Strong Promoter Activity of Human and Rat Islet Amyloid Polypeptide / Amylin Gene Constructs in Mouse Beta Cells (βTC 3)

Islet amyloid polypeptide (IAPP)(′amylin′) is co-produced with insulin in pancreatic β cells and is the formative polypeptide of pancreatic amyloid in patients with type 2 (non-insulin-dependent) diabetes mellitus. Islet amyloid and type 2 diabetes occur in man, but not in rat. To study transcription regulation of IAPP gene expression in man and rat, luciferase reporter constructs containing different portions of the upstream region of both IAPP genes were expressed in transfected cells. Both the human and the rat IAPP gene constructs revealed higher promoter activity in β cells (particularly in βTC3 cells) than in non-β cells. In both IAPP genes potential transcription elements, with homology to insulin gene transcription elements, were identified. βTC3 cells provide a good model system in which to study regulation of human and rat IAPP gene expression.