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Payen T, Palermo CF, Sastra SA, Chen H, Han Y, Olive KP, Konofagou EE. Elasticity mapping of murine abdominal organs in vivo using harmonic motion imaging (HMI). Phys Med Biol 2016; 61:5741-54. [PMID: 27401609 PMCID: PMC5048218 DOI: 10.1088/0031-9155/61/15/5741] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Recently, ultrasonic imaging of soft tissue mechanics has been increasingly studied to image otherwise undetectable pathologies. However, many underlying mechanisms of tissue stiffening remain unknown, requiring small animal studies and adapted elasticity mapping techniques. Harmonic motion imaging (HMI) assesses tissue viscoelasticity by inducing localized oscillation from a periodic acoustic radiation force. The objective of this study was to evaluate the feasibility of HMI for in vivo elasticity mapping of abdominal organs in small animals. Pathological cases, i.e. chronic pancreatitis and pancreatic cancer, were also studied in vivo to assess the capability of HMI for detection of the change in mechanical properties. A 4.5 MHz focused ultrasound transducer (FUS) generated an amplitude-modulated beam resulting in 50 Hz harmonic tissue oscillations at its focus. Axial tissue displacement was estimated using 1D-cross-correlation of RF signals acquired with a 7.8 MHz diagnostic transducer confocally aligned with the FUS. In vitro results in canine liver and kidney showed the correlation between HMI displacement and Young's moduli measured by rheometry compression testing. HMI was capable of providing reproducible elasticity maps of the mouse abdominal region in vivo allowing the identification of, from stiffest to softest, the murine kidney, pancreas, liver, and spleen. Finally, pancreata affected by pancreatitis and pancreatic cancer showed HMI displacements 1.7 and 2.2 times lower than in the control case, respectively, indicating higher stiffness. The HMI displacement amplitude was correlated with the extent of fibrosis as well as detecting the very onset of stiffening even before fibrosis could be detected on H&E. This work shows that HMI can produce reliable elasticity maps of mouse abdominal region in vivo, thus providing a potentially critical tool to assess pathologies affecting organ elasticity.
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Affiliation(s)
- Thomas Payen
- Biomedical Engineering, Columbia University, USA
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202
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Shishido A, Caicedo A, Rodriguez-Diaz R, Pileggi A, Berggren PO, Abdulreda MH. Clinical intraocular islet transplantation is not a number issue. CELLR4-- REPAIR, REPLACEMENT, REGENERATION, & REPROGRAMMING 2016; 4:e2120. [PMID: 29497631 PMCID: PMC5828508] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
It is now well established that beta cell replacement through pancreatic islet transplantation results in significant improvement in the quality-of-life of type 1 diabetes (T1D) patients. This is achieved through improved control and prevention of severe drops in blood sugar levels. Islet transplant therapy is on the verge of becoming standard-of-care in the USA. Yet, as with other established transplantation therapies, there remain hurdles to overcome to bring islet transplantation to full fruition as a long-lasting therapy of T1D. One of these hurdles is establishing reliable new sites, other than the liver, where durable efficacy and survival of transplanted islets can be achieved. In this article, we discuss the anterior chamber of the eye as a new site for clinical islet transplantation in the treatment of T1D. We specifically focus on the common conceptions, and preconceptions, on the requirements of islet mass, and whether or not the anterior chamber can accommodate sufficient islets to achieve meaningful efficacy and significant impact on hyperglycemia in clinical application.
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Affiliation(s)
- A Shishido
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - A Caicedo
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Medicine, Division of Endocrinology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - R Rodriguez-Diaz
- Department of Medicine, Division of Endocrinology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - A Pileggi
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
- Departments of Microbiology and Immunology and Biomedical Engineering, University of Miami, Miami, FL, USA
| | - P-O Berggren
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - M H Abdulreda
- Diabetes Research Institute, University of Miami Miller School of Medicine, Miami, FL, USA
- Department of Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
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203
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Del Toro-Arreola A, Robles-Murillo AK, Daneri-Navarro A, Rivas-Carrillo JD. The role of endothelial cells on islet function and revascularization after islet transplantation. Organogenesis 2016; 12:28-32. [PMID: 27002241 DOI: 10.1080/15476278.2016.1165378] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Islet transplantation has become a widely accepted therapeutic option for selected patients with type 1 diabetes mellitus. However, in order to achieve insulin independence a great number of islets are often pooled from 2 to 4 pancreata donors. Mostly, it is due to the massive loss of islets immediately after transplant. The endothelium plays a key role in the function of native islets and during the revascularization process after islet transplantation. However, if a delayed revascularization occurs, even the remaining islets will also undergo to cell death and late graft dysfunction. Therefore, it is essential to understand how the signals are released from endothelial cells, which might regulate both differentiation of pancreatic progenitors and thereby maintenance of the graft function. New strategies to facilitate islet engraftment and a prompt revascularization could be designed to intervene and might lead to improve future results of islet transplantation.
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Affiliation(s)
- Alicia Del Toro-Arreola
- a Department of Physiology, Laboratory of Immunology, Tissue Engineering and Transplant , University Center for Health Sciences, University of Guadalajara , Mexico
| | | | - Adrian Daneri-Navarro
- a Department of Physiology, Laboratory of Immunology, Tissue Engineering and Transplant , University Center for Health Sciences, University of Guadalajara , Mexico
| | - Jorge David Rivas-Carrillo
- a Department of Physiology, Laboratory of Immunology, Tissue Engineering and Transplant , University Center for Health Sciences, University of Guadalajara , Mexico
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204
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Ramírez-Domínguez M. Isolation of Mouse Pancreatic Islets of Langerhans. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 938:25-34. [DOI: 10.1007/978-3-319-39824-2_3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
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205
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Ramírez-Domínguez M. Historical Background of Pancreatic Islet Isolation. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2016; 938:1-9. [PMID: 27586418 DOI: 10.1007/978-3-319-39824-2_1] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Until the discovery of insulin in the twentieth century, diabetes mellitus was a mortal disease with an unclear origin and physiology. Despite the appearance of the concept in an Egyptian papyrus dated c.1550 BC, and the documentation of its study by ancient Chinese, the term "diabetes" was only coined by the Greek Aretaeus in the second century AD. In Europe, the study of diabetes was largely ignored until the seventeenth century, when the characteristic sweet flavor of diabetic urine was first described. However, the link between diabetes and the pancreas was not discovered until 1889 by Minkowski and von Mering, long after the first description of the pancreatic islets by Paul Langerhans in 1869. One of the most significant milestones in the field was the discovery of insulin by Banting and collaborators in 1922, which led to the therapeutic development of insulin administration as a life-saving intervention for type 1 diabetic patients. On the other hand, the isolation of islets was first reported by Bensley in 1911, a critical technical achievement that paved the way for clinical islet transplantation. Here we discuss the history of islet isolation, since the firsts studies of diabetes by ancient civilizations to the birth and parallel evolution of islet isolation and transplantation.
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Affiliation(s)
- Miriam Ramírez-Domínguez
- Laboratory of Cell Therapy of Diabetes, Department of Pediatrics, Faculty of Medicine and Odontology, Hospital Cruces, University of the Basque Country (UPV/EHU), Barrio Sarriena, s/n, 48940, Leioa, Biscay, Spain.
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206
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Lau J, Grapengiesser E, Hellman B. Small Mouse Islets Are Deficient in Glucagon-Producing Alpha Cells but Rich in Somatostatin-Secreting Delta Cells. J Diabetes Res 2016; 2016:4930741. [PMID: 27504459 PMCID: PMC4967688 DOI: 10.1155/2016/4930741] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/10/2016] [Accepted: 06/26/2016] [Indexed: 11/26/2022] Open
Abstract
Small and big mouse islets were compared with special reference to their content of glucagon-producing α-cells and somatostatin-producing δ-cells. Areas stained for glucagon and somatostatin were measured in the largest cross section of small (diameter < 60 μm) and big (diameter > 100 μm) islets. Comparison of the areas indicated proportionally more δ- than α-cells in the small islets. After isolation with collagenase these islets were practically devoid of α-cells. We evaluated the functional importance of the islet size by measuring the Ca(2+) signal for insulin release. A majority of the small islets responded to the hyperpolarization action of somatostatin with periodic decrease of cytoplasmic Ca(2+) when glucose was elevated after tolbutamide blockade of the KATP channels.
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Affiliation(s)
- Joey Lau
- Department of Medical Cell Biology, Uppsala University, Box 571, 751 23 Uppsala, Sweden
- *Joey Lau:
| | - Eva Grapengiesser
- Department of Medical Cell Biology, Uppsala University, Box 571, 751 23 Uppsala, Sweden
| | - Bo Hellman
- Department of Medical Cell Biology, Uppsala University, Box 571, 751 23 Uppsala, Sweden
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207
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Renner S, Blutke A, Streckel E, Wanke R, Wolf E. Incretin actions and consequences of incretin-based therapies: lessons from complementary animal models. J Pathol 2015; 238:345-58. [DOI: 10.1002/path.4655] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 10/02/2015] [Accepted: 10/05/2015] [Indexed: 12/30/2022]
Affiliation(s)
- Simone Renner
- Gene Centre, Centre for Innovative Medical Models (CiMM) and German Centre for Diabetes Research (DZD); Ludwig-Maximilians-Universität München; Germany
| | - Andreas Blutke
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine; Ludwig-Maximilians-Universität München; Germany
| | - Elisabeth Streckel
- Gene Centre, Centre for Innovative Medical Models (CiMM) and German Centre for Diabetes Research (DZD); Ludwig-Maximilians-Universität München; Germany
| | - Rüdiger Wanke
- Institute of Veterinary Pathology, Centre for Clinical Veterinary Medicine; Ludwig-Maximilians-Universität München; Germany
| | - Eckhard Wolf
- Gene Centre, Centre for Innovative Medical Models (CiMM) and German Centre for Diabetes Research (DZD); Ludwig-Maximilians-Universität München; Germany
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208
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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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