Calcium Signaling of Chondrocytes Under Osmotic Stress and Mechanical Stimulation

Chondrocytes play a critical role in cartilage remodeling by mediating the biosynthesis, organization, and modification of extracellular matrix (ECM) ^[1]. Previous studies showed that chondrocytes are highly sensitive to the surrounding mechanical and osmotic environments ^[2]. However, how these signals are perceived and transduced by chondrocytes remains unclear. One of the earliest responses of chondrocytes to stimuli is a transient oscillation in intracellular Ca²⁺ concentration ([Ca²⁺]_i) ^[3]. The major objective of this study was to investigate and compare the Ca²⁺ signaling of chondrocytes, including both primary cells and chondrogenic cell line, under mechanical stimulus ^[4] and osmotic stress. The roles of seven essential pathways in Ca²⁺ signaling were further examined using pharmacological inhibitors.