Cytosine methylation pattern are established early in development. Although several DNA methyltransferases have been identified it remains unknown how specific genomic methylation patterns are generated that allow tissue specific gene expression. We examined the possibility that Lsh controls not only cytosine methylation at repetitive sequences, but may be also involved in the control of DNA methylation at unique promoter regions. To investigate how genome-wide DNA methylation patterns are established in mice and how they may specifically depend on Lsh, we generated a comprehensive genomic map of cytosine methylation in cells derived from mice with a targeted deletion of Lsh. We performed a MeDIP assay (immunoprecipitation of methylated DNA using anti-methyl-cytidine antibody) comparing DNA derived from wild type murine embryonal fibroblast cell lines (MEFs) with Lsh-/- MEFs. The precipitated DNA was hybridized to the MM8 tiling whole mouse genomic array which covers a region of about 3 billion bps excluding repeat masked regions at a resolution of a 100 bp. In addition, a histone 3 lysine 4 tri-methylation (H3K4me3) chromatin map was generated using chromatin immunoprecipitation followed by high-throughput sequencing (ChIP-Seq) and genome-wide gene expression was evaluated using cDNA microarrays. Total MeDIP enrichment of the genomic array was of similar magnitude comparing WT to the Lsh-/- sample, indicating that there was not a major net loss of cytosine methylation at unique sequences. Chromosomal maps based on mean methylation enrichment values at 50 kb windows revealed specific sites that were either hypo- or hypo-methylated in the absence of Lsh. For the whole genome about 6.4% or 8.6% was distinctively differentially methylated (hypo- or hypermethylated) in the absence of Lsh. Contiguous regions for cytosine methylation changes extended up to 2Mb suggesting that discrete chromosomal domains share a common epigenetic pathway, controlled by Lsh. Cytosine methylation pattern at protein coding genes revealed differences at the 5-end but not at the 3-ends of genes comparing wild type and Lsh-/- samples. A subset of genes containing CpG islands exhibited cytosine hypermethylation at their 5-ends. For the majority of genes the hypermethylation was associated with an increase in H3K4me3 enrichment, but a small subset showed a loss of H3k4me3. In order to gain further insight into how changes in cytosine methylation may be linked to gene expression, we analyzed the subset of genes that were differentially expressed more than two-fold. Whereas up-regulated genes had H3K4me3 increases in conjunction with DNA methylation changes, down-regulated genes displayed unchanged or reduced H3K4me3 or in the immediate TSS region in Lsh-/- MEFs. This suggests that the combination of both epigenetic marks (cytosine methylation and H3K4me3) determines the outcome of gene expression and, in addition, that DNA methylation increases in Lsh-/- MEFs can be linked to up- or down-regulation. Gene ontology analysis of differentially expressed genes in Lsh-/- MEFs showed an enrichment for genes involved in angiogenesis, lung development, skeletal system development, embryonic morphogenesis, and organ development, thus pointing to a role of Lsh in murine development. Taken together, Lsh controls the normal distribution of cytosine methylation at chromosomal domains and at promoter regions. Thus Lsh is a genome wide epigenetic regulator at non-repetitive sequences and plays a unique role in gene expression during embryonic development. Elucidating the basic mechanisms of epigenetics provide fundamental insights into biologic processes of cellular differentiation, cellular transformation and nuclear reprogramming.

Agency
National Institute of Health (NIH)
Institute
National Cancer Institute (NCI)
Type
Investigator-Initiated Intramural Research Projects (ZIA)
Project #
1ZIABC010014-16
Application #
8348943
Study Section
Project Start
Project End
Budget Start
Budget End
Support Year
16
Fiscal Year
2011
Total Cost
$863,768
Indirect Cost
Name
National Cancer Institute Division of Basic Sciences
Department
Type
DUNS #
City
State
Country
Zip Code
Han, Yixing; Ren, Jianke; Lee, Eunice et al. (2017) Lsh/HELLS regulates self-renewal/proliferation of neural stem/progenitor cells. Sci Rep 7:1136
Ren, Jianke; Hathaway, Nathaniel A; Crabtree, Gerald R et al. (2017) Tethering of Lsh at the Oct4 locus promotes gene repression associated with epigenetic changes. Epigenetics :0
He, Xiaozhen; Yan, Bin; Liu, Shuang et al. (2016) Chromatin Remodeling Factor LSH Drives Cancer Progression by Suppressing the Activity of Fumarate Hydratase. Cancer Res 76:5743-5755
Han, Yixing; Gao, Shouguo; Muegge, Kathrin et al. (2015) Advanced Applications of RNA Sequencing and Challenges. Bioinform Biol Insights 9:29-46
Ren, Jianke; Briones, Victorino; Barbour, Samantha et al. (2015) The ATP binding site of the chromatin remodeling homolog Lsh is required for nucleosome density and de novo DNA methylation at repeat sequences. Nucleic Acids Res 43:1444-55
Jiang, Y; Yan, B; Lai, W et al. (2015) Repression of Hox genes by LMP1 in nasopharyngeal carcinoma and modulation of glycolytic pathway genes by HoxC8. Oncogene 34:6079-91
Terashima, Minoru; Barbour, Samantha; Ren, Jianke et al. (2015) Effect of high fat diet on paternal sperm histone distribution and male offspring liver gene expression. Epigenetics 10:861-71
Lungu, Cristiana; Muegge, Kathrin; Jeltsch, Albert et al. (2015) An ATPase-deficient variant of the SNF2 family member HELLS shows altered dynamics at pericentromeric heterochromatin. J Mol Biol 427:1903-15
Yu, Weishi; McIntosh, Carl; Lister, Ryan et al. (2014) Genome-wide DNA methylation patterns in LSH mutant reveals de-repression of repeat elements and redundant epigenetic silencing pathways. Genome Res 24:1613-23
Yu, Weishi; Briones, Victorino; Lister, Ryan et al. (2014) CG hypomethylation in Lsh-/- mouse embryonic fibroblasts is associated with de novo H3K4me1 formation and altered cellular plasticity. Proc Natl Acad Sci U S A 111:5890-5

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