The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant
β-Cell replacement therapy by either whole-organ pancreas or islets of Langerhans transplantation can restore carbohydrate control to diabetic patients and reduces complications associated with the disease. One of the variables inherent in islet transplantation is the isolation of functional islets...
| Main Authors: | , , , , , , |
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| Format: | Article |
| Language: | English |
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SAGE Publishing
2012-12-01
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| Series: | Cell Transplantation |
| Online Access: | https://doi.org/10.3727/096368912X653273 |
| _version_ | 1818842240559087616 |
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| author | Andrew R. Pepper Craig P. Hasilo C. W. James Melling Delfina M. Mazzuca Greg Vilk Guangyong Zou David J. G. White |
| author_facet | Andrew R. Pepper Craig P. Hasilo C. W. James Melling Delfina M. Mazzuca Greg Vilk Guangyong Zou David J. G. White |
| author_sort | Andrew R. Pepper |
| collection | DOAJ |
| description | β-Cell replacement therapy by either whole-organ pancreas or islets of Langerhans transplantation can restore carbohydrate control to diabetic patients and reduces complications associated with the disease. One of the variables inherent in islet transplantation is the isolation of functional islets from donor pancreata. Islet isolations fail to consistently produce good-quality functional islets. A rapid pretransplant assay to determine posttransplant function of islets would be an invaluable tool. We have tested the novel hypothesis that modified oxygen consumption rates (OCR), standardized to DNA quantity (nmol/min-mg DNA), would serve as a pretransplant assessment of the metabolic potency of the islets postisolation. This study compares the ability of current in vitro assays to predict in vivo restoration of normoglycemia in a diabetic nude mouse posttransplantation of adult pig islets. There is known to be a diversity of islet sizes within each preparation. This parameter has not heretofore been effectively considered a critical factor in islet engraftment. Our results suggest a surprising finding that islet size influences the probability of restoring carbohydrate control. Based on this observation, we thus developed a novel predictor of islet graft function that combines the effects of both islet OCR and size. When OCR was divided by the islet index (size), a highly significant predictor of graft function was established ( p = 0.0002, n = 75). Furthermore, when OCR/islet index values exceeded 70.0 nmol/min-mg DNA/islet index, an effective threshold of diabetes reversal was observed. This assay can be performed with as few as 1,000 islet equivalents (IEQ) and conducted in less than 60 min. Our data suggest that, using this novel method to assess islet cell function prior to transplantation, OCR/islet index thresholds provide a valuable tool in identifying which islet preparations are most likely to restore glycemic control posttransplant. |
| first_indexed | 2024-12-19T04:38:50Z |
| format | Article |
| id | doaj.art-1573c731b8d04d72a20d4ab05850525b |
| institution | Directory Open Access Journal |
| issn | 0963-6897 1555-3892 |
| language | English |
| last_indexed | 2024-12-19T04:38:50Z |
| publishDate | 2012-12-01 |
| publisher | SAGE Publishing |
| record_format | Article |
| series | Cell Transplantation |
| spelling | doaj.art-1573c731b8d04d72a20d4ab05850525b2022-12-21T20:35:41ZengSAGE PublishingCell Transplantation0963-68971555-38922012-12-012110.3727/096368912X653273The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes PosttransplantAndrew R. Pepper0Craig P. Hasilo1C. W. James Melling2Delfina M. Mazzuca3Greg Vilk4Guangyong Zou5David J. G. White6Multi-Organ Transplantation Program, London Health Science Centre, London, ON, CanadaMulti-Organ Transplantation Program, London Health Science Centre, London, ON, CanadaDepartment of Health Sciences, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, CanadaMulti-Organ Transplantation Program, London Health Science Centre, London, ON, CanadaMulti-Organ Transplantation Program, London Health Science Centre, London, ON, CanadaDepartment of Epidemiology and Biostatistics, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, CanadaDepartment of Surgery, Schulich School of Medicine and Dentistry, University of Western Ontario, London, ON, Canadaβ-Cell replacement therapy by either whole-organ pancreas or islets of Langerhans transplantation can restore carbohydrate control to diabetic patients and reduces complications associated with the disease. One of the variables inherent in islet transplantation is the isolation of functional islets from donor pancreata. Islet isolations fail to consistently produce good-quality functional islets. A rapid pretransplant assay to determine posttransplant function of islets would be an invaluable tool. We have tested the novel hypothesis that modified oxygen consumption rates (OCR), standardized to DNA quantity (nmol/min-mg DNA), would serve as a pretransplant assessment of the metabolic potency of the islets postisolation. This study compares the ability of current in vitro assays to predict in vivo restoration of normoglycemia in a diabetic nude mouse posttransplantation of adult pig islets. There is known to be a diversity of islet sizes within each preparation. This parameter has not heretofore been effectively considered a critical factor in islet engraftment. Our results suggest a surprising finding that islet size influences the probability of restoring carbohydrate control. Based on this observation, we thus developed a novel predictor of islet graft function that combines the effects of both islet OCR and size. When OCR was divided by the islet index (size), a highly significant predictor of graft function was established ( p = 0.0002, n = 75). Furthermore, when OCR/islet index values exceeded 70.0 nmol/min-mg DNA/islet index, an effective threshold of diabetes reversal was observed. This assay can be performed with as few as 1,000 islet equivalents (IEQ) and conducted in less than 60 min. Our data suggest that, using this novel method to assess islet cell function prior to transplantation, OCR/islet index thresholds provide a valuable tool in identifying which islet preparations are most likely to restore glycemic control posttransplant.https://doi.org/10.3727/096368912X653273 |
| spellingShingle | Andrew R. Pepper Craig P. Hasilo C. W. James Melling Delfina M. Mazzuca Greg Vilk Guangyong Zou David J. G. White The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant Cell Transplantation |
| title | The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant |
| title_full | The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant |
| title_fullStr | The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant |
| title_full_unstemmed | The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant |
| title_short | The Islet Size to Oxygen Consumption Ratio Reliably Predicts Reversal of Diabetes Posttransplant |
| title_sort | islet size to oxygen consumption ratio reliably predicts reversal of diabetes posttransplant |
| url | https://doi.org/10.3727/096368912X653273 |
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