Insulin granule dynamics in pancreatic beta cells

Granule docking and cargo release in pancreatic beta-cells.

Biphasic insulin secretion is required for proper insulin action and is observed not only in vivo, but also in isolated pancreatic islets and even single beta-cells. Late events in the granule life cycle are thought to underlie this temporal pattern. In the last few years, we have therefore combined live cell imaging and electrophysiology to study insulin secretion at the level of individual gr...

Cytoskeletal Dependence of Insulin Granule Movement Dynamics in INS-1 Beta-Cells in Response to Glucose

For pancreatic β-cells to secrete insulin in response to elevated blood glucose, insulin granules retained within the subplasmalemmal space must be transported to sites of secretion on the plasma membrane. Using a combination of super-resolution STORM imaging and live cell TIRF microscopy we investigate how the organization and dynamics of the actin and microtubule cytoskeletons in INS-1 β-cell...

Cannabinoids Inhibit Insulin Receptor Signaling in Pancreatic \(\beta\)-Cells

Insulin granule trafficking in beta-cells: mathematical model of glucose-induced insulin secretion.

A mathematical model that represents the dynamics of intracellular insulin granules in beta-cells is proposed. Granule translocation and exocytosis are controlled by signals assumed to be essentially related to ATP-to-ADP ratio and cytosolic Ca(2+) concentration. The model provides an interpretation of the roles of the triggering and amplifying pathways of glucose-stimulated insulin secretion. ...

Fusion pore dynamics and insulin granule exocytosis in the pancreatic islet.

Insulin secretion from intact mouse pancreatic islets was investigated with two-photon excitation imaging. Insulin granule exocytosis occurred mainly toward the interstitial space, away from blood vessels. The fusion pore was unusually stable with a lifetime of 1.8 seconds. Opening of the 1.4-nanometer-diameter pore was preceded by unrestricted lateral diffusion of lipids along the inner wall o...