Transcriptome analysis of the role of SMAD6 in mediating endothelial cell response to laminar shear stress by high throughput RNA sequencing
Ontology highlight
ABSTRACT: Laminar shear stress regulates blood vessel morphogenesis and subsequent quiescence, but how endothelial cells (EC) enact and maintain the vascular homeostasis required in most vessels for proper vessel function is poorly understood. SMAD6, a scaffold for several signaling pathways, is expressed in developing arteries and its expression is flow-regulated. We found that SMAD6 is essential for endothelial cell flow-mediated responses, and that it functions downstream of the mechanosensor Notch1. Endothelial cells with reduced SMAD6 levels failed to align under stable laminar shear flow that promotes vascular homeostasis, while forced SMAD6 expression rescued misalignment induced by reduced Notch1 signaling. SMAD6-dependent homeostatic laminar flow required the Notch ligand Dll4 and Notch transcriptional activity. Mechanistically, neither the N-terminal nor the C-terminal domain of SMAD6 alone rescued flow alignment upon loss of Notch signaling. Endothelial cells with reduced Smad6 levels has compromised barrier function, and RNA profiling revealed upregulation of proliferation-associated genes and down regulation of junction-associated genes. Among junction-related genes affected by SMAD6 levels, the proto-cadherin PCDH12 was upregulated by homeostatic flow and required for proper flow-mediated endothelial cell alignment. Thus, SMAD6 is a critical integrator of flow-mediated signaling inputs downstream of Notch1, as vessels transition from an angiogenic to a homeostatic phenotype.
ORGANISM(S): Homo sapiens
PROVIDER: GSE147036 | GEO | 2021/03/29
REPOSITORIES: GEO
ACCESS DATA