PMID- 20485553
OWN - NLM
STAT- MEDLINE
DCOM- 20100907
LR  - 20211020
IS  - 1932-6203 (Electronic)
IS  - 1932-6203 (Linking)
VI  - 5
IP  - 5
DP  - 2010 May 12
TI  - Brg1 is required for Cdx2-mediated repression of Oct4 expression in mouse 
      blastocysts.
PG  - e10622
LID - 10.1371/journal.pone.0010622 [doi]
LID - e10622
AB  - During blastocyst formation the segregation of the inner cell mass (ICM) and 
      trophectoderm is governed by the mutually antagonistic effects of the 
      transcription factors Oct4 and Cdx2. Evidence indicates that suppression of Oct4 
      expression in the trophectoderm is mediated by Cdx2. Nonetheless, the underlying 
      epigenetic modifiers required for Cdx2-dependent repression of Oct4 are largely 
      unknown. Here we show that the chromatin remodeling protein Brg1 is required for 
      Cdx2-mediated repression of Oct4 expression in mouse blastocysts. By employing a 
      combination of RNA interference (RNAi) and gene expression analysis we found that 
      both Brg1 Knockdown (KD) and Cdx2 KD blastocysts exhibit widespread expression of 
      Oct4 in the trophectoderm. Interestingly, in Brg1 KD blastocysts and Cdx2 KD 
      blastocysts, the expression of Cdx2 and Brg1 is unchanged, respectively. To 
      address whether Brg1 cooperates with Cdx2 to repress Oct4 transcription in the 
      developing trophectoderm, we utilized preimplantation embryos, trophoblast stem 
      (TS) cells and Cdx2-inducible embryonic stem (ES) cells as model systems. We 
      found that: (1) combined knockdown (KD) of Brg1 and Cdx2 levels in blastocysts 
      resulted in increased levels of Oct4 transcripts compared to KD of Brg1 or Cdx2 
      alone, (2) endogenous Brg1 co-immunoprecipitated with Cdx2 in TS cell extracts, 
      (3) in blastocysts Brg1 and Cdx2 co-localize in trophectoderm nuclei and (4) in 
      Cdx2-induced ES cells Brg1 and Cdx2 are recruited to the Oct4 promoter. Lastly, 
      to determine how Brg1 may induce epigenetic silencing of the Oct4 gene, we 
      evaluated CpG methylation at the Oct4 promoter in the trophectoderm of Brg1 KD 
      blastocysts. This analysis revealed that Brg1-dependent repression of Oct4 
      expression is independent of DNA methylation at the blastocyst stage. In toto, 
      these results demonstrate that Brg1 cooperates with Cdx2 to repress Oct4 
      expression in the developing trophectoderm to ensure normal development.
FAU - Wang, Kai
AU  - Wang K
AD  - Developmental Epigenetics Laboratory, Department of Animal Science, Michigan 
      State University, East Lansing, Michigan, United States of America.
FAU - Sengupta, Satyaki
AU  - Sengupta S
FAU - Magnani, Luca
AU  - Magnani L
FAU - Wilson, Catherine A
AU  - Wilson CA
FAU - Henry, R William
AU  - Henry RW
FAU - Knott, Jason G
AU  - Knott JG
LA  - eng
GR  - R01 GM095347/GM/NIGMS NIH HHS/United States
GR  - R01 GM095347-01A1/GM/NIGMS NIH HHS/United States
GR  - R01GM095347/GM/NIGMS NIH HHS/United States
PT  - Journal Article
PT  - Research Support, N.I.H., Extramural
PT  - Research Support, Non-U.S. Gov't
DEP - 20100512
PL  - United States
TA  - PLoS One
JT  - PloS one
JID - 101285081
RN  - 0 (CDX2 Transcription Factor)
RN  - 0 (Cdx2 protein, mouse)
RN  - 0 (Homeodomain Proteins)
RN  - 0 (Nuclear Proteins)
RN  - 0 (Octamer Transcription Factor-3)
RN  - 0 (Pou5f1 protein, mouse)
RN  - 0 (Repressor Proteins)
RN  - 0 (Transcription Factors)
RN  - EC 3.6.1.- (Smarca4 protein, mouse)
RN  - EC 3.6.4.- (DNA Helicases)
SB  - IM
MH  - Animals
MH  - Blastocyst/cytology/*metabolism
MH  - CDX2 Transcription Factor
MH  - DNA Helicases/genetics/*metabolism
MH  - DNA Methylation/genetics
MH  - Ectoderm/metabolism
MH  - Female
MH  - Gene Expression Regulation, Developmental
MH  - Gene Knockdown Techniques
MH  - Homeodomain Proteins/genetics/*metabolism
MH  - Mice
MH  - Models, Biological
MH  - Nuclear Proteins/genetics/*metabolism
MH  - Octamer Transcription Factor-3/genetics/*metabolism
MH  - Protein Binding
MH  - Protein Transport
MH  - Repressor Proteins/genetics/*metabolism
MH  - Transcription Factors/genetics/*metabolism
MH  - Transcription, Genetic
PMC - PMC2868905
COIS- Competing Interests: The authors have declared that no competing interests exist.
EDAT- 2010/05/21 06:00
MHDA- 2010/09/08 06:00
PMCR- 2010/05/12
CRDT- 2010/05/21 06:00
PHST- 2010/01/06 00:00 [received]
PHST- 2010/04/22 00:00 [accepted]
PHST- 2010/05/21 06:00 [entrez]
PHST- 2010/05/21 06:00 [pubmed]
PHST- 2010/09/08 06:00 [medline]
PHST- 2010/05/12 00:00 [pmc-release]
AID - 10-PONE-RA-15358R1 [pii]
AID - 10.1371/journal.pone.0010622 [doi]
PST - epublish
SO  - PLoS One. 2010 May 12;5(5):e10622. doi: 10.1371/journal.pone.0010622.