Islet neogenesis from non pancreatic stem cells

Abstract

Although insulin was discovered over 85 years ago, the complications of diabetes still produce devastating consequences. An obvious path to prevention of complications is some kind of beta cell replacement therapy in the form of transplantation. Introduction of Edmonton protocol in the year 2000 provided better results in islet preparation, transplantation and improved immunosuppression. In-spite of this success, the supply of insulin producing cells, currently only from heart beating cadaver donor is insufficient and limits the extension of this therapy. Hence, the quest to find an alternative source of insulin producing cells that might be used for transplantation is intense. Rapid improvement in our understanding of the mechanism of cellular development and a wide array of potential stem/precursor cell candidates provide fuel for optimization of the short supply of insulin producing cells. newline An important issue of interest in stem cell studies is the availability of the source and the efficacy of isolation techniques to yield a reasonable amount of viable cells to expand. Although, embryonic stem (ES) cells showed some gene characteristics similar to normal beta cells; ethical issues surrounding ES cells are major concern. newline A variety of studies support the concept that adult stem cells can be directed to become insulin producing cells. Current claims about differentiation / transdifferentiation of adult stem cells to insulin producing cells includes pancreatic ductal cells, intra islet precursor cells, hepatic stem cells, neural progenitor cells, and bone marrow-derived cells. These adult stem cells are of enormous interest because of their general accessibility and potential to avoid ethical issues that are associated with embryonic stem cells. Also, adult stem cells are non immuno-compatible unless isolated from the same patient whereas ethical and scientific issues surrounding embryonic and fetal stem cells hinder their widespread implementation.