De novo DNA methyltransferases DNMT3A and DNMT3B are essential for XIST silencing for erosion of dosage compensation in pluripotent stem cells

Stem Cell Reports. 2021 Sep 14;16(9):2138-2148. doi: 10.1016/j.stemcr.2021.07.015. Epub 2021 Aug 19.

Abstract

Human pluripotent stem cells (hPSCs) have proven to be valuable tools for both drug discovery and the development of cell-based therapies. However, the long non-coding RNA XIST, which is essential for the establishment and maintenance of X chromosome inactivation, is repressed during culture, thereby causing erosion of dosage compensation in female hPSCs. Here, we report that the de novo DNA methyltransferases DNMT3A/3B are necessary for XIST repression in female hPSCs. We found that the deletion of both genes, but not the individual genes, inhibited XIST silencing, maintained the heterochromatin mark of H3K27me3, and did not cause global overdosage in X-linked genes. Meanwhile, DNMT3A/3B deletion after XIST repression failed to restore X chromosome inactivation. Our findings revealed that de novo DNA methyltransferases are primary factors responsible for initiating erosion of dosage compensation in female hPSCs, and XIST silencing is stably maintained in a de novo DNA-methylation-independent manner.

Keywords: DNA methylation; DNMT3A/3B; Lnc RNA XIST; dosage compensation; pluripotent stem cells.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatin Assembly and Disassembly
  • DNA (Cytosine-5-)-Methyltransferases / genetics*
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA Methylation
  • DNA Methyltransferase 3A / genetics*
  • DNA Methyltransferase 3A / metabolism
  • DNA Methyltransferase 3B
  • Dosage Compensation, Genetic
  • Epigenesis, Genetic
  • Gene Expression Profiling
  • Gene Expression Regulation*
  • Gene Silencing*
  • Genes, X-Linked
  • Genetic Background
  • Heterochromatin / genetics
  • Heterochromatin / metabolism
  • Humans
  • Models, Biological
  • Pluripotent Stem Cells / cytology
  • Pluripotent Stem Cells / metabolism*
  • RNA, Long Noncoding / genetics*

Substances

  • DNMT3A protein, human
  • Heterochromatin
  • RNA, Long Noncoding
  • XIST non-coding RNA
  • DNA (Cytosine-5-)-Methyltransferases
  • DNA Methyltransferase 3A