Targeted Epigenetic Editing of SPDEF Reduces Mucus Production in Lung Epithelial Cells

Am J Physiol Lung Cell Mol Physiol. 2017 Mar 1;312(3):L334-L347. doi: 10.1152/ajplung.00059.2016. Epub 2016 Dec 23.

Abstract

Airway mucus hypersecretion contributes to the morbidity and mortality in patients with chronic inflammatory lung diseases. Reducing mucus production is crucial for improving patients' quality of life. The transcription factor SAM-pointed domain-containing Ets-like factor (SPDEF) plays a critical role in the regulation of mucus production and, therefore, represents a potential therapeutic target. This study aims to reduce lung epithelial mucus production by targeted silencing SPDEF using the novel strategy, epigenetic editing. Zinc fingers and CRISPR/dCas platforms were engineered to target repressors (KRAB, DNA methyltransferases, histone methyltransferases) to the SPDEF promoter. All constructs were able to effectively suppress both SPDEF mRNA and protein expression, which was accompanied by inhibition of downstream mucus-related genes [anterior gradient 2 (AGR2), mucin 5AC (MUC5AC)]. For the histone methyltransferase G9A, and not its mutant or other effectors, the obtained silencing was mitotically stable. These results indicate efficient SPDEF silencing and downregulation of mucus-related gene expression by epigenetic editing, in human lung epithelial cells. This opens avenues for epigenetic editing as a novel therapeutic strategy to induce long-lasting mucus inhibition.

Keywords: DNA methylation; SPDEF; epigenetic editing; mucus production.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Base Sequence
  • Cell Line
  • DNA (Cytosine-5-)-Methyltransferases / genetics
  • DNA (Cytosine-5-)-Methyltransferases / metabolism
  • DNA Methylation / genetics
  • Down-Regulation / genetics
  • Epigenesis, Genetic*
  • Epithelial Cells / metabolism*
  • Gene Editing*
  • Gene Silencing
  • Histocompatibility Antigens / genetics
  • Histocompatibility Antigens / metabolism
  • Histone-Lysine N-Methyltransferase / genetics
  • Histone-Lysine N-Methyltransferase / metabolism
  • Humans
  • Lung / cytology*
  • Models, Biological
  • Mucin 5AC / metabolism
  • Mucus / metabolism*
  • Promoter Regions, Genetic / genetics
  • Protein Domains
  • Proto-Oncogene Proteins c-ets / genetics*
  • Proto-Oncogene Proteins c-ets / metabolism
  • Zinc Fingers

Substances

  • Histocompatibility Antigens
  • Mucin 5AC
  • Proto-Oncogene Proteins c-ets
  • SPDEF protein, human
  • DNA (Cytosine-5-)-Methyltransferases
  • DNA methyltransferase 3A
  • EHMT2 protein, human
  • Histone-Lysine N-Methyltransferase