Characteristics and transplantation of the porcine neonatal pancreatic cell clusters isolated from 1- to 3-day-old versus 1-month-old pigs

Porcine neonatal pancreatic cell clusters (NPCCs) isolated from 1- to 3-day-old pigs (I-A) cured diabetic nude mice within 8 weeks after transplantation. To shorten the latent period between transplantation and reversal of hyperglycemia, we studied NPCCs isolated from 1-month-old pigs (I-B). One- to 3-day-old or 1-month-old pig pancreata were cut into fragments, digested by collagenase, and then studied for islet characteristics. In addition, 300 cultured NPCCs were transplanted under kidney capsule of nondiabetic nude mice. At 1 and 3 months after transplantation, the grafts were removed to measure the insulin content and β-cell mass. Immediately after isolation, I-B was larger than I-A (0.211 ± 0.006 vs 0.189 ± 0.003 mm², P = .0003) and after a 6-day culture period, I-B contained more insulin than I-A (6.8 ± 1.4 vs 2.3 ± 0.2 μg/150 NPCCs, P = .02). However, the stimulation indices of I-A and I-B during static incubation with 500 mg/dL glucose (26.5 ± 3.2 vs 23.9 ± 1.7) or 500 mg/dL glucose plus 50 mol/L IBMX (41.9 ± 4.4 vs 62.2 ± 14.0) were not significantly different. Furthermore, neither I-A nor I-B showed first or second phase insulin secretion during sequential perifusion with 100 or 300 mg/dL glucose. In nondiabetic recipients, the insulin content of the graft at 1 month after transplantation was 0.3 ± 0.0 and 0.3 ± 0.1 μg, and the β-cell mass of the graft at 3 months was 0.069 ± 0.022 and 0.067 ± 0.023 mg in mice receiving I-A or I-B, respectively (P > .05). Our data indicate NPCCs isolated from 1- to 3-day-old and 1-month-old pigs have different characteristics but similar transplantation effects.