Complexin I Regulates Glucose-Induced Secretion in Pancreatic Beta-Cells

Research conducted in Switzerland has shed light on the role of complexin I (CPX I) in regulating glucose-induced secretion in pancreatic beta-cells. The study, published in the Journal of Cell Science, found that CPX I plays a critical role in controlling the stimulated-exocytosis of insulin. The researchers discovered that pancreatic islets and several insulin-secreting cell lines express high levels of CPX I, and that its overexpression or silencing impairs beta-cell secretion in response to nutrients such as glucose, leucine, and KCl.

Key Takeaways:

• Complexin I (CPX I) regulates glucose-induced secretion in pancreatic beta-cells, controlling stimulated-exocytosis of insulin.
• Pancreatic islets and several insulin-secreting cell lines express high levels of CPX I, suggesting a crucial role in beta-cell function.
• Overexpression of CPX I or silencing of the Cplx1 gene led to strong impairment in beta-cell secretion in response to glucose, leucine, and KCl.
• The beta-cell expression of CPX I is mediated by the presence of a neuron restrictive silencer element located in the regulatory region of the gene.
• The researchers found that this effect was detected both in the early and sustained secretory phases, but was more pronounced in the early phase.
• REST, a transcriptional repressor, binds to the neuron restrictive silencer element and is found in most cell types except mature neuronal cells and beta-cells.
• Abdul Abderrahmani and colleagues at the University of Lausanne made these findings and published them in the Journal of Cell Science (Complexin I regulates glucose-induced secretion in pancreatic beta-cells. J Cell Sci, 2004;117(11):2239-2247).

Statistics:

• 117(11) is the volume and page number where the article was published in the Journal of Cell Science.
• The study investigated the potential role of CPX I in insulin-secreting cells, demonstrating a critical role in beta-cell function.
• The early phase of beta-cell secretion was more pronounced, with effects detected in both the early and sustained secretory phases.

Sources:

• Abderrahmani, A., et al. "Complexin I regulates glucose-induced secretion in pancreatic beta-cells. J Cell Sci, 2004;117(11):2239-2247."
• University of Lausanne, Department of Internal Medicine, Lausanne, Switzerland.
• Journal of Cell Science, published by the Company of Biologists Ltd., Bidder Building Cambridge Commercial Park Cowley Road, Cambridge CB4 4DL, Cambs, England.