Abstract
Objective: The aim of this study was to investigate the effects of hypo-osmotically induced calcium (Ca2+) 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 [Ca2+]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 [Ca2+]i caused reorganization of intracellular actin through a mechanism that required Ca2+ 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 [Ca2+]i.
Original language | English |
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Pages (from-to) | 187-197 |
Number of pages | 11 |
Journal | Osteoarthritis and Cartilage |
Volume | 11 |
Issue number | 3 |
DOIs | |
State | Published - Mar 1 2003 |
Keywords
- Ca
- Cartilage
- Chondrocyte
- F-actin
- Gelsolin
- Inositol triphosphate
- Osmotic
- Osteoarthritis