Regenerative medicine of the pancreatic β cells

Abstract

Diabetes mellitus is a metabolic disorder that affects millions of people. The number of patients suffering from diabetes continues to increase all over the world. Both type 1 and type 2 diabetes result from an inadequate mass of functioning beta cells. To achieve the ultimate goal of curing diabetes in the future, the mechanism of the regenerative process of the adult human pancreas must be elucidated. In this review, we first summarize the regenerative processes of the pancreas observed in animal models in vivo, and approaches to promote the regeneration of the pancreas in vivo. Next we consider other new approaches, such as stem cell research and cell-based therapy, for the cure of diabetes in the future. Based on the innovative success of the Edmonton protocol, islet transplantation has been considered to be a new therapeutic option for the treatment of diabetes. However, a serious shortage of donor pancreata is a critical problem. We suggest that the following issues should be solved in order to realize cell-based therapy. The first is to establish a source of stem/progenitor cells that will multiply easily in vitro and maintain their property as progenitor cells. The probable use of adult stem cells will circumvent potential ethical problems, and autotransplantation will become possible. The most difficult and as yet unsolved issue is how to differentiate these cells and acquire fully functional islets. Further investigations to understand the regenerative process of the adult pancreas and the appropriate induction of stem cell differentiation will help to establish cell-based therapy in diabetes.