Diabetes is a life-threatening disease caused by insufficient circulating insulin, a key metabolic hormone produced by pancreatic β cells. A promising approach to diabetes treatment is cell replacement therapy, yet this is currently limited by shortage of donor β cells. To address this, direct reprogramming of somatic non-β cells has been suggested as a potential source of β cells. The goal of this research is to clarify the molecular mechanisms involved in the process of reprogramming to β cells. We developed and characterized an in vitro system for reprogramming of primary mouse pancreatic acinar cells to β-like cells. Reprogrammed cells exhibit many similarities to native β-cells. Furthermore, this system allowed the identification of the transcriptional repressor REST (RE-1 silencing transcription factor) as a novel regulator of reprogramming which acts by modifying the chromatin around endocrine gene enhancers, thereby altering accessibility and function of endocrine transcription factors. Improved understanding of the mechanisms underlying reprogramming are essential to permit its application in the future for regenerative and cell therapy-based treatment of diabetes.
