Effects of telomerase activity and apoptosis on ex vivo expansion of cord blood CD34+ cells
Article first published online: 15 DEC 2012
© 2012 Blackwell Publishing Ltd
Volume 46, Issue 1, pages 38–44, February 2013
How to Cite
Ge, J., Cai, H., Li, Q., Du, Z. and Tan, W. S. (2013), Effects of telomerase activity and apoptosis on ex vivo expansion of cord blood CD34+ cells. Cell Proliferation, 46: 38–44. doi: 10.1111/cpr.12006
- Issue published online: 7 JAN 2013
- Article first published online: 15 DEC 2012
- Manuscript Accepted: 15 SEP 2012
- Manuscript Revised: 2 AUG 2012
- Manuscript Received: 6 JUN 2012
- the National Nature Science Foundation of China. Grant Number: 20776043
- the Key Project of Medicine, Shanghai. Grant Number: 074319109
- the International Peace Maternity and Child Health Hospital (Shanghai, China)
Ex vivo expansion of CD34+ cells has become critically important in order to obtain sufficient haematopoietic stem cells for clinical application. Among major regulators involved in ex vivo expansion, telomerase activity and apoptosis have been revealed to be closely linked to cell cycle progression. However, all exact roles remain to be elucidated. Here, change in telomerase activity and level of apoptosis in cord blood (CB) CD34+ cells were evaluated together with specific cell population growth rate during ex vivo culture.
Materials and methods
CD34+ cells isolated from human CB were expanded ex vivo over a 28-day period. Besides monitoring cell proliferation kinetics of the CD34+ cells, changes in telomerase activity and apoptotic levels were investigated. Several relevant genes were quantified by qRT-PCR during the culture period.
Significant elevation of telomerase activity had close relationship to activation of CB CD34+ cell expansion. Peak apoptotic level was accompanied by a remarkable decline in cell-specific growth rate, and apoptotic level of differentiated CD34– population was significantly higher than that of the CD34+ population.
Although telomerase activity was activated during the culture, expansion of CB CD34+ cells seemed to be more susceptible to apoptotic suppression when cultured ex vivo, which implied that apoptosis may serve as a rate-limiting factor involved in controlling expansion efficiency.