This project has sought to exploit genetic manipulation of the mouse genome in order to study the development and characteristics of the cells comprising the pancreatic islets. Our proposition has been that such information will contribute to basic knowledge of the pancreas and its diseases (not only diabetes but also cancer), and perhaps to the eventual design of strategies to replenish the beta cells through the control of beta cell growth and differentiation. A major new focus of this project is applying to diabetes research the technology of homologous integration into embryonic stems cells so as to produce mice with targeted gene disruptions (or knockouts). A second new focus is on an exciting cell type associated with pancreatic islets that may represent a multipotential 'stem-like' cell for islet neogenesis and pancreatic cancer.
Our specific aims are to: 1. Produce mice carrying a targeted knockout of the gene encoding the autoantigen glutamic acid decarboxylase (GAD65), discovered by Project 2 during the last funding period, and assess by its absence the functional contributions of GAD65 to normal development and postnatal activities of the pancreatic islets. 2. Produce mice carrying a knockout of betacellulin, a TGF/alpha family member implicated in beta cell tumorigenesis, so as to investigate its involvement in islet cell development and islet morphogenesis, as well as physiological function in the adult. 3. Homologously integrate the oncogene SV40 T-antigen into the somatostatin and pancreatic polypeptide genes in embryonic stem cells, and derive mice that carry the modified SMS/Tag and PP/Tag alleles with consequent d and PP cell tumorigenesis, from which representative tumor cell lines will be established. The knockout mice will also be bred to homozygosity, to assess the effects that absence of somatostatin and pancreatic polypeptide have on embryogenesis, as well as islet development, morphogenesis, and function. 4. Introduction of polyomavirus mT oncogene into juvenile islets resulted in establishment of epitheloid cell lines (mPAC) that heterogeneously co-express a pancreatic duct cell marker, cytokeratin, and a neuroendocrine marker, A2B5, in addition to somatostatin and pancreatic polypeptide mRNAs. Upon transplantation, mPAC cells produce classic ductal adenocarcinomas analogous to the major human pancreatic cancer. The cell type from which mPAC originate within juvenile islets, the cellular characteristics of mPAC, and the signaling pathway used in their transformation will be studied to clarify the possibility that mPAC cells represent on the one hand a duct cell progenitor of the islets, and on the other a target cell for pancreatic cancer.

Project Start
Project End
Budget Start
Budget End
Support Year
7
Fiscal Year
1995
Total Cost
Indirect Cost
Name
University of California San Francisco
Department
Type
DUNS #
073133571
City
San Francisco
State
CA
Country
United States
Zip Code
94143
Wilson, Maria E; Scheel, David; German, Michael S (2003) Gene expression cascades in pancreatic development. Mech Dev 120:65-80
Sander, M; Paydar, S; Ericson, J et al. (2000) Ventral neural patterning by Nkx homeobox genes: Nkx6.1 controls somatic motor neuron and ventral interneuron fates. Genes Dev 14:2134-9
Roll, U; Turck, C W; Gitelman, S E et al. (2000) Peptide mapping and characterisation of glycation patterns of the glima 38 antigen recognised by autoantibodies in Type I diabetic patients. Diabetologia 43:598-608
Sander, M; Sussel, L; Conners, J et al. (2000) Homeobox gene Nkx6.1 lies downstream of Nkx2.2 in the major pathway of beta-cell formation in the pancreas. Development 127:5533-40
Shi, Y; Kanaani, J; Menard-Rose, V et al. (2000) Increased expression of GAD65 and GABA in pancreatic beta-cells impairs first-phase insulin secretion. Am J Physiol Endocrinol Metab 279:E684-94
Kanaani, J; Lissin, D; Kash, S F et al. (1999) The hydrophilic isoform of glutamate decarboxylase, GAD67, is targeted to membranes and nerve terminals independent of dimerization with the hydrophobic membrane-anchored isoform, GAD65. J Biol Chem 274:37200-9
Schwartz, H L; Chandonia, J M; Kash, S F et al. (1999) High-resolution autoreactive epitope mapping and structural modeling of the 65 kDa form of human glutamic acid decarboxylase. J Mol Biol 287:983-99
Smith, S B; Ee, H C; Conners, J R et al. (1999) Paired-homeodomain transcription factor PAX4 acts as a transcriptional repressor in early pancreatic development. Mol Cell Biol 19:8272-80
Bridgett, M; Cetkovic-Cvrlje, M; O'Rourke, R et al. (1998) Differential protection in two transgenic lines of NOD/Lt mice hyperexpressing the autoantigen GAD65 in pancreatic beta-cells. Diabetes 47:1848-56
Damert, A; Machein, M; Breier, G et al. (1997) Up-regulation of vascular endothelial growth factor expression in a rat glioma is conferred by two distinct hypoxia-driven mechanisms. Cancer Res 57:3860-4

Showing the most recent 10 out of 27 publications