Calcium signaling is required for ultrasound-stimulated aggrecan synthesis by rat chondrocytes

Javad Parvizi, Vladimir Parpura, James F. Greenleaf, Mark E. Bolander

Research output: Contribution to journalArticle

122 Scopus citations

Abstract

Low-intensity ultrasound accelerates fracture healing in humans. In rat femur fracture models, ultrasound advanced healing is associated with increased proteoglycan expression. Here we report that ultrasound stimulation of primary rat chondrocytes elevated the intracellular concentration of calcium [Ca2+]i. The [Ca2+]i increase was rapid and transient at lower pressures (175-320 kPa), but rapid and sustained at higher ultrasound exposures (350-500 kPa). Chelating internal [Ca2+]i with 1,2-bis(2-aminophenoxy) ethane-N-N-N′,N′-tetraacetic acid (BAPTA-AM), stopping the Ca2+/ATP-ase induced mitochondrial release of [Ca2+]i with Thapsigargin, or removing [Ca2+]i from the medium with EGTA inhibited the stimulatory effects of ultrasound on proteoglycan synthesis. These results imply that ultrasound-stimulated synthesis of cell matrix proteoglycan, associated with accelerated fracture healing, is mediated by intracellular calcium signaling.

Original languageEnglish (US)
Pages (from-to)51-57
Number of pages7
JournalJournal of Orthopaedic Research
Volume20
Issue number1
DOIs
StatePublished - Jan 1 2002

ASJC Scopus subject areas

  • Orthopedics and Sports Medicine

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