Epigenetic regulation of Nanog gene in embryonic stem and trophoblast stem cells.
The Nanog and Oct-4 genes are essential for maintaining pluripotency of embryonic stem (ES) cells and early embryos. We previously reported that DNA methylation and chromatin remodeling underlie the cell type-specific mechanism of Oct-4 gene expression. In the present study, we found that there is a tissue-dependent and differentially methylated region (T-DMR) in the Nanog up-stream region. The T-DMR is hypomethylated in ES cells, but is heavily methylated in trophoblast stem (TS) cells and NIH/3T3 cells, in which the Nanog gene is repressed. Furthermore, in vitro methylation of T-DMR suppressed Nanog promoter activity in reporter assay. Chromatin immunoprecipitation assay revealed that histone H3 and H4 are highly acetylated, and H3 lysine (K) 4 is hypermethylated at the Nanog locus in ES cells. Conversely, histone deacetylation and H3-K4 demethylation occurred in TS cells. Importantly, in TS cells, hypermethylation of H3-K9 and -K27 is found only at the Nanog locus, not the Oct-4 locus, indicating that the combination of histone modifications associated with the Nanog gene is distinct from that of the Oct-4 gene. In conclusion, the Nanog gene is regulated by epigenetic mechanisms involving DNA methylation and histone modifications.
Hattori
Naoko
N
Laboratory of Cellular Biochemistry, Department of Animal Resource Sciences/Veterinary Medical Sciences, The University of Tokyo, Yayoi 1-1-1, Bunkyo-ku, Tokyo 113-8657, Japan.
Imao
Yuko
Y
Nishino
Koichiro
K
Hattori
Naka
N
Ohgane
Jun
J
Yagi
Shintaro
S
Tanaka
Satoshi
S
Shiota
Kunio
K
D024506:5' Flanking Region; D000107:Acetylation; D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D001483:Base Sequence; D002460:Cell Line; D019175:DNA Methylation; D017931:DNA Primers / Q000235:genetics; D004268:DNA-Binding Proteins / Q000235:genetics*; D000077209:Decitabine; D053595:Embryonic Stem Cells / Q000378:metabolism*; D044127:Epigenesis, Genetic / Q000187:drug effects; D006657:Histones / Q000378:metabolism; D018398:Homeodomain Proteins / Q000235:genetics*; D006877:Hydroxamic Acids / Q000494:pharmacology; D051379:Mice; D008810:Mice, Inbred C57BL; D041681:NIH 3T3 Cells; D000071317:Nanog Homeobox Protein; D050814:Octamer Transcription Factor-3 / Q000235:genetics; D039904:Pluripotent Stem Cells / Q000378:metabolism; D011401:Promoter Regions, Genetic; D014327:Trophoblasts / Q000166:cytology / Q000378:metabolism
D017931:DNA Primers; D004268:DNA-Binding Proteins; D006657:Histones; D018398:Homeodomain Proteins; D006877:Hydroxamic Acids; D000071317:Nanog Homeobox Protein; C475540:Nanog protein, mouse; D050814:Octamer Transcription Factor-3; C012589:trichostatin A; D000077209:Decitabine; D001374:Azacitidine