Triamcinolone Modulates Chondrocyte Biomechanics and Calcium-Dependent Mechanosensitivity

Area of Science:

• Biomedical Engineering
• Cell Biology
• Rheumatology

Background:

• Intra-articular glucocorticoids are common osteoarthritis (OA) treatments.
• High-dose or repeated glucocorticoid use may harm chondrocytes and accelerate OA.
• The impact of glucocorticoids on chondrocyte mechanosensitivity and biomechanics is unknown.

Purpose of the Study:

• To investigate the dose-dependent effects of triamcinolone acetonide (TA) on human chondrocyte biomechanics and mechanosensitivity.
• To explore how TA influences the cellular cytoskeleton, elasticity, and calcium signaling pathways.

Main Methods:

• Primary human chondrocytes were cultured with varying TA concentrations (2 µM–2 mM).
• F-actin staining, atomic force microscopy (AFM), and Ca2+ imaging were used to assess cellular changes.
• Gene expression of matrix-related and mechanosensitive markers was analyzed via qPCR.

Main Results:

• TA induced a concentration-dependent increase in chondrocyte stiffness and F-actin reorganization.
• TA amplified Ca2+ signaling under basal and mechanically stimulated conditions.
• TA treatment reduced MMP1 gene expression, despite enhancing mechanotransduction.

Conclusions:

• TA alters chondrocyte biomechanics by increasing stiffness and augmenting Ca2+-dependent mechanotransduction.
• The observed reduction in MMP1 suggests a complex, potentially protective, transcriptional response to TA.
• These findings highlight the dual biomechanical effects of TA on chondrocytes in OA.