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Non-viral transient transfection of hTERT gene into hBMSCs from elderly patients delays cellular aging in vitro

Abstract Background: Human bone marrow stem cell (hBMSC) is a promising candidate in regenerative medicine due to its plasticity and homing ability. However, in vitro survival and therapeutic efficacy of hBMSCs decline with donor age as a result of physiological cellular aging. Objectives: We transfected human telomerase reverse transcriptase (hTERT) into hBMSCs from patients more than 60 years old in the hope of extending cellular life span. Methods: In our study on 11 donors (aged 16-74 years), no telomerase activity was detected in hBMSCs from donors ≥60 years old. We then performed transient transfection on hBMSC from these elderly donors (n = 4) with hTERT gene using non-viral methods. Results: Transfection efficiency of 38.5% and 55.6% was achieved by lipofection and electroporation with viability at 83% and 44%, respectively. Telomerase was detected on day 5 for all post-transfected samples. Maximum passage number achieved after transfection was ≥13 (≈45 doublings) compared with 6 (≈15 doublings) before transfection. Conclusion: We conclude that transient expression of hTERT increased cellular life span of hBMSCs from elderly patients, while maintaining a normal cell morphology and growth rate.