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Abstract
Type 1 diabetes (insulin-dependent, IDDM) results in immune-mediated destruction of pancreatic beta cells, which leads to a deficiency in insulin secretion and as a result, to hyperglycaemia. Keeping blood glucose levels under tight control represents the most effective way either to prevent the onset or to reduce the progression of the chronic complications of IDDM. At present, pancreatic islet transplantation is emerging as the most promising clinical modality, which can stop diabetes progression without increasing the incidence of hypoglycaemic events. Although early results of clinical trials using the Edmonton Protocol and its variations are very encouraging, it is still unclear how long the islets will survive and how often the transplantation procedure will be successful. In order to monitor transplantation efficiency and graft survival, reliable non-invasive imaging methods are critically needed. If such methods are introduced clinically, essential information regarding the location, function and viability of transplanted islets can be obtained repeatedly and non-invasively. This review will focus on the latest advancements in the field of in vivo imaging of islet transplantation and describe various islet labelling and imaging techniques. In addition, we will critically look into limitations and obstacles currently present on the way to successful clinical implementation of this approach.
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Affiliation(s)
- Z Medarova
- Molecular Imaging Program, MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Boston, MA 02129, USA
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Juang JH, Kuo CH, Wu CH, Juang C. Exendin-4 treatment expands graft beta-cell mass in diabetic mice transplanted with a marginal number of fresh islets. Cell Transplant 2008; 17:641-7. [PMID: 18819252 DOI: 10.3727/096368908786092766] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Exendin-4 stimulates insulin secretion, suppresses glucagons secretion, increases beta-cell replication and neogenesis, and reduces beta-cell apoptosis. However, it has been shown that posttransplant exendin-4 treatment did not improve glucose homeostasis in diabetic mice transplanted with a large number of freshly isolated islets. The aim of this study was to test if exendin-4 is beneficial for hyperglycemic recipients with a marginal number of fresh islets. We transplanted 150 C57BL/6 mouse islets under the kidney capsule of inbred streptozotocin-diabetic mice, and then treated the recipients with and without exendin-4 for 6 weeks. Before and after transplantation, recipients' blood glucose, body weight, and intraperitoneal glucose tolerance test were measured. At 6 weeks, the grafts were removed to determine beta-cell mass. Blood glucose levels in both groups decreased progressively after transplantation, and the exendin-4-treated group had had lower blood glucose than controls since day 3. By 6 weeks, euglycemia was achieved more in mice treated with exendin-4 than in controls (100% vs. 62.5%, p = 0.018). The time to obtain normoglycemia was shorter in the exendin-4-treated group than in controls (12 +/- 8 vs. 29 +/- 13 days, p < 0.001). Blood glucose at 6 weeks was 123 +/- 18 and 170 +/- 62 mg/dl in the exendin-4-treated group and controls, respectively (p = 0.008). Additionally, the exendin-4-treated group had better glucose tolerance than controls at 2 and 4 weeks (p <0.02). However, both groups exhibited increased body weight over time, and weight changes did not significantly differ between the two groups throughout the study period. At 6 weeks after transplantation, grafts in the exendin-4-treated group were more prominent and contained more insulin-stained cells than those of controls. They had 2.3-fold beta-cell mass of the graft compared with controls (0.30 +/- 0.11 vs. 0.13 +/- 0.03 mg, p = 0.012). These results indicate posttransplant exendin-4 treatment in the diabetic recipient with a marginal number of fresh islets expands graft beta-cell mass and improves transplantation outcome.
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Affiliation(s)
- Jyuhn-Huarng Juang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Chang Gung University and Memorial Hospital, Taoyuan, Taiwan.
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253
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Ihm SH, Matsumoto I, Zhang HJ, Ansite JD, Hering BJ. Effect of short-term culture on functional and stress-related parameters in isolated human islets. Transpl Int 2008; 22:207-16. [DOI: 10.1111/j.1432-2277.2008.00769.x] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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254
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Wilson JT, Chaikof EL. Thrombosis and inflammation in intraportal islet transplantation: a review of pathophysiology and emerging therapeutics. J Diabetes Sci Technol 2008; 2:746-59. [PMID: 19885257 PMCID: PMC2769789 DOI: 10.1177/193229680800200502] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
With the inception of the Edmonton Protocol, intraportal islet transplantation (IPIT) has re-emerged as a promising cell-based therapy for type 1 diabetes. However, current clinical islet transplantation remains limited, in part, by the need to transplant islets from 2-4 donor organs, often through several separate infusions, to reverse diabetes in a single patient. Results from clinical islet transplantation and experimental animal models now indicate that the majority of transplanted islets are destroyed in the immediate post-transplant period, a process largely facilitated by deleterious inflammatory responses triggered by islet-derived procoagulant and proinflammatory mediators. Herein, mechanisms that underlie the pathophysiology of thrombosis and inflammation in IPIT are reviewed, and emerging approaches to improve islet engraftment through attenuation of inflammatory responses are discussed.
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Affiliation(s)
- John T. Wilson
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia
| | - Elliot L. Chaikof
- Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, Georgia
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology, Atlanta, Georgia
- Department of Surgery, Emory University School of Medicine, Atlanta, Georgia
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255
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Guillausseau PJ, Meas T, Virally M, Laloi-Michelin M, Médeau V, Kevorkian JP. Abnormalities in insulin secretion in type 2 diabetes mellitus. DIABETES & METABOLISM 2008; 34 Suppl 2:S43-8. [PMID: 18640585 DOI: 10.1016/s1262-3636(08)73394-9] [Citation(s) in RCA: 121] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Type 2 diabetes mellitus is a multifactorial disease, due to decreased glucose peripheral uptake, and increased hepatic glucose production, due to reduced both insulin secretion and insulin sensitivity. Multiple insulin secretory defects are present, including absence of pulsatility, loss of early phase of insulin secretion after glucose, decreased basal and stimulated plasma insulin concentrations, excess in prohormone secretion, and progressive decrease in insulin secretory capacity with time. beta-cell dysfunction is genetically determined and appears early in the course of the disease. The interplay between insulin secretory defect and insulin resistance is now better understood. In subjects with normal beta-cell function, increase in insulin is compensated by an increase in insulin secretion and plasma glucose levels remain normal. In subjects genetically predisposed to type 2 diabetes, failure of beta-cell to compensate leads to a progressive elevation in plasma glucose levels, then to overt diabetes. When permanent hyperglycaemia is present, progressive severe insulin secretory failure with time ensues, due to glucotoxicity and lipotoxicity, and oxidative stress. A marked reduction in beta-cell mass at post-mortem examination of pancreas of patients with type 2 diabetes has been reported, with an increase in beta-cell apoptosis non-compensated by neogenesis.
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Affiliation(s)
- P-J Guillausseau
- AP-HP, Department of Internal Medicine B, Hôpital Lariboisière, 2, rue Ambroise Raré, 75010, Paris, France.
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256
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Kriz J, Jirak D, White D, Foster P. Magnetic resonance imaging of pancreatic islets transplanted into the right liver lobes of diabetic mice. Transplant Proc 2008; 40:444-8. [PMID: 18374096 DOI: 10.1016/j.transproceed.2008.02.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
INTRODUCTION Pancreatic islets (PI) labeled with Feridex can be visualized using magnetic resonance imaging (MRI) after transplantation into the liver. However, there is still no accurate method of quantifying the signal loss caused by the iron contrast agent within transplanted tissue. The aim of this study was to test a new method for quantifying signal loss during the early posttransplantation period. METHODS Isolated mouse PI (C57BL/6 and BALB/c) were labeled in CMRL-1066 culture media supplemented with Feridex. Two hundred twenty PI were injected directly into the right liver lobes of BALB/c diabetic (streptozotocine 220 mg/kg) recipients (isografts, n = 3; allografts, n = 3). Animals were scanned at 3 T, on a whole body scanner equipped with a high-performance gradient insert and using the 3D FIESTA sequence, on days 1, 7, and 14. Signal loss was quantified by comparison of liver tissue with and without labeled PI. Signal loss detected on the first scan was rated as 100% and subsequent measurements were recalculated as relative numbers. RESULTS While the function of the isografts remained stable throughout the study, the allografts failed on days 5 and 10. A decrease in the amount of signal loss was observed in all animals and was comparable after the first week in both groups. However, there was a difference between groups after the second week (mean +/- SD; isografts, 100% --> 61.8 +/- 6.74% --> 47.18 +/- 7.14%; allografts, 100% --> 59.39 +/- 8.54% --> 38.16 +/- 6.81%). CONCLUSION Disappearance of signal loss is comparable in all animals during the first week and seems to be independent of acute rejection.
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Affiliation(s)
- J Kriz
- Robarts Research Institute of Schulich School of Medicine at University of Western Ontario, London, Ontario, Canada.
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257
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Emamaullee JA, Davis J, Pawlick R, Toso C, Merani S, Cai SX, Tseng B, Shapiro AMJ. The caspase selective inhibitor EP1013 augments human islet graft function and longevity in marginal mass islet transplantation in mice. Diabetes 2008; 57:1556-66. [PMID: 18356409 DOI: 10.2337/db07-1452] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
OBJECTIVE Clinical islet transplantation can provide insulin independence in patients with type 1 diabetes, but chronic graft failure has been observed. This has been attributed in part to loss of >or=60% of the transplanted islets in the peritransplant period, resulting in a marginal implant mass. Strategies designed to maximize survival of the initial islet mass are likely to have major impact in enhancing long-term clinical outcomes. EP1013 (N-benzyloxycabonyl-Val Asp-fluoromethyl ketone [zVD-FMK]), is a broad-spectrum caspase selective inhibitor with no observed toxicity in rodents. RESEARCH DESIGN AND METHODS The therapeutic benefit of EP1013 was examined in a syngeneic rodent islet transplant model using deceased donor human islets to determine whether the amount of tissue required to restore euglycemia in diabetic animals could be reduced. RESULTS EP1013 (combined pretransplant islet culture for 2 h and in vivo treatment for days 0-5 posttransplant) significantly improved marginal islet mass function following syngeneic islet transplantation in mice, even at lower doses, compared with previous studies using the pan-caspase inhibitor N-benzyloxycabonyl-Val Ala-Asp-fluoromethyl ketone (zVAD-FMK). EP1013 supplementation in vitro improved human islet yields following prolonged culture and reversed diabetes following implantation of a marginal human islet mass (80-90% reduction) into mice. CONCLUSIONS Our data suggest that EP1013 therapy will markedly reduce the islet mass required in clinical islet transplantation, improving insulin independence rates following single-donor infusion.
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258
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Effects of glucose toxicity and islet purity on in vivo magnetic resonance imaging of transplanted pancreatic islets. Transplantation 2008; 85:1091-8. [PMID: 18431227 DOI: 10.1097/tp.0b013e31816b183e] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Pancreatic islet transplantation has recently emerged as a powerful clinical modality to restore normoglycemia in diabetic patients. Despite the success of the Edmonton protocol, these patients still experience a significant islet loss immediately after transplantation. Noninvasive magnetic resonance imaging (MRI) allows for longitudinal monitoring of graft loss providing that islets are labeled with a magnetically "visible" contrast agent. To fully interpret the imaging data, it is critical to investigate factors normally present during clinical transplantation and influencing MRI of transplanted islets. METHODS Here, we focused on both the effect of hyperglycemia and the effect of contaminating nonendocrine tissue, which is always present in islet preparations, on MRI imaging of islet grafts. Human pancreatic islets labeled with Feridex were transplanted in diabetic and healthy animals. Separate groups of animals were transplanted with Feridex-labeled pure and nonpure (50% islets and 50% nonendocrine tissue) preparations. The fate of the graft in all groups was monitored by in vivo MRI. RESULTS We found that diabetic animals with transplanted islets showed a significantly higher rate of islet death than their healthy counterparts on in vivo MR images. Interestingly, transplantation of islets contaminated with nonendocrine tissue did not have any significant influence on MR images, presumably because of a low labeling rate of this tissue and a fast rate of its disappearance after transplantation. CONCLUSIONS We believe that this study serves as yet another step on our way to clinical use of in vivo imaging of islet transplantation.
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259
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Zhang KZ, Liu YF, Zhang JL. Protective effects of taurine on the islet viability and function in rats. Shijie Huaren Xiaohua Zazhi 2008; 16:1388-1395. [DOI: 10.11569/wcjd.v16.i13.1388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
AIM: To investigate the protective effect of taurine on the islets during culturing and its mechanism in rats.
METHODS: Wistar rats were divided into 2 groups: RPMI-1640 group and taurine group. The percentage of active Caspase-9-positive cells or phospho-Akt 473-positive cells was determined by flow cytometry. The mRNA levels of tumor necrosis factor (TNF-α), interleukin-1β (IL-1β), nuclear factor-κB (NF-κB), and heme oxygenase-1 (HO-1) were evaluated by reverse transcription-polymerase chain reaction (RT-PCR) in the isolated rat islets of both groups.
RESULTS: After 1-wk culture, the percentage of Caspase-9-positive cells was significantly higher in the taurine group than that in the RPMI-1640 group (41.03% ± 4.46% vs 23.85% ± 3.09%, P < 0.05). The mRNAs of TNF-α, IL-1β, NF-κB and HO-1 were significantly expressed after the islets were isolated and purified. However, the mRNAs of TNF-α, IL-1β, NF-κB expression were decreased gradually while HO-1 expression was increased with the culturing time. After 6-h, 72-h and 1-wk culture, the mRNA levels of TNF-α, IL-1β, and NF-κB were significantly lower in the taurine group (TNF-α: 0.34 ± 0.02, 0.24 ± 0.01, 0.19 ± 0.02; IL-1β: 0.24 ± 0.09, 0.09 ± 0.01, 0.05 ± 0.01; NF-κB: 1.76 ± 0.30, 0.93 ± 0.15, 0.37 ± 0.02) than those in the RPMI-1640 group (TNF-α: 0.57 ± 0.1, 0.39 ± 0.02, 0.29 ± 0.02; IL-1β: 0.34 ± 0.02, 0.24 ± 0.01, 0.19 ± 0.02; NF-κB: 2.52 ± 0.24, 1.21 ± 0.14, 0.76 ± 0.07) (all P < 0.05), but the HO-1 mRNA level was markedly higher in the taurine group (3.74 ± 0.10, 4.33 ± 0.29, 5.28 ± 0.29 vs 2.46±0.30, 3.13 ± 0.07, 3.59 ± 0.22; all P < 0.05).
CONCLUSION: Taurine can protect the islet cells from apoptosis by inhibiting the transcription of TNF-α, IL-1β and NF-κB gene or by increasing phospho-Akt activity.
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260
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Li F, Mahato RI. iNOS Gene Silencing Prevents Inflammatory Cytokine-Induced β-Cell Apoptosis. Mol Pharm 2008; 5:407-17. [DOI: 10.1021/mp700145f] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Affiliation(s)
- Feng Li
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee
| | - Ram I. Mahato
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, Memphis, Tennessee
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261
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Wilson JT, Chaikof EL. Challenges and emerging technologies in the immunoisolation of cells and tissues. Adv Drug Deliv Rev 2008; 60:124-45. [PMID: 18022728 DOI: 10.1016/j.addr.2007.08.034] [Citation(s) in RCA: 129] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2007] [Accepted: 08/13/2007] [Indexed: 12/22/2022]
Abstract
Protection of transplanted cells from the host immune system using immunoisolation technology will be important in realizing the full potential of cell-based therapeutics. Microencapsulation of cells and cell aggregates has been the most widely explored immunoisolation strategy, but widespread clinical application of this technology has been limited, in part, by inadequate transport of nutrients, deleterious innate inflammatory responses, and immune recognition of encapsulated cells via indirect antigen presentation pathways. To reduce mass transport limitations and decrease void volume, recent efforts have focused on developing conformal coatings of micron and submicron scale on individual cells or cell aggregates. Additionally, anti-inflammatory and immunomodulatory capabilities are being integrated into immunoisolation devices to generate bioactive barriers that locally modulate host responses to encapsulated cells. Continued exploration of emerging paradigms governed by the inherent challenges associated with immunoisolation will be critical to actualizing the clinical potential of cell-based therapeutics.
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262
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Dror V, Nguyen V, Walia P, Kalynyak TB, Hill JA, Johnson JD. Notch signalling suppresses apoptosis in adult human and mouse pancreatic islet cells. Diabetologia 2007; 50:2504-15. [PMID: 17922104 DOI: 10.1007/s00125-007-0835-5] [Citation(s) in RCA: 77] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/19/2007] [Accepted: 08/13/2007] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS The pathogenesis of diabetes and the success of islet transplantation depend on the control of pancreatic beta cell fate. The Notch signalling pathway is essential for normal prenatal pancreatic development, but the presence and function of this gene network in adult islets has received much less attention. METHODS The presence of Notch signalling components was assessed in vitro using RT-PCR, western blotting and immunofluorescence. The functional consequences of altering Notch signalling on insulin secretion and programmed cell death were examined. RESULTS Adult mouse islets, human islets and mouse insulinoma MIN6 cells possess key components of the Notch pathway. RT-PCR, western blotting and immunofluorescence indicated that the Notch target gene, neurogenin3 (Ngn3, also known as Neurog3), is also present in adult islet cells. Inhibiting Notch signalling with N-[N-(3,5-difluorophenacetyl-L-alanyl)]-S-phenylglycine t-butyl ester (DAPT) increased Ngn3 mRNA expression and protein levels in adult islets. The activated notch homologue 1 (NOTCH1) protein level was decreased upon serum withdrawal, as well as after treatment with a phosphatidylinositol 3-kinase inhibitor, or hydroxy-2-naphthalenylmethylphosphonic acid, an insulin receptor inhibitor. While islets cultured in DAPT did not exhibit defects in insulin secretion, indicating that differentiation is unaltered, inhibiting gamma-secretase-dependent Notch activation led to a dose-dependent increase in caspase-3-dependent apoptosis in both MIN6 cells and human islets. Conversely, gamma-secretase overactivity resulted in an accumulation of cleaved NOTCH1 and protection from apoptosis. CONCLUSIONS/INTERPRETATION Together these results show that the Notch/Ngn3 signalling network is intact and functional in adult islets. This pathway represents an attractive target for modulating beta cell fate in diabetes, islet transplantation and efforts to derive beta cell surrogates in vitro.
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Affiliation(s)
- V Dror
- Laboratory of Molecular Signalling in Diabetes, Diabetes Research Group, Department of Cellular and Physiological Sciences and the Department of Surgery, University of British Columbia, Vancouver, BC, Canada
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263
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Laybutt DR, Hawkins YC, Lock J, Lebet J, Sharma A, Bonner-Weir S, Weir GC. Influence of diabetes on the loss of beta cell differentiation after islet transplantation in rats. Diabetologia 2007; 50:2117-25. [PMID: 17641871 DOI: 10.1007/s00125-007-0749-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/07/2007] [Accepted: 05/30/2007] [Indexed: 10/23/2022]
Abstract
AIMS/HYPOTHESIS Hyperglycaemia can impair beta cell function after islet transplantation. Appropriate glucose-induced insulin secretion is dependent on a unique expression pattern of genes. Here we examined the effects of diabetes on gene expression in transplanted islets. MATERIALS AND METHODS Streptozotocin-induced diabetic or control non-diabetic Lewis rats were transplanted under the kidney capsule with an insufficient number (2,000) of syngeneic islets to normalise blood glucose levels in diabetic rats. Eighteen days after transplantation, islet grafts were retrieved and RT-PCR used to assess expression of selected genes critical for beta cell function. Islet grafts from diabetic rats transplanted with a sufficient number of islets (3,000) to normalise hyperglycaemia were used to assess the effects of correcting blood glucose levels. Additionally, gene expression of transplanted islets from non-diabetic rats was compared with freshly isolated islets. RESULTS In islet grafts from diabetic rats, mRNA levels of several transcription factors important for the maintenance of beta cell differentiation were reduced (pancreatic and duodenal homeobox 1 [Pdx1], neurogenic differentiation 1 [Neurod1], NK6 transcription factor related, locus 1 [Nkx6.1], paired box gene 6 [Pax6]), as were genes implicated in beta cell function (Glut2 [also known as solute carrier family 2 [facilitated glucose transporter], member 2 [Slc2a2], glucokinase, insulin, islet amyloid polypeptide [Iapp]). Conversely, mRNA levels of lactate dehydrogenase, which is normally suppressed in beta cells, were increased. The majority of the changes in gene expression were normalised after correction of hyperglycaemia, indicating that the severe loss of beta cell differentiation correlates with continuous exposure to diabetes. Even islet grafts from non-diabetic rats showed a few alterations in beta cell gene expression in comparison with fresh islets. CONCLUSIONS/INTERPRETATION Chronic hyperglycaemia contributes to the deterioration of beta cell differentiation after islet transplantation.
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Affiliation(s)
- D R Laybutt
- Section of Islet Transplantation and Cell Biology, Research Division, Joslin Diabetes Center, Harvard Medical School, One Joslin Place, Boston, MA, 02215, USA
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264
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Berman DM, Cabrera O, Kenyon NM, Miller J, Tam SH, Khandekar VS, Picha KM, Soderman AR, Jordan RE, Bugelski PJ, Horninger D, Lark M, Davis JE, Alejandro R, Berggren PO, Zimmerman M, O'Neil JJ, Ricordi C, Kenyon NS. Interference with tissue factor prolongs intrahepatic islet allograft survival in a nonhuman primate marginal mass model. Transplantation 2007; 84:308-15. [PMID: 17700154 DOI: 10.1097/01.tp.0000275401.80187.1e] [Citation(s) in RCA: 62] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Tissue factor (TF) expression on islets can result in an instant blood-mediated inflammatory reaction (IBMIR) that contributes to early islet loss. We tested whether peritransplant protection of islets from IBMIR with a monoclonal anti-TF antibody (CNTO859) would enhance engraftment in our nonhuman primate marginal mass model. METHODS Each of six pairs of cynomolgus monkeys (CM) with streptozotocin-induced diabetes was closely matched for metabolic control and was transplanted with 5,000 IEQ/kg allogeneic, ABO-compatible islets from the same donor under the cover of steroid-free immunosuppression. For each pair, experimental animals received islets cultured with 20 microg/mL anti-TF and were dosed with 6 mg/kg anti-TF intravenously, 10-25 min before islet infusion; control monkeys received an equal number of islets from the same preparation cultured without anti-TF and no in vivo treatment. RESULTS Early fasting C-peptide (CP) values were different between (P<0.01), but not within, pairs and correlated with in vitro functional capacity of islets as assessed by perifusion (r=0.60; P=0.022). Compared to their matched controls, experimental animals had decreased posttransplant markers of coagulation, higher fasting CP levels (1 month posttransplant and end of study) and prolonged graft function. CONCLUSIONS These data suggest that pretreatment of islets and the recipient with anti-TF may limit the effects of IBMIR, thereby enhancing islet engraftment and survival.
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Affiliation(s)
- Dora M Berman
- Diabetes Research Institute, Miller School of Medicine, University of Miami, Miami, FL 33136, USA.
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265
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Montolio M, Téllez N, Soler J, Montanya E. Role of blood glucose in cytokine gene expression in early syngeneic islet transplantation. Cell Transplant 2007; 16:517-25. [PMID: 17708341 DOI: 10.3727/000000007783464920] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
In islet transplantation, local production of cytokines at the grafted site may contribute to the initial nonspecific inflammation response. We have determined whether the metabolic condition of the recipient modulates the cytokine expression in islet grafts in the initial days after transplantation. Normoglycemic and hyperglycemic streptozotocin-diabetic Lewis rats were transplanted with 500 syngeneic islets, an insufficient beta cell mass to restore normoglycemia in hyperglycemic recipients. The expression of IL-1beta, TNF-alpha, IFN-gamma, IL-6, IL-10, and IL-4 genes was determined by real-time PCR in freshly isolated islets, in 24-h cultured islets and in islet grafts on days 1, 3, and 7 after transplantation. IL-1beta mRNA was strongly and similarly increased in normoglycemic and hyperglycemic groups on days 1, 3, and 7 after transplantation compared with freshly isolated and cultured islets. TNF-alpha mRNA was also strongly increased on day 1, and it remained increased on days 3 and 7. IL-6 and IL-10 were not detected in freshly isolated islets, but their expression was clearly enhanced in 24-h cultured islets and islet grafts. IL-6 was further increased in hyperglycemic grafts. IL-10 expression was increased in both normoglycemic and hyperglycemic grafts on day 1 after transplantation, and remained increased in hyperglycemic grafts compared to 24-h cultured islets. IFN-gamma mRNA was barely detected in a few grafts, and IL-4 mRNA was never detected. Thus, the inflammatory response in islet grafts was maximal on day 1 after transplantation, it was sustained, although at lower levels, on days 3 and 7, and it was partly enhanced by hyperglycemia.
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Affiliation(s)
- Marta Montolio
- Laboratory of Diabetes and Experimental Endocrinology, Department of Clinical Sciences, University of Barcelona
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266
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Virally M, Blicklé JF, Girard J, Halimi S, Simon D, Guillausseau PJ. Type 2 diabetes mellitus: epidemiology, pathophysiology, unmet needs and therapeutical perspectives. DIABETES & METABOLISM 2007; 33:231-44. [PMID: 17703979 DOI: 10.1016/j.diabet.2007.07.001] [Citation(s) in RCA: 78] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/30/2007] [Accepted: 06/25/2007] [Indexed: 12/25/2022]
Abstract
In France, prevalence of drug-treated diabetes reached 3.60% in 2005, with 92% of type 2 diabetic patients. In 2007, there are probably nearly 3000 000 diagnosed or undiagnosed diabetic patients. Ageing of the population and increase in obesity are the main causes of this "diabetes epidemic". Type 2 diabetes is a multifactorial disease, defined as resulting from defects in insulin secretion (including abnormalities in pulsatility and kinetics, quantitative and qualitative abnormalities of insulin, beta-cell loss progressing with time) associated with insulin resistance (affecting liver, and skeletal muscle) and increased glucagon secretion. The lack of compensation of insulin resistance by augmented insulin secretion results in rise in blood glucose. To achieve satisfactory glycaemic control in order to prevent diabetes related complications, drug therapy is generally required in addition to life style changes. Currently available oral therapies offer a large panel of complementary drugs, but they have several contraindications and side effects. In spite of major advances in the management of type 2 diabetes, and the strictness of new guidelines, some goals remain unachieved and the new family of insulin-secretors (DPP-IV inhibitors, GLP-1 analogues) should enrich therapeutic approaches.
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Affiliation(s)
- M Virally
- Service de médecine B, APHP, hôpital Lariboisière, 2, rue Ambroise-Paré, 75010 Paris, France
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267
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Emamaullee JA, Shapiro AMJ. Factors influencing the loss of beta-cell mass in islet transplantation. Cell Transplant 2007; 16:1-8. [PMID: 17436849 DOI: 10.3727/000000007783464461] [Citation(s) in RCA: 119] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Recent advances in clinical islet transplantation have clearly demonstrated that this procedure can provide excellent glycemic control and often insulin independence in a population of patients with type 1 diabetes. A key limitation in the widespread application of clinical islet transplantation is the requirement of 10,000 islet equivalents/kg in most recipients, generally derived from two or more cadaveric donors. It has been determined that a majority of the transplanted islets fail to engraft and become fully functional. In this review article, the factors that contribute to this early loss of islets following transplantation are discussed in depth.
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268
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Johansson M, Jansson L, Carlsson PO. Improved vascular engraftment and function of autotransplanted pancreatic islets as a result of partial pancreatectomy in the mouse and rat. Diabetologia 2007; 50:1257-66. [PMID: 17406853 DOI: 10.1007/s00125-007-0649-5] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2006] [Accepted: 01/15/2007] [Indexed: 11/29/2022]
Abstract
AIMS/HYPOTHESIS The few patients subjected to autotransplantation of pancreatic islets after pancreatectomy usually become normoglycaemic after using islets from the resected organ only, whereas allogeneic recipients usually require at least two grafts to retain normoglycaemia. Previous experimental studies have demonstrated that islets transplanted to non-pancreatectomised recipients acquire a markedly decreased blood vessel density, which leads to a hypoxic microenvironment. The aim of the present study was to test the hypothesis that autotransplanted islets have better vascular engraftment and function as a result of the pancreatic surgery involved. MATERIALS AND METHODS In the present study, athymic mice and inbred rats were subjected to a 60% pancreatectomy and transplanted with human or rat islets, respectively, 4 days later. Control animals underwent sham surgery. Blood flow, oxygen tension, vascular density and endocrine volume in the islet grafts were measured 1 month after transplantation. Separate grafts were used for perfusion experiments and for assessment of beta cell proliferation and endocrine cellular apoptosis at different time periods after transplantation. RESULTS Islet grafts in partially pancreatectomised recipients had an increased blood flow, oxygen tension, blood vessel density and endocrine mass 1 month post-transplantation compared with control animals. They also exhibited increased insulin release in perfusion experiments performed 1 month post-transplantation, and decreased cellular apoptosis early after transplantation. CONCLUSIONS/INTERPRETATION The present study shows that the pancreatectomy procedure itself has beneficial effects on the engraftment of transplanted human and rat islets. Our results provide an additional explanation, besides diminished immunological responses, of the much better outcome of islet autotransplantations compared with allogeneic transplantations in the clinic.
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Affiliation(s)
- M Johansson
- Department of Medical Cell Biology, Uppsala University, Husargatan 3, Box 571, 751 23 Uppsala, Sweden
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269
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Emamaullee JA, Stanton L, Schur C, Shapiro AMJ. Caspase inhibitor therapy enhances marginal mass islet graft survival and preserves long-term function in islet transplantation. Diabetes 2007; 56:1289-98. [PMID: 17303806 DOI: 10.2337/db06-1653] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Islet transplantation can provide insulin independence in patients with type 1 diabetes, but islets derived from two or more donors are often required. A significant fraction of the functional islet mass is lost to apoptosis in the immediate posttransplant period. The caspase inhibitor N-benzyloxycabonyl-Val-Ala-Asp-fluoromethyl ketone (zVAD-FMK) has been used therapeutically to prevent apoptosis in experimental animal models of ischemic injury, autoimmunity, and degenerative disease. In the current study, zVAD-FMK therapy was examined in a syngeneic islet transplant model to determine whether caspase inhibition could improve survival of transplanted islets. zVAD-FMK therapy significantly improved marginal islet mass function in renal subcapsular transplantation, where 90% of zVAD-FMK-treated mice became euglycemic with 250 islets, versus 27% of the control animals (P < 0.001). The benefit of zVAD-FMK therapy was further demonstrated after intraportal transplantation, where 75% of zVAD-FMK-treated animals established euglycemia with only 500 islets, and all of the controls remained severely diabetic (P < 0.001). zVAD-FMK pretreatment of isolated islets in the absence of systemic therapy resulted in no significant benefit compared with controls. Long-term follow-up of transplanted animals beyond 1 year posttransplant using glucose tolerance tests confirmed that a short course of zVAD-FMK therapy could prevent metabolic dysfunction of islet grafts over time. In addition, short-term zVAD-FMK treatment significantly reduced posttransplant apoptosis in islet grafts and resulted in preservation of graft insulin reserve over time. Our data suggest that caspase inhibitor therapy will reduce the islet mass required in clinical islet transplantation, perhaps to a level that would routinely allow for insulin independence after single-donor infusion.
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270
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Rivas-Carrillo JD, Soto-Gutierrez A, Navarro-Alvarez N, Noguchi H, Okitsu T, Chen Y, Yuasa T, Tanaka K, Narushima M, Miki A, Misawa H, Tabata Y, Jun HS, Matsumoto S, Fox IJ, Tanaka N, Kobayashi N. Cell-permeable pentapeptide V5 inhibits apoptosis and enhances insulin secretion, allowing experimental single-donor islet transplantation in mice. Diabetes 2007; 56:1259-67. [PMID: 17287463 DOI: 10.2337/db06-1679] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
OBJECTIVE Treatment of diabetic patients by pancreatic islet transplantation often requires the use of islets from two to four donors to produce insulin independence in a single recipient. Following isolation and transplantation, islets are susceptible to apoptosis, which limits their function and probably long-term islet graft survival. RESEARCH DESIGN AND METHODS To address this issue, we examined the effect of the cell-permeable apoptosis inhibitor pentapeptide Val-Pro-Met-Leu-Lys, V5, on pancreatic islets in a mouse model. RESULTS V5 treatment upregulated expression of anti-apoptotic proteins Bcl-2 and XIAP (X-linked inhibitor of apoptosis protein) by more than 3- and 11-fold and downregulated expression of apoptosis-inducing proteins Bax, Bad, and nuclear factor-kappaB-p65 by 10, 30, and nearly 50%, respectively. Treatment improved the recovered islet mass following collagenase digestion and isolation by 44% and in vitro glucose-responsive insulin secretion nearly fourfold. Following transplantation in streptozotocin-induced diabetic mice, 150 V5-treated islet equivalents functioned as well as 450 control untreated islet equivalents in normalizing blood glucose. CONCLUSIONS These studies indicate that inhibition of apoptosis by V5 significantly improves islet function following isolation and improves islet graft function following transplantation. Use of this reagent in clinical islet transplantation could have a dramatic impact on the number of patients that might benefit from this therapy and could affect long-term graft survival.
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Affiliation(s)
- Jorge D Rivas-Carrillo
- Department of Surgery, Okayama University Graduate School of Medicine and Dentistry, Shikata-cho, Okayama, Japan
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271
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Balibrea del Castillo JM, Vara Ameigeiras E, Arias-Díaz J, García Martín MC, García-Pérez JC, Balibrea Cantero JL. Estado actual del trasplante de islotes pancreáticos. Cir Esp 2007; 81:177-91. [PMID: 17403353 DOI: 10.1016/s0009-739x(07)71297-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Due to the numerous advances in islet transplantation in the last few years, clinical outcomes following this procedure are continually improving. Novel immunosuppression protocols, improved donor and recipient selection, and careful attention to the process of organ extraction, preservation and islet isolation have contributed to long-term success. The present article reviews the results of clinical islet transplantation and their relationship with the different advances introduced. The use of new islet sources such as living and non-heart-beating donors, as well as recent advances in our knowledge of the mechanisms of rejection and its prevention, are also reviewed.
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272
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Téllez N, Montolio M, Estil-les E, Escoriza J, Soler J, Montanya E. Adenoviral overproduction of interleukin-1 receptor antagonist increases beta cell replication and mass in syngeneically transplanted islets, and improves metabolic outcome. Diabetologia 2007; 50:602-11. [PMID: 17221214 DOI: 10.1007/s00125-006-0548-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/31/2006] [Accepted: 10/18/2006] [Indexed: 01/27/2023]
Abstract
AIMS/HYPOTHESIS Interleukin-1 receptor antagonist (IL1RN, also known as IL1RA) is a naturally occurring inhibitor of IL-1 action and its overproduction protects pancreatic islets from the deleterious effects of IL-1beta on beta cell replication, apoptosis and function. The aim of this study was to determine whether viral gene transfer of the Il1rn gene into rat islets ex vivo had a beneficial effect on the outcome of the graft. MATERIALS AND METHODS Streptozotocin-diabetic Lewis rats were syngeneically transplanted with 500 or 800 Ad-Il1rn-infected or uninfected islets. Islet grafts were collected on day 3, 10 or 28 after transplantation and beta cell apoptosis, replication, size and mass were determined. RESULTS Animals transplanted with 500 islets remained hyperglycaemic throughout the follow-up, as expected. Beta cell replication increased in the Ad-Il1rn group on days 3, 10 and 28 after transplantation compared with normal pancreas. In uninfected islets, by contrast, beta cell replication was increased only on day 10. Beta cell apoptosis was increased in all transplanted groups; it was 25% lower in the Ad-Il1rn than in uninfected groups, but differences were not statistically significant. The initially transplanted beta cell mass was reduced on day 3, increasing subsequently in Ad-Il1rn grafts, but not in uninfected grafts. When 800 islets were transplanted, all animals grafted with Ad-Il1rn-infected islets, but only 40% of those transplanted with uninfected islets, achieved normoglycaemia 14 days after transplantation. CONCLUSIONS/INTERPRETATION Overproduction of IL1RN increased beta cell replication and mass of islet grafts and reduced the beta cell number required to achieve normoglycaemia.
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Affiliation(s)
- N Téllez
- Laboratory of Diabetes and Experimental Endocrinology, Department of Clinical Sciences, University of Barcelona, L'Hospitalet de Llobregat, Barcelona, Spain
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273
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Mathe Z, Dupraz P, Rinsch C, Thorens B, Bosco D, Zbinden M, Morel P, Berney T, Pepper MS. Tetracycline-regulated expression of VEGF-A in beta cells induces angiogenesis: improvement of engraftment following transplantation. Cell Transplant 2007; 15:621-36. [PMID: 17176614 DOI: 10.3727/000000006783981675] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Early revascularization of pancreatic islet cells after transplantation is crucial for engraftment, and it has been suggested that vascular endothelial growth factor-A (VEGF-A) plays a significant role in this process. Although VEGF gene therapy can improve angiogenesis, uncontrolled VEGF secretion can lead to vascular tumor formation. Here we have explored the role of temporal VEGF expression, controlled by a tetracycline (TC)-regulated promoter, on revascularization and engraftment of genetically modified beta cells following transplantation. To this end, we modified the CDM3D beta cell line using a lentiviral vector to promote secretion of VEGF-A either in a TC-regulated (TET cells) or a constitutive (PGK cells) manner. VEGF secretion, angiogenesis, cell proliferation, and stimulated insulin secretion were assessed in vitro. VEGF secretion was increased in TET and PGK cells, and VEGF delivery resulted in angiogenesis, whereas addition of TC inhibited these processes. Insulin secretion by the three cell types was similar. We used a syngeneic mouse model of transplantation to assess the effects of this controlled VEGF expression in vivo. Time to normoglycemia, intraperitoneal glucose tolerance test, graft vascular density, and cellular mass were evaluated. Increased expression of VEGF resulted in significantly better revascularization and engraftment after transplantation when compared to control cells. In vivo, there was a significant increase in vascular density in grafted TET and PGK cells versus control cells. Moreover, the time for diabetic mice to return to normoglycemia and the stimulated plasma glucose clearance were also significantly accelerated in mice transplanted with TET and PGK cells when compared to control cells. VEGF was only needed during the first 2-3 weeks after transplantation; when removed, normoglycemia and graft vascularization were maintained. TC-treated mice grafted with TC-treated cells failed to restore normoglycemia. This approach allowed us to switch off VEGF secretion when the desired effects had been achieved. TC-regulated temporal expression of VEGF using a gene therapy approach presents a novel way to improve early revascularization and engraftment after islet cell transplantation.
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Affiliation(s)
- Zoltan Mathe
- Transplantation and Surgical Department, Semmelweis University, Budapest, H-1089, Hungary
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274
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Huang Q, Bu S, Yu Y, Guo Z, Ghatnekar G, Bu M, Yang L, Lu B, Feng Z, Liu S, Wang F. Diazoxide prevents diabetes through inhibiting pancreatic beta-cells from apoptosis via Bcl-2/Bax rate and p38-beta mitogen-activated protein kinase. Endocrinology 2007; 148:81-91. [PMID: 17053028 DOI: 10.1210/en.2006-0738] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Increased apoptosis of pancreatic beta-cells plays an important role in the occurrence and development of type 2 diabetes. We examined the effect of diazoxide on pancreatic beta-cell apoptosis and its potential mechanism in Otsuka Long Evans Tokushima Fatty (OLETF) rats, an established animal model of human type 2 diabetes, at the prediabetic and diabetic stages. We found a significant increase with age in the frequency of apoptosis, the sequential enlargement of islets, and the proliferation of the connective tissue surrounding islets, accompanied with defective insulin secretory capacity and increased blood glucose in untreated OLETF rats. In contrast, diazoxide treatment (25 mg.kg(-1).d(-1), administered ip) inhibited beta-cell apoptosis, ameliorated changes of islet morphology and insulin secretory function, and increased insulin stores significantly in islet beta-cells whether diazoxide was used at the prediabetic or diabetic stage. Linear regression showed the close correlation between the frequency of apoptosis and hyperglycemia (r = 0.913; P < 0.0001). Further study demonstrated that diazoxide up-regulated Bcl-2 expression and p38beta MAPK, which expressed at very low levels due to the high glucose, but not c-jun N-terminal kinase and ERK. Hence, diazoxide may play a critical role in protection from apoptosis. In this study, we demonstrate that diazoxide prevents the onset and development of diabetes in OLETF rats by inhibiting beta-cell apoptosis via increasing p38beta MAPK, elevating Bcl-2/Bax ratio, and ameliorating insulin secretory capacity and action.
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Affiliation(s)
- Qin Huang
- Department of Endocrinology, Changhai Hospital, Shanghai 200433, People's Republic of China.
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275
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Lu Y, Dang H, Middleton B, Campbell-Thompson M, Atkinson MA, Gambhir SS, Tian J, Kaufman DL. Long-Term Monitoring of Transplanted Islets Using Positron Emission Tomography. Mol Ther 2006; 14:851-6. [PMID: 16982215 DOI: 10.1016/j.ymthe.2006.08.007] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2006] [Revised: 08/03/2006] [Accepted: 08/17/2006] [Indexed: 02/05/2023] Open
Abstract
Islet transplantation can restore glucose homeostasis in those with type 1 diabetes; however, most recipients eventually lose graft function. A noninvasive method to monitor islets following transplantation would enable assessment of their survival and aid the development of therapeutics to prolong graft survival. Here, we show that recombinant lentivirus can be used to engineer human islets to express a positron emission tomography (PET) reporter gene. Following transplantation into mice, transduced islets could be imaged in vivo using microPET and a radiolabeled probe approved by the FDA for clinical use in humans. The magnitude of signal from engineered islets implanted into the axillary cavity reflected the implanted islet mass. Signals from implanted islets decreased by approximately one-half during the first few weeks following transplantation, which may reflect islet cell death shortly after transplantation. Thereafter, the magnitude of signals from the implanted islets remained fairly constant when the recipients were repetitively reimaged over 90 days. Histological analysis of the implants showed healthy islets with PET reporter-expressing cells distributed throughout the islet architecture. These studies suggest that PET imaging of lentivirus-transduced islets could provide a safe and feasible method for long-term monitoring of islet graft survival.
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Affiliation(s)
- Yuxin Lu
- Department of Molecular and Medical Pharmacology, University of California at Los Angeles School of Medicine, Los Angeles, CA 90095-1735, USA
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276
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Hsu BRS, Chen ST, Fu SH. Enhancing engraftment of islets using perioperative sodium 4-phenylbutyrate. Int Immunopharmacol 2006; 6:1952-9. [DOI: 10.1016/j.intimp.2006.09.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2006] [Accepted: 09/15/2006] [Indexed: 01/22/2023]
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277
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Kim WH, Lee JW, Suh YH, Lee HJ, Lee SH, Oh YK, Gao B, Jung MH. AICAR potentiates ROS production induced by chronic high glucose: roles of AMPK in pancreatic beta-cell apoptosis. Cell Signal 2006; 19:791-805. [PMID: 17127032 DOI: 10.1016/j.cellsig.2006.10.004] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2006] [Accepted: 10/09/2006] [Indexed: 12/19/2022]
Abstract
We previously demonstrated that chronic high glucose (33.3 mM) induced beta-cell dysfunction and apoptosis through glucokinase (GCK) downregulation, but the exact mechanisms involved remain unclear. Here, we show that prolonged exposure of 5-aminoimidazole-4-carboxamide (AICA)-riboside potentiated apoptosis induced by high glucose in MIN6N8 pancreatic beta-cells, correlating with enhanced GCK downregulation and decreased production of ATP and insulin. These events are potentiated in AMPK-overexpressing cells, but are prevented in cells transfected with mutant dominant-negative AMPK (AMPK-K45R). Furthermore, AMPK activation increases production of reactive oxygen species (ROS) and loss of mitochondria membrane potential induced by high glucose, which is significantly inhibited by treatment with compound C or by AMPK-K45R overexpression. Overexpression of GCK prevents apoptosis; decreased cellular ATP and insulin secretion, and ROS production enhanced by AICAR, but does not affect AMPK activation. Similar results are obtained using isolated primary islet cells. Collectively, these data demonstrate that AMPK activation potentiates beta-cell apoptosis induced by chronic high glucose through augmented GCK downregulation mediated by enhanced ROS production.
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Affiliation(s)
- Won-Ho Kim
- Division of Metabolic Diseases, Center for Biomedical Sciences, National Institutes of Health, 194 Tongillo, Eunpyeong-Gu, Seoul, South Korea
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278
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Emamaullee JA, Shapiro AMJ, Rajotte RV, Korbutt G, Elliott JF. Neonatal porcine islets exhibit natural resistance to hypoxia-induced apoptosis. Transplantation 2006; 82:945-52. [PMID: 17038911 DOI: 10.1097/01.tp.0000238677.00750.32] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND Despite the success of the Edmonton protocol for human islet transplantation, an alternate source of islet tissue must be developed if beta-cell replacement therapy is to see widespread application. Neonatal porcine islets (NPI) represent one potential source of tissue. When human or rodent islets are transplanted, the majority of cells undergo hypoxia-induce apoptosis soon after the grafts are placed in the recipient. In the present study, we investigated whether NPI were similarly sensitive to hypoxia. METHODS NPI were exposed to hypoxia and hypoxia/reoxygenation using an in vitro hypoxic chamber. Afterwards, viability, frequency of apoptosis, and beta-cell function were evaluated. NPI and adult porcine islets were transplanted into chemically diabetic, immunodeficient mice and graft apoptosis was assessed 24 hours and seven days posttransplant. RESULTS NPI demonstrated a remarkable capacity to resist apoptosis and maintain insulin secretion despite severe stresses such as hypoxia/reoxygenation. One day after transplantation, NPI grafts showed limited apoptosis, confined to rare strongly insulin positive cells. In contrast, adult porcine islet grafts underwent widespread apoptosis. Western blotting revealed that NPI express high levels of at least one potent endogenous antiapoptotic protein (XIAP). CONCLUSIONS The majority of cells within transplanted human islets undergo apoptosis soon after portal infusion. In contrast, NPI have the capacity to resist this early posttransplant apoptosis, with likely reduced antigen release and diminished immune stimulation. NPI appear to contain a population of insulin-low to insulin-negative pre-beta-cells, which are resistant to hypoxia-induced apoptosis and still capable of differentiating into mature beta-cells.
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Affiliation(s)
- Juliet A Emamaullee
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta, Canada
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279
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Protection of human islets from induction of apoptosis and improved islet function with HO-1 gene transduction. Chin Med J (Engl) 2006. [DOI: 10.1097/00029330-200610010-00008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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280
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Li Y, Li G, Dong W, Chen J, Lu D, Tan J. Transplantation of rat islets transduced with human heme oxygenase-1 gene using adenovirus vector. Pancreas 2006; 33:280-6. [PMID: 17003650 DOI: 10.1097/01.mpa.0000236735.39241.d0] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/10/2022]
Abstract
OBJECTIVE To investigate whether human heme oxygenase-1 (HO-1) gene has protective action on islets cultured in vitro, and to explore whether transduction of HO-1 gene to donor islets could enhance engrafted islets survival and suppress local lymphocytic infiltration in islet grafts. METHODS Newly isolated rat islets were isolated from the Sprague-Dawley rats and were divided into 3 groups in vitro study as follows: enhanced green fluorescent protein (EGFP) group, islets transduced with adenovirus vectors containing EGFP gene using multiplicities of infection (MOI) = 2, 5, 10, and 20 to determine the transduction efficacy; HO-1 group, islets transduced with adenovirus vectors containing human HO-1 gene using MOI = 20; and control group, mock transduced islets. Flow cytometry was used to detect apoptotic cells after induction by recombinant human tumor necrosis factor-alpha (rTNF-alpha) and cycloheximide (CHX) for 48 hours. Diabetic recipients were randomly divided into the following groups: HO-1 group (n = 9), receiving islets transduced with recombinant adenovirus-HO-1; control group (n = 9), receiving mock transduced islets; and phosphate buffer solution (PBS) group (n = 6), receiving only 0.8 mL PBS. About 1200 rat islet equivalents were transplanted into each recipient rendered by streptozotocin using the portal vein as transplant site. Allograft survival, apoptosis, and the state of lymphocytic infiltration were analyzed. RESULTS After treatment with rTNF-alpha and CHX, the apoptotic ratio of islet cells was 4.22% +/- 2.38% in the HO-1 group (MOI = 20), significantly lower than 23.81% +/- 8.51% in the control group (P < 0.05), and 28.76% +/- 14.76% in the EGFP group (MOI = 20; P < 0.05). Maintenance of normoglycemia was prolonged in the HO-1 group, indicated by results that islet survival time was 10.56 +/- 4.33 days significantly longer than that of untreated islets which was 5.33 +/- 4.18 days (P < 0.05). The lymphocytic infiltration degree in engrafted islets treated with HO-1 gene was lower than that in the control group. CONCLUSIONS HO-1 gene overexpression in rat islets by adenovirus transduction can protect cultured islets against rTNF-alpha and CHX-mediated cytotoxicity. HO-1 gene has cytoprotective effects on engrafted islets, which could prolong engrafted islets survival in allogenic transplantation model, and diminish the degree of lymphocytic infiltration in islet grafts. These findings suggest a potential therapeutic application for HO-1 gene in improving islet survival/function in human islet transplantation.
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Affiliation(s)
- Yongxiang Li
- Department of Urology and Center of Renal Transplantation, Shanghai Organ Transplant and Research Center, Shanghai First People's Hospital, China.
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281
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Evgenov NV, Medarova Z, Pratt J, Pantazopoulos P, Leyting S, Bonner-Weir S, Moore A. In vivo imaging of immune rejection in transplanted pancreatic islets. Diabetes 2006; 55:2419-28. [PMID: 16936189 DOI: 10.2337/db06-0484] [Citation(s) in RCA: 140] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
As islet transplantation becomes an acceptable clinical modality for restoring normoglycemia in type 1 diabetic patients, there is a crucial need for noninvasive assessment of the fate of the grafts. In spite of the success of the Edmonton Protocol, a significant graft loss occurs due to immunological and nonimmunological events immediately after transplantation. Allogeneic rejection in graft recipients is one of the major reasons for islet death and graft failure. Therefore, monitoring the islet rejection using reliable noninvasive methods would significantly aid in clinical assessment of graft success. We have previously developed a method to detect transplanted islets noninvasively using magnetic resonance imaging (MRI). For this procedure, human pancreatic islets are labeled with an MRI contrast agent that enables their visualization on magnetic resonance images. In our present study, we not only detected labeled human islets in a preclinical intrahepatic model of human islet transplantation in mice but also showed that islet rejection can be monitored noninvasively and repeatedly in real time by MRI. In addition, in this study, we have adapted, for islet cell labeling, a Food and Drug Administration-approved commercially available contrast agent, Feridex, that is used clinically for liver imaging. We believe that this agent, in combination with our preclinical model of islet transplantation, will facilitate the transition of imaging immune rejection to clinical trials.
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Affiliation(s)
- Natalia V Evgenov
- Molecular Imaging Laboratory, Department of Radiology, Massachusetts General Hospital/Massachusetts Institute of Technology/Harvard Medical School, Charlestown, MA 02129, USA
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282
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Wideman RD, Yu ILY, Webber TD, Verchere CB, Johnson JD, Cheung AT, Kieffer TJ. Improving function and survival of pancreatic islets by endogenous production of glucagon-like peptide 1 (GLP-1). Proc Natl Acad Sci U S A 2006; 103:13468-73. [PMID: 16938896 PMCID: PMC1569187 DOI: 10.1073/pnas.0600655103] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Glucagon-like peptide 1 (GLP-1) is a hormone that has received significant attention as a therapy for diabetes because of its ability to stimulate insulin biosynthesis and release and to promote growth and survival of insulin-producing beta cells. While GLP-1 is produced from the proglucagon precursor by means of prohormone convertase (PC) 1/3 activity in enteroendocrine L cells, the same precursor is differentially processed by PC2 in pancreatic islet alpha cells to release glucagon, leaving GLP-1 trapped within a larger fragment with no known function. We hypothesized that we could induce GLP-1 production directly within pancreatic islets by means of delivery of PC1/3 and, further, that this intervention would improve the viability and function of islets. Here, we show that adenovirus-mediated expression of PC1/3 in alpha cells increases islet GLP-1 secretion, resulting in improved glucose-stimulated insulin secretion and enhanced survival in response to cytokine treatment. PC1/3 expression in alpha cells also improved performance after islet transplantation in a mouse model of type 1 diabetes, possibly by enhancing nuclear Pdx1 and insulin content of islet beta cells. These results demonstrate a unique strategy for liberating GLP-1 from directly within the target organ and highlight the potential for up-regulating islet GLP-1 production as a means of treating diabetes.
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Affiliation(s)
- Rhonda D. Wideman
- Laboratories of *Molecular and Cellular Medicine and
- Cellular and Physiological Sciences and
| | - Irene L. Y. Yu
- Laboratories of *Molecular and Cellular Medicine and
- Cellular and Physiological Sciences and
| | - Travis D. Webber
- Laboratories of *Molecular and Cellular Medicine and
- Cellular and Physiological Sciences and
| | - C. Bruce Verchere
- Department of Pathology and Laboratory Medicine, Child and Family Research Institute, University of British Columbia, Room 3084, 950 West 28th Avenue, Vancouver, BC, Canada V5Z 4H4; and
| | - James D. Johnson
- Molecular Signaling in Diabetes and Departments of
- Cellular and Physiological Sciences and
- Surgery, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
| | | | - Timothy J. Kieffer
- Laboratories of *Molecular and Cellular Medicine and
- Cellular and Physiological Sciences and
- Surgery, Life Sciences Institute, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC, Canada V6T 1Z3
- **To whom correspondence should be addressed. E-mail:
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Abstract
DM (diabetes mellitus) is a metabolic disorder of either absolute or relative insulin deficiency. Optimized insulin injections remain the mainstay life-sustaining therapy for patients with T1DM (Type I DM) in 2006; however, a small subset of patients with T1DM (approx. 10%) are exquisitely sensitive to insulin and lack counter-regulatory measures, putting them at higher risk of neuroglycopenia. One alternative strategy to injected insulin therapy is pancreatic islet transplantation. Islet transplantation came of age when Paul E. Lacy successfully reversed chemical diabetes in rodent models in 1972. In a landmark study published in 2000, Shapiro et al. [A. M. Shapiro, J. R. Lakey, E. A. Ryan, G. S. Korbutt, E. Toth, G. L. Warnock, N. M. Kneteman and R. V. Rajotte (2000) N. Engl. J. Med. 343, 230-238] reported seven consecutive patients treated with islet transplants under the Edmonton protocol, all of whom maintained insulin independence out to 1 year. Substantial progress has occurred in aspects of pancreas procurement, transportation (using the oxygenated two-layer method) and in islet isolation (with controlled enzymatic perfusion and subsequent digestion in the Ricordi chamber). Clinical protocols to optimize islet survival and function post-transplantation improved dramatically with the introduction of the Edmonton protocol, but it is clear that this approach still has potential limitations. Newer pharmacotherapies and interventions designed to promote islet survival, prevent apoptosis, to promote islet growth and to protect islets in the long run from immunological injury are rapidly approaching clinical trials, and it seems likely that clinical outcomes of islet transplantation will continue to improve at the current exponential pace.
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Affiliation(s)
- Shaheed Merani
- Clinical Islet Transplant Program, University of Alberta, Roberts Centre, 2000 College Plaza, Edmonton, Alberta, Canada T6G 2C8
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284
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Olsson R, Maxhuni A, Carlsson PO. Revascularization of Transplanted Pancreatic Islets Following Culture with Stimulators of Angiogenesis. Transplantation 2006; 82:340-7. [PMID: 16906031 DOI: 10.1097/01.tp.0000229418.60236.87] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Insufficient revascularization of transplanted islets may result in chronic hypoxia and loss of islet function. This study investigated whether simple culture of islets with angiogenic substances before transplantation could improve graft revascularization. METHODS Mouse islets were cultured with vascular endothelial growth factor (VEGF; 20 ng/ml), fibroblast growth factor 2 (FGF-2; 20 ng/ml) or matrix metalloproteinase 9 (MMP-9; 1 mug/ml). Thereafter, 250 islets were implanted beneath the renal capsule of syngeneic C57Bl/6 mice. One month posttransplantation, blood flow (laser-Doppler flowmetry), oxygen tension (Clark microelectrodes), and vascular density were measured and correlated to graft function. RESULTS Treatment of islets with VEGF during culture caused islet blood vessels to dilate, whereas FGF-2 treatment induced endothelial cell proliferation. However, the number of capillaries in both cases decreased during culture. When investigated one month posttransplantation, both VEGF and FGF-2 pretreated islets had similar or worse vascular engraftment when compared to transplanted control islets. MMP-9 pretreatment of islets increased vascular density, blood flow and oxygen tension within the grafts. Animals receiving MMP-9 pretreated islets returned, however, more slowly to normoglycemia than control animals, and performed worse than controls in a glucose tolerance test one month posttransplantation. CONCLUSIONS Treatment of islets during culture with VEGF or FGF-2 changed the islet vascular phenotype, but capillaries were still lost. Notably, the number of capillaries in the grafted islets one month posttransplantation was in all cases strikingly similar to that observed prior to transplantation. MMP-9 pretreatment of islets elicited an angiogenic response, which improved revascularization of the transplanted islets.
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Affiliation(s)
- Richard Olsson
- Department of Medical Cell Biology, Uppsala University, Sweden.
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285
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Chen X, Zhang X, Larson CS, Baker MS, Kaufman DB. In vivo bioluminescence imaging of transplanted islets and early detection of graft rejection. Transplantation 2006; 81:1421-7. [PMID: 16732180 DOI: 10.1097/01.tp.0000206109.71181.bf] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
BACKGROUND Bioluminescence imaging (BLI) modalities are being developed to monitor islet transplant mass and function in vivo. The aim of this study was to use the BLI system to determine how the change in functional islet mass correlated to metabolic abnormalities during the course of alloimmune rejection in a murine transplant model. METHODS Islets obtained from a transgenic mouse strain (FVB/NJ-luc) that constitutively expressed firefly luciferase were transplanted to various implantation sites of syngeneic wild-type FVB/NJ or allogeneic Balb/C streptozotocin-induced diabetic recipients. In vivo graft luminescent signals were repeatedly measured after transplantation using the BLI system and related to blood glucose levels and graft site histologic findings. RESULTS The BLI signals were detected in as few as 10 islets implanted in the renal subcapsular space, intrahepatic, intraabdominal, and subcutaneous locations. There was a linear relationship between the number of islets transplanted and luminescence intensity. In isografts, stable luminescence intensity signals occurred within 2 weeks of transplantation and remained consistent on a long-term basis (18 months) after transplantation. In allografts, after normoglycemia was achieved and stable luminescence intensity occurred, graft bioluminescent intensity progressively decreased several days before permanent recurrence of hyperglycemia as a result of histologically proven rejection ensued. CONCLUSIONS Bioluminescence imaging is a sensitive method for tracking the fate of islets after transplantation and is a useful method to detect early loss of functional islet mass caused by host immune responses even before overt metabolic dysfunction is evident. Bioluminescence imaging holds promise for use in designing and testing interventions to prolong islet graft survival.
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Affiliation(s)
- Xiaojuan Chen
- Department of Surgery, Division of Organ Transplantation, Feinberg School of Medicine, Northwestern University, Chicago, IL 60611, USA
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286
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Emamaullee JA, Shapiro AMJ. Interventional strategies to prevent beta-cell apoptosis in islet transplantation. Diabetes 2006; 55:1907-14. [PMID: 16804057 DOI: 10.2337/db05-1254] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
A substantial proportion of the transplanted islet mass fails to engraft due to death by apoptosis, and a number of strategies have been explored to inhibit beta-cell loss. Inhibition of extrinsic signals of apoptosis (i.e., cFLIP or A20) have been explored in experimental islet transplantation but have only shown limited impact. Similarly, strategies targeted at intrinsic signal inhibition (i.e., BCL-2) have not yet provided substantial improvement in islet engraftment. Recently, investigation of downstream apoptosis inhibitors that block the final common pathway (i.e., X-linked inhibitor of apoptosis protein [XIAP]) have demonstrated promise in both human and rodent models of engraftment. In addition, XIAP has enhanced long-term murine islet allograft survival. The complexities of both intrinsic and extrinsic apoptotic pathway inhibition are discussed in depth.
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Affiliation(s)
- Juliet A Emamaullee
- Surgical Medical Research Institute, University of Alberta, Edmonton, AB T6G 2N8.
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287
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Narang AS, Mahato RI. Biological and Biomaterial Approaches for Improved Islet Transplantation. Pharmacol Rev 2006; 58:194-243. [PMID: 16714486 DOI: 10.1124/pr.58.2.6] [Citation(s) in RCA: 137] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Islet transplantation may be used to treat type I diabetes. Despite tremendous progress in islet isolation, culture, and preservation, the clinical use of this modality of treatment is limited due to post-transplantation challenges to the islets such as the failure to revascularize and immune destruction of the islet graft. In addition, the need for lifelong strong immunosuppressing agents restricts the use of this option to a limited subset of patients, which is further restricted by the unmet need for large numbers of islets. Inadequate islet supply issues are being addressed by regeneration therapy and xenotransplantation. Various strategies are being tried to prevent beta-cell death, including immunoisolation using semipermeable biocompatible polymeric capsules and induction of immune tolerance. Genetic modification of islets promises to complement all these strategies toward the success of islet transplantation. Furthermore, synergistic application of more than one strategy is required for improving the success of islet transplantation. This review will critically address various insights developed in each individual strategy and for multipronged approaches, which will be helpful in achieving better outcomes.
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Affiliation(s)
- Ajit S Narang
- Department of Pharmaceutical Sciences, University of Tennessee Health Science Center, 26 S. Dunlap St., Feurt Building, Room 413, Memphis, TN 38163, USA
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288
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Abstract
Heme oxygenase-1 (HO-1) has been described as a protein capable of cytoprotection via radical scavenging and apoptosis prevention. The aim of this study was to analyze whether HO-1 overexpression in freshly isolated murine transgenic islets resulted in cell protection and improved in vivo functional performance after transplantation. We produced transgenic mice in which the human HO-1 transgene driven by chicken beta-actin promoter was expressed in the heart, liver, spleen, lung, kidney, muscle, intestine, and pancreas in Balb/c mice. One hundred fifty islets isolated from HO-1 transgenic and control Balb/c mice were syngeneically transplanted under the left kidney capsule of the streptozotocin-diabetic Balb/c mice. The recipients who underwent transplantation with HO-1 transgenic islets showed higher blood glucose than those with control islets at 4 weeks (320 +/- 25 vs 189 +/- 43 mg/dL; P < .05). Body weight was not significantly different between the 2 groups. Our data indicate transgenic islets with high HO-1 expression did not improve transplantation outcome.
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Affiliation(s)
- C-F Tu
- Division of Biotechnology, Animal Technology Institute Taiwan, Miaoli, Taiwan
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289
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Ortis F, Cardozo AK, Crispim D, Störling J, Mandrup-Poulsen T, Eizirik DL. Cytokine-induced proapoptotic gene expression in insulin-producing cells is related to rapid, sustained, and nonoscillatory nuclear factor-kappaB activation. Mol Endocrinol 2006; 20:1867-79. [PMID: 16556731 DOI: 10.1210/me.2005-0268] [Citation(s) in RCA: 107] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Cytokines, such as IL-1beta and TNF-alpha, contribute to pancreatic beta-cell death in type 1 diabetes mellitus. The transcription factor nuclear factor-kappaB (NF-kappaB) mediates cytokine-induced beta-cell apoptosis. Paradoxically, NF-kappaB has mostly antiapoptotic effects in other cell types. The cellular actions of NF-kappaB depend on the cell type, the nature and duration of the stimulus, the periodicity, and the degree of activity of the particular dimers involved. To clarify the reasons behind the proapoptotic effects of NF-kappaB in pancreatic beta-cells, we compared the pattern of cytokine-induced NF-kappaB activation between rat insulin-producing cells (INS-1E cells) and fibroblasts (208F cells). NF-kappaB activation was induced in INS-1E cells and in 208F cells after exposure to cytokines, but apoptosis was induced only in INS-1E cells, with a more pronounced proapoptotic effect of IL-1beta than of TNF-alpha. NF-kappaB activation in IL-1beta-exposed INS-1E cells was earlier and more marked as compared with TNF-alpha-exposed INS-1E cells or IL-1beta-exposed 208F cells. Both cytokines induced a prolonged (up to 48 h) and stable NF-kappaB activation in INS-1E cells, whereas IL-1beta induced an oscillatory NF-kappaB activation in 208F cells. p65/p65 and p65/p50 were the predominant NF-kappaB dimers in IL-1beta-exposed INS-1E cells and 208F cells, respectively. IL-1beta induced a differential usage of cis-elements in the inducible nitric oxide synthase promoter region in the two cell-lines and an increase in ERK1/2 activity in INS-1E cells but not in 208F cells. Cytokine-induced expression of IkappaB isoforms and other NF-kappaB target genes (Fas, MCP-1, and inducible nitric oxide synthase) was severalfold higher in INS-1E cells than in 208F cells. These results suggest that cytokine-induced NF-kappaB activation in insulin-producing cells is more rapid, marked, and sustained than in fibroblasts, which correlates with a more pronounced activation of downstream genes and a proapoptotic outcome.
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Affiliation(s)
- Fernanda Ortis
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, Brussels, Belgium
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290
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Finzi G, Davalli A, Placidi C, Usellini L, La Rosa S, Folli F, Capella C. Morphological and ultrastructural features of human islet grafts performed in diabetic nude mice. Ultrastruct Pathol 2006; 29:525-33. [PMID: 16316953 DOI: 10.1080/01913120500323563] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Islet transplantation is a new therapeutic approach to type 1 diabetes mellitus. However, in several patients insulin levels are not restored and the glycemic control is inadequate. To clarify the cause of graft failure, the authors investigated with light and electron microscopy some human islet grafts before and after transplantation under the kidney capsule of streptozotocin-induced diabetic nude mice. In isolated islets, both pre- and post-transplantation, the endocrine component was scarcely represented, the beta/alpha cell ratio was reduced, and beta cells showed degenerative aspects such as apoptosis, immature secretory granules, and amylin fibrils deposition. The authors conclude that islet graft failure may be due to an insufficient beta cell mass related to their distress probably caused by anoxia and/or overstimulation.
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Affiliation(s)
- Giovanna Finzi
- Department of Pathology, Ospedale di Circolo, Varese, Italy.
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291
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Magnusson NE, Cardozo AK, Kruhøffer M, Eizirik DL, Ørntoft TF, Jensen JL. Construction and validation of the APOCHIP, a spotted oligo-microarray for the study of beta-cell apoptosis. BMC Bioinformatics 2005; 6:311. [PMID: 16384535 PMCID: PMC1368999 DOI: 10.1186/1471-2105-6-311] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2005] [Accepted: 12/29/2005] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Type 1 diabetes mellitus (T1DM) is a autoimmune disease caused by a long-term negative balance between immune-mediated beta-cell damage and beta-cell repair/regeneration. Following immune-mediated damage the beta-cell fate depends on several genes up- or down-regulated in parallel and/or sequentially. Based on the information obtained by the analysis of several microarray experiments of beta-cells exposed to pro-apoptotic conditions (e.g. double stranded RNA (dsRNA) and cytokines), we have developed a spotted rat oligonucleotide microarray, the APOCHIP, containing 60-mer probes for 574 genes selected for the study of beta-cell apoptosis. RESULTS The APOCHIP was validated by a combination of approaches. First we performed an internal validation of the spotted probes based on a weighted linear regression model using dilution series experiments. Second we profiled expression measurements in ten dissimilar rat RNA samples for 515 genes that were represented on both the spotted oligonucleotide collection and on the in situ-synthesized 25-mer arrays (Affymetrix GeneChips). Internal validation showed that most of the spotted probes displayed a pattern of reaction close to that predicted by the model. By using simple rules for comparison of data between platforms we found strong correlations (rmedian= 0.84) between relative gene expression measurements made with spotted probes and in situ-synthesized 25-mer probe sets. CONCLUSION In conclusion our data suggest that there is a high reproducibility of the APOCHIP in terms of technical replication and that relative gene expression measurements obtained with the APOCHIP compare well to the Affymetrix GeneChip. The APOCHIP is available to the scientific community and is a useful tool to study the molecular mechanisms regulating beta-cell apoptosis.
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Affiliation(s)
- Nils E Magnusson
- Molecular Diagnostic Laboratory, Department of Clinical Biochemistry, Aarhus University Hospital, Denmark
| | - Alessandra K Cardozo
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, B-1070 Brussels, Belgium
| | - Mogens Kruhøffer
- Molecular Diagnostic Laboratory, Department of Clinical Biochemistry, Aarhus University Hospital, Denmark
| | - Decio L Eizirik
- Laboratory of Experimental Medicine, Université Libre de Bruxelles, B-1070 Brussels, Belgium
| | - Torben F Ørntoft
- Molecular Diagnostic Laboratory, Department of Clinical Biochemistry, Aarhus University Hospital, Denmark
| | - Jens L Jensen
- Molecular Diagnostic Laboratory, Department of Clinical Biochemistry, Aarhus University Hospital, Denmark
- Department of Theoretical Statistics, Department of Mathematical Sciences, Aarhus University, Denmark
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292
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Bogdani M, Suenens K, Bock T, Pipeleers-Marichal M, In't Veld P, Pipeleers D. Growth and functional maturation of beta-cells in implants of endocrine cells purified from prenatal porcine pancreas. Diabetes 2005; 54:3387-94. [PMID: 16306353 DOI: 10.2337/diabetes.54.12.3387] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The development of islet cell transplantation as a cure for diabetes is limited by the shortage of human donor organs. Moreover, currently used grafts exhibit a marginal beta-cell mass with an apparently low capacity for beta-cell renewal and growth. Although duct-associated nonendocrine cells have often been suggested as a potential source for beta-cell production, recent work in mice has demonstrated the role of beta-cells in postnatal growth of the pancreatic beta-cell mass. The present study investigated whether the beta-cell mass can grow in implants that are virtually devoid of nonendocrine cells. Endocrine islet cells were purified from prenatal porcine pancreases (gestation >110 days) and implanted under the kidney capsule of nude mice. beta-Cells initially presented with signs of immaturity: small size, low insulin content, undetectable C-peptide release, and an inability to correct hyperglycemia. They exhibited a proliferative activity that was highest during posttransplant week 1 (2.6 and 5% bromodeoxyuridine [BrdU]-positive beta-cells 4 and 72 h posttransplant) and then decreased over 20 weeks to rates measured in the pancreas (0.2% BrdU-positive cells). beta-Cell proliferation in implants first compensated for beta-cell loss during posttransplant week 1 and then increased the beta-cell number fourfold between posttransplant weeks 1 and 20. Rates of alpha-cell proliferation were only shortly and moderately increased, which explained the shift in cellular composition of the implant (beta-cell 40 vs. 90% and alpha-cell 40 vs. 7% at the start and posttransplant week 20, respectively). beta-Cells progressively matured during the 20 weeks after transplantation, with a twofold increase in cell volume, a sixfold increase in cellular insulin content, plasma C-peptide levels of 1-2 ng/ml, and an ability to correct diabetes. They became structurally organized as homogenous clusters with their secretory vesicles polarized toward fenestrated capillaries. We concluded that the immature beta-cell phenotype provides grafts with a marked potential for beta-cell growth and differentiation and hence may have a potential role in curing diabetes. Cells with this phenotype can be isolated from prenatal organs; their presence in postnatal organs needs to be investigated.
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Affiliation(s)
- Marika Bogdani
- Diabetes Research Center, Brussels Free University (VUB), Laarbeeklaan 103, 1090 Brussels, Belgium
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293
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Abstract
To solve the problems of islet engraftment, we investigated the effects of insulin sensitizers, metformin and rosiglitazone, on the in vitro and in vivo function of mouse islets. The in vitro study was done by culturing 30 isolated C57BL/6 mouse islets with glucose (100 or 300 mg/dL) or rosiglitazone (4.5 mumol/L) for 2, 4, 8, or 12 hours. The in vivo study was performed by syngeneically transplanting 150 C57BL/6 mouse islets under the kidney capsule of streptozotocin-diabetic mice. The metformin group was treated with 200 mg/kg/d in water and the control group was pair-fed the same volume of liquid diet. In the in vitro study, insulin release stimulated by 300 mg/dL glucose (n = 6) was the highest at all time points. That stimulated by rosiglitazone (n = 6) was greater than by 100 mg/dL glucose (n = 6) only at 8 hours. In the recipients treated with metformin (n = 17) and controls (n = 13), the blood glucose decreased and body weight increased gradually after transplantation. However, there was no significant difference between the two groups. Their tolerance to intraperitoneal glucose challenge at 2 and 4 weeks was also comparable. At 4 weeks, 12/17 (71%) in the metformin group and 8/13 (62%) in the control group achieved normoglycemia (P = .60). At 4 weeks, the insulin content of the graft was 8.35 +/- 3.42 mg in the metformin group and 5.28 +/- 4.28 mg in the control group (P = .59). Our data indicate that (1) rosiglitazone stimulated isolated islets to release insulin but was less effective than high levels of glucose; and (2) metformin treatment had no beneficial effect on islet recipients.
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Affiliation(s)
- J-H Juang
- Division of Endocrinology and Metabolism, Department of Internal Medicine, Chang Gung Memorial Hospital, 5 Fu-Shin Street, Taoyuan, Taiwan.
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294
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Jones GL, Juszczak MT, Hughes SJ, Powis SH, Press M. An Improved Method of Fluorescent Dual Insulin and Endothelial Staining Allows Visualisation of the Revascularisation of Intraportally Transplanted Islets. Transplant Proc 2005; 37:3509-11. [PMID: 16298644 DOI: 10.1016/j.transproceed.2005.09.137] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
BACKGROUND Intraportally transplanted islets are avascular at the time of transplantation and take up to 14 days to fully revascularize, during which time up to 60% of islet mass may be lost. To investigate and improve islet revascularization, a robust method for the visualization and quantification of this process is required. METHODS Islets isolated from Lewis rats were transplanted intraportally into the liver of diabetic syngeneic Lewis recipients. The animals were humanely killed either on the day of transplant or at 3, 5, 7, or 14 days posttransplant. The harvested livers were sectioned and stained with Bandeiraea simplicifolia lectin (for endothelial cells) and anti-insulin antibody and counterstained with DAPI. The slides were visualized with a fluorescent microscope. RESULTS Islets were visualized over the whole time course. Insulin and endothelial staining was clearly visualized on the day of transplantation, but by day 3 endothelial staining was scarce within the islet. By day 5, early vessel formation could be seen within the islet, but insulin staining was patchy and associated with apoptotic nuclei. By day 7, vessels could be seen throughout the islet and insulin staining had returned. Day 14 sections showed a fully revascularized islet. CONCLUSIONS The staining provided good delineation of islet endothelium and beta-cell location, with clear observation of the revascularization process. This technique also suggests that days 3 through 5 may be a critical period for islet survival and provides a good model for studying the effects of manipulating the revascularization process.
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Affiliation(s)
- G L Jones
- Centre for Nephrology and Department of Endocrinology, Royal Free and University College Medical School, Rowland Hill Street, London NW3 2PF, United Kingdom.
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295
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Rodriguez-Mulero S, Montanya E. Selection of a Suitable Internal Control Gene for Expression Studies in Pancreatic Islet Grafts. Transplantation 2005; 80:650-2. [PMID: 16177640 DOI: 10.1097/01.tp.0000173790.12227.7b] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The use of real-time reverse transcription polymerase chain reaction to compare gene expression in different tissues and conditions requires normalization to an internal control that must be expressed at a constant level. Although a previous validation step is required to confirm that an internal control is appropriate, no comparison of frequently used "housekeeping" genes is available for islet grafts. We have investigated the effect of transplantation and metabolic environment on the expression of 18S, glyceraldehyde-3-phosphate dehydrogenase (GAPDH), beta-actin, and cyclophilin A genes in pancreatic islets. The expression of these genes was determined on days 1, 3, and 7 after transplantation into normoglycemic or hyperglycemic rats and in isolated islets. Only 18S gene expression remained stable in all studied conditions, indicating that it is the best internal control for gene expression analysis in islet grafts. The significant variation found in other housekeeping genes, particularly GAPDH and beta-actin, question their use as internal controls in islet grafts.
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Affiliation(s)
- Sílvia Rodriguez-Mulero
- Laboratory of Diabetes and Experimental Endocrinology, Department of Medicine, IDIBELL-University of Barcelona, Spain
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296
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Emamaullee JA, Rajotte RV, Liston P, Korneluk RG, Lakey JRT, Shapiro AMJ, Elliott JF. XIAP overexpression in human islets prevents early posttransplant apoptosis and reduces the islet mass needed to treat diabetes. Diabetes 2005; 54:2541-8. [PMID: 16123341 DOI: 10.2337/diabetes.54.9.2541] [Citation(s) in RCA: 93] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
The Edmonton Protocol for treatment of type 1 diabetes requires islets from two or more donors to achieve euglycemia in a single recipient, primarily because soon after portal infusion, the majority of the transplanted cells undergo apoptosis due to hypoxia and hypoxia reperfusion injury. X-linked inhibitor of apoptosis protein (XIAP) is a potent endogenous inhibitor of apoptosis that is capable of blocking the activation of multiple downstream caspases, and XIAP overexpression has previously been shown to enhance engraftment of a murine beta-cell line. In this study, human islets transduced with a XIAP-expressing recombinant adenovirus were resistant to apoptosis and functionally recovered following in vitro stresses of hypoxia and hypoxia with reoxygenation (models reperfusion injury). Furthermore Ad-XIAP transduction dramatically reduced the number of human islets required to reverse hyperglycemia in chemically diabetic immunodeficient mice. These results suggest that by transiently overexpressing XIAP in the immediate posttransplant period, human islets from a single donor might be used to effectively treat two diabetic recipients.
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Affiliation(s)
- Juliet A Emamaullee
- 1-21 Medical Sciences Building, Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Alberta T6G 2S2, Canada.
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297
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Mysore TB, Shinkel TA, Collins J, Salvaris EJ, Fisicaro N, Murray-Segal LJ, Johnson LEA, Lepore DA, Walters SN, Stokes R, Chandra AP, O'Connell PJ, d'Apice AJF, Cowan PJ. Overexpression of glutathione peroxidase with two isoforms of superoxide dismutase protects mouse islets from oxidative injury and improves islet graft function. Diabetes 2005; 54:2109-16. [PMID: 15983212 DOI: 10.2337/diabetes.54.7.2109] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Primary nonfunction of transplanted islets results in part from their sensitivity to reactive oxygen species (ROS) generated during the isolation and transplantation process. Our aim was to examine whether coexpression of antioxidant enzymes to detoxify multiple ROS increased the resistance of mouse islets to oxidative stress and improved the initial function of islet grafts. Islets from transgenic mice expressing combinations of human copper/zinc superoxide dismutase (SOD), extracellular SOD, and cellular glutathione peroxidase (Gpx-1) were subjected to oxidative stress in vitro. Relative viability after hypoxanthine/xanthine oxidase treatment was as follows: extracellular SOD + Gpx-1 + Cu/Zn SOD > extracellular SOD + Gpx-1 > extracellular SOD > wild type. Expression of all three enzymes was the only combination protective against hypoxia/reoxygenation. Islets from transgenic or control wild-type mice were then transplanted into streptozotocin-induced diabetic recipients in a syngeneic marginal islet mass model, and blood glucose levels were monitored for 7 days. In contrast to single- and double-transgenic grafts, triple-transgenic grafts significantly improved control of blood glucose compared with wild type. Our results indicate that coexpression of antioxidant enzymes has a complementary beneficial effect and may be a useful approach to reduce primary nonfunction of islet grafts.
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Affiliation(s)
- Tharun B Mysore
- Immunology Research Centre, St. Vincent's Hospital Melbourne, P.O. Box 2900, Fitzroy 3065, Victoria, Australia
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298
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Abstract
Evidence exists for an essential role of beta-cell apoptosis in the pathology of type 1 and type 2 diabetes. Current methods for diabetes-associated apoptosis detection, however, suffer the drawbacks of relying on in situ-based strategies. In this study, we attempted to measure, both in vitro and ex vivo, levels of beta-cell apoptosis in diabetic mice using Cy5.5-labeled annexin V. We used streptozotocin-treated BALB/c mice and NOD mice of different ages as models of type 1 diabetes and db/db mice as a model of type 2 diabetes. With annexin V Cy5.5, we established differences in levels of apoptosis between diabetic and control animals. Intravenously administered annexin V Cy5.5 accumulated in pancreata of diabetic mice but not in nondiabetic controls. Furthermore, its localization was specific to apoptotic events within diabetic islets; its selectivity was supported by transferase-mediated dUTP nick-end labeling staining. Because annexin V defines an early marker of apoptosis and the developed probe is suitable for in vivo administration, it may provide a promising tool for real-time identification in intact animals of the earliest stages of diabetes-associated beta-cell death and for tracing the events that characterize the pathology of the disease.
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Affiliation(s)
- Zdravka Medarova
- MGH/MIT/HMS Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital/Harvard Medical School, Charlestown, MA 02129, USA
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Emamaullee J, Liston P, Korneluk RG, Shapiro AMJ, Elliott JF. XIAP overexpression in islet beta-cells enhances engraftment and minimizes hypoxia-reperfusion injury. Am J Transplant 2005; 5:1297-305. [PMID: 15888033 DOI: 10.1111/j.1600-6143.2005.00891.x] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Recent advances in clinical islet transplantation have allowed patients with type 1 diabetes to become insulin independent, but the procedure is limited since islets from two donors per recipient are typically required. This limitation arises because within a few days of the islets being embolized into the portal circulation, at least half of the transplanted beta-cells have undergone apoptotic cell death triggered by hypoxic and chemokine/cytokine-mediated stress. We hypothesized that the survival of beta-cells in the early post-transplant period would be enhanced if naturally occurring inhibitor of apoptosis proteins (IAPs) were transiently overexpressed in the grafts. In the present study, we used a growth-regulatable beta-cell line (betaTC-Tet) as a model for beta-cells within islets, and examined whether adenovirally delivered XIAP (X-linked IAP-a highly potent IAP) could enhance beta-cell survival. In vitro, XIAP-expressing betaTC-Tet cells were markedly resistant to apoptosis in an ischemia-reperfusion injury model system and following exposure to cytokines. When Ad-XIAP transduced betaTC-Tet cells were transplanted subcutaneously into immunodeficient mice, the grafts were able to reverse diabetes in 3 days, vs. 21 days for Ad-betaGal transduced cells. This approach may allow more efficient use of the limited existing supply of human islets.
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Affiliation(s)
- Juliet Emamaullee
- Department of Medical Microbiology and Immunology, University of Alberta, Edmonton, Canada
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Abstract
Type 2 diabetes is a disease characterised by peripheral insulin resistance, as well as by pancreatic beta cell dysfunction. This process is in part due to elevated blood glucose and free fatty acids--termed glucolipotoxicity. The traditional pathway of treating type 2 diabetes in a stepwise manner, beginning with life style modifications and continuing with oral hypoglycaemic agents leads to a protracted period of unnecessary hyperglycaemia. A new approach, targeted at alleviating the deleterious effects of hyperglycaemia and elevated free fatty acids by acutely lowering both with intensive insulin therapy, has yielded prolonged remissions in therapy in which only diet was necessary to maintain normoglycaemia. This new approach, its rationale, benefits and misgivings are discussed in this review.
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Affiliation(s)
- Roy Eldor
- Diabetes Research Center, Department of Medicine, Hadassah-Hebrew University Hospital, Jerusalem 91120, Israel.
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