In type 1 diabetes patients, pancreatic insulin-producing β cells are absolutely deficient. It is possible to heal them by pancreas and islet transplantation. Currently the pancreas from human cadaver donor are being used for the treatments, but the lack of donor is a big problem. Several cell sources to replace these beta cells are being extensively investigated. Among them, Young Porcine Islets has become as a big expectation as a new source for the type 1 diabetes treatment. But the problem of the Young Porcine Islets are immature, so it is needed to develop the methods for the maturation in vitro. Our research has introduced the approach using the Helper dependent adenovirus (HDAdV) to insert Venus gene under the Insulin promoter (HDAdv INS-Venus), which system is available to recombiner into the genome. The Helper dependent adenovirus was previously developed to allow us carrying the long arm that to be able to recombiner efficiently. Current HDAdv INS-Venus specifically constructed to recombiner into human induced pluripotent stem (iPS) cells was previously demonstrated (1). We tested if this Adenovirus could infect also in porcine islets, and how long we could monitor. The results showed that, after 2 days of infection of 1moi, the Venus positive cells could be seen. (Fig.1). The Venus positive cells and dithizone positive cells, that is another easy indicative of the beta cells, are almost concordant. The ratio of Venus positive cells in the islets also was augmented after 3 weeks, indicating the possibility to monitor in a long time.(Fig.2)Thus, this system would enable us to develop the adequate culture methods for maturation of the cells in-vitro. We are now developing the appropriate culture methods by which the Young Porcine Islets can normalize the glucose levels in experimental induced diabetic mice.
Reference
1)Yamashita-Sugahara Y, Matsumoto M, Ohtaka M, Nishimura K, Nakanishi M, Mitani K, Okazaki Y. An inhibitor of fibroblast growth factor receptor-1 (FGFR1) promotes late-stage terminal differentiation from NGN3+ pancreatic endocrine progenitors. Sci Rep. 2016 Oct 27;6:35908