Direct evidence for pitavastatin induced chromatin structure change in the KLF4 gene in endothelial cells

PLoS One. 2014 May 5;9(5):e96005. doi: 10.1371/journal.pone.0096005. eCollection 2014.

Abstract

Statins exert atheroprotective effects through the induction of specific transcriptional factors in multiple organs. In endothelial cells, statin-dependent atheroprotective gene up-regulation is mediated by Kruppel-like factor (KLF) family transcription factors. To dissect the mechanism of gene regulation, we sought to determine molecular targets by performing microarray analyses of human umbilical vein endothelial cells (HUVECs) treated with pitavastatin, and KLF4 was determined to be the most highly induced gene. In addition, it was revealed that the atheroprotective genes induced with pitavastatin, such as nitric oxide synthase 3 (NOS3) and thrombomodulin (THBD), were suppressed by KLF4 knockdown. Myocyte enhancer factor-2 (MEF2) family activation is reported to be involved in pitavastatin-dependent KLF4 induction. We focused on MEF2C among the MEF2 family members and identified a novel functional MEF2C binding site 148 kb upstream of the KLF4 gene by chromatin immunoprecipitation along with deep sequencing (ChIP-seq) followed by luciferase assay. By applying whole genome and quantitative chromatin conformation analysis {chromatin interaction analysis with paired end tag sequencing (ChIA-PET), and real time chromosome conformation capture (3C) assay}, we observed that the MEF2C-bound enhancer and transcription start site (TSS) of KLF4 came into closer spatial proximity by pitavastatin treatment. 3D-Fluorescence in situ hybridization (FISH) imaging supported the conformational change in individual cells. Taken together, dynamic chromatin conformation change was shown to mediate pitavastatin-responsive gene induction in endothelial cells.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Chromatin / genetics
  • Chromatin / metabolism*
  • Chromatin Assembly and Disassembly / drug effects*
  • Gene Expression Regulation / drug effects*
  • Gene Expression Regulation / genetics
  • Gene Knockdown Techniques
  • Human Umbilical Vein Endothelial Cells / cytology
  • Human Umbilical Vein Endothelial Cells / metabolism*
  • Humans
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors / pharmacology*
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors / biosynthesis*
  • Kruppel-Like Transcription Factors / genetics
  • MEF2 Transcription Factors / genetics
  • MEF2 Transcription Factors / metabolism
  • Nitric Oxide Synthase Type III / biosynthesis
  • Nitric Oxide Synthase Type III / genetics
  • Quinolines / pharmacology*
  • Response Elements
  • Thrombomodulin / biosynthesis
  • Thrombomodulin / genetics

Substances

  • Chromatin
  • Hydroxymethylglutaryl-CoA Reductase Inhibitors
  • KLF4 protein, human
  • Kruppel-Like Factor 4
  • Kruppel-Like Transcription Factors
  • MEF2 Transcription Factors
  • MEF2C protein, human
  • Quinolines
  • Thrombomodulin
  • NOS3 protein, human
  • Nitric Oxide Synthase Type III
  • pitavastatin

Associated data

  • GEO/GSE32547
  • GEO/GSE32644
  • GEO/GSE32693
  • GEO/GSE41553