BACKGROUND: Human induced pluripotent stem cells (hiPSCs) play roles in both disease modelling and regenerative medicine. It is critical that the genomic integrity of the cells remains intact and that the DNA repair systems are fully functional. In this article, we focused on the detection of DNA double-strand breaks (DSBs) by phosphorylated histone H2AX (known as γH2AX) and p53-binding protein 1 (53BP1) in three distinct lines of hiPSCs, their source cells, and one line of human embryonic stem cells (hESCs). METHODS: We measured spontaneously occurring DSBs throughout the process of fibroblast reprogramming and during long-term in vitro culturing. To assess the variations in the functionality of the DNA repair system among the samples, the number of DSBs induced by γ-irradiation and the decrease over time was analysed. The foci number was detected by fluorescence microscopy separately for the G1 and S/G2 cell cycle phases. RESULTS: We demonstrated that fibroblasts contained a low number of non-replication-related DSBs, while this number increased after reprogramming into hiPSCs and then decreased again after long-term in vitro passaging. The artificial induction of DSBs revealed that the repair mechanisms function well in the source cells and hiPSCs at low passages, but fail to recognize a substantial proportion of DSBs at high passages. CONCLUSIONS: Our observations suggest that cellular reprogramming increases the DSB number but that the repair mechanism functions well. However, after prolonged in vitro culturing of hiPSCs, the repair capacity decreases.

• MeSH
• 53BP1 genetika   metabolismus   MeSH
• buněčné linie MeSH
• DNA genetika   metabolismus   MeSH
• dvouřetězcové zlomy DNA * účinky záření   MeSH
• exprese genu MeSH
• fibroblasty cytologie   metabolismus   účinky záření   MeSH
• fosforylace účinky záření   MeSH
• histony genetika   metabolismus   MeSH
• indukované pluripotentní kmenové buňky cytologie   metabolismus   účinky záření   MeSH
• kontrolní body fáze G1 buněčného cyklu genetika   MeSH
• kontrolní body fáze G2 buněčného cyklu genetika   MeSH
• lidé MeSH
• lidské embryonální kmenové buňky cytologie   metabolismus   účinky záření   MeSH
• oprava DNA genetika   MeSH
• přeprogramování buněk MeSH
• stárnutí buněk genetika   účinky záření   MeSH
• záření gama MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH