Die nukleär-cytosolische Translokation von PTB1 in Langerhans-Inseln — ein potentieller Marker für die Inselqualität vor der Transplantation

High glucose concentrations trigger the translocation of polypyrimidine-tract-binding protein 1 (PTB1) from the nucleus to the cytosol, where it stabilizes the mRNA of insulin and secretory granule proteins, thereby increasing their translation. This mechanism is required for rapid restoration of the secretory granule pool upon glucose stimulation. Its functional importance suggests that PTB1 signal-ling might be a good candidate for islet quality assessment prior to transplantation. However, all data concerning the »PTB1 pathway« was obtained in insulinoma cell lines and isolated rodent islets. Therefore, we investigated the glucose stimulated nucleocytoplasmic PTB1 translocation in human islets