title: Regulation of Pax6 by CTCF during induction of mouse ES cell differentiation.
abstract: Pax6 plays an important role in embryonic cell (ES) differentiation during embryonic development. Expression of Pax6 undergoes from a low level to high levels following ES cell differentiation to neural stem cells, and then fades away in most of the differentiated cell types. There is a limited knowledge concerning how Pax6 is regulated in ES cell differentiation. We report that Pax6 expression in mouse ES cells was controlled by CCCTC binding factor (CTCF) through a promoter repression mechanism. Pax6 expression was significantly enhanced while CTCF activity was kept in the constant during ES cell differentiation to radial glial cells. Instead, the interaction of CTCF with Pax6 gene was regulated by decreased CTCF occupancy in its binding motifs upstream from Pax6 P0 promoter following the course of ES cell differentiation. Reduced occupancy of CTCF in the binding motif region upstream from the P0 promoter was due to increased DNA methylations in the CpG sites identified in the region. Furthermore, changes in DNA methylation levels in vitro and in vivo effectively altered methylation status of these identified CpG sites, which affected ability of CTCF to interact with the P0 promoter, resulting in increases in Pax6 expression. We conclude that there is an epigenetic mechanism involving regulations of Pax6 gene during ES cell differentiation to neural stem cells, which is through increases or decreases in methylation levels of Pax6 gene to effectively alter the ability of CTCF in control of Pax6 expression, respectively.
authors.affiliation: Division of Molecular Medicine, Department of Medicine, David Geffen School of Medicine, University of California Los Angeles, Torrance, California, United States of America.
authors.forename: Jie
authors.initials: J
authors.lastname: Gao
authors.forename: Jie
authors.initials: J
authors.lastname: Wang
authors.forename: Yumei
authors.initials: Y
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Dai
authors.forename: Luo
authors.initials: L
authors.lastname: Lu
mesh_terms: D000818:Animals; D001665:Binding Sites; D000076246:CCCTC-Binding Factor; D002454:Cell Differentiation / Q000187:drug effects / Q000235:genetics*; D019175:DNA Methylation / Q000187:drug effects / Q000235:genetics; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D044127:Epigenesis, Genetic / Q000187:drug effects; D005136:Eye Proteins / Q000235:genetics*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D018398:Homeodomain Proteins / Q000235:genetics*; D051379:Mice; D009457:Neuroglia / Q000166:cytology / Q000187:drug effects; D009711:Nucleotides / Q000378:metabolism; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors / Q000235:genetics*; D012097:Repressor Proteins / Q000235:genetics* / Q000378:metabolism*; D014212:Tretinoin / Q000494:pharmacology
chemical_list: D000076246:CCCTC-Binding Factor; C000619698:Ctcf protein, mouse; D005136:Eye Proteins; D018398:Homeodomain Proteins; D009711:Nucleotides; D000071841:PAX6 Transcription Factor; D051761:Paired Box Transcription Factors; C000605732:Pax6 protein, mouse; D012097:Repressor Proteins; D014212:Tretinoin