Luis E. Flores , Héctor Del Zotto , Florencia Fragapane , Bárbara Maiztegui , Carolina L. Román , Antonio C. Boschero , Juan J. Gagliardino
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引用次数: 5
Abstract
Islet neogenesis-associated protein (INGAP) is a peptide found in pancreatic exocrine-, duct- and islet- non-β-cells from normal hamsters. Its increase induced by either its exogenous administration or by the overexpression of its gene enhances β-cell secretory function and increases β-cell mass by a combination of stimulation of cell replication and islet neogenesis and reduction of β-cell apoptosis. We studied the potential modulatory role of endogenous INGAP in insulin secretion using two different experimental approaches. Hamster islets transfected with INGAP-small interfering RNA (INGAP-siRNA) were used to study glucose-stimulated insulin secretion (GSIS). In parallel, freshly isolated islets were incubated with high glucose and the same concentration of either a specific anti-INGAP rabbit serum or normal rabbit serum. INGAP-siRNA transfected islets reduced their INGAP mRNA and protein content by 35.1% and 47.2%, respectively whereas GSIS decreased by 25.8%. GSIS by transfected islets attained levels comparable to those recorded in control islets when INGAP pentadecapeptide (INGAP-PP) was added to the culture medium. INGAP antibody in the medium decreased significantly GSIS in a dose-dependent manner. These results indicate that endogenous INGAP plays a “physiological” positive modulatory role in insulin secretion, supporting its possible use in the treatment of prediabetes and Type 2 diabetes.
期刊介绍:
Regulatory Peptides provides a medium for the rapid publication of interdisciplinary studies on the physiology and pathology of peptides of the gut, endocrine and nervous systems which regulate cell or tissue function. Articles emphasizing these objectives may be based on either fundamental or clinical observations obtained through the disciplines of morphology, cytochemistry, biochemistry, physiology, pathology, pharmacology or psychology.