Novel roles for scleraxis in regulating adult tenocyte function

Area of Science:

• Biomedical Engineering
• Cell Biology
• Orthopedics

Background:

• Tendinopathies involve scar tissue, reduced mechanical integrity, and frequent reinjury.
• Tenocytes respond to mechanical stress by producing pro-inflammatory mediators, contributing to tendon degeneration.
• The transcription factor scleraxis (Scx) is vital for tendon development but its adult role is unclear.

Purpose of the Study:

• To investigate the role of scleraxis (Scx) in mediating adult tenocyte mechanosensing.
• To define the function of Scx in adult tenocytes under mechanical strain.

Main Methods:

• Equine tenocytes were treated with siRNA targeting Scx or control siRNA.
• Cells were subjected to cyclic mechanical strain and analyzed using RNA-seq.
• Cellular mechanics, focal adhesion dynamics, and migration were assessed.

Main Results:

• Scx knockdown downregulated focal adhesions and extracellular matrix-receptor interactions.
• Scx-deficient tenocytes exhibited reduced stiffness, altered focal adhesions, and impaired migration.
• Scx knockdown affected oxidative phosphorylation and endoplasmic reticular stress pathways.

Conclusions:

• Scx facilitates adult tenocyte mechanosensing by regulating mechanosensitive focal adhesion proteins.
• Scx plays a broader role in maintaining tenocyte homeostasis.
• Findings may elucidate tenocyte involvement in degenerative tendinopathy development.