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Engineering an endocrine Neo-Pancreas by repopulation of a decellularized rat pancreas with islets of Langerhans. Sci Rep 2017; 7:41777. [PMID: 28150744 PMCID: PMC5288794 DOI: 10.1038/srep41777] [Citation(s) in RCA: 46] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2016] [Accepted: 12/29/2016] [Indexed: 01/06/2023] Open
Abstract
Decellularization of pancreata and repopulation of these non-immunogenic matrices with islets and endothelial cells could provide transplantable, endocrine Neo- Pancreata. In this study, rat pancreata were perfusion decellularized and repopulated with intact islets, comparing three perfusion routes (Artery, Portal Vein, Pancreatic Duct). Decellularization effectively removed all cellular components but conserved the pancreas specific extracellular matrix. Digital subtraction angiography of the matrices showed a conserved integrity of the decellularized vascular system but a contrast emersion into the parenchyma via the decellularized pancreatic duct. Islets infused via the pancreatic duct leaked from the ductular system into the peri-ductular decellularized space despite their magnitude. TUNEL staining and Glucose stimulated insulin secretion revealed that islets were viable and functional after the process. We present the first available protocol for perfusion decellularization of rat pancreata via three different perfusion routes. Furthermore, we provide first proof-of-concept for the repopulation of the decellularized rat pancreata with functional islets of Langerhans. The presented technique can serve as a bioengineering platform to generate implantable and functional endocrine Neo-Pancreata.
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52
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Bellin MD, Beilman GJ, Dunn TB, Pruett TL, Sutherland DER, Chinnakotla S, Hodges JS, Lane A, Ptacek P, Berry KL, Hering BJ, Moran A. Sitagliptin Treatment After Total Pancreatectomy With Islet Autotransplantation: A Randomized, Placebo-Controlled Study. Am J Transplant 2017; 17:443-450. [PMID: 27459721 PMCID: PMC5266635 DOI: 10.1111/ajt.13979] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 06/19/2016] [Accepted: 07/12/2016] [Indexed: 01/25/2023]
Abstract
Insulin independence after total pancreatectomy and islet autotransplant (TPIAT) for chronic pancreatitis is limited by a high rate of postprocedure beta cell apoptosis. Endogenous glucagon-like peptide-1 and glucose-dependent insulinotropic peptide, which are increased by dipeptidyl peptidase 4 inhibitor therapy (sitagliptin) may protect against beta cell apoptosis. To determine the effect of sitagliptin after TPIAT, 83 adult TPIAT recipients were randomized to receive sitagliptin (n = 54) or placebo (n = 29) for 12 months after TPIAT. At 12 and 18 months after TPIAT, participants were assessed for insulin independence; metabolic testing was performed with mixed meal tolerance testing and frequent sample intravenous glucose tolerance testing. Insulin independence did not differ between the sitagliptin and placebo groups at 12 months (42% vs. 45%, p = 0.82) or 18 months (36% vs. 44%, p = 0.48). At 12 months, insulin dose was 9.0 (standard error 1.7) units/day and 7.9 (2.2) units/day in the sitagliptin and placebo groups, respectively (p = 0.67) and at 18 months 10.3 (1.9) and 7.1 (2.6) units/day, respectively (p = 0.32). Hemoglobin A1c levels and insulin secretory measures were similar in the two groups, as were adverse events. In conclusion, sitagliptin could be safely administered but did not improve metabolic outcomes after TPIAT.
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Affiliation(s)
- M D Bellin
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - G J Beilman
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - T B Dunn
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - T L Pruett
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - D E R Sutherland
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - S Chinnakotla
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - J S Hodges
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - A Lane
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - P Ptacek
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - K L Berry
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - B J Hering
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
| | - A Moran
- Departments of Pediatrics, Surgery, Biostatistics, Schulze Diabetes Institute, University of Minnesota, Minneapolis, MN
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53
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Espes D, Lau J, Quach M, Ullsten S, Christoffersson G, Carlsson PO. Rapid Restoration of Vascularity and Oxygenation in Mouse and Human Islets Transplanted to Omentum May Contribute to Their Superior Function Compared to Intraportally Transplanted Islets. Am J Transplant 2016; 16:3246-3254. [PMID: 27321369 DOI: 10.1111/ajt.13927] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 06/08/2016] [Accepted: 06/12/2016] [Indexed: 01/25/2023]
Abstract
Transplantation of islets into the liver confers several site-specific challenges, including a delayed vascularization and prevailing hypoxia. The greater omentum has in several experimental studies been suggested as an alternative implantation site for clinical use, but there has been no direct functional comparison to the liver. In this experimental study in mice, we characterized the engraftment of mouse and human islets in the omentum and compared engraftment and functional outcome with those in the intraportal site. The vascularization and innervation of the islets transplanted into the omentum were restored within the first month by paralleled ingrowth of capillaries and nerves. The hypoxic conditions in the islets early posttransplantation were transient and restricted to the first days. Newly formed blood vessels were fully functional, and the blood perfusion and oxygenation of the islets became similar to that of endogenous islets. Furthermore, islet grafts in the omentum showed at 1 month posttransplantation functional superiority to intraportally transplanted grafts. We conclude that in contrast to the liver the omentum provides excellent engraftment conditions for transplanted islets. Future studies in humans will be of great interest to investigate the capability of this site to also harbor larger grafts without interfering with islet functionality.
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Affiliation(s)
- D Espes
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden. .,Department of Medical Sciences, Uppsala University, Uppsala, Sweden.
| | - J Lau
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.,Department of Medical Sciences, Uppsala University, Uppsala, Sweden
| | - M Quach
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - S Ullsten
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - G Christoffersson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.,La Jolla Institute for Allergy and Immunology, La Jolla, CA
| | - P O Carlsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden.,Department of Medical Sciences, Uppsala University, Uppsala, Sweden
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54
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Quantification of β-Cell Mass in Intramuscular Islet Grafts Using Radiolabeled Exendin-4. Transplant Direct 2016; 2:e93. [PMID: 27819034 PMCID: PMC5082995 DOI: 10.1097/txd.0000000000000598] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Accepted: 04/28/2016] [Indexed: 12/27/2022] Open
Abstract
Background There is an increasing interest in alternative implantation sites to the liver for islet transplantation. Intramuscular implantation has even been tested clinically. Possibilities to monitor β-cell mass would be of huge importance not only for the understanding of islet engraftment but also for the decision of changing the immunosuppressive regime. We have therefore evaluated the feasibility of quantifying intramuscular β-cell mass using the radiolabeled glucagon like peptide-1 receptor agonist DO3A-VS-Cys40-Exendin-4. Methods One hundred to 400 islets were transplanted to the abdominal muscle of nondiabetic mice. After 3 to 4 weeks, 0.2 to 0.5 MBq [177Lu]DO3A-VS-Cys40-Exendin-4 was administered intravenously. Sixty minutes postinjection abdominal organs and graft bearing muscle were retrieved, and the radioactive uptake measured in a well counter within 10 minutes. The specific uptake in native and transplanted islets was assessed by autoradiography. The total insulin-positive area of the islet grafts was determined by immunohistochemistry. Results Intramuscular islet grafts could easily be visualized by this tracer, and the background uptake was very low. There was a linear correlation between the radioactivity uptake and the number of transplanted islets, both for standardized uptake values and the total radiotracer uptake in each graft (percentage of injected dose). The quantified total insulin area of surviving β cells showed an even stronger correlation to both standardized uptake values (R = 0.96, P = 0.0002) and percentage of injected dose (R = 0.88, P = 0.0095). There was no correlation to estimated α cell mass. Conclusions [177Lu]DO3A-VS-Cys40-Exendin-4 could be used to quantify β-cell mass after experimental intramuscular islet transplantation. This technique may well be transferred to the clinical setting by exchanging Lutetium-177 radionuclide to a positron emitting Gallium-68.
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55
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Bensellam M, Maxwell EL, Chan JY, Luzuriaga J, West PK, Jonas JC, Gunton JE, Laybutt DR. Hypoxia reduces ER-to-Golgi protein trafficking and increases cell death by inhibiting the adaptive unfolded protein response in mouse beta cells. Diabetologia 2016; 59:1492-1502. [PMID: 27039902 DOI: 10.1007/s00125-016-3947-y] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/26/2015] [Accepted: 03/16/2016] [Indexed: 12/13/2022]
Abstract
AIMS/HYPOTHESIS Hypoxia may contribute to beta cell failure in type 2 diabetes and islet transplantation. The adaptive unfolded protein response (UPR) is required for endoplasmic reticulum (ER) homeostasis. Here we investigated whether or not hypoxia regulates the UPR in beta cells and the role the adaptive UPR plays during hypoxic stress. METHODS Mouse islets and MIN6 cells were exposed to various oxygen (O2) tensions. DNA-damage inducible transcript 3 (DDIT3), hypoxia-inducible transcription factor (HIF)1α and HSPA5 were knocked down using small interfering (si)RNA; Hspa5 was also overexpressed. db/db mice were used. RESULTS Hypoxia-response genes were upregulated in vivo in the islets of diabetic, but not prediabetic, db/db mice. In isolated mouse islets and MIN6 cells, O2 deprivation (1-5% vs 20%; 4-24 h) markedly reduced the expression of adaptive UPR genes, including Hspa5, Hsp90b1, Fkbp11 and spliced Xbp1. Coatomer protein complex genes (Copa, Cope, Copg [also known as Copg1], Copz1 and Copz2) and ER-to-Golgi protein trafficking were also reduced, whereas apoptotic genes (Ddit3, Atf3 and Trb3 [also known as Trib3]), c-Jun N-terminal kinase (JNK) phosphorylation and cell death were increased. Inhibition of JNK, but not HIF1α, restored adaptive UPR gene expression and ER-to-Golgi protein trafficking while protecting against apoptotic genes and cell death following hypoxia. DDIT3 knockdown delayed the loss of the adaptive UPR and partially protected against hypoxia-induced cell death. The latter response was prevented by HSPA5 knockdown. Finally, Hspa5 overexpression significantly protected against hypoxia-induced cell death. CONCLUSIONS/INTERPRETATION Hypoxia inhibits the adaptive UPR in beta cells via JNK and DDIT3 activation, but independently of HIF1α. Downregulation of the adaptive UPR contributes to reduced ER-to-Golgi protein trafficking and increased beta cell death during hypoxic stress.
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Affiliation(s)
- Mohammed Bensellam
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia
| | - Emma L Maxwell
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia
| | - Jeng Yie Chan
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia
| | - Jude Luzuriaga
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia
| | - Phillip K West
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia
| | - Jean-Christophe Jonas
- Université catholique de Louvain, Institut de recherche expérimentale et clinique, Pôle d'endocrinologie, diabète et nutrition, Brussels, Belgium
| | - Jenny E Gunton
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia
- Westmead Hospital, Sydney, NSW, Australia
- The Westmead Millennium Institute for Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - D Ross Laybutt
- Garvan Institute of Medical Research, St Vincent's Hospital, UNSW Australia, 384 Victoria Street, Darlinghurst, Sydney, NSW, 2010, Australia.
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56
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Barkai U, Rotem A, de Vos P. Survival of encapsulated islets: More than a membrane story. World J Transplant 2016; 6:69-90. [PMID: 27011906 PMCID: PMC4801806 DOI: 10.5500/wjt.v6.i1.69] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/02/2015] [Accepted: 12/20/2015] [Indexed: 02/05/2023] Open
Abstract
At present, proven clinical treatments but no cures are available for diabetes, a global epidemic with a huge economic burden. Transplantation of islets of Langerhans by their infusion into vascularized organs is an experimental clinical protocol, the first approach to attain cure. However, it is associated with lifelong use of immunosuppressants. To overcome the need for immunosuppression, islets are encapsulated and separated from the host immune system by a permselective membrane. The lead material for this application is alginate which was tested in many animal models and a few clinical trials. This review discusses all aspects related to the function of transplanted encapsulated islets such as the basic requirements from a permselective membrane (e.g., allowable hydrodynamic radii, implications of the thickness of the membrane and relative electrical charge). Another aspect involves adequate oxygen supply, which is essential for survival/performance of transplanted islets, especially when using large retrievable macro-capsules implanted in poorly oxygenated sites like the subcutis. Notably, islets can survive under low oxygen tension and are physiologically active at > 40 Torr. Surprisingly, when densely crowded, islets are fully functional under hyperoxic pressure of up to 500 Torr (> 300% of atmospheric oxygen tension). The review also addresses an additional category of requirements for optimal performance of transplanted islets, named auxiliary technologies. These include control of inflammation, apoptosis, angiogenesis, and the intra-capsular environment. The review highlights that curing diabetes with a functional bio-artificial pancreas requires optimizing all of these aspects, and that significant advances have already been made in many of them.
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57
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Suszynski TM, Avgoustiniatos ES, Papas KK. Oxygenation of the Intraportally Transplanted Pancreatic Islet. J Diabetes Res 2016; 2016:7625947. [PMID: 27872862 PMCID: PMC5107248 DOI: 10.1155/2016/7625947] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2016] [Accepted: 04/27/2016] [Indexed: 12/04/2022] Open
Abstract
Intraportal islet transplantation (IT) is not widely utilized as a treatment for type 1 diabetes. Oxygenation of the intraportally transplanted islet has not been studied extensively. We present a diffusion-reaction model that predicts the presence of an anoxic core and a larger partly functional core within intraportally transplanted islets. Four variables were studied: islet diameter, islet fractional viability, external oxygen partial pressure (P) (in surrounding portal blood), and presence or absence of a thrombus on the islet surface. Results indicate that an islet with average size and fractional viability exhibits an anoxic volume fraction (AVF) of 14% and a function loss of 72% at a low external P. Thrombus formation increased AVF to 30% and function loss to 92%, suggesting that the effect of thrombosis may be substantial. External P and islet diameter accounted for the greatest overall impact on AVF and loss of function. At our institutions, large human alloislets (>200 μm diameter) account for ~20% of total islet number but ~70% of total islet volume; since most of the total transplanted islet volume is accounted for by large islets, most of the intraportal islet cells are likely to be anoxic and not fully functional.
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Affiliation(s)
| | | | - Klearchos K. Papas
- Department of Surgery, University of Minnesota, Minneapolis, MN 55455, USA
- Institute for Cellular Transplantation, Department of Surgery, University of Arizona, Tucson, AZ 85724, USA
- *Klearchos K. Papas:
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58
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Quantitating intracellular oxygen tension in vivo by phosphorescence lifetime measurement. Sci Rep 2015; 5:17838. [PMID: 26644023 PMCID: PMC4672317 DOI: 10.1038/srep17838] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/03/2015] [Accepted: 11/05/2015] [Indexed: 12/22/2022] Open
Abstract
Hypoxia appears to have an important role in pathological conditions in many organs such as kidney; however, a method to quantify intracellular oxygen tension in vivo has not been well established. In this study, we established an optical method to quantify oxygen tension in mice kidneys using a cationic lipophilic phosphorescence probe, BTPDM1, which has an intracellular oxygen concentration-sensitive phosphorescence lifetime. Since this probe is distributed inside the tubular cells of the mice kidney, we succeeded in detecting acute renal hypoxic conditions and chronic kidney disease. This technique enabled us to estimate intracellular partial pressures of oxygen in vivo by extrapolating the calibration curve generated from cultured tubular cells. Since intracellular oxygen tension is directly related to cellular hypoxic reactions, such as the activation of hypoxia-inducible factors, our method will shed new light on hypoxia research in vivo.
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59
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Köllmer M, Appel AA, Somo SI, Brey EM. Long-Term Function of Alginate-Encapsulated Islets. TISSUE ENGINEERING PART B-REVIEWS 2015; 22:34-46. [PMID: 26414084 DOI: 10.1089/ten.teb.2015.0140] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
Human trials have demonstrated the feasibility of alginate-encapsulated islet cells for the treatment of type 1 diabetes. Encapsulated islets can be protected from the host's immune system and remain viable and functional following transplantation. However, the long-term success of these therapies requires that alginate microcapsules maintain their immunoprotective capacity and stability in vivo for sustained periods. In part, as a consequence of different encapsulation strategies, islet encapsulation studies have produced inconsistent results in regard to graft functioning time, stability, and overall metabolic benefits. Alginate composition (proportion of M- and G-blocks), alginate purity, the cross-linking ions (calcium or barium), and the presence or absence of additional polymer coating layers influence the success of cell encapsulation. This review summarizes the outcomes of long-term studies of alginate-encapsulated islet transplants in animals and humans and provides a critical discussion of the graft failure mechanisms, including issues with graft biocompatibility, transplantation site, and integrity of the encapsulated islet grafts. Strategies to improve the mechanical stability of alginate capsules and methods for monitoring graft survival and function in vivo are presented.
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Affiliation(s)
- Melanie Köllmer
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois
| | - Alyssa A Appel
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
| | - Sami I Somo
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
| | - Eric M Brey
- 1 Department of Biomedical Engineering, Illinois Institute of Technology , Chicago, Illinois.,2 Research Service, Hines Veterans Administration Hospital , Hines, Illinois
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60
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Abstract
A total pancreatectomy and islet autotransplant (TPIAT) offers substantial pain relief and improved quality of life for children who are severely affected by chronic or recurrent acute pancreatitis and for whom the usual medical and endoscopic therapies have failed. The pancreas is entirely resected, and the pancreatic islets are isolated from the pancreas and infused back into the patient's liver. Because this is an autologous transplant, no immunosuppression is required. Over several months, the islets engraft in the liver; the patient is then slowly weaned off insulin therapy. Slightly more than 40 % of patients become and remain insulin independent, yet even among patients who remain on insulin, most have some islet function, permitting easier diabetes control. The majority of patients experience pain relief, with significant improvements in health-related quality of life. A TPIAT should be considered for children who are significantly disabled by chronic pancreatitis.
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Affiliation(s)
- Melena D Bellin
- Department of Surgery, University of Minnesota Medical School, University of Minnesota, Minneapolis, MN, USA,
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61
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Cotransplantation of Polymerized Hemoglobin Reduces β-Cell Hypoxia and Improves β-Cell Function in Intramuscular Islet Grafts. Transplantation 2015; 99:2077-82. [DOI: 10.1097/tp.0000000000000815] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
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62
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Liljebäck H, Grapensparr L, Olerud J, Carlsson PO. Extensive Loss of Islet Mass Beyond the First Day After Intraportal Human Islet Transplantation in a Mouse Model. Cell Transplant 2015; 25:481-9. [PMID: 26264975 DOI: 10.3727/096368915x688902] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Clinical islet transplantation is characterized by a progressive deterioration of islet graft function, which renders many patients once again dependent on exogenous insulin administration within a couple of years. In this study, we aimed to investigate possible engraftment factors limiting the survival and viability of experimentally transplanted human islets beyond the first day after their transplantation to the liver. Human islets were transplanted into the liver of nude mice and characterized 1 or 30 days after transplantation by immunohistochemistry. The factors assessed were endocrine mass, cellular death, hypoxia, vascular density and amyloid formation in the transplanted islets. One day posttransplantation, necrotic cells, as well as apoptotic cells, were commonly observed. In contrast to necrotic death, apoptosis rates remained high 1 month posttransplantation, and the total islet mass was reduced by more than 50% between 1 and 30 days posttransplantation. Islet mass at 30 days posttransplantation correlated negatively to apoptotic death. Vascular density within the transplanted islets remained less than 30% of that in native human islets up to 30 days posttransplantation and was associated with prevailing hypoxia. Amyloid formation was rarely observed in the 1-day-old transplants, but was commonly observed in the 30-day-old islet transplants. We conclude that substantial islet cell death occurs beyond the immediate posttransplantation phase, particularly through apoptotic events. Concomitant low vascularization with prevailing hypoxia and progressive amyloid development was observed in the human islet grafts. Strategies to improve engraftment at the intraportal site or change of implantation site in the clinical setting are needed.
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Affiliation(s)
- Hanna Liljebäck
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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63
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Pepper AR, Gala-Lopez B, Pawlick R, Merani S, Kin T, Shapiro AMJ. A prevascularized subcutaneous device-less site for islet and cellular transplantation. Nat Biotechnol 2015; 33:518-23. [PMID: 25893782 DOI: 10.1038/nbt.3211] [Citation(s) in RCA: 259] [Impact Index Per Article: 28.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Accepted: 03/12/2015] [Indexed: 02/07/2023]
Abstract
Transplantation of donor-derived islets into the liver is a successful cellular replacement therapy for individuals with diabetes. However, the hepatic vasculature is not an optimal transplant site for several reasons, including graft attrition and the inability to retrieve or image the islets. Here we describe islet transplantation into a prevascularized, subcutaneous site created by temporary placement of a medically approved vascular access catheter. In mice with streptozotocin (STZ)-induced diabetes, transplantation of ∼500 syngeneic islets into the resulting 'device-less' space reversed diabetes in 91% of mice and maintained normoglycemia for >100 days. The approach was also effective in mice with pre-existing diabetes, in another mouse strain that mounts a more vigorous inflammatory response, and across an allogeneic barrier. These results demonstrate that transient priming of a subcutaneous site supports diabetes-reversing islet transplantation in mouse models without the need for a permanent cell-encapsulation device.
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Affiliation(s)
- Andrew R Pepper
- Clinical Islet Transplant Program, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Boris Gala-Lopez
- Clinical Islet Transplant Program, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Rena Pawlick
- Clinical Islet Transplant Program, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Shaheed Merani
- Clinical Islet Transplant Program, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Tatsuya Kin
- 1] Clinical Islet Transplant Program, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada. [2] Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
| | - A M James Shapiro
- 1] Clinical Islet Transplant Program, Alberta Diabetes Institute, University of Alberta, Edmonton, Alberta, Canada. [2] Department of Surgery, University of Alberta, Edmonton, Alberta, Canada
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64
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Abstract
A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis. The session was held on July 23, 2014 and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, GI complications in this population, and unique features of children with chronic pancreatitis considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of chronic pancreatitis and total pancreatectomy outcomes and postsurgical diabetes outcomes was repeatedly emphasized.
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65
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Moore SJ, Gala-Lopez BL, Pepper AR, Pawlick RL, Shapiro AMJ. Bioengineered stem cells as an alternative for islet cell transplantation. World J Transplant 2015; 5:1-10. [PMID: 25815266 PMCID: PMC4371156 DOI: 10.5500/wjt.v5.i1.1] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2014] [Revised: 02/18/2014] [Accepted: 10/29/2014] [Indexed: 02/05/2023] Open
Abstract
Type 1 diabetes is an autoimmune and increasingly prevalent condition caused by immunological destruction of beta cells. Insulin remains the mainstay of therapy. Endeavours in islet transplantation have clearly demonstrated that type 1 diabetes is treatable by cellular replacement. Many challenges remain with this approach. The opportunity to use bioengineered embryonic or adult pluripotential stem cells, or islets derived from porcine xenograft sources could address future demands, but are still associated with considerable challenges. This detailed review outlines current progress in clinical islet transplantation, and places this in perspective for the remarkable scientific advances now occurring in stem cell and regenerative medicine approaches in the treatment of future curative treatment of diabetes.
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66
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Qiao N, Xu C, Zhu YX, Cao Y, Liu DC, Han X. Ets-1 as an early response gene against hypoxia-induced apoptosis in pancreatic β-cells. Cell Death Dis 2015; 6:e1650. [PMID: 25695603 PMCID: PMC4669796 DOI: 10.1038/cddis.2015.8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2014] [Revised: 12/21/2014] [Accepted: 01/02/2015] [Indexed: 12/17/2022]
Abstract
Hypoxia complicates islet isolation for transplantation and may contribute to pancreatic β-cell failure in type 2 diabetes. Pancreatic β-cells are susceptible to hypoxia-induced apoptosis. Severe hypoxic conditions during the immediate post-transplantation period are a main non-immune factor leading to β-cell death and islet graft failure. In this study, we identified the transcription factor Ets-1 (v-ets erythroblastosis virus E26 oncogene homolog 1) as an early response gene against hypoxia-induced apoptosis in pancreatic β-cells. Hypoxia regulates Ets-1 at multiple levels according to the degree of β-cell oxygen deprivation. Moderate hypoxia promotes Ets-1 gene transcription, whereas severe hypoxia promotes its transactivation activity, as well as its ubiquitin-proteasome mediated degradation. This degradation causes a relative insufficiency of Ets-1 activity, and limits the transactivation effect of Ets-1 on downstream hypoxic-inducible genes and its anti-apoptotic function. Overexpression of ectopic Ets-1 in MIN6 and INS-1 cells protects them from severe hypoxia-induced apoptosis in a mitochondria-dependent manner, confirming that a sufficient amount of Ets-1 activity is critical for protection of pancreatic β-cells against hypoxic injury. Targeting Ets-1 expression may be a useful strategy for islet graft protection during the immediate post-transplantation period.
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Affiliation(s)
- N Qiao
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Jiangsu Diabetes Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - C Xu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Jiangsu Diabetes Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Y-X Zhu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Jiangsu Diabetes Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - Y Cao
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Jiangsu Diabetes Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - D-C Liu
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Jiangsu Diabetes Center, Nanjing Medical University, Nanjing, Jiangsu, China
| | - X Han
- Key Laboratory of Human Functional Genomics of Jiangsu Province, Jiangsu Diabetes Center, Nanjing Medical University, Nanjing, Jiangsu, China
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Robertson RP, Bogachus LD, Oseid E, Parazzoli S, Patti ME, Rickels MR, Schuetz C, Dunn T, Pruett T, Balamurugan AN, Sutherland DER, Beilman G, Bellin MD. Assessment of β-cell mass and α- and β-cell survival and function by arginine stimulation in human autologous islet recipients. Diabetes 2015; 64:565-72. [PMID: 25187365 PMCID: PMC4303963 DOI: 10.2337/db14-0690] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
We used intravenous arginine with measurements of insulin, C-peptide, and glucagon to examine β-cell and α-cell survival and function in a group of 10 chronic pancreatitis recipients 1-8 years after total pancreatectomy and autoislet transplantation. Insulin and C-peptide responses correlated robustly with the number of islets transplanted (correlation coefficients range 0.81-0.91; P < 0.01-0.001). Since a wide range of islets were transplanted, we normalized the insulin and C-peptide responses to the number of islets transplanted in each recipient for comparison with responses in normal subjects. No significant differences were observed in terms of magnitude and timing of hormone release in the two groups. Three recipients had a portion of the autoislets placed within their peritoneal cavities, which appeared to be functioning normally up to 7 years posttransplant. Glucagon responses to arginine were normally timed and normally suppressed by intravenous glucose infusion. These findings indicate that arginine stimulation testing may be a means of assessing the numbers of native islets available in autologous islet transplant candidates and is a means of following posttransplant α- and β-cell function and survival.
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Affiliation(s)
- R Paul Robertson
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA Departments of Pediatrics and Surgery, University of Minnesota, Minneapolis, MN Pacific Northwest Diabetes Research Institute, Seattle, WA
| | - Lindsey D Bogachus
- Division of Metabolism, Endocrinology and Nutrition, Department of Medicine, University of Washington, Seattle, WA Pacific Northwest Diabetes Research Institute, Seattle, WA
| | | | | | | | - Michael R Rickels
- Division of Endocrinology, Diabetes, and Metabolism, Department of Medicine, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | | | - Ty Dunn
- Departments of Pediatrics and Surgery, University of Minnesota, Minneapolis, MN
| | - Timothy Pruett
- Departments of Pediatrics and Surgery, University of Minnesota, Minneapolis, MN
| | - A N Balamurugan
- Departments of Pediatrics and Surgery, University of Minnesota, Minneapolis, MN
| | | | - Gregory Beilman
- Departments of Pediatrics and Surgery, University of Minnesota, Minneapolis, MN
| | - Melena D Bellin
- Departments of Pediatrics and Surgery, University of Minnesota, Minneapolis, MN
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Lau J, Vasylovska S, Kozlova EN, Carlsson PO. Surface coating of pancreatic islets with neural crest stem cells improves engraftment and function after intraportal transplantation. Cell Transplant 2015; 24:2263-72. [PMID: 25581301 DOI: 10.3727/096368915x686184] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The present study aimed to develop techniques for surface coating of islets with neural crest stem cells (NCSCs) in order to enable cotransplantation to the clinically used liver site and then investigate engraftment and function intraportally of such bioengineered islets. Mouse islets were coated during incubation with enhanced green fluorescent protein (EGFP)-expressing mouse NCSCs and transplanted into the portal vein to cure diabetic mice. An intravenous glucose tolerance test was performed at 1 month posttransplantation. Islet grafts were retrieved and evaluated for vascular density, nerves, and glial cells. NCSCs expressed a vast number of key angiogenic and neurotrophic factors. Mice transplanted with NCSC-bioengineered islets responded better to the glucose load than recipient mice with control islets. NCSCs remained present in the vicinity or had often migrated into the NCSC-coated islets, and an improved islet graft reinnervation and revascularization was observed. Transplanted NCSCs differentiated into both glial and neural cells in the islet grafts. We conclude that bioengineering of islets with NCSCs for intraportal transplantation provides a possibility to improve islet engraftment and function. Pending successful establishment of protocols for expansion of NCSCs from, for example, human skin or bone marrow, this strategy may be applied to clinical islet transplantation.
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Affiliation(s)
- Joey Lau
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
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Ullsten S, Lau J, Carlsson PO. Vascular heterogeneity between native rat pancreatic islets is responsible for differences in survival and revascularisation post transplantation. Diabetologia 2015; 58:132-9. [PMID: 25257098 DOI: 10.1007/s00125-014-3385-7] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2014] [Accepted: 09/01/2014] [Indexed: 10/24/2022]
Abstract
AIMS/HYPOTHESIS Highly blood-perfused islets have been observed to be the most functional islets in the native pancreas. We hypothesised that differences in vascular support of islets in donor pancreases influence their susceptibility to cellular stress and capacity for vascular engraftment after transplantation. METHODS Highly blood-perfused islets in rats were identified by injection of microspheres into the ascending aorta before islet isolation. Cell death was evaluated after in vitro cytokine or hypoxia exposure, and 2 days post transplantation. One month post transplantation, islet engraftment, including vascular density, blood perfusion and oxygen tension (pO2) in the tissue, was evaluated. RESULTS Microsphere-containing islets had a similar frequency of cell death during standard culture conditions but increased cell death after exposure to cytokines and hypoxia in comparison with other islets. Two days after transplantation the percentage of apoptotic or necrotic cells was also higher in grafts of such islets and 1 month post transplantation these grafts were composed of substantially more connective tissue. Grafts of highly blood-perfused islets in the native pancreas regained a higher vascular density, blood perfusion and pO2 in comparison with grafts of other islets. CONCLUSIONS/INTERPRETATION Native islets that are highly blood-perfused regained this feature after transplantation, indicating a superior capacity for revascularisation and post-transplant function. However, the same group of islets was more vulnerable to different kinds of cellular stress, which limited their early survival post transplantation. Preferential death of these most active islets may contribute to the high number of islets needed to provide cure with islet transplantation.
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Affiliation(s)
- Sara Ullsten
- Department of Medical Cell Biology, Uppsala University, Husargatan 3, Box 571, SE-75123, Uppsala, Sweden
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Total pancreatectomy with islet autotransplantation: summary of a National Institute of Diabetes and Digestive and Kidney diseases workshop. Pancreas 2014; 43:1163-71. [PMID: 25333399 PMCID: PMC4205476 DOI: 10.1097/mpa.0000000000000236] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis (CP). The session was held on July 23, 2014, and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, gastrointestinal complications in this population, and unique features of children with CP considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of CP and total pancreatectomy outcomes as well as postsurgical diabetes outcomes was repeatedly emphasized.
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Total pancreatectomy with islet autotransplantation: summary of a National Institute of Diabetes and Digestive and Kidney diseases workshop. Pancreas 2014. [PMID: 25333399 DOI: 10.1097/mpa.000000000000 0236] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
A workshop sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases focused on research gaps and opportunities in total pancreatectomy with islet autotransplantation (TPIAT) for the management of chronic pancreatitis (CP). The session was held on July 23, 2014, and structured into 5 sessions: (1) patient selection, indications, and timing; (2) technical aspects of TPIAT; (3) improving success of islet autotransplantation; (4) improving outcomes after total pancreatectomy; and (5) registry considerations for TPIAT. The current state of knowledge was reviewed; knowledge gaps and research needs were specifically highlighted. Common themes included the need to identify which patients best benefit from and when to intervene with TPIAT, current limitations of the surgical procedure, diabetes remission and the potential for improvement, opportunities to better address pain remission, gastrointestinal complications in this population, and unique features of children with CP considered for TPIAT. The need for a multicenter patient registry that specifically addresses the complexities of CP and total pancreatectomy outcomes as well as postsurgical diabetes outcomes was repeatedly emphasized.
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Abstract
BACKGROUND The islet size distribution in a preparation may contribute to islet transplant outcomes. At the same islet equivalent (IE) dose, larger islets may exhibit poorer therapeutic value and this may be because of oxygen diffusion limitations that worsen in proportion to islet size. METHODS To test this hypothesis, we studied the impact of islet size index (ISI) and other islet product characteristics on outcomes after islet autotransplant (IAT) in recipients receiving a marginal islet dose (2000-4999 IEs per kg body weight) from January 1, 2009 to June 11, 2012, at the University of Minnesota (n=58). ISI was defined as the number of IE divided by the number of islet particles (IPs) in a preparation; an ISI less than 1 indicates a mean islet diameter that is less than 150 μm. The primary post-IAT outcome was 6-month insulin use status. RESULTS Logistic regression analysis indicate that IPs/kg (P=0.001), IEs/kg (P=0.019), total IPs transplanted (P=0.040), and ISI (P=0.074) were most strongly correlated with the primary outcome. The ISI (mean±standard error) was lower for recipients achieving insulin independence at 6 months (0.71±0.05) versus those partially (0.83±0.05) or completely (1.00±0.07) insulin dependent. The combination of islet dose (expressed as units IPs/kg) and ISI exhibited a sensitivity of 75% and specificity of 74% in predicting insulin independence in this population of patients. CONCLUSION Islet autotransplant recipients of a marginal islet doses were more likely to achieve insulin independence when transplanted with a greater number of smaller islets.
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Gerber PA, Bellomo EA, Hodson DJ, Meur G, Solomou A, Mitchell RK, Hollinshead M, Chimienti F, Bosco D, Hughes SJ, Johnson PRV, Rutter GA. Hypoxia lowers SLC30A8/ZnT8 expression and free cytosolic Zn2+ in pancreatic beta cells. Diabetologia 2014; 57:1635-44. [PMID: 24865615 PMCID: PMC4079946 DOI: 10.1007/s00125-014-3266-0] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Accepted: 04/23/2014] [Indexed: 12/16/2022]
Abstract
AIMS/HYPOTHESIS Hypoxic damage complicates islet isolation for transplantation and may contribute to beta cell failure in type 2 diabetes. Polymorphisms in the SLC30A8 gene, encoding the secretory granule zinc transporter 8 (ZnT8), influence type 2 diabetes risk, conceivably by modulating cytosolic Zn(2+) levels. We have therefore explored the role of ZnT8 and cytosolic Zn(2+) in the response to hypoxia of pancreatic islet cells. METHODS Human, mouse or rat islets were isolated and exposed to varying O2 tensions. Cytosolic free zinc was measured using the adenovirally expressed recombinant targeted zinc probe eCALWY4. Gene expression was measured using quantitative (q)RT-PCR, western (immuno-) blotting or immunocytochemistry. Beta cells were identified by insulin immunoreactivity. RESULTS Deprivation of O2 (1% vs 5% or 21%) for 24 h lowered free cytosolic Zn(2+) concentrations by ~40% (p < 0.05) and ~30% (p < 0.05) in mouse and human islet cells, respectively. Hypoxia similarly decreased SLC30A8 mRNA expression in islets, and immunoreactivity in beta cells. Implicating lowered ZnT8 levels in the hypoxia-induced fall in cytosolic Zn(2+), genetic ablation of Slc30a8 from mouse islets lowered cytosolic Zn(2+) by ~40% (p < 0.05) and decreased the induction of metallothionein (Mt1, Mt2) genes. Cell survival in the face of hypoxia was enhanced in small islets of older (>12 weeks) Slc30a8 null mice vs controls, but not younger animals. CONCLUSIONS/INTERPRETATION The response of pancreatic beta cells to hypoxia is characterised by decreased SLC30A8 expression and lowered cytosolic Zn(2+) concentrations. The dependence on ZnT8 of hypoxia-induced changes in cell survival may contribute to the actions of SLC30A8 variants on diabetes risk in humans.
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Affiliation(s)
- Philipp A. Gerber
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
- Division of Endocrinology, Diabetes and Clinical Nutrition, University Hospital Zurich, Zurich, Switzerland
| | - Elisa A. Bellomo
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - David J. Hodson
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Gargi Meur
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Antonia Solomou
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Ryan K. Mitchell
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
| | - Michael Hollinshead
- Section of Microscopy, Department of Medicine, Imperial College London, London, UK
| | | | - Domenico Bosco
- Cell Isolation and Transplantation Centre, Department of Surgery, Geneva University Hospital, Geneva, Switzerland
| | - Stephen J. Hughes
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
- DRWF Human Islet Isolation Facility, Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Oxford, UK
| | - Paul R. V. Johnson
- Nuffield Department of Surgical Sciences, University of Oxford, Oxford, UK
- DRWF Human Islet Isolation Facility, Oxford Centre for Diabetes, Endocrinology and Metabolism, Oxford, UK
- Oxford NIHR Biomedical Research Centre, Oxford, UK
| | - Guy A. Rutter
- Section of Cell Biology, Division of Diabetes, Endocrinology and Metabolism, Department of Medicine, Imperial College London, London, W12 ONN UK
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Abstract
Islet transplantation (IT) is a promising therapy for the treatment of diabetes. The large number of islets required to achieve insulin independence limit its cost-effectiveness and the number of patients who can be treated. It is believed that >50% of islets are lost in the immediate post-IT period. Poor oxygenation in the early post-IT period is recognized as a possible reason for islet loss and dysfunction but has not been extensively studied. Several key variables affect oxygenation in this setting, including (1) local oxygen partial pressure (pO(2)), (2) islet oxygen consumption, (3) islet size (diameter, D), and (4) presence or absence of thrombosis on the islet surface. We discuss implications of oxygen-limiting conditions on intraportal islet viability and function. Of the 4 key variables, the islet size appears to be the most important determinant of the anoxic and nonfunctional islet volume fractions. Similarly, the effect of thrombus formation on the islet surface may be substantial. At the University of Minnesota, average size distribution data from clinical alloislet preparations (n = 10) indicate that >150-µm D islets account for only ~30% of the total islet number, but >85% of the total islet volume. This suggests that improved oxygen supply to the islets may have a profound impact on islet survivability and function since most of the β-cell volume is within large islets which are most susceptible to oxygen-limiting conditions. The assumption that the liver is a suitable islet transplant site from the standpoint of oxygenation should be reconsidered.
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Colton CK. Oxygen supply to encapsulated therapeutic cells. Adv Drug Deliv Rev 2014; 67-68:93-110. [PMID: 24582600 DOI: 10.1016/j.addr.2014.02.007] [Citation(s) in RCA: 100] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2013] [Revised: 01/06/2014] [Accepted: 02/19/2014] [Indexed: 02/07/2023]
Abstract
Therapeutic cells encapsulated in immunobarrier devices have promise for treatment of a variety of human diseases without immunosuppression. The absence of sufficient oxygen supply to maintain viability and function of encapsulated tissue has been the most critical impediment to progress. Within the framework of oxygen supply limitations, we review the major issues related to development of these devices, primarily in the context of encapsulated islets of Langerhans for treating diabetes, including device designs and materials, supply of tissue, protection from immune rejection, and maintenance of cell viability and function. We describe various defensive measures investigated to enhance survival of transplanted tissue, and we review the diverse approaches to enhancement of oxygen transport to encapsulated tissue, including manipulation of diffusion distances and oxygen permeability of materials, induction of neovascularization with angiogenic factors and vascularizing membranes, and methods for increasing the oxygen concentration adjacent to encapsulated tissue so as to exceed that in the microvasculature. Recent developments, particularly in this latter area, suggest that the field is ready for clinical trials of encapsulated therapeutic cells to treat diabetes.
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Rackham CL, Dhadda PK, Le Lay AM, King AJF, Jones PM. Preculturing Islets With Adipose-Derived Mesenchymal Stromal Cells Is an Effective Strategy for Improving Transplantation Efficiency at the Clinically Preferred Intraportal Site. CELL MEDICINE 2014; 7:37-47. [PMID: 26858891 DOI: 10.3727/215517914x680047] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
We have recently shown that preculturing islets with kidney-derived mesenchymal stromal cells (MSCs) improves transplantation outcome in streptozotocin-diabetic mice implanted with a minimal mass of islets beneath the kidney capsule. In the present study, we have extended our previous observations to investigate whether preculturing islets with MSCs can also be used to enhance islet function at the clinically used intraportal site. We have used MSCs derived from adipose tissue, which are more readily accessible than alternative sources in human subjects and can be expanded to clinically efficacious numbers, to preculture islets throughout this study. The in vivo efficacy of grafts consisting of islets precultured alone or with MSCs was tested using a syngeneic streptozotocin-diabetic minimal islet mass model at the clinically relevant intraportal site. Blood glucose concentrations were monitored for 1 month. The vascularization of islets precultured alone or with MSCs was investigated both in vitro and in vivo, using immunohistochemistry. Islet insulin content was measured by radioimmunoassay. The effect of preculturing islets with MSCs on islet function in vitro was investigated using static incubation assays. There was no beneficial angiogenic influence of MSC preculture, as demonstrated by the comparable vascularization of islets precultured alone or with MSCs, both in vitro after 3 days and in vivo 1 month after islet transplantation. However, the in vitro insulin secretory capacity of MSC precultured islets was superior to that of islets precultured alone. In vivo, this was associated with improved glycemia at 7, 14, 21, and 28 days posttransplantation, in recipients of MSC precultured islets compared to islets precultured alone. The area of individual islets within the graft-bearing liver was significantly higher in recipients of MSC precultured islets compared to islets precultured alone. Our experimental studies suggest that preculturing islets with MSCs represents a favorable strategy for improving the efficiency of clinical islet transplantation.
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Affiliation(s)
- Chloe L Rackham
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London , London , UK
| | - Paramjeet K Dhadda
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London , London , UK
| | - Aurélie M Le Lay
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London , London , UK
| | - Aileen J F King
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London , London , UK
| | - Peter M Jones
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, Faculty of Life Sciences and Medicine, King's College London , London , UK
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Cantley J, Walters SN, Jung MH, Weinberg A, Cowley MJ, Whitworth PT, Kaplan W, Hawthorne WJ, O'connell PJ, Weir G, Grey ST. A Preexistent Hypoxic Gene Signature Predicts Impaired Islet Graft Function and Glucose Homeostasis. Cell Transplant 2013; 22:2147-59. [DOI: 10.3727/096368912x658728] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
We examined whether hypoxic exposure prior to the event of transplantation would have a positive or negative effect upon later islet graft function. Mouse islets exposed to hypoxic culture were transplanted into syngeneic recipients. Islet graft function, β-cell physiology, as well as molecular changes were examined. Expression of hypoxia-response genes in human islets pre- and posttransplant was examined by microarray. Hypoxia-preexposed murine islet grafts provided poor glycemic control in their syngeneic recipients, marked by persistent hyperglycemia and pronounced glucose intolerance with failed first- and second-phase glucose-stimulated insulin secretion in vivo. Mechanistically, hypoxic preexposure stabilized HIF-1α with a concomitant increase in hypoxic-response genes including LDHA, and a molecular gene set, which would favor glycolysis and lactate production and impair glucose sensing. Indeed, static incubation studies showed that hypoxia-exposed islets exhibited dysregulated glucose responsiveness with elevated basal insulin secretion. Isolated human islets, prior to transplantation, express a characteristic hypoxia-response gene expression signature, including high levels of LDHA, which is maintained posttransplant. Hypoxic preexposure of an islet graft drives a HIF-dependent switch to glycolysis with subsequent poor glycemic control and loss of glucose-stimulated insulin secretion (GSIS). Early intervention to reverse or prevent these hypoxia-induced metabolic gene changes may improve clinical islet transplantation.
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Affiliation(s)
- James Cantley
- Diabetes and Obesity Research Program, Garvan Institute, Darlinghurst, New South Wales, Australia
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
| | - Stacey N. Walters
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
- Immunology Program, Garvan Institute, Darlinghurst, New South Wales, Australia
| | - Min-Ho Jung
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
| | - Anita Weinberg
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
- Immunology Program, Garvan Institute, Darlinghurst, New South Wales, Australia
| | - Mark J. Cowley
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
- Cancer Program, Garvan Institute, Darlinghurst, New South Wales, Australia
| | - P. Tess Whitworth
- Diabetes and Obesity Research Program, Garvan Institute, Darlinghurst, New South Wales, Australia
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
| | - Warren Kaplan
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
- Peter Wills Bioinformatics Centre, Garvan Institute, Darlinghurst, New South Wales, Australia
| | - Wayne J. Hawthorne
- The Centre for Transplant and Renal Research, Westmead Hospital, Westmead, New South Wales, Australia
| | - Philip J. O'connell
- The Centre for Transplant and Renal Research, Westmead Hospital, Westmead, New South Wales, Australia
| | - Gordon Weir
- Islet Cell and Regenerative Biology, Joslin Diabetes Center, Boston, MA, USA
| | - Shane T. Grey
- St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Darlinghurst, New South Wales, Australia
- Immunology Program, Garvan Institute, Darlinghurst, New South Wales, Australia
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Perez-Basterrechea M, Obaya AJ, Meana A, Otero J, Esteban MM. Cooperation by fibroblasts and bone marrow-mesenchymal stem cells to improve pancreatic rat-to-mouse islet xenotransplantation. PLoS One 2013; 8:e73526. [PMID: 24009755 PMCID: PMC3756982 DOI: 10.1371/journal.pone.0073526] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2013] [Accepted: 07/21/2013] [Indexed: 12/15/2022] Open
Abstract
Experimental and clinical experiences highlight the need to review some aspects of islet transplantation, especially with regard to site of grafting and control of the immune response. The subcutaneous space could be a good alternative to liver but its sparse vasculature is its main limitation. Induction of graft tolerance by using cells with immunoregulatory properties is a promising approach to avoid graft rejection. Both Fibroblasts and Mesenchymal Stem Cells (MSCs) have shown pro-angiogenic and immunomodulatory properties. Transplantation of islets into the subcutaneous space using plasma as scaffold and supplemented with fibroblasts and/or Bone Marrow-MSCs could be a promising strategy to achieve a functional extra-hepatic islet graft, without using immunosuppressive drugs. Xenogenic rat islets, autologous fibroblasts and/or allogenic BM-MSCs, were mixed with plasma, and coagulation was induced to constitute a Plasma-based Scaffold containing Islets (PSI), which was transplanted subcutaneously both in immunodeficient and immunocompetent diabetic mice. In immunodeficient diabetic mice, PSI itself allowed hyperglycemia reversion temporarily, but the presence of pro-angiogenic cells (fibroblasts or BM-MSCs) within PSI was necessary to improve graft re-vascularization and, thus, consistently maintain normoglycemia. In immunocompetent diabetic mice, only PSI containing BM-MSCs, but not those containing fibroblasts, normalized glycemia lasting up to one week after transplantation. Interestingly, when PSI contained both fibroblasts and BM-MSCs, the normoglycemia period showed an increase of 4-times with a physiological-like response in functional tests. Histology of immunocompetent mice showed an attenuation of the immune response in those grafts with BM-MSCs, which was improved by co-transplantation with fibroblasts, since they increased BM-MSC survival. In summary, fibroblasts and BM-MSCs showed similar pro-angiogenic properties in this model of islet xenotransplantation, whereas only BM-MSCs exerted an immunomodulatory effect, which was improved by the presence of fibroblasts. These results suggest that cooperation of different cell types with islets will be required to achieve a long-term functional graft.
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Affiliation(s)
- Marcos Perez-Basterrechea
- Transplants, Cell therapy and Regenerative Medicine Unit, Hospital Universitario Central de Asturias, Oviedo, Spain.
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Duncanson S, Sambanis A. Dual factor delivery of CXCL12 and Exendin-4 for improved survival and function of encapsulated beta cells under hypoxic conditions. Biotechnol Bioeng 2013; 110:2292-300. [DOI: 10.1002/bit.24872] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 02/06/2013] [Accepted: 02/08/2013] [Indexed: 12/16/2022]
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80
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Kerby A, Jones ES, Jones PM, King AJ. Co-transplantation of islets with mesenchymal stem cells in microcapsules demonstrates graft outcome can be improved in an isolated-graft model of islet transplantation in mice. Cytotherapy 2013; 15:192-200. [PMID: 23321331 DOI: 10.1016/j.jcyt.2012.10.018] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 08/14/2012] [Accepted: 10/05/2012] [Indexed: 01/12/2023]
Abstract
BACKGROUND AIMS Co-transplantation of islets with mesenchymal stem cells (MSCs) has been shown to improve graft outcome in mice, which has been partially attributed to the effects of MSCs on revascularization and preservation of islet morphology. Microencapsulation of islets provides an isolated-graft model of islet transplantation that is non-vascularized and prevents islet aggregation to preserve islet morphology. The aim of this study was to investigate whether MSCs could improve graft outcome in a microencapsulated/isolated-graft model of islet transplantation. METHODS Mouse islets and kidney MSCs were co-encapsulated in alginate, and their function was assessed in vitro. A minimal mass of 350 syngeneic islets encapsulated alone or co-encapsulated with MSCs (islet+MSC) were transplanted intraperitoneally into diabetic mice, and blood glucose concentrations were monitored. Capsules were recovered 6 weeks after transplantation, and islet function was assessed. RESULTS Islets co-encapsulated with MSCs in vitro had increased glucose-stimulated insulin secretion and content. The average blood glucose concentration of transplanted mice was significantly lower by 3 weeks in the islet+MSC group. By week 6, 71% of the co-encapsulated group were cured compared with 16% of the islet-alone group. Capsules recovered at 6 weeks had greater glucose-stimulated insulin secretion and insulin content in the islet+MSC group. CONCLUSIONS MSCs improved the efficacy of microencapsulated islet transplantation. Using an isolated-graft model, we were able to eliminate the impact of MSC-mediated enhancement of revascularization and preservation of islet morphology and demonstrate that the improvement in insulin secretion and content is sustained in vivo and can significantly improve graft outcome.
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Affiliation(s)
- Alan Kerby
- Diabetes Research Group, Division of Diabetes and Nutritional Sciences, School of Medicine, King's College London, London, UK
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81
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Liu S, Kilic G, Meyers MS, Navarro G, Wang Y, Oberholzer J, Mauvais-Jarvis F. Oestrogens improve human pancreatic islet transplantation in a mouse model of insulin deficient diabetes. Diabetologia 2013; 56:370-81. [PMID: 23132340 PMCID: PMC3536964 DOI: 10.1007/s00125-012-2764-1] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2012] [Accepted: 10/12/2012] [Indexed: 01/01/2023]
Abstract
AIMS/HYPOTHESIS Pancreatic islet transplantation (PIT) offers a physiological treatment for type 1 diabetes, but the failure of islet engraftment hinders its application. The female hormone 17β-oestradiol (E2) favours islet survival and stimulates angiogenesis, raising the possibility that E2 may enhance islet engraftment following PIT. METHODS To explore this hypothesis, we used an insulin-deficient model with xenotransplantation of a marginal dose of human islets in nude mice rendered diabetic with streptozotocin. This was followed by 4 weeks of treatment with vehicle, E2, the non-feminising oestrogen 17α-oestradiol (17α-E2), the oestrogen receptor (ER) α agonist propyl-pyrazole-triol (PPT), the ERβ agonist diarylpropionitrile (DPN) or the G protein-coupled oestrogen receptor (GPER) agonist G1. RESULTS Treatment with E2, 17α-E2, PPT, DPN or G1 acutely improved blood glucose and eventually promoted islet engraftment, thus reversing diabetes. The effects of E2 were retained in the presence of immunosuppression and persisted after discontinuation of E2 treatment. E2 produced an acute decrease in graft hypoxic damage and suppressed beta cell apoptosis. E2 also acutely suppressed hyperglucagonaemia without altering insulin secretion, leading to normalisation of blood glucose. CONCLUSIONS/INTERPRETATION During PIT, E2 synergistic actions contribute to enhancing human islet-graft survival, revascularisation and functional mass. This study identifies E2 as a short-term treatment to improve PIT.
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Affiliation(s)
- S. Liu
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Tarry 15-761, Chicago, IL 60611 USA
- Present Address: Diabetes Institute, the First Affiliated Hospital of Xiamen University, Xiamen, China
| | - G. Kilic
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Tarry 15-761, Chicago, IL 60611 USA
| | - M. S. Meyers
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Tarry 15-761, Chicago, IL 60611 USA
| | - G. Navarro
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Tarry 15-761, Chicago, IL 60611 USA
| | - Y. Wang
- Department of Surgery, Division of Transplant Surgery, University of Illinois at Chicago, Chicago, IL USA
| | - J. Oberholzer
- Department of Surgery, Division of Transplant Surgery, University of Illinois at Chicago, Chicago, IL USA
| | - F. Mauvais-Jarvis
- Department of Medicine, Division of Endocrinology, Metabolism and Molecular Medicine, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Tarry 15-761, Chicago, IL 60611 USA
- Northwestern Comprehensive Center on Obesity, Northwestern University Feinberg School of Medicine, Chicago, IL USA
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82
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Williams S, Schwasinger-Schmidt T, Zamierowski D, Stehno-Bittel L. Diffusion into human islets is limited to molecules below 10kDa. Tissue Cell 2012; 44:332-41. [DOI: 10.1016/j.tice.2012.05.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Revised: 05/14/2012] [Accepted: 05/25/2012] [Indexed: 11/30/2022]
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83
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Stem cells as a tool to improve outcomes of islet transplantation. J Transplant 2012; 2012:736491. [PMID: 22970344 PMCID: PMC3437295 DOI: 10.1155/2012/736491] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 07/02/2012] [Indexed: 12/24/2022] Open
Abstract
The publication of the promising results of the Edmonton protocol in 2000 generated optimism for islet transplantation as a potential cure for Type 1 Diabetes Mellitus. Unfortunately, follow-up data revealed that less than 10% of patients achieved long-term insulin independence. More recent data from other large trials like the Collaborative Islet Transplant Registry show incremental improvement with 44% of islet transplant recipients maintaining insulin independence at three years of follow-up. Multiple underlying issues have been identified that contribute to islet graft failure, and newer research has attempted to address these problems. Stem cells have been utilized not only as a functional replacement for β cells, but also as companion or supportive cells to address a variety of different obstacles that prevent ideal graft viability and function. In this paper, we outline the manners in which stem cells have been applied to address barriers to the achievement of long-term insulin independence following islet transplantation.
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84
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Acute hypoxia induces apoptosis of pancreatic β-cell by activation of the unfolded protein response and upregulation of CHOP. Cell Death Dis 2012; 3:e322. [PMID: 22695615 PMCID: PMC3388238 DOI: 10.1038/cddis.2012.66] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
The success of pancreatic β-cells transplantation to treat type 1 diabetes has been hindered by massive β-cell dysfunction and loss of β-cells that follows the procedure. Hypoxia-mediated cell death has been considered one of the main difficulties that must be overcome for transplantation to be regarded as a reliable therapy. Here we have investigated the mechanisms underlying β-cell death in response to hypoxia (1% O2). Our studies show that mouse insulinoma cell line 6 (Min6) cells undergo apoptosis with caspase-3 activation occurring as early as 2 h following exposure to hypoxia. Hypoxia induces endoplasmic reticulum stress in Min6 cells leading to activation of the three branches of the unfolded protein response pathway. In response to hypoxia the pro-apoptotic transcription factor C/EBP homologous protein (CHOP) is upregulated. The important role of CHOP in the apoptotic process was highlighted by the rescue of Min6 cells from hypoxia-mediated apoptosis observed in CHOP-knockdown cells. Culturing isolated pancreatic mouse islets at normoxia showed intracellular hypoxia with accumulation of hypoxia-inducible factor-1α and upregulation of CHOP, the latter one occurring as early as 4 h after isolation. Finally, we observed that pancreatic islets of type 2 db/db diabetic mice were more hypoxic than their counterpart in normoglycemic animals. This finding indicates that hypoxia-mediated apoptosis may occur in type 2 diabetes.
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85
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Henriksnäs J, Lau J, Zang G, Berggren PO, Köhler M, Carlsson PO. Markedly decreased blood perfusion of pancreatic islets transplanted intraportally into the liver: disruption of islet integrity necessary for islet revascularization. Diabetes 2012; 61:665-73. [PMID: 22315321 PMCID: PMC3282819 DOI: 10.2337/db10-0895] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Experimental studies indicate low revascularization of intraportally transplanted islets. This study aimed to quantify, for the first time, the blood perfusion of intrahepatically transplanted islets and elucidate necessary factors for proper islet graft revascularization at this site. Yellow chameleon protein 3.0 islets expressing fluorescent protein in all cells were transplanted. Graft blood perfusion was determined by microspheres. The vascular density and relative contribution of donor blood vessels in revascularization was evaluated using islets expressing green fluorescent protein under the Tie-2 promoter. Blood perfusion of intrahepatic islets was as a mean only 5% of that of native islets at 1-month posttransplantation. However, there was a marked heterogeneity where blood perfusion was less decreased in islets transplanted without prior culture and in many cases restored in islets with disrupted integrity. Analysis of vascular density showed that distorted islets were well revascularized, whereas islets still intact at 1-month posttransplantation were almost avascular. Few donor endothelial cells were observed in the new islet vasculature. The very low blood perfusion of intraportally transplanted islets is likely to predispose for ischemia and hamper islet function. Since donor endothelial cells do not expand posttransplantation, disruption of islet integrity is necessary for revascularization to occur by recipient blood vessels.
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Affiliation(s)
| | - Joey Lau
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Guangxiang Zang
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
| | - Per-Olof Berggren
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Martin Köhler
- Rolf Luft Research Center for Diabetes and Endocrinology, Karolinska Institutet, Stockholm, Sweden
| | - Per-Ola Carlsson
- Department of Medical Cell Biology, Uppsala University, Uppsala, Sweden
- Department of Medical Sciences, Uppsala University, Uppsala, Sweden
- Corresponding author: Per-Ola Carlsson,
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86
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Striated muscle as implantation site for transplanted pancreatic islets. J Transplant 2011; 2011:352043. [PMID: 22174984 PMCID: PMC3235886 DOI: 10.1155/2011/352043] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Accepted: 09/20/2011] [Indexed: 01/27/2023] Open
Abstract
Islet transplantation is an attractive treatment for selected patients with brittle type 1 diabetes. In the clinical setting, intraportal transplantation predominates. However, due to extensive early islet cell death, the quantity of islets needed to restore glucose homeostasis requires in general a minimum of two donors. Moreover, the deterioration of islet function over time results in few insulin-independent patients after five-year followup. Specific obstacles to the success of islet transplantation include site-specific concerns for the liver such as the instant blood mediated inflammatory reaction, islet lipotoxicity, low oxygen tension, and poor revascularization, impediments that have led to the developing interest for alternative implantation sites over recent years. Within preclinical settings, several alternative sites have now been investigated and proven favorable in various aspects. Muscle is considered a very promising site and has physiologically properties and technical advantages that could make it optimal for islet transplantation.
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87
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Rodriguez-Rilo HL, Grigsby BM, Gruessner RWG. Pharmacologic strategies for improvement of islet survival: targeting the enterohormonal axis. Transpl Int 2011; 24:1156-8. [PMID: 22050184 DOI: 10.1111/j.1432-2277.2011.01377.x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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