Propagation of intercellular Ca2+ waves in mechanically stimulated articular chondrocytes

FEBS Lett. 1997 Jan 2;400(1):58-64. doi: 10.1016/s0014-5793(96)01356-7.

Abstract

Intercellular Ca2+ signalling in primary cultures of articular chondrocytes was investigated with digital fluorescence video imaging. Mechanical stimulation of a single cell induced a wave of increased Ca2+ that was communicated to surrounding cells. Intercellular Ca2+ spreading was inhibited by 18alpha-glycyrrhetinic acid, demonstrating the involvement of gap junctions in signal propagation. In the absence of extracellular Ca2+ mechanical stimulation failed to induce Ca2+ responses and communicated Ca2+ waves. Under these conditions Ca2+ microinjection induced intercellular waves involving the cells immediately surrounding the stimulated one. Mechanical stress induced Ca2+ influx in the stimulated, but not in the adjacent cells, as assessed by the Mn2+ quenching technique. Cell treatment with thapsigargin failed to block mechanically induced signal propagation, but significantly reduced the number of cells involved in the communicated Ca2+ wave. Similar results were obtained with the phospholipase C inhibitor U73122, which is known to prevent InsP3 generation. These results provide evidence that mechanical stimulation induces a cytosolic Ca2+ increase that may permeate gap junctions, thus acting as an intercellular messenger mediating cell-to-cell communication in articular chondrocytes.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism*
  • Calcium-Transporting ATPases / antagonists & inhibitors
  • Cartilage, Articular / cytology
  • Cartilage, Articular / metabolism*
  • Cell Membrane / metabolism
  • Enzyme Inhibitors / pharmacology
  • Estrenes / pharmacology
  • Image Processing, Computer-Assisted
  • Microscopy, Fluorescence
  • Microscopy, Video
  • Phosphodiesterase Inhibitors
  • Physical Stimulation
  • Pyrrolidinones / pharmacology
  • Signal Transduction
  • Swine
  • Thapsigargin / pharmacology
  • Type C Phospholipases / antagonists & inhibitors

Substances

  • Enzyme Inhibitors
  • Estrenes
  • Phosphodiesterase Inhibitors
  • Pyrrolidinones
  • 1-(6-((3-methoxyestra-1,3,5(10)-trien-17-yl)amino)hexyl)-1H-pyrrole-2,5-dione
  • Thapsigargin
  • Type C Phospholipases
  • Calcium-Transporting ATPases
  • Calcium