title: The roles of apoptotic pathways in the low recovery rate after cryopreservation of dissociated human embryonic stem cells.
abstract: Human embryonic stem (hES) cells have enormous potential for clinical applications. However, one major challenge is to achieve high cell recovery rate after cryopreservation. Understanding how the conventional cryopreservation protocol fails to protect the cells is a prerequisite for developing efficient and successful cryopreservation methods for hES cell lines and banks. We investigated how the stimuli from cryopreservation result in apoptosis, which causes the low cell recovery rate after cryopreservation. The level of reactive oxygen species (ROS) is significantly increased, F-actin content and distribution is altered, and caspase-8 and caspase-9 are activated after cryopreservation. p53 is also activated and translocated into nucleus. During cryopreservation apoptosis is induced by activation of both caspase-8 through the extrinsic pathway and caspase-9 through the intrinsic pathway. However, exactly how the extrinsic pathway is activated is still unclear and deserves further investigation.
authors.affiliation: Dept. of Engineering Science, Institute of Biomedical Engineering, University of Oxford, Oxford, UK.
authors.forename: Xia
authors.initials: X
authors.lastname: Xu
authors.forename: Sally
authors.initials: S
authors.lastname: Cowley
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Flaim
authors.forename: William
authors.initials: W
authors.lastname: James
authors.forename: Leonard
authors.initials: L
authors.lastname: Seymour
authors.forename: Zhanfeng
authors.initials: Z
authors.lastname: Cui
mesh_terms: D000199:Actins / Q000378:metabolism; D000704:Analysis of Variance; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D053181:Caspase 8 / Q000378:metabolism; D053453:Caspase 9 / Q000378:metabolism; D018929:Cell Culture Techniques; D002470:Cell Survival; D015925:Cryopreservation / Q000379:methods*; D003451:Cryoprotective Agents / Q000494:pharmacology; D004121:Dimethyl Sulfoxide / Q000494:pharmacology; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D016159:Tumor Suppressor Protein p53 / Q000378:metabolism
chemical_list: D000199:Actins; D003451:Cryoprotective Agents; D017382:Reactive Oxygen Species; C495901:TP53 protein, human; D016159:Tumor Suppressor Protein p53; D053181:Caspase 8; D053453:Caspase 9; D004121:Dimethyl Sulfoxide