Advantages of combined fetal and adult porcine islets as donor tissue for transplantation

Abstract

Abstract: The molecular similarity between human and porcine insulin is the primary reason for selecting the pig as a donor for islet xenotransplantation in order to treat type I diabetes. Porcine islets can be prepared from adult, newborn, or fetal pigs. However, each of these islet types possesses advantages and disadvantages due to their anatomical, developmental, and physiological characteristics. We have evaluated both adult and fetal porcine islets for their ability to reverse diabetes using an allograft model. Based on our accumulated data, we recommend transplantation of combined adult and fetal porcine islets as a prospective approach for pig to man islet xenotransplantation. The advantages of combined adult and fetal islet transplantation are as follows: 1) Adult porcine islets can reverse hyperglycemia soon after transplantation; 2) well controlled blood glucose at the critical developmental stage of fetal islets will provide the time and environment necessary to achieve the optimal proliferation, growth and maturation of fetal β cells; 3) after 2 to 3 months, fetal islets will functionally mature and begin to share the insulin‐producing load previously carried by adult islets, while new islets will continuously emerge and proliferate from stem cells; and 4) islets from fetal pigs will subsequently play a primary role in controlling hyperglycemia, and provide long‐lasting insulin independence.