ESPE Abstracts

The ultimate therapy for type 1 diabetes is the replacement of the lost insulin producing cells instead of the actual life-saving but imperfect substitution of insulin. The isolation of embryonic stem cells (ESC) and later the reprogramming of somatic cells into induced pluripotent stem cells (iPSC) raised enormous hopes for cell based therapies in diabetes type 1. The first important stage in the differentiation process of ESC/iPSC is the generation of definite endoderm that contain cells which are positive for critical pancreatic transcription factors such as Pdx1 and Nkx6.1. At this time the decision to enter the pancreatic endocrine pathway is triggered by induction of Ngn3 and followed by the successive activation of other critical transcription factors required for differentiation and maturation of insulin secreting beta cells. Despite recent progress in the generation of insulin secreting cells from pluripotent stem cells, there is a considerable variability in the differentiation efficacy and each cell lines require protocol adjustments. One reason for these observations is the inability to really control cell fate decisions at critical stages of the differentiation process such as the timely and efficient activation of Ngn3 for determination of the pancreatic endocrine phenotype. In order to overcome this hurdle we engineered a genetic software using the tools of synthetic biology, that allows to control the timing and intensity of Ngn3 activation as well as the following sequential induction of Pdx1 and MafA, that are required for differentiation and maturation of functional insulin secreting cells. More than 75% of iPSC that were regulated by this genetic software differentiated into insulin positive cells that displayed glucose stimulated insulin secretion. Cell fate controlling genetic software may help to unveil the real potential of iPS for the replacement of insulin producing cells in type 1 diabetes through reliable control of critical developmental steps.