Hypo-osmotic stress induces calcium-dependent actin reorganization in articular chondrocytes.


Journal Article

OBJECTIVE:The aim of this study was to investigate the effects of hypo-osmotically induced calcium (Ca(2+)) transients on the organization of the actin cytoskeleton in articular chondrocytes. The secondary hypothesis tested was that actin restructuring following hypo-osmotic stress is mediated by gelsolin. METHODS:Isolated porcine chondrocytes were exposed to hypo-osmotic stress, and [Ca(2+)](i)was monitored using laser scanning microscopy. Calcium transients were monitored using fluorescent ratiometric imaging. The intracellular distribution of actin was examined using fluorescent immunohistochemistry and transient transfection with the pEGFP-actin plasmid. The intracellular distribution of gelsolin was investigated using fluorescent immunohistochemistry. RESULTS:Osmotic stress induced transient increases in [Ca(2+)](i)caused reorganization of intracellular actin through a mechanism that required Ca(2+)in the extracellular media. Fluorescence microscopy revealed that gelsolin was colocalized with F-actin immediately following hypo-osmotic stress but dissociated over time. CONCLUSION:These results indicate that hypo-osmotic stress induces a gelsolin-mediated reorganization of actin through a transient increase in [Ca(2+)](i).

Full Text

Cited Authors

  • Erickson, GR; Northrup, DL; Guilak, F

Published Date

  • March 2003

Published In

Volume / Issue

  • 11 / 3

Start / End Page

  • 187 - 197

PubMed ID

  • 12623290

Pubmed Central ID

  • 12623290

Electronic International Standard Serial Number (EISSN)

  • 1522-9653

International Standard Serial Number (ISSN)

  • 1063-4584

Digital Object Identifier (DOI)

  • 10.1053/s1063-4584(02)00347-3


  • eng