Transient Accumulation of 5-Carboxylcytosine Indicates Involvement of Active Demethylation in Lineage Specification of Neural Stem Cells
Lee M. Wheldon,
Abdulkadir Abakir,
Zoltan Ferjentsik,
Tatiana Dudnakova,
Stephanie Strohbuecker,
Denise Christie,
Nan Dai,
Shengxi Guan,
Jeremy M. Foster,
Ivan R. Corrêa, Jr.,
Matthew Loose,
James E. Dixon,
Virginie Sottile,
Andrew D. Johnson,
Alexey Ruzov
Affiliations
Lee M. Wheldon
Medical Molecular Sciences, Centre for Biomolecular Sciences, University of Nottingham, Nottingham NG7 2RD, UK
Abdulkadir Abakir
Division of Cancer and Stem Cells, School of Medicine, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Zoltan Ferjentsik
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Tatiana Dudnakova
School of Biological Sciences, University of Edinburgh, King’s Buildings, Mayfield Road, Edinburgh EH9 3JR, UK
Stephanie Strohbuecker
Division of Cancer and Stem Cells, School of Medicine, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Denise Christie
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Nan Dai
New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
Shengxi Guan
New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
Jeremy M. Foster
New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
Ivan R. Corrêa, Jr.
New England Biolabs, Inc., 240 County Road, Ipswich, MA 01938, USA
Matthew Loose
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
James E. Dixon
Division of Cancer and Stem Cells, School of Medicine, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Virginie Sottile
Division of Cancer and Stem Cells, School of Medicine, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Andrew D. Johnson
School of Life Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
Alexey Ruzov
Division of Cancer and Stem Cells, School of Medicine, Centre for Biomolecular Sciences, University of Nottingham, University Park, Nottingham NG7 2RD, UK
5-Methylcytosine (5mC) is an epigenetic modification involved in regulation of gene activity during differentiation. Tet dioxygenases oxidize 5mC to 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5-carboxylcytosine (5caC). Both 5fC and 5caC can be excised from DNA by thymine-DNA glycosylase (TDG) followed by regeneration of unmodified cytosine via the base excision repair pathway. Despite evidence that this mechanism is operative in embryonic stem cells, the role of TDG-dependent demethylation in differentiation and development is currently unclear. Here, we demonstrate that widespread oxidation of 5hmC to 5caC occurs in postimplantation mouse embryos. We show that 5fC and 5caC are transiently accumulated during lineage specification of neural stem cells (NSCs) in culture and in vivo. Moreover, 5caC is enriched at the cell-type-specific promoters during differentiation of NSCs, and TDG knockdown leads to increased 5fC/5caC levels in differentiating NSCs. Our data suggest that active demethylation contributes to epigenetic reprogramming determining lineage specification in embryonic brain.
