ECE2007 Poster Presentations (1) (659 abstracts)
1Medical University Vienna, Department of Medicine III, Vienna, Austria; 2Bulgarian Academy of Sciences, Institute of Molecular Immunology, Sofia, Bulgaria; 3Medical University Vienna, Department of Immunology, Vienna, Austria; 4Medical University Vienna, Department of Endocrinology and Metabolism, Vienna, Austria.
Objective: Establishment of rodent in vitro cell systems for the extension of the functional data about the recently cloned neuroendocrine marker secretagogin.
Methods: 1. DNA-cloning; 2. Antibody generation; 3. Immunoblotting and Immunohistochemistry; 4. Cell-transfection; 5. Luciferase Reporter Assays; 6. ELISA.
Results: 1. We characterized the rat homologue of human secretagogin (rat secretagogin) and demonstrated the homologous tissue expression pattern of both proteins. 2. Highest rat secretagogin expression levels were found in rat pancreatic islets and in the rat insulinoma cell lines Rin-5F and INS-1. 3. There exists a considerable degree of sequence homology between human and rat secretagogin, indicating comparable functional properties. 4. Overexpression of rat secretagogin in Rin-5F and in INS-1 cells induced an increase in insulin secretion and expression, which is mediated mainly via the promoter elements AP-1 and CRE. 5. Insulin and rat secretagogin are secreted in an inverse ratio by Rin-5F and INS-1 cells upon incubation with dexamethasone and other agents known for influencing the insulin secretion.
Conclusion: We characterized the rat homologue of human secretagogin and present an in vitro system for its functional analysis, which emphasize its regulative involvement in insulin secretion and expression.