The effect of cryopreservation on umbilical cord blood endothelial progenitor cell differentiation.
Endothelial progenitor cells (EPCs) has been shown to be present in umbilical cord blood (UCB) in addition to hematopoietic stem cells. Cryopreservation is the accepted method for long-term storage of UCB. However, whether EPCs can be derived from cryopreserved UCB samples is unclear. The aim of this study was to investigate the differentiation potential of EPCs from cryopreserved CB samples. CD34+ cells were isolated from fresh or frozen and thawed UCB using magnetic beads. Cells were then cultured on fibronectin-coated plates containing endothelial differentiation medium. After 4-5 weeks in culture, endothelial-like cells were generated from fresh UCB samples, but not cryopreserved UCB samples. Examining this further, both fresh and frozen/thawed UCB MNCs were stained with Annexin V-PE and 7-actinomycin D (7-AAD) using flow cytometry. We found that there were a significant number of apoptotic cells in cryopreserved UCB samples compared to fresh UCB samples. In conclusion, cryopreservation induced UCB cell apoptosis and impaired EPC differentiation.
Haematological Sciences, School of Clinical & Laboratory Sciences, Institute of Cellular Medicine, Newcastle University, Newcastle upon Tyne, UK. x.lu@leeds.ac.uk
Xiaomei
X
Lu
Steve J
SJ
Proctor
Anne M
AM
Dickinson
D017209:Apoptosis; D016923:Cell Death; D002454:Cell Differentiation; D015925:Cryopreservation / Q000379:methods*; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology; D005312:Fetal Blood / Q000166:cytology* / Q000502:physiology; D005434:Flow Cytometry; D006412:Hematopoietic Stem Cells / Q000166:cytology / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D008077:Lipoproteins, LDL / Q000032:analysis; D014841:von Willebrand Factor / Q000032:analysis
D008077:Lipoproteins, LDL; D014841:von Willebrand Factor