Although approximately 1 million islets exist in the adult human pancreas, current pancreas preservation and islet isolation techniques recover fewer than 50% of the islets. Studies demonstrated organ deterioration following brain death (BD) by multiple interrelated events, including the effects of cerebral injury, homodynamic instability that generates oxidative stress, release of pro-inflammatory cytokines, as well as endocrine abnormalities including rapid loss of circulatory triiodothyroxine (T3), cortisol, insulin, and vasopressin. This hormonal depletion is associated with increased inability of organs to metabolize aerobically with a consequent increase in anaerobic metabolism. Hence, depletion of high-energy stores (ATP, creatine phosphate, and glycogen), and accumulation of lactate are associated with deterioration of organ function. Our preliminary studies demonstrated that BD in both animals and humans is associated with a significant reduction in isolated islet recovery, functionality, and engraftment. Furthermore, islets recovered from BD animals presented higher inflammation-related nuclear transcriptional activity and lower expression of anti-apoptotic factors, compared with islets obtained from normal donors. Strategies to optimize the use of available organs have focused on the importance of hemodynamic stability, replacing hormonal deficiencies, and possible dampening the effects of oxidative stress and PIC release. In this regard, the change to anaerobic metabolism, loss of energy stores, and deterioration of cardiac function can all be reversed by Ta administration. Accordingly, by recommendation of the American Society of Transplant Surgeons, multiorgan donors should receive """"""""Hormonal Therapy"""""""", which includes a combination of T3, vasopressin, insulin, and cortisol, to """"""""improve"""""""" donor management and increase both quality and number of procured organs. However, to date, this approach has not been widely followed and no information is available about the potential beneficial/detrimental effects on human islet recovery, functionality, and engraftment. Furthermore, hormonal therapy usually is implemented with the intention to achieve hemodynamic stability, not to supplement endocrine abnormalities developed early after the establishment of BD. We hypothesize that early multiorgan donor intervention with Ts, insulin, cortisol, and vasopressin will prevent/decrease deleterious effects of BD on islet recovery, function and engraftment.
Our specific aims are:1) To analyze the effects of early treatment of multiorgan donors with Ts, cortisol, vasopressin, and insulin therapy on islet recovery, functionality, and engraftment. These studies will include analysis of islet recovery, purity, functionality, inflammation- and apoptosis-related transcriptional profiles, and engraftment of islets obtained from multiorgan donors treated with hormonal therapy versus donors given vehicle. 2) To evaluate hormonal therapy as a therapeutic intervention to improve islet recovery and functionality from marginal multiorgan donors. We will explore potential to increase the quality of marginal multiorgan donors. Islet recovery, purity, functionality, inflammation- and apoptosis-related transcriptional profiles, and engraftment will be evaluated from marginal donors given hormonal therapy versus saline. 3: To provide high quality isolated human islets for clinical transplantation and for diabetes research. The Alabama Organ Center (AOC) is the only Organ Procurement Organization in the state of Alabama and provides organs to The University of Alabama at Birmingham (the only Transplant Center in the state). At this Institution, >300 kidneys, 80-110 livers, 12-25 hearts and 19-36 lung transplants are performed each year. 90-130 organ donors are processed by the AOC per year and 10-25 pancreases per year have been used for whole pancreas transplantation during the last 10 years. Accordingly, a large pool of pancreases is available for the proposed studies. DAB clinical activity in islet transplantation includes 3 patients with type 1 diabetes, 4 auto-transplants, and a clinical protocol recently approved for islets-after-kidney transplantation. To date, >90% of the pancreases obtained through the AOC and processed by our islet isolation team resulted in """"""""clinical grade"""""""" islet preparations. The proposed studies fulfill all the objectives of this RFA, which include the establishment of an ICR center capable of obtaining high yields and high quality isolated islets for clinical or basic research and implement procedures that result in maximal islet function upon transplantation.
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