Caveolin-1 is essential for glimepiride-induced insulin secretion in the pancreatic betaTC-6 cell line

Biochem Biophys Res Commun. 2008 Oct 17;375(2):235-7. doi: 10.1016/j.bbrc.2008.08.003. Epub 2008 Aug 12.

Abstract

The K(ATP) channels play a pivotal role in the complex mechanism of insulin secretion. K(ATP) channels represent the target of sulphonylureas, a class of drugs widely used in type 2 diabetes to stimulate insulin secretion. We previously showed that caveolin-1 depletion impairs action of the sulphonylurea glimepiride in human endothelial cells. The aim of this work was to investigate the possible role of caveolin-1 in glimepiride-induced insulin secretion. Caveolin-1 was depleted using siRNA method in the pancreatic betaTC-6 cell line. Then stimulation of insulin secretion was performed with different secretagogues (glucose, KCl, and glimepiride). Here, we show that betaTC-6 caveolin-1 depleted cells maintained high rate of insulin secretion after KCl, but not after glucose and glimepiride stimulation. Moreover, we find a direct interaction between caveolin-1 and Kir6.2, one of the K(ATP) channel subunit. These results demonstrate that Cav-1 plays a critical role for glucose and sulfonylurea-stimulated insulin secretion.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Caveolin 1 / genetics
  • Caveolin 1 / metabolism
  • Caveolin 1 / physiology*
  • Cell Line
  • Hypoglycemic Agents / pharmacology*
  • Insulin / metabolism*
  • Insulin Secretion
  • Insulin-Secreting Cells / drug effects*
  • Insulin-Secreting Cells / metabolism*
  • Mice
  • Potassium Channels, Inwardly Rectifying / metabolism
  • RNA, Small Interfering / genetics
  • Sulfonylurea Compounds / pharmacology*

Substances

  • Caveolin 1
  • Hypoglycemic Agents
  • Insulin
  • Kir6.2 channel
  • Potassium Channels, Inwardly Rectifying
  • RNA, Small Interfering
  • Sulfonylurea Compounds
  • glimepiride