Long term culture of CB-MSCs deteriorates their stemness nature through a series of biomolecular changes

Abstract

1Kesmat Maher, 2Hanan El-Baz, 3Zeinab Demerdash, 4Shereen Shawky, *5Marwa Hassan,6Salwa Mohamed, 7Faten Mahmoud, 8Mariam Khalil, 9 Olfat Hammam and 10Tamer Taha

This study was designed to evaluate the effect of long term in vitro culture on morphology, proliferation, telomere length, pluripotency genes expression, and differentiation potentials of cord blood (CB)-derived MSCs. This would allow us to choose the optimum passage number maintaining the MSCs stemness nature and providing the sufficient count intended for their clinical applications. Upon repeated passaging, CB-MSCs telomere length has decreased from 10.0168 kb ± 0.27 to 7.4186 kb ± 0.996 and this decrease was statistically highly significant (p < 0.01) which coincided with negative telomerase activity. Pluripotency and proliferation genes expression also decreased at the late passages. The adipogenic and chondrogenic differentiation potentials declined gradually whereas the osteogenic differentiation increased gradually and then dropped at the late passages. Based on the results, in vitro expansion attenuated the parameters that were commonly used to define CB-MSCs stemness nature except for the osteogenic differentiation potential which was highest at the intermediate passages. Therefore, we suggest considering CB-MSCs for cell and gene therapy at an early passage, as soon as a clinically sufficient MSCs co