing islet cell function prior to transplantation. In this study we propose a synthetic biology approach to genetically engineer cellular signalling pathways in islet cells. Methods We established a novel procedure to modify islet beta cell function by combining adenovirus-mediated transduction with reaggregation of islet cells into pseudoislets. As a proof-of-concept for the genetic engineering of islets prior to transplantation, this methodology was applied to increase the expression of the V1b receptor specifically in insulin-secreting beta cells. The functional outcomes were assessed in vitro and in vivo following transplantation into the anterior chamber of the eye. Findings Pseudoislets produced from mouse dissociated islet cells displayed basic functions similar to intact native islets in terms of glucose induced intracellular signalling and insulin release, and after transplantation were properly vascularized and contributed to blood glucose homeostasis. The synthetic amplification of the V1b receptor signalling in beta cells successfully modulated pseudoislet function in vitro. Finally, in vivo responses of these pseudoislet grafts to vasopressin allowed evaluation of the potential benefits of this approach in regenerative medicine. Interpretation These results are promising first steps towards the generation of high-quality islets and suggest synthetic biology as an important tool in future clinical islet transplantations. Moreover, the presented methodology might serve as a useful research strategy to dissect cellular signalling mechanisms of relevance for optimal islet function.
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Affiliation(s)
- Pim P van Krieken
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Anna Voznesenskaya
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Andrea Dicker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Yan Xiong
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Jae Hong Park
- Department of Otolaryngology-Head and Neck Surgery, Soonchunhyang University College of Medicine, Cheonan, Republic of Korea
| | - Jeong Ik Lee
- Department of Veterinary Obstetrics and Theriogenology, College of Veterinary Medicine, Konkuk University, Seoul, Republic of Korea; Department of Biomedical Science and Technology, Institute of Biomedical Science & Technology (IBST), Konkuk University, Seoul, Republic of Korea
| | - Erwin Ilegems
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden.
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden; Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, USA; Lee Kong Chian School of Medicine, Nanyang Technological University, Imperial College London, Novena Campus, Singapore, Singapore
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22
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Salem V, Silva LD, Suba K, Georgiadou E, Neda Mousavy Gharavy S, Akhtar N, Martin-Alonso A, Gaboriau DCA, Rothery SM, Stylianides T, Carrat G, Pullen TJ, Singh SP, Hodson DJ, Leclerc I, Shapiro AMJ, Marchetti P, Briant LJB, Distaso W, Ninov N, Rutter GA. Leader β-cells coordinate Ca 2+ dynamics across pancreatic islets in vivo. Nat Metab 2019; 1:615-629. [PMID: 32694805 DOI: 10.1038/s42255-019-0075-2] [Citation(s) in RCA: 108] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Accepted: 05/08/2019] [Indexed: 02/06/2023]
Abstract
Pancreatic β-cells form highly connected networks within isolated islets. Whether this behaviour pertains to the situation in vivo, after innervation and during continuous perfusion with blood, is unclear. In the present study, we used the recombinant Ca2+ sensor GCaMP6 to assess glucose-regulated connectivity in living zebrafish Danio rerio, and in murine or human islets transplanted into the anterior eye chamber. In each setting, Ca2+ waves emanated from temporally defined leader β-cells, and three-dimensional connectivity across the islet increased with glucose stimulation. Photoablation of zebrafish leader cells disrupted pan-islet signalling, identifying these as likely pacemakers. Correspondingly, in engrafted mouse islets, connectivity was sustained during prolonged glucose exposure, and super-connected 'hub' cells were identified. Granger causality analysis revealed a controlling role for temporally defined leaders, and transcriptomic analyses revealed a discrete hub cell fingerprint. We thus define a population of regulatory β-cells within coordinated islet networks in vivo. This population may drive Ca2+ dynamics and pulsatile insulin secretion.
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Affiliation(s)
- Victoria Salem
- Department of Medicine, Imperial College London, London, UK.
| | - Luis Delgadillo Silva
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - Kinga Suba
- Department of Medicine, Imperial College London, London, UK
| | | | | | - Nadeem Akhtar
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | | | - David C A Gaboriau
- Facility for Imaging by Light Microscopy, Imperial College London, London, UK
| | - Stephen M Rothery
- Facility for Imaging by Light Microscopy, Imperial College London, London, UK
| | | | - Gaelle Carrat
- Department of Medicine, Imperial College London, London, UK
| | - Timothy J Pullen
- Department of Diabetes, Faculty of Life Science and Medicine, King's College London, London, UK
| | - Sumeet Pal Singh
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany
| | - David J Hodson
- Institute of Metabolism and Systems Research, University of Birmingham, Edgbaston, UK
- Centre for Endocrinology, Diabetes and Metabolism, Birmingham Health Partners, Birmingham, UK
- Centre of Membrane Proteins and Receptors, University of Birmingham and University of Nottingham, Nottingham, UK
| | | | - A M James Shapiro
- Clinical Islet Laboratory and Clinical Islet Transplant Program, University of Alberta, Edmonton, Alberta, Canada
| | | | | | | | - Nikolay Ninov
- Center for Regenerative Therapies Dresden, Technische Universität Dresden, Dresden, Germany.
- Paul Langerhans Institute Dresden of the Helmholtz Center Munich at the University Hospital Carl Gustav Carus of TU Dresden, German Center for Diabetes Research, Dresden, Germany.
| | - Guy A Rutter
- Department of Medicine, Imperial College London, London, UK.
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Local release of rapamycin by microparticles delays islet rejection within the anterior chamber of the eye. Sci Rep 2019; 9:3918. [PMID: 30850640 PMCID: PMC6408557 DOI: 10.1038/s41598-019-40404-0] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 02/14/2019] [Indexed: 12/23/2022] Open
Abstract
The anterior chamber of the eye (ACE) has emerged as a promising clinical islet transplantation site because of its multiple advantages over the conventional intra-hepatic portal site. This includes reduced surgical invasiveness and increased islet graft survival rate. It also allows for enhanced accessibility and monitoring of the islets. Although the ACE is initially an immuno-privileged site, this privilege is disrupted once the islet grafts are re-vascularized. Given that the ACE is a confined space, achieving graft immune tolerance through local immunosuppressive drug delivery is therefore feasible. Here, we show that islet rejection in the ACE of mice can be significantly suppressed through local delivery of rapamycin by carefully designed sustained-release microparticles. In this 30-day study, allogeneic islet grafts with blank microparticles were completely rejected 18 days post-transplantation into mice. Importantly, allogeneic islet grafts co-injected with rapamycin releasing microparticles into a different eye of the same recipient were preserved much longer, with some grafts surviving for more than 30 days. Hence, islet allograft survival was enhanced by a localized and prolonged delivery of an immunosuppressive drug. We envisage that this procedure will relieve diabetic transplant recipients from harsh systemic immune suppression, while achieving improved glycemic control and reduced insulin dependence.
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Abstract
Diabetes develops due to deficient functional β cell mass, insulin resistance, or both. Yet, various challenges in understanding the mechanisms underlying diabetes development in vivo remain to be overcome owing to the lack of appropriate intravital imaging technologies. To meet these challenges, we have exploited the anterior chamber of the eye (ACE) as a novel imaging site to understand diabetes basics and clinics in vivo. We have developed a technology platform transplanting pancreatic islets into the ACE where they later on can be imaged non-invasively for long time. It turns out that the ACE serves as an optimal imaging site and provides implanted islets with an oxygen-rich milieu and an immune-privileged niche where they undergo optimal engraftment, rich vascularization and dense innervation, preserve organotypic features and live with satisfactory viability and functionality. The ACE technology has led to a series of significant observations. It enables in vivo microscopy of islet cytoarchitecture, function and viability in the physiological context and intravital imaging of a variety of pathological events such as autoimmune insulitis, defects in β cell function and mass and insulin resistance during diabetes development in a real-time manner. Furthermore, application of the ACE technology in humanized mice and non-human primates verifies translational and clinical values of the technology. In this article, we describe the ACE technology in detail, review accumulated knowledge gained by means of the ACE technology and delineate prospective avenues for the ACE technology.
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25
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Ferri G, Bugliani M, Marchetti P, Cardarelli F. Probing the light scattering properties of insulin secretory granules in single live cells. Biochem Biophys Res Commun 2018; 503:2710-2714. [PMID: 30119894 DOI: 10.1016/j.bbrc.2018.08.029] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2018] [Accepted: 08/03/2018] [Indexed: 11/22/2022]
Abstract
Light scattering was recently demonstrated to serve as an intrinsic indicator for pancreatic islet cell mass and secretion. The insulin secretory granule (ISG), in particular, was proposed to be a reasonable candidate as the main intracellular source of scattered light due to the densely-packed insulin semi-crystal in the granule lumen. This scenario, if confirmed, would in principle open new perspectives for label-free single-granule imaging, tracking, and analysis. Contrary to such expectations, here we demonstrate that ISGs are not a primary source of scattering in primary human β-cells, as well as in immortalized β-like cells, quantitatively not superior to other intracellular organelles/structures, such as lysosomes and internal membranes. This result is achieved through multi-channel imaging of scattered light along with fluorescence arising from selectively-labelled ISGs. Co-localization and spatiotemporal cross-correlation analysis is performed on these signals, and compared among different cell lines. Obtained results suggest a careful re-thinking of the possibility to exploit intrinsic optical properties originating from ISGs for single-granule imaging purposes.
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Affiliation(s)
- Gianmarco Ferri
- NEST - Scuola Normale Superiore, Istituto Nanoscienze - CNR (CNR NANO), Pisa, Italy; Nanoscopy, Nanophysics, Istituto Italiano di Tecnologia, via Morego 30, Genova, 16163 Italy
| | - Marco Bugliani
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Piero Marchetti
- Department of Clinical and Experimental Medicine, Islet Cell Laboratory, University of Pisa, Pisa, Italy
| | - Francesco Cardarelli
- NEST - Scuola Normale Superiore, Istituto Nanoscienze - CNR (CNR NANO), Pisa, Italy.
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26
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Paschen M, Moede T, Valladolid-Acebes I, Leibiger B, Moruzzi N, Jacob S, García-Prieto CF, Brismar K, Leibiger IB, Berggren PO. Diet-induced β-cell insulin resistance results in reversible loss of functional β-cell mass. FASEB J 2018; 33:204-218. [PMID: 29957055 PMCID: PMC6355083 DOI: 10.1096/fj.201800826r] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Although convincing in genetic models, the relevance of β-cell insulin resistance in diet-induced type 2 diabetes (T2DM) remains unclear. Exemplified by diabetes-prone, male, C57B1/6J mice being fed different combinations of Western-style diet, we show that β-cell insulin resistance occurs early during T2DM progression and is due to a combination of lipotoxicity and increased β-cell workload. Within 8 wk of being fed a high-fat, high-sucrose diet, mice became obese, developed impaired insulin and glucose tolerances, and displayed noncompensatory insulin release, due, at least in part, to reduced expression of syntaxin-1A. Through reporter islets transplanted to the anterior chamber of the eye, we demonstrated a concomitant loss of functional β-cell mass. When mice were changed from diabetogenic diet to normal chow diet, the diabetes phenotype was reversed, suggesting a remarkable plasticity of functional β-cell mass in the early phase of T2DM development. Our data reinforce the relevance of diet composition as an environmental factor determining different routes of diabetes progression in a given genetic background. Employing the in vivo reporter islet–monitoring approach will allow researchers to define key times in the dynamics of reversible loss of functional β-cell mass and, thus, to investigate the underlying, molecular mechanisms involved in the progression toward T2DM manifestation.—Paschen, M., Moede, T., Valladolid-Acebes, I., Leibiger, B., Moruzzi, N., Jacob, S., García-Prieto, C. F., Brismar, K., Leibiger, I. B., Berggren, P.-O. Diet-induced β-cell insulin resistance results in reversible loss of functional β-cell mass.
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Affiliation(s)
- Meike Paschen
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Tilo Moede
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Ismael Valladolid-Acebes
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Barbara Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Noah Moruzzi
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Stefan Jacob
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Concha F García-Prieto
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Kerstin Brismar
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Ingo B Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
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27
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Pancreatic Islet Blood Flow Dynamics in Primates. Cell Rep 2018; 20:1490-1501. [PMID: 28793270 PMCID: PMC5575201 DOI: 10.1016/j.celrep.2017.07.039] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Revised: 05/05/2017] [Accepted: 07/14/2017] [Indexed: 12/26/2022] Open
Abstract
Blood flow regulation in pancreatic islets is critical for function but poorly understood. Here, we establish an in vivo imaging platform in a non-human primate where islets transplanted autologously into the anterior chamber of the eye are monitored non-invasively and longitudinally at single-cell resolution. Engrafted islets were vascularized and innervated and maintained the cytoarchitecture of in situ islets in the pancreas. Blood flow velocity in the engrafted islets was not affected by increasing blood glucose levels and/or the GLP-1R agonist liraglutide. However, islet blood flow was dynamic in nature and fluctuated in various capillaries. This was associated with vasoconstriction events resembling a sphincter-like action, most likely regulated by adrenergic signaling. These observations suggest a mechanism in primate islets that diverts blood flow to cell regions with higher metabolic demand. The described imaging technology applied in non-human primate islets may contribute to a better understanding of human islet pathophysiology. Monkey islets transplanted autologously into the anterior chamber of the eye (ACE) Monkey ACE islets imaged in vivo, longitudinally, and at single-cell resolution Monkey islet blood flow is dynamic and unaffected by glucose/liraglutide treatment Directional blood flow may be explained by islet structure-function relationship
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28
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van Krieken PP, Dicker A, Eriksson M, Herrera PL, Ahlgren U, Berggren PO, Ilegems E. Kinetics of functional beta cell mass decay in a diphtheria toxin receptor mouse model of diabetes. Sci Rep 2017; 7:12440. [PMID: 28963457 PMCID: PMC5622115 DOI: 10.1038/s41598-017-12124-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2017] [Accepted: 09/04/2017] [Indexed: 11/26/2022] Open
Abstract
Functional beta cell mass is an essential biomarker for the diagnosis and staging of diabetes. It has however proven technically challenging to study this parameter during diabetes progression. Here we have detailed the kinetics of the rapid decline in functional beta cell mass in the RIP-DTR mouse, a model of hyperglycemia resulting from diphtheria toxin induced beta cell ablation. A novel combination of imaging modalities was employed to study the pattern of beta cell destruction. Optical projection tomography of the pancreas and longitudinal in vivo confocal microscopy of islets transplanted into the anterior chamber of the eye allowed to investigate kinetics and tomographic location of beta cell mass decay in individual islets as well as at the entire islet population level. The correlation between beta cell mass and function was determined by complementary in vivo and ex vivo characterizations, demonstrating that beta cell function and glucose tolerance were impaired within the first two days following treatment when more than 50% of beta cell mass was remaining. Our results illustrate the importance of acquiring quantitative functional and morphological parameters to assess the functional status of the endocrine pancreas.
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Affiliation(s)
- Pim P van Krieken
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Andrea Dicker
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Maria Eriksson
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Pedro L Herrera
- Department of Genetic Medicine and Development, University of Geneva Medical School, Geneva, Switzerland
| | - Ulf Ahlgren
- Umeå Centre for Molecular Medicine, Umeå University, Umeå, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden. .,Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, USA. .,Lee Kong Chian School of Medicine, Nanyang Technological University, Imperial College London, Novena Campus, Singapore, Singapore.
| | - Erwin Ilegems
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
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Leibiger IB, Berggren PO. Intraocular in vivo imaging of pancreatic islet cell physiology/pathology. Mol Metab 2017; 6:1002-1009. [PMID: 28951824 PMCID: PMC5605725 DOI: 10.1016/j.molmet.2017.03.014] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/07/2017] [Accepted: 03/18/2017] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND Diabetes mellitus has reached epidemic proportions and requires new strategies for treatment. Unfortunately, the efficacy of treatment regimens on maintaining/re-gaining functional beta cell mass can, at the present, only be determined indirectly. Direct monitoring of beta cell mass is complicated by the anatomy of the endocrine pancreas, which consists of thousands to a million of discrete micro-organs, i.e. islets of Langerhans, which are scattered throughout the pancreas. SCOPE OF REVIEW Here, we review the progress made over the last years using the anterior chamber of the eye as a transplantation site for functional imaging of pancreatic islet cells in the living organism. Islets engrafted on the iris are vascularized and innervated and the cornea, serving as a natural body-window, allows for microscopic, non-invasive, longitudinal evaluation of islet/beta cell function and survival with single-cell resolution in health and disease. MAJOR CONCLUSIONS Data provided by us and others demonstrate the high versatility of this imaging platform. The use of 'reporter islets' engrafted in the eye, reporting on the status of in situ endogenous islets in the pancreas of the same animal, allows the identification of key-events in the development and progression of diabetes. This will not only serve as a versatile research tool but will also lay the foundation for a personalized medicine approach and will serve as a screening platform for new drugs and/or treatment protocols. 'Metabolic' islet transplantation, in which islets engrafted in the eye replace the endogenous beta cells, will allow for the establishment of islet-specific transgenic models and 'humanized' mouse models as well as serving as the basis for a new clinical transplantation site for the cure of diabetes.
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Affiliation(s)
- Ingo B. Leibiger
- The Rolf Luft Research Center for Diabetes and Endocrinology, L1:03 Karolinska Institutet, SE-171 76 Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, L1:03 Karolinska Institutet, SE-171 76 Stockholm, Sweden
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30
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Park S, Lee DY. The anterior chamber of the eye as a site for pancreatic islet transplantation. J IND ENG CHEM 2017. [DOI: 10.1016/j.jiec.2017.02.027] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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31
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Berclaz C, Szlag D, Nguyen D, Extermann J, Bouwens A, Marchand PJ, Nilsson J, Schmidt-Christensen A, Holmberg D, Grapin-Botton A, Lasser T. Label-free fast 3D coherent imaging reveals pancreatic islet micro-vascularization and dynamic blood flow. BIOMEDICAL OPTICS EXPRESS 2016; 7:4569-4580. [PMID: 27895996 PMCID: PMC5119596 DOI: 10.1364/boe.7.004569] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/10/2016] [Revised: 09/16/2016] [Accepted: 10/03/2016] [Indexed: 05/14/2023]
Abstract
In diabetes, pancreatic β-cells play a key role. These cells are clustered within structures called islets of Langerhans inside the pancreas and produce insulin, which is directly secreted into the blood stream. The dense vascularization of islets of Langerhans is critical for maintaining a proper regulation of blood glucose homeostasis and is known to be affected from the early stage of diabetes. The deep localization of these islets inside the pancreas in the abdominal cavity renders their in vivo visualization a challenging task. A fast label-free imaging method with high spatial resolution is required to study the vascular network of islets of Langerhans. Based on these requirements, we developed a label-free and three-dimensional imaging method for observing islets of Langerhans using extended-focus Fourier domain Optical Coherence Microscopy (xfOCM). In addition to structural imaging, this system provides three-dimensional vascular network imaging and dynamic blood flow information within islets of Langerhans. We propose our method to deepen the understanding of the interconnection between diabetes and the evolution of the islet vascular network.
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Affiliation(s)
- Corinne Berclaz
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
| | - Daniel Szlag
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
| | - David Nguyen
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
| | - Jérôme Extermann
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
- Hepia, University of Applied Science of Western Switzerland, 1202 Genève,
Switzerland
| | - Arno Bouwens
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
| | - Paul J. Marchand
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
| | | | | | - Dan Holmberg
- EMV Immunology, Lund University, 22100 Lund,
Sweden
| | | | - Theo Lasser
- Laboratoire d’Optique Biomédicale, Ecole Polytechnique Fédérale de Lausanne (EPFL),1015 Lausanne,
Switzerland
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32
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Satin LS, Ha J, Sherman AS. Islets Transplanted Into the Eye: Do They Improve Our Insight Into Islet Adaptation to Insulin Resistance? Diabetes 2016; 65:2470-2. [PMID: 27555572 PMCID: PMC5001186 DOI: 10.2337/dbi16-0025] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Affiliation(s)
- Leslie S Satin
- Department of Pharmacology and Brehm Center for Diabetes Research, University of Michigan Medical School, Ann Arbor, MI Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Joon Ha
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
| | - Arthur S Sherman
- Laboratory of Biological Modeling, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD
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Corritore E, Lee YS, Pasquale V, Liberati D, Hsu MJ, Lombard CA, Van Der Smissen P, Vetere A, Bonner-Weir S, Piemonti L, Sokal E, Lysy PA. V-Maf Musculoaponeurotic Fibrosarcoma Oncogene Homolog A Synthetic Modified mRNA Drives Reprogramming of Human Pancreatic Duct-Derived Cells Into Insulin-Secreting Cells. Stem Cells Transl Med 2016; 5:1525-1537. [PMID: 27405779 DOI: 10.5966/sctm.2015-0318] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2015] [Accepted: 05/12/2016] [Indexed: 12/17/2022] Open
Abstract
: β-Cell replacement therapy represents the most promising approach to restore β-cell mass and glucose homeostasis in patients with type 1 diabetes. Safety and ethical issues associated with pluripotent stem cells stimulated the search for adult progenitor cells with endocrine differentiation capacities. We have already described a model for expansion and differentiation of human pancreatic duct-derived cells (HDDCs) into insulin-producing cells. Here we show an innovative and robust in vitro system for large-scale production of β-like cells from HDDCs using a nonintegrative RNA-based reprogramming technique. Synthetic modified RNAs for pancreatic transcription factors (pancreatic duodenal homeobox 1, neurogenin3, and V-Maf musculoaponeurotic fibrosarcoma oncogene homolog A [MAFA]) were manufactured and daily transfected in HDDCs without strongly affecting immune response and cell viability. MAFA overexpression was efficient and sufficient to induce β-cell differentiation of HDDCs, which acquired a broad repertoire of mature β-cell markers while downregulating characteristic epithelial-mesenchymal transition markers. Within 7 days, MAFA-reprogrammed HDDC populations contained 37% insulin-positive cells and a proportion of endocrine cells expressing somatostatin and pancreatic polypeptide. Ultrastructure analysis of differentiated HDDCs showed both immature and mature insulin granules with light-backscattering properties. Furthermore, in vitro HDDC-derived β cells (called β-HDDCs) secreted human insulin and C-peptide in response to glucose, KCl, 3-isobutyl-1-methylxanthine, and tolbutamide stimulation. Transplantation of β-HDDCs into diabetic SCID-beige mice confirmed their functional glucose-responsive insulin secretion and their capacity to mitigate hyperglycemia. Our data describe a new, reliable, and fast procedure in adult human pancreatic cells to generate clinically relevant amounts of new β cells with potential to reverse diabetes. SIGNIFICANCE β-Cell replacement therapy represents the most promising approach to restore glucose homeostasis in patients with type 1 diabetes. This study shows an innovative and robust in vitro system for large-scale production of β-like cells from human pancreatic duct-derived cells (HDDCs) using a nonintegrative RNA-based reprogramming technique. V-Maf musculoaponeurotic fibrosarcoma oncogene homolog A overexpression was efficient and sufficient to induce β-cell differentiation and insulin secretion from HDDCs in response to glucose stimulation, allowing the cells to mitigate hyperglycemia in diabetic SCID-beige mice. The data describe a new, reliable, and fast procedure in adult human pancreatic cells to generate clinically relevant amounts of new β cells with the potential to reverse diabetes.
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Affiliation(s)
- Elisa Corritore
- Pediatric Research Laboratory, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Yong-Syu Lee
- Pediatric Research Laboratory, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Valentina Pasquale
- Diabetes Research Institute, Istituti di Ricovero e Cura a Carattere Scientifico, San Raffaele Scientific Institute, Milan, Italy
| | - Daniela Liberati
- Diabetes Research Institute, Istituti di Ricovero e Cura a Carattere Scientifico, San Raffaele Scientific Institute, Milan, Italy
| | - Mei-Ju Hsu
- Pediatric Research Laboratory, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Catherine Anne Lombard
- Pediatric Research Laboratory, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | | | - Amedeo Vetere
- Chemical Biology Program, Broad Institute of Harvard and MIT, Cambridge, Massachusetts, USA
| | - Susan Bonner-Weir
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Harvard Medical School, Boston, Massachusetts, USA
| | - Lorenzo Piemonti
- Diabetes Research Institute, Istituti di Ricovero e Cura a Carattere Scientifico, San Raffaele Scientific Institute, Milan, Italy
| | - Etienne Sokal
- Pediatric Research Laboratory, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
| | - Philippe A Lysy
- Pediatric Research Laboratory, Institut de Recherche Expérimentale et Clinique, Université Catholique de Louvain, Brussels, Belgium
- Pediatric Endocrinology Unit, Cliniques Universitaires Saint Luc, Université Catholique de Louvain, Brussels, Belgium
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Shalaly ND, Ria M, Johansson U, Åvall K, Berggren PO, Hedhammar M. Silk matrices promote formation of insulin-secreting islet-like clusters. Biomaterials 2016; 90:50-61. [PMID: 26986856 DOI: 10.1016/j.biomaterials.2016.03.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 02/26/2016] [Accepted: 03/01/2016] [Indexed: 11/29/2022]
Abstract
Ex vivo expansion of endocrine cells constitutes an interesting alternative to be able to match the unmet need of transplantable pancreatic islets. However, endocrine cells become fragile once removed from their extracellular matrix (ECM) and typically become senescent and loose insulin expression during conventional 2D culture. Herein we develop a protocol where 3D silk matrices functionalized with ECM-derived motifs are used for generation of insulin-secreting islet-like clusters from mouse and human primary cells. The obtained clusters were shown to attain an islet-like spheroid shape and to maintain functional insulin release upon glucose stimulation in vitro. Furthermore, in vivo imaging of transplanted murine clusters showed engraftment with increasing vessel formation during time. There was no sign of cell death and the clusters maintained or increased in size throughout the period, thus suggesting a suitable cluster size for transplantation.
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Affiliation(s)
- Nancy Dekki Shalaly
- Division of Protein Technology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Massimiliano Ria
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden
| | - Ulrika Johansson
- Division of Protein Technology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden
| | - Karin Åvall
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden
| | - Per-Olof Berggren
- The Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Karolinska University Hospital, S-17176 Stockholm, Sweden
| | - My Hedhammar
- Division of Protein Technology, School of Biotechnology, KTH Royal Institute of Technology, S-106 91 Stockholm, Sweden; Department of Anatomy, Physiology and Biochemistry, Swedish University of Agricultural Sciences, S-750 07 Uppsala, Sweden.
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35
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Non-invasive cell type selective in vivo monitoring of insulin resistance dynamics. Sci Rep 2016; 6:21448. [PMID: 26899548 PMCID: PMC4761884 DOI: 10.1038/srep21448] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2015] [Accepted: 01/22/2016] [Indexed: 01/18/2023] Open
Abstract
Insulin resistance contributes to the development of cardio-vascular disease and diabetes. An important but unresolved task is to study the dynamics of insulin resistance in selective cell types of insulin target tissues in vivo. Here we present a novel technique to monitor insulin resistance dynamics non-invasively and longitudinally in vivo in a cell type-specific manner, exemplified by the pancreatic β-cell situated within the micro-organ the islet of Langerhans. We utilize the anterior chamber of the eye (ACE) as a transplantation site and the cornea as a natural body-window to study the development and reversibility of insulin resistance. Engrafted islets in the ACE that express a FoxO1-GFP-based biosensor in their β-cells, report on insulin resistance measured by fluorescence microscopy at single-cell resolution in the living mouse. This technique allows monitoring of cell type specific insulin sensitivity/resistance in real-time in the context of whole body insulin resistance during progression and intervention of disease.
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Fang M, Dong D, Zeng C, Liang X, Yang X, Arranz A, Ripoll J, Hui H, Tian J. Polarization-sensitive optical projection tomography for muscle fiber imaging. Sci Rep 2016; 6:19241. [PMID: 26752330 PMCID: PMC4707546 DOI: 10.1038/srep19241] [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: 07/21/2015] [Accepted: 12/07/2015] [Indexed: 01/22/2023] Open
Abstract
Optical projection tomography (OPT) is a tool used for three-dimensional imaging of millimeter-scale biological samples, with the advantage of exhibiting isotropic resolution typically in the micron range. OPT can be divided into two types: transmission OPT (tOPT) and emission OPT (eOPT). Compared with eOPT, tOPT discriminates different tissues based on their absorption coefficient, either intrinsic or after specific staining. However, it fails to distinguish muscle fibers whose absorption coefficients are similar to surrounding tissues. To circumvent this problem, in this article we demonstrate a polarization sensitive OPT system which improves the detection and 3D imaging of muscle fibers by using polarized light. We also developed image acquisition and processing protocols that, together with the system, enable the clear visualization of muscles. Experimental results show that the muscle fibers of diaphragm and stomach, difficult to be distinguished in regular tOPT, were clearly displayed in our system, proving its potential use. Moreover, polarization sensitive OPT was fused with tOPT to investigate the stomach tissue comprehensively. Future applications of polarization sensitive OPT could be imaging other fiber-like structures such as myocardium or other tissues presenting high optical anisotropy.
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Affiliation(s)
- Mengjie Fang
- Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Beijing Key Laboratory of Molecular Imaging, Beijing 100190, China
| | - Di Dong
- Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Beijing Key Laboratory of Molecular Imaging, Beijing 100190, China
| | - Chaoting Zeng
- Department of Hepatobiliary Surgery, Zhujiang Hospital, Southern Medical University, Guangdong 510282, China
| | - Xiao Liang
- Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Beijing Key Laboratory of Molecular Imaging, Beijing 100190, China
| | - Xin Yang
- Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Beijing Key Laboratory of Molecular Imaging, Beijing 100190, China
| | - Alicia Arranz
- Center for Molecular Biology "Severo Ochoa" (CSIC-UAM), Madrid 28049, Spain
| | - Jorge Ripoll
- Department of Bioengineering and Aerospace Engineering, Universidad Carlos III of Madrid, Madrid 28911, Spain
| | - Hui Hui
- Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Beijing Key Laboratory of Molecular Imaging, Beijing 100190, China
| | - Jie Tian
- Key Laboratory of Molecular Imaging, Institute of Automation, Chinese Academy of Sciences, Beijing 100190, China.,Beijing Key Laboratory of Molecular Imaging, Beijing 100190, China
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Dolenšek J, Špelič D, Skelin Klemen M, Žalik B, Gosak M, Slak Rupnik M, Stožer A. Membrane Potential and Calcium Dynamics in Beta Cells from Mouse Pancreas Tissue Slices: Theory, Experimentation, and Analysis. SENSORS 2015; 15:27393-419. [PMID: 26516866 PMCID: PMC4701238 DOI: 10.3390/s151127393] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 10/11/2015] [Accepted: 10/14/2015] [Indexed: 12/17/2022]
Abstract
Beta cells in the pancreatic islets of Langerhans are precise biological sensors for glucose and play a central role in balancing the organism between catabolic and anabolic needs. A hallmark of the beta cell response to glucose are oscillatory changes of membrane potential that are tightly coupled with oscillatory changes in intracellular calcium concentration which, in turn, elicit oscillations of insulin secretion. Both membrane potential and calcium changes spread from one beta cell to the other in a wave-like manner. In order to assess the properties of the abovementioned responses to physiological and pathological stimuli, the main challenge remains how to effectively measure membrane potential and calcium changes at the same time with high spatial and temporal resolution, and also in as many cells as possible. To date, the most wide-spread approach has employed the electrophysiological patch-clamp method to monitor membrane potential changes. Inherently, this technique has many advantages, such as a direct contact with the cell and a high temporal resolution. However, it allows one to assess information from a single cell only. In some instances, this technique has been used in conjunction with CCD camera-based imaging, offering the opportunity to simultaneously monitor membrane potential and calcium changes, but not in the same cells and not with a reliable cellular or subcellular spatial resolution. Recently, a novel family of highly-sensitive membrane potential reporter dyes in combination with high temporal and spatial confocal calcium imaging allows for simultaneously detecting membrane potential and calcium changes in many cells at a time. Since the signals yielded from both types of reporter dyes are inherently noisy, we have developed complex methods of data denoising that permit for visualization and pixel-wise analysis of signals. Combining the experimental approach of high-resolution imaging with the advanced analysis of noisy data enables novel physiological insights and reassessment of current concepts in unprecedented detail.
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Affiliation(s)
- Jurij Dolenšek
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
| | - Denis Špelič
- Faculty of Electrical Engineering and Computer Science, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (D.Š.); (B.Ž.)
| | - Maša Skelin Klemen
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
| | - Borut Žalik
- Faculty of Electrical Engineering and Computer Science, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (D.Š.); (B.Ž.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
| | - Marko Gosak
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
- Department of Physics, Faculty of Natural Sciences and Mathematics, University of Maribor, SI-2000 Maribor, Slovenia
| | - Marjan Slak Rupnik
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
- Center for Physiology and Pharmacology, Medical University of Vienna, A-1090 Vienna, Austria
| | - Andraž Stožer
- Institute of Physiology, Faculty of Medicine, University of Maribor, SI-2000 Maribor, Slovenia; E-Mails: (J.D.); (M.S.K.); (M.G.); (M.S.R.)
- Center for Open Innovation and Research, Core@UM, University of Maribor, SI-2000 Maribor, Slovenia
- Author to whom correspondence should be addressed; E-Mail: ; Tel.: +386-2-2345843
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