Immortalizing Mesenchymal Stromal Cells from Aged Donors While Keeping Their Essential Features

Area of Science:

• Regenerative Medicine
• Cell Biology
• Biotechnology

Background:

• Mesenchymal stromal cells (MSCs) from aged individuals senesce, limiting their use in regenerative medicine and disease studies like osteoarthritis.
• Transducing primary, slow-dividing MSCs for immortalization is challenging.
• Existing methods to enhance transduction efficiency require system-specific parameter optimization.

Purpose of the Study:

• To develop an optimized spinoculation-based transduction method for immortalizing human bone marrow-derived MSCs from aged donors.
• To generate and characterize immortalized MSC (iMSC) lines for enhanced proliferation and differentiation potential.

Main Methods:

• Optimized spinoculation parameters including packaging cell incubation, centrifugation speed/time, and valproic acid concentration for transgene induction.
• Generated four immortalized MSC lines (iMSC#6, iMSC#8, iMSC#9, iMSC#10).
• Characterized iMSCs for senescence bypass, proliferation rate, surface marker expression (including CD105), and differentiation capacity (osteogenic, adipogenic, chondrogenic).

Main Results:

• Successfully generated four iMSC lines from aged donors that bypassed senescence and exhibited higher proliferation rates than primary MSCs.
• iMSCs retained key mesenchymal surface markers and multipotency, differentiating into osteoblasts, adipocytes, and chondrocytes.
• Observed alterations in CD105 expression and a bias towards osteogenic lineage commitment in the generated iMSCs.

Conclusions:

• The developed spinoculation method effectively immortalizes MSCs from aged donors, addressing a key limitation in regenerative medicine research.
• The generated iMSC lines retain crucial mesenchymal characteristics, offering valuable tools for bone and cartilage regenerative medicine and osteoarthritis research.