Specific dynamic and noninvasive labeling of pancreatic β cells in reporter mice

✍ Scribed by Ahmi Ben-Yehudah; Bonnie Reinhart; Chris Navara; Joyce Kotzuk; Selma Witchel; Gerald Schatten; J. Richard Chaillet

• Publisher: John Wiley and Sons
• Year: 2005
• Tongue: English
• Weight: 561 KB
• Volume: 43
• Category: Article
• ISSN: 1526-954X
• DOI: 10.1002/gene.20165

✦ Synopsis

Abstract

Noninvasive detection of differentiated cells is increasingly demanded for accurate and reliable assessments of both in vitro and in vivo experimental systems. Here we present an efficient, innovative approach for imaging the β cells of the pancreatic islets of Langerhans. The main physiologic function of β cells is glucose‐stimulated insulin secretion. This function is facilitated through the synthesis and storage of insulin in secretory vesicles of β cells, which then release their contents when β cells are exposed to hyperglycemic conditions. To visualize β cells in vivo in the mouse, we used targeted mutagenesis techniques to construct a modified insulin II (InsII) gene allele, InsII^EGFP^, that expresses a proinsulin‐EGFP (enhanced green fluorescent protein) fusion peptide. The EGFP portion of this fusion is entirely within the C‐peptide portion of the proinsulin peptide. This fusion protein is processed in β cells to insulin and EGFP‐tagged C peptide, which are stored together in cytoplasmic secretory vesicles. The large amount of vesicular EGFP‐tagged C peptide is evident as a characteristic robust and specific fluorescence pattern in the β cells of InsII^EGFP^ mice. This innovative method of visualizing β cells will be a useful tool in the study of both β cell physiology and the development of the endocrine cells of the pancreas.genesis 43:166–174, 2005. © 2005 Wiley‐Liss, Inc.