Integrin Tension Represents the Directed Differentiation of Mesenchymal Stem Cells via Mechanoadaptation

Area of Science:

• Cell Biology
• Biophysics
• Biomaterials Science

Background:

• Mesenchymal stromal cells (MSCs) differentiation is crucial for tissue repair.
• Integrins, focal adhesions, cytoskeleton, and lamin A are involved in MSC differentiation.
• The precise roles of integrin tension and mechanoadaptation in MSC differentiation are not fully understood.

Purpose of the Study:

• To quantify integrin tension during MSC differentiation into osteogenesis and chondrogenesis.
• To investigate the mechanical adaptation of MSCs in response to biochemical induction.
• To elucidate the roles of F-actin and lamin A in force transduction and differentiation.

Main Methods:

• Utilized reversible shearing DNA-based tension probes (RSDTPs) to measure integrin tension.
• Assayed mechanical transmitters including paxillin, F-actin, and lamin A.
• Quantified MSC differentiation following biochemical induction.

Main Results:

• Identified critical integrin tensions: 44 pN for osteogenesis and 5-18 pN for chondrogenesis.
• Observed distinct focal adhesion orientations: radial for osteogenesis and tangential for chondrogenesis.
• Demonstrated that F-actin and lamin A differentially regulate osteogenesis and chondrogenesis via integrin tension and focal adhesion dynamics.

Conclusions:

• Integrin tension magnitude is a key determinant of MSC differentiation fate.
• MSCs exhibit specific mechanical adaptations in focal adhesion orientation and cytoskeletal organization.
• F-actin and lamin A play distinct regulatory roles in mechanotransduction pathways governing MSC differentiation.