Beta-cell sparing in transplanted islets by vascular endothelial growth factor
Autor: | Lathakumari Parthasarathy, Ranganathan Parthasarathy, E. Samols, M. Stagner, John I. Stagner, S. Mokshagundam, H. Rilo, K. Wyler |
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Rok vydání: | 2004 |
Předmět: |
Graft Rejection
Vascular Endothelial Growth Factor A medicine.medical_specialty Necrosis Cell Survival Islets of Langerhans Transplantation Apoptosis Biology Diabetes Mellitus Experimental chemistry.chemical_compound Islets of Langerhans Annexin Internal medicine medicine Animals Transplantation Homologous Propidium iodide Transplantation geography geography.geographical_feature_category Islet Rats Vascular endothelial growth factor Endocrinology chemistry Rats Inbred Lew Models Animal Surgery medicine.symptom Beta cell Subrenal Capsule Assay |
Zdroj: | Transplantation proceedings. 36(4) |
ISSN: | 0041-1345 |
Popis: | We have reported that vascular endothelial growth factor (VEGF) promotes the revascularization of transplanted islets, thereby reducing the initial number required to prevent diabetes. The present study was undertaken to assess other mechanisms of beta-cell sparing by VEGF. For in vitro studies, islets were cultured for 14 days with versus without 20 ng/mL VEGF. Viability, necrosis, and apoptosis were examined by specific staining (Alcein AM, propidium iodide, and annexin/phosphatidylserine). The effects of VEGF on islets were also examined in a proteomic study. In vivo streptozotocin-treated diabetic Lewis rats received 1000 Lewis or Sprague-Dawley islets beneath the renal capsule. Oxygen levels at the transplant site were monitored by a Clark-type oxygen electrode. Fasting blood glucose served as an indicator of islet survival and function. VEGF enhanced oxygen levels at the transplant site. Syngeneic recipients were euglycemic for over 6 months, whereas control islets failed within 30 to 60 days. VEGF prevented allograft rejection for over 14 days, whereas controls were rejected within 6 to 7 days. Immunostaining suggested that VEGF inhibited the presentation of MHC II antigen and promoted islet survival by the inhibition of necrosis and apoptosis. Our proteomic study suggested VEGF preserved systems required for cellular preservation (heat shock proteins) and insulin secretion. VEGF promotes the preservation of isolated and transplanted islets by a variety of mechanisms, including enhanced oxygenation and inhibition of immune rejection, necrosis, and apoptosis. The provision of exogenous VEGF may be a useful adjunct to islet transplantation. |
Databáze: | OpenAIRE |
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