Identification of genes that are involved in differentiation of pancreatic ductal cells to pancreatic β-cells.

2006 Fiscal Year Final Research Report Summary

• Project/Area Number: 17590924
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Single-year Grants
• Section: 一般
• Research Field: Metabolomics
• Research Institution: University of Yamanashi
• Principal Investigator: AIDA Kaoru University of Yamanashi, University of Yamanashi Hospital, Assistant professor, 医学部附属病院, 講師 (50184015)
• Co-Investigator(Kenkyū-buntansha): HARII Norikazu University of Yamanashi, University of Yamanashi Hospital, Senior Resident, 医学部附属病院, シニアレジデント (80377522) ; KOBAYASHI Tetsuro University of Yamanashi, Department of research Interdisciplinary Graduate school of Mediciine and Engireering, Professor, 大学院医学工学総合研究部, 教授 (30113442)
• Project Period (FY): 2005 – 2006
• Keywords: pancreatic β-cell regeneration / differentiation / pancreas specific gene / molecular biology

Research Abstract

In the developing endocrine pancreas, islet cells arise from endodermal stem cells which lie in the primitive duct epithelium, and the islet structure is thought to be formed by budding from the pancreatic duct cells.
In mouse fetus of embryonic day 18 (E18), we found cells that have both characters of ductal cells and of β-cells. Those cells were positive for insulin (a marker of β-cells) and cytokeratin 19 (a marker of ductal cells) by immunohistochemistry. We assumed that those cells are differentiating (3-cells. We, therefore, tried to isolate genes that are specifically expressed in those cells. Using laser capture microdissection technique and differential display method from the ductal cells (cytokeratin 19-positive cells) and the putative differentiating (3-cells (both cytokeratin 19-and insulin-positive cells), we cloned cDNAs that are expressed more in the cultured β-cells than in the cultured ductal cells by Northern blot and are also express in the pancreatic islet by immunohistochemistry or in situ hybridization. We study the clone 950-5-81, one of those clones. The clone 950-5-81 contains a zinc finger domain. We found that the clone upregulates Glut 2 gene expression. We then examined the effect of the clone on Glut 2 promoter activity by luciferase assya. The clone activated the activity to 2-fold. A series of 5'-deletion reporter plasmids revealed that the Zn finger responsive element reside in a region of-106 b to-55 b.