Endothelial activation, a shift in endothelial phenotype from quiescent anti-inflammatory to proinflammatory and leaky phenotype, regulates atherosclerosis formation. Endothelial activation is triggered by a low oscillatory shear stress (OSS) and the mechanism remains largely unknown. We previously showed that deletion of the Src homology (SH) domain-containing adaptor protein Nck (non-catalytic region of receptor tyrosine kinase) in endothelial cells reduced the activation of NF-kB and endothelial permeability. There are two forms of the Nck proteins, Nck1 and Nck2, and it was believed to play redundant roles, particularly in actin cytoskeletal remodeling and endothelial migration in angiogenesis. However, our preliminary data propose non-compensating functions for Nck1 and Nck2 in endothelial activation, with only Nck1 regulates NF-kB activation, proinflammatory gene expression and endothelial permeability in vitro and in vivo. Whereas Nck2 does not exert any major effects on endothelial activation. Our central hypothesis is that endothelial Nck1-specific signaling critically mediates flow-induced NF-kB activation to drive atherogenic inflammation while having a limited effect on ischemic angiogenesis. Aim 1: To identify the specific mediators involved in Nck1-dependent NF-kB activation. We will utilize both non-biased proteomic analysis and targeted analysis of a known Nck1 binding partner to characterize the mechanisms by which Nck1 signaling drives endothelial activation. Aim 2: To assess the effect of endothelial Nck1 inhibition on atherosclerotic inflammation and ischemic angiogenesis in vivo. We will utilize a Nck1 inhibitor and our recently developed Nck1 conditional knockouts to assess the specific effect of endothelial Nck1 inhibition on atherogenic endothelial activation and on ischemic angiogenesis. This work will provide novel insights to the Nck1 downstream pathway and by targeting Nck1 signaling we can mitigate atherosclerosis.
|Program type||Postdoctoral Fellowship|
|Effective start/end date||01/01/2020 → 12/31/2021|