Abstract 16392: Oxido-Reductive Regulation of Human Vascular Remodeling by the Orphan Receptor Tyrosine Kinase Ros1
Atherosclerosis is responsible for more deaths worldwide than any other disease process. When medical therapy fail, ischemia can be reversed by balloon angioplasty and stenting (BAS). However, BAS continues to be limited by pathological remodeling, delayed re-endothelialization and thrombosis. To better understand these processes, we characterized gene expression topology in coronary atheroma from 89 patients with either de novo atherosclerosis or in-stent stenosis (ISS). Using a systems biology approach, we identified the network hub gene glutathione peroxidase-1 (GPX1) as a putative mediator of the response to vascular injury. Mice with constitutive deletion of GPX1 were crossed onto an atherosclerotic (ApoE-/-) background and underwent BAS, demonstrating a marked elevation of ISS associated with increased medial superoxide generation and reduced endothelialization. In an independent cohort of patients that developed ISS (n=107), gene variant pair analysis identified a strong interaction of GPX1 with the orphan proto-oncogene receptor tyrosine kinase ROS1 (P<0.002). The association of the ROS1 variant with ISS was confirmed in an independent meta-analysis of the only genome wide association studies of human ISS (1033 cases/2669 controls; P=0.05). Decreased GPX1 expression in GPx1-/-/ApoE-/- mice led to reductive stress via a time-dependent increase in GSH reaching nearly 10-fold higher than baseline (P<0.01) and a corresponding increase in phosphorylation of ROS1 at Y2274 (P<0.01), a phosphorylation site known to activate the kinase. Loss of GPX1 function was thus associated with both oxidative and reductive stress, the latter driving ROS1 activity via s-glutathiolation of critical cysteine residues 463 and 333 of the ROS1 tyrosine phosphatase SHP-2 in vitro and in vivo. Finally, specific ROS1 inhibition with crizotinib and deglutathiolation of SHP-2 by adenoviral overexpression of glutaredoxin abolished GPX1-mediated increases in vascular smooth muscle cell proliferation in vitro and reduced ISS while leaving endothelialization intact in vivo. In summary, we identify a new mechanism of vascular remodeling and show efficacy and new therapeutic use of an already approved drug for its more selective abrogation.
Author Disclosures: Z.A. Ali: None. V. de Jesus Perez: None. K. Yuan: None. M. Orcholski: None. S. Pan: None. W. Qi: None. G. Chopra: None. C. Adams: None. Y. Kojima: None. N.J. Leeper: None. K. Zaleta-Rivera: None. K. Kato: None. Y. Yamada: None. M. Oguri: None. S.L. Hazen: None. J. Jukema: None. S.K. Ganesh: Research Grant; Modest; Doris Duke Charitable Foundation, NHLBI. Research Grant; Significant; Significant, Significant. E.G. Nabel: None. K. Channon: None. M.B. Leon: None. A. Charest: None. T. Quertermous: None. E.A. Ashley: None.
- © 2014 by American Heart Association, Inc.