Abstract:

Objective  To observe differentiation rate of Pancreatic stem cells (PSCs) when they were cocultured with islet, and then study its mechanism. Methods  Isolation of rat islets was performed with collagenase-V digestion and purification by using Ficoll-400. At the same time,  PSCs were harvested from pancreatic rudiments of fetal rats by using collagenase digestion and identified by immuocytochemistry and RT-PCR after culture in the second generation.  Then islet and PSCs were cultured together, and  insulin expression of PSCs was observed to evaluate the rate of PSCs to differentiate to insulin-producing cells. Results  Islets with biological viability   were obtained  by using collagenase-V and Ficoll-400 in digestion and purification. Most of the PSCs expressed CK-19, nestin and glucogon, and some of the PSCs also expressed insulin after induction. The rates of insulin-positive PSCs in islet-stem cell cocultured group and stem cell cultured group were 38.2% and 23.9% (P<0.05)  respectively, and  the rates of CK-19 positive PSCs in the two group were 89.3% and 81.6% respectively (P<0.05). Conclusio  nCocultivation with islet can make PSCs differentiate into insulin-producing cells, which is closely related to the expression of intracellular CK-19.

Key words: Diabetes mellitus; Islet transplantation; Stem cells; Induction; Differentiation; Rats, Wistar