TITLE: Phosphorylation of endothelial histone H3.3 serine 31 by PKN1 links flow-induced signaling to proatherogenic gene expression
ABSTRACT:
Atherosclerotic lesion develop preferentially in arterial regions exposed to disturbed blood flow, such as vessel curvatures, bifurcations and branching points, where endothelial cells develop an inflammatory phenotype. How disturbed flow induces endothelial cell inflammation is incompletely understood. We show here that histone H3.3 phosphorylation at serine 31 (H3.3S31) plays a critical role in disturbed flow-induced endothelial inflammation, as it allows the rapid induction of FOS and FOSB, which are required for disturbed flow-induced inflammatory gene expression. We identified protein kinase N1 (PKN1) as the kinase responsible for disturbed flow-induced H3.3S31 phosphorylation. PKN1 becomes activated by disturbed flow in an integrin α5β1-dependent manner and then translocates to the cell nucleus. We found that PKN1 is also involved in the phosphorylation of the AP-1 transcription factor JUN. Mice with endothelium-specific loss of PKN1 or endothelial expression of S31 phosphorylation-deficient mutants of H.3.3 show reduced endothelial inflammation and disturbed flow-induced vascular remodeling in vitro and in vivo. Together, we identified a pathway whereby disturbed flow through PKN1-mediated histone phosphorylation and FOS/FOSB induction promotes inflammatory gene expression and vascular inflammation.
This repository contains all scripts used to analyze data sets described in this study. We applied a range of existing tools for calculations and visualizations. The repository is divided into separate folders containing miscellaneous scripts (misc) and code specific to data types (RNA/ATAC-Seq).