title: Effect of streptavidin-biotin on endothelial vasoregulation and leukocyte adhesion.
abstract: The current study examines whether the adhesion promoting arginine-glycine-aspartate-streptavidin mutant (RGD-SA) also affects two important endothelial cell (EC) functions in vitro: vasoregulation and leukocyte adhesion. EC adherent to surfaces via fibronectin (Fn) or Fn plus RGD-SA were subjected to laminar shear flow and media samples were collected over a period of 4h to measure the concentration of nitric oxide (NO), prostacyclin (PGI(2)), and endothelin-1 (ET-1). Western blot analysis was used to quantify the levels of endothelial-derived nitric oxide synthase (eNOS) and cyclooxygenase II (COX II). In a separate set of experiments, fluorescent polymorphonuclear leukocyte (PMN) adhesion to EC was quantified for EC with and without exposure to flow preconditioning. When cell adhesion was supplemented with the SA-biotin system, flow-induced production of NO and PGI(2) increased significantly relative to cells adherent on Fn alone. Previous exposure of EC to shear flow also significantly decreased PMN attachment to SA-biotin supplemented EC, but only after 2h of exposure to shear flow. The observed decrease in PMN-EC adhesion was negated by NG-nitro-L-arginine methyl ester (L-NAME), an antagonist of NO synthesis, but not by indomethacin, an inhibitor to PGI(2) synthesis, indicating the induced effect of PMN-EC interaction is primarily NO-dependent. Results from this study suggest that the use of SA-biotin to supplement EC adhesion encourages vasodilation and PMN adhesion in vitro under physiological shear-stress conditions. We postulate that the presence of SA-biotin more efficiently transmits the shear-stress signal and amplifies the downstream events including the NO and PGI(2) release and leukocyte-EC inhibition. These results may have ramifications for reducing thrombus-induced vascular graft failure.
authors.affiliation: Biomedical Engineering, Duke University, Box 90281 Rm. 136, Hudson Hall, Durham, NC 27708-0281, USA.
authors.forename: Bernard P
authors.initials: BP
authors.lastname: Chan
authors.forename: William M
authors.initials: WM
authors.lastname: Reichert
authors.forename: George A
authors.initials: GA
authors.lastname: Truskey
mesh_terms: D001710:Biotin / Q000737:chemistry / Q000494:pharmacology*; D001783:Blood Flow Velocity; D002448:Cell Adhesion / Q000502:physiology; D048429:Cell Size / Q000187:drug effects; D002478:Cells, Cultured; D020099:Coated Materials, Biocompatible / Q000737:chemistry / Q000494:pharmacology; D004730:Endothelium, Vascular / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D005343:Fibrinolytic Agents / Q000378:metabolism; D006487:Hemostasis / Q000187:drug effects / Q000502:physiology*; D006801:Humans; D007962:Leukocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology; D008422:Materials Testing; D040542:Mechanotransduction, Cellular / Q000502:physiology; D009504:Neutrophils / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D033081:Shear Strength; D019809:Streptavidin / Q000737:chemistry / Q000494:pharmacology*; D023822:Tissue Engineering / Q000379:methods*; D014653:Vascular Headaches
chemical_list: D020099:Coated Materials, Biocompatible; D005343:Fibrinolytic Agents; D001710:Biotin; D019809:Streptavidin