CD47-dependent molecular mechanisms of blood outgrowth endothelial cell attachment on cholesterol-modified polyurethane
✍ Scribed by Masako Ueda; Ivan S. Alferiev; Stacey B. Simons; Robert P. Hebbel; Robert J. Levy; Stanley J. Stachelek
- Book ID
- 104003999
- Publisher
- Elsevier Science
- Year
- 2010
- Tongue
- English
- Weight
- 478 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0142-9612
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✦ Synopsis
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 a v b 3 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 a v and integrin b 3 as well as G aiÀ2 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 a v and integrin b 3 . Similar results were observed with the addition of methyl-betacyclodextrin (MbCD), 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.