Effects of Insulin-Like Growth Factor-1 and Donor Age on Transplantation of Porcine Neonatal Pancreatic Cell Clusters

Porcine neonatal pancreatic cell clusters (NPCCs) isolated from 1- to 3-day-old pigs cured diabetic nude mice more than 14 weeks after transplantation. To shorten the latent period between transplantation and reversal of hyperglycemia, we investigated the effects of insulin-like growth factor-1 (IGF-1) and NPCCs isolated from 1-month-old pigs after transplantation. Pig pancreata were cut into fragments, collagenase digested, and then cultured. Three hundred and 2000 NPCCs were transplanted under the kidney capsule of nondiabetic and diabetic nude mice, respectively. After transplantation, the graft-bearing kidneys were removed to measure insulin content. NPCCs isolated from 1- to 3-day-old pigs were cultured with or without IGF-1 for 6 days. The stimulation index was not significantly different between the 2 groups at 1, 2, or 4 weeks. Moreover, at 4 weeks after transplantation of 300 NPCCs to nondiabetic nude mice yielded comparable graft insulin content as the recipients of NPCCs precultured with or without IGF-1. Two thousand cultured NPCCs isolated from 1-to 3-day-old pigs or 1-month-old pigs were transplanted into diabetic nude mice. The blood glucose levels of diabetic recipients in both groups decreased at the same rate after transplantation, achieving normoglycemia at 8 weeks. The graft insulin content at 12 weeks was not different between the 2 groups. Our data indicated that isolated NPCCs cultured with IGF-1 showed no beneficial effects on insulin secretion and transplantation; NPCCs isolated from 1-to 3-day-old and 1-month-old pigs displayed similar effects on transplantation.