We previously showed that blood outgrowth endothelial cells (BOECs) had a high affinity for polyurethane (PU) covalently configured with cholesterol residues (PU-Chol). However, the molecular mechanisms responsible for this enhanced affinity were not determined. CD47, a multifunctional transmembrane glycoprotein involved in cellular attachment, can form a cholesterol-dependent complex with integrin αvβ3 and heterotrimeric G proteins. We tested herein the hypothesis that CD47, and the other components of the multi-molecular complex, enhance the attachment of BOECs to PU-Chol. Immunoprecipitation studies, of human and ovine BOECs, demonstrated that CD47 associates with integrin αv and integrin β3 as well as Gαi-2 protein. The three-fold increase in BOEC attachment to PU-Chol, compared to unmodified PU, was reversed with the addition of blocking antibodies specific for CD47 and integrin αv and integrin β3. Similar results were observed with the addition of methyl-beta-cyclodextrin (MβCD), a known disruptor of the CD47 complex as well as of the membrane cholesterol content, to seeded BOEC or PU-Chol films. Reducing CD47 expression, via lentivirus transduced shRNA, decreased BOEC binding to PU-Chol by 50% compared to control groups. These data are the first demonstration of a role for the CD47 cholesterol-dependent signaling complex in BOEC attachment onto synthetic surfaces.
|Original language||English (US)|
|Number of pages||6|
|State||Published - Sep 2010|
Bibliographical noteFunding Information:
Funding for this research was provided by NIH grant RO1-HL090605 (RJL), NIH training grant T32-HL007915 (M.U.), a Scientist Development Grant from the American Heart Association (SJS), and NIH grant PO1-HL55552 (RPH).
- Cell adhesion
- RGD peptide