Bone formation by human postnatal bone marrow stromal stem cells is enhanced by telomerase expression

Area of Science:

• Stem cell biology
• Regenerative medicine
• Molecular biology

Background:

• Human postnatal bone marrow stromal stem cells (BMSSCs) have limited lifespan and lose stemness during ex vivo expansion.
• Maintaining stem cell properties during expansion is crucial for therapeutic applications.

Purpose of the Study:

• To investigate the effect of ectopic human telomerase reverse transcriptase (hTERT) expression on BMSSC lifespan and osteogenic potential.
• To evaluate the bone-forming capacity of hTERT-expressing BMSSCs in vivo.

Main Methods:

• Ectopic expression of hTERT in human BMSSCs.
• Ex vivo expansion and characterization of BMSSCs and hTERT-expressing BMSSCs (BMSSC-Ts).
• Xenogenic transplantation of BMSSCs and BMSSC-Ts to assess bone formation.

Main Results:

• hTERT expression extended BMSSC lifespan and maintained osteogenic potential.
• BMSSC-Ts generated significantly more mineralized bone tissue with marrow in xenogenic transplants compared to control BMSSCs.
• Enhanced bone formation correlated with sustained STRO-1 expression, an early osteogenic marker.

Conclusions:

• Telomerase expression overcomes limitations in ex vivo expansion of BMSSCs.
• Telomerase therapy is a promising strategy for improving bone regeneration and repair.
• Sustained osteogenic stem cell pool is maintained by telomerase expression during expansion.