Type 1 or “juvenile” Diabetes is an autoimmune disease in which the insulin secreting beta-cells, essential for glucose homeostasis, are destroyed by a target immune attack. To date, patients with type 1 Diabetes can rely only on exogenous insulin injection to control the glucose levels, but, unfortunately, the related chronic and devastating complications cannot be prevented. Identification of beta-cell-specific genes playing critical roles during the development will help to create new sources of beta-cells from stem/progenitor cells. Interestingly, endocrine cell fate appears to be governed by the “peaked” expression of the transcription factor Ngn3. However, Ngn3’s targets are still not well identified. As for pancreas development also insulin gene regulation lacks important information. Therefore the aims of this Thesis work have been to test an set-up an efficient system for the transient expression of Ngn3, mimicking its physiological behavior; identify the major factors that lie directly downstream the Ngn3 expression and characterize a novel beta-cell specific insulin gene regulator. As result from this work, an innovative system mimicking pancreatic differentiation and Ngn3 pulsed expression has been developed. Furthermore, a novel Ngn3’s downstream target, the zinc-finger protein “OVO_like 1, has been identified opening a new, and interesting, scenario of Ngn3 gene’s regulation. Last, but not least, the beta-cell-insulin-gene regulator A2.2 has been characterized and a reproducible purification system has been developed.
