Directing iPSC differentiation into iTenocytes using combined scleraxis overexpression and cyclic loading.

Area of Science:

• Regenerative Medicine
• Stem Cell Biology
• Tendon Tissue Engineering

Background:

• Tendon regenerative therapies lag behind other tissues due to a lack of effective cell candidates.
• Scleraxis (Scx) is the sole known direct molecular regulator of tendon differentiation.
• Mechanoregulation plays a crucial role in tendon development and healing processes.

Purpose of the Study:

• To induce tenogenesis in induced pluripotent stem cell-derived mesenchymal stromal-like cells (iMSCs).
• To investigate the combined effects of stable Scleraxis (Scx) overexpression and uniaxial mechanical stretch.
• To evaluate iMSCs as a potential cell therapy for tendon repair compared to bone marrow-derived MSCs (BM-MSCs).

Main Methods:

• Stable Scleraxis (Scx) overexpression was introduced into iPSC-derived mesenchymal stromal-like cells (iMSCs).
• Uniaxial mechanical stretch was applied to the Scx-overexpressing iMSCs.
• Bone marrow-derived mesenchymal stem cells (BM-MSCs) were used as a reference group for comparison.

Main Results:

• Scx overexpression alone significantly upregulated tenogenic markers in iMSCs compared to BM-MSCs.
• Combined Scx overexpression and mechanical stretch induced morphometric and cytoskeletal changes in iMSCs.
• Enhanced extracellular matrix deposition, alignment, and tenomodulin perinuclear localization were observed in treated iMSCs.

Conclusions:

• iPSC-derived cells, under Scx overexpression and mechanical stimulation, can be effectively differentiated into tenocytes.
• This combination therapy promotes key tenogenic markers and extracellular matrix characteristics essential for tendon tissue.
• These modified iMSCs represent a promising and potentially superior cell candidate for tendon regenerative therapy applications.