title: Transient p53 suppression increases reprogramming of human fibroblasts without affecting apoptosis and DNA damage.
abstract: The discovery of human-induced pluripotent stem cells (iPSCs) has sparked great interest in the potential treatment of patients with their own in vitro differentiated cells. Recently, knockout of the Tumor Protein 53 (p53) gene was reported to facilitate reprogramming but unfortunately also led to genomic instability. Here, we report that transient suppression of p53 during nonintegrative reprogramming of human fibroblasts leads to a significant increase in expression of pluripotency markers and overall number of iPSC colonies, due to downstream suppression of p21, without affecting apoptosis and DNA damage. Stable iPSC lines generated with or without p53 suppression showed comparable expression of pluripotency markers and methylation patterns, displayed normal karyotypes, contained between 0 and 5 genomic copy number variations and produced functional neurons in vitro. In conclusion, transient p53 suppression increases reprogramming efficiency without affecting genomic stability, rendering the method suitable for in vitro mechanistic studies with the possibility for future clinical translation.
authors.affiliation: Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Groennegaardsvej 7, Frederiksberg C 1870, Denmark. Electronic address: mar@bioneer.dk.
authors.forename: Mikkel A
authors.initials: MA
authors.lastname: Rasmussen
authors.affiliation: Bioneer A/S, Kogle Alle 2, Hoersholm 2970, Denmark.
authors.forename: Bjørn
authors.initials: B
authors.lastname: Holst
authors.affiliation: Applied Human Molecular Genetics, Kennedy Center, Copenhagen University Hospital, Rigshospitalet, Gl. Landevej 7, Glostrup 2600, Denmark.
authors.forename: Zeynep
authors.initials: Z
authors.lastname: Tümer
authors.affiliation: Bioneer A/S, Kogle Alle 2, Hoersholm 2970, Denmark.
authors.forename: Mads G
authors.initials: MG
authors.lastname: Johnsen
authors.affiliation: Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Groennegaardsvej 7, Frederiksberg C 1870, Denmark.
authors.forename: Shuling
authors.initials: S
authors.lastname: Zhou
authors.affiliation: H. Lundbeck A/S, Ottiliavej 9, Valby 2500, Denmark.
authors.forename: Tina C
authors.initials: TC
authors.lastname: Stummann
authors.affiliation: Department of Veterinary Clinical and Animal Sciences, Faculty of Health and Medical Sciences, University of Copenhagen, Groennegaardsvej 7, Frederiksberg C 1870, Denmark.
authors.forename: Poul
authors.initials: P
authors.lastname: Hyttel
authors.affiliation: Bioneer A/S, Kogle Alle 2, Hoersholm 2970, Denmark.
authors.forename: Christian
authors.initials: C
authors.lastname: Clausen
mesh_terms: D017209:Apoptosis; D002460:Cell Line; D065150:Cellular Reprogramming; D056915:DNA Copy Number Variations; D004249:DNA Damage; D005347:Fibroblasts / Q000166:cytology / Q000378:metabolism*; D055786:Gene Knockout Techniques; D042822:Genomic Instability; D006801:Humans; D057026:Induced Pluripotent Stem Cells / Q000166:cytology / Q000378:metabolism*; D055495:Neurogenesis; D009474:Neurons / Q000166:cytology; D016159:Tumor Suppressor Protein p53 / Q000235:genetics*
chemical_list: D016159:Tumor Suppressor Protein p53