title: Fluid shear stress induces upregulation of COX-2 and PGI2release in endothelial cells via a pathway involving PECAM-1, PI3K, FAK, and p38.
abstract: Vascular endothelial cells play an important role in the regulation of vascular function in response to mechanical stimuli in both healthy and diseased states. Prostaglandin I2(PGI2) is an important antiatherogenic prostanoid and vasodilator produced in endothelial cells through the action of the cyclooxygenase (COX) isoenzymes COX-1 and COX-2. However, the mechanisms involved in sustained, shear-induced production of COX-2 and PGI2have not been elucidated but are determined in the present study. We used cultured endothelial cells exposed to steady fluid shear stress (FSS) of 10 dyn/cm2for 5 h to examine shear stress-induced induction of COX-2/PGI2Our results demonstrate the relationship between the mechanosensor platelet endothelial cell adhesion molecule-1 (PECAM-1) and the intracellular mechanoresponsive molecules phosphatidylinositol 3-kinase (PI3K), focal adhesion kinase (FAK), and mitogen-activated protein kinase p38 in the FSS induction of COX-2 expression and PGI2release. Knockdown of PECAM-1 (small interference RNA) expression inhibited FSS-induced activation of α5β1-integrin, upregulation of COX-2, and release of PGI2in both bovine aortic endothelial cells (BAECs) and human umbilical vein endothelial cells (HUVECs). Furthermore, inhibition of the PI3K pathway (LY294002) substantially inhibited FSS activation of α5β1-integrin, upregulation of COX-2 gene and protein expression, and release of PGI2in BAECs. Inhibition of integrin-associated FAK (PF573228) and MAPK p38 (SB203580) also inhibited the shear-induced upregulation of COX-2. Finally, a PECAM-1-/-mouse model was characterized by reduced COX-2 immunostaining in the aorta and reduced plasma PGI2levels compared with wild-type mice, as well as complete inhibition of acute flow-induced PGI2release compared with wild-type animals.NEW & NOTEWORTHYIn this study we determined the major mechanotransduction pathway by which blood flow-driven shear stress activates cyclooxygenase-2 (COX-2) and prostaglandin I2(PGI2) release in endothelial cells. Our work has demonstrated for the first time that COX-2/PGI2mechanotransduction is mediated by the mechanosensor platelet endothelial cell adhesion molecule-1 (PECAM-1).
authors.affiliation: Department of Biomedical Engineering, City College of New York, New York, New York.
authors.forename: Sparkle
authors.initials: S
authors.lastname: Russell-Puleri
authors.affiliation: La Jolla Bioengineering Institute, La Jolla, California.
authors.forename: Nathaniel G
authors.initials: NG
authors.lastname: Dela Paz
authors.affiliation: La Jolla Bioengineering Institute, La Jolla, California.
authors.forename: Diana
authors.initials: D
authors.lastname: Adams
authors.affiliation: James J. Peters Veteran Affairs Medical Center, Bronx, New York, New York.
authors.forename: Mitali
authors.initials: M
authors.lastname: Chattopadhyay
authors.affiliation: Department of Biomedical Engineering, City College of New York, New York, New York.
authors.forename: Limary
authors.initials: L
authors.lastname: Cancel
authors.affiliation: Department of Chemical Engineering, Northeastern University, Boston, Massachusetts; and.
authors.forename: Eno
authors.initials: E
authors.lastname: Ebong
authors.affiliation: Department of Pathology, Louisiana State University, Shreveport, Louisiana.
authors.forename: A Wayne
authors.initials: AW
authors.lastname: Orr
authors.affiliation: La Jolla Bioengineering Institute, La Jolla, California.
authors.forename: John A
authors.initials: JA
authors.lastname: Frangos
authors.affiliation: Department of Biomedical Engineering, City College of New York, New York, New York; jtarbell@ccny.cuny.edu.
authors.forename: John M
authors.initials: JM
authors.lastname: Tarbell
mesh_terms: D000818:Animals; D002417:Cattle; D002460:Cell Line; D002923:Cilia / Q000378:metabolism; D051546:Cyclooxygenase 2 / Q000096:biosynthesis*; D042783:Endothelial Cells / Q000378:metabolism*; D011464:Epoprostenol / Q000096:biosynthesis*; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism; D006801:Humans; D007150:Immunohistochemistry; D016023:Integrins / Q000378:metabolism; D010455:Peptides / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism; D010766:Phosphorylation; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D013314:Stress, Mechanical; D015854:Up-Regulation; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: C587174:FAK peptide; D016023:Integrins; D010455:Peptides; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D011464:Epoprostenol; D051546:Cyclooxygenase 2; D019869:Phosphatidylinositol 3-Kinases; D048051:p38 Mitogen-Activated Protein Kinases
keywords: PECAM-1; cyclooxygenase-2; glycocalyx; integrins; primary cilia; prostaglandin I2; shear stress; syndecan-4