Nutrients induce different Ca(2+) signals in cytosol and nucleus in pancreatic beta-cells

Diabetes. 2004 Feb:53 Suppl 1:S92-5. doi: 10.2337/diabetes.53.2007.s92.

Abstract

Specific activation of Ca(2+)-dependent functions is achieved by the particular dynamics and local restriction of Ca(2+) signals. It has been shown that changes in amplitude, duration, or frequency of Ca(2+) signals modulate gene transcription. Thus, Ca(2+) variations should be finely controlled within the nucleus. Although a variety of mechanisms in the nuclear membrane have been demonstrated to regulate nuclear Ca(2+), the existence of an autonomous Ca(2+) homeostasis within the nucleus is still questioned. In the pancreatic beta-cell, besides their effect on insulin secretion, Ca(2+) messages generated by nutrients also exert their action on gene expression. However, the dynamics of these Ca(2+) signals in relation to nuclear function have been explored little in islet cells. In the current study, Ca(2+) changes both in the nucleoplasm and in the cytosol of INS-1 and pancreatic beta-cells were monitored using spot confocal microscopy. We show that nutrients trigger Ca(2+) signals of higher amplitude in the nucleus than in the cytosol. These amplitude-modulated Ca(2+) signals transmitted to the nucleus might play an important role in the control of gene expression in the pancreatic beta-cell.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • ATP-Binding Cassette Transporters
  • Animals
  • Calcium Signaling / physiology*
  • Cell Nucleus / physiology*
  • Cells, Cultured
  • Cytosol / physiology
  • Islets of Langerhans / cytology
  • Islets of Langerhans / physiology*
  • KATP Channels
  • Male
  • Mice
  • Microscopy, Confocal
  • Potassium Channel Blockers / pharmacology
  • Potassium Channels / physiology
  • Potassium Channels, Inwardly Rectifying
  • Tolbutamide / pharmacology

Substances

  • ATP-Binding Cassette Transporters
  • KATP Channels
  • Potassium Channel Blockers
  • Potassium Channels
  • Potassium Channels, Inwardly Rectifying
  • uK-ATP-1 potassium channel
  • Tolbutamide