Role of Cbfa1/Runx2 in the fluid shear stress induction of COX-2 in osteoblasts

2006 ◽  
Vol 341 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
Meenal Mehrotra ◽  
Masatomo Saegusa ◽  
Olga Voznesensky ◽  
Carol Pilbeam
Keyword(s):  
Shear Stress ◽  
Fluid Shear Stress ◽  
Fluid Shear ◽  
Stress Induction ◽  
Cox 2

Role of cadherins and plakoglobin in interendothelial adhesion under resting conditions and shear stress

1997 ◽  
Vol 273 (5) ◽  
pp. H2396-H2405 ◽  
Author(s):  
Hans-Joachim Schnittler ◽  
Bernd Püschel ◽  
Detlev Drenckhahn
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Time Course ◽  
Fluid Shear Stress ◽  
Vascular Endothelial ◽  
Fluid Shear ◽  
Platelet Endothelial Cell Adhesion ◽  
Cell Adhesion Molecule 1 ◽  
Arterial Endothelial Cells

The role of cadherins and the cadherin-binding cytosolic protein plakoglobin in intercellular adhesion was studied in cultured human umbilical venous endothelial cells exposed to fluid shear stress. Extracellular Ca2+depletion (<10−7 M) caused the disappearance of both cadherins and plakoglobin from junctions, whereas the distribution of platelet endothelial cell adhesion molecule 1 (PECAM-1) remained unchanged. Cells stayed fully attached to each other for several hours in low Ca2+ but began to dissociate under flow conditions. At the time of recalcification, vascular endothelial (VE) cadherin and β-catenin became first visible at junctions, followed by plakoglobin with a delay of ∼20 min. Full fluid shear stress stability of the junctions correlated with the time course of the reappearance of plakoglobin. Inhibition of plakoglobin expression by microinjection of antisense oligonucleotides did not interfere with the junctional association of VE-cadherin, PECAM-1, and β-catenin. The plakoglobin-deficient cells remained fully attached to each other under resting conditions but began to dissociate in response to flow. Shear stress-induced junctional dissociation was also observed in cultures of plakoglobin-depleted arterial endothelial cells of the porcine pulmonary trunk. These observations show that interendothelial adhesion under hydrodynamic but not resting conditions requires the junctional location of cadherins associated with plakoglobin. β-Catenin cannot functionally compensate for the junctional loss of plakoglobin, and PECAM-1-mediated adhesion is not sufficient for monolayer integrity under flow.

Pattern formation of vascular smooth muscle cells subject to nonuniform fluid shear stress: role of PDGF-β receptor and Src

2003 ◽  
Vol 285 (3) ◽  
pp. H1081-H1090 ◽  
Author(s):  
Shu Q. Liu ◽  
Christopher Tieche ◽  
Dalin Tang ◽  
Paul Alkema
Keyword(s):  
Shear Stress ◽  
Smooth Muscle ◽  
Cell Density ◽  
Fluid Shear Stress ◽  
Density Gradients ◽  
Dependent Manner ◽  
Fluid Shear ◽  
Polymer Implants ◽  
Β Receptor

Blood vessels are subject to fluid shear stress, a hemodynamic factor that inhibits the mitogenic activities of vascular cells. The presence of nonuniform shear stress has been shown to exert graded suppression of cell proliferation and induces the formation of cell density gradients, which in turn regulate the direction of smooth muscle cell (SMC) migration and alignment. Here, we investigated the role of platelet-derived growth factor (PDGF)-β receptor and Src in the regulation of such processes. In experimental models with vascular polymer implants, SMCs migrated from the vessel media into the neointima of the implant under defined fluid shear stress. In a nonuniform shear model, blood shear stress suppressed the expression of PDGF-β receptor and the phosphorylation of Src in a shear level-dependent manner, resulting in the formation of mitogen gradients, which were consistent with the gradient of cell density as well as the alignment of SMCs. In contrast, uniform shear stress in a control model elicited an even influence on the activity of mitogenic molecules without modulating the uniformity of cell density and did not significantly influence the direction of SMC alignment. The suppression of the PDGF-β receptor tyrosine kinase and Src with pharmacological substances diminished the gradients of mitogens and cell density and reduced the influence of nonuniform shear stress on SMC alignment. These observations suggest that PDGF-β receptor and Src possibly serve as mediating factors in nonuniform shear-induced formation of cell density gradients and alignment of SMCs in the neointima of vascular polymer implants.

Role of actin filaments in endothelial cell-cell adhesion and membrane stability under fluid shear stress

2001 ◽  
Vol 442 (5) ◽  
pp. 675-687 ◽  
Author(s):  
Hans-Joachim Schnittler ◽  
Stefan Schneider ◽  
Hartmann Raifer ◽  
Fei Luo ◽  
Peter Dieterich ◽  
...  
Keyword(s):  
Shear Stress ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
Actin Filaments ◽  
Fluid Shear Stress ◽  
Membrane Stability ◽  
Fluid Shear ◽  
Cell Cell

scholarly journals Fluid Shear Stress Induction of the Tissue Factor Promoter In Vitro and In Vivo Is Mediated by Egr-1

1999 ◽  
Vol 19 (2) ◽  
pp. 281-289 ◽  
Author(s):  
Parul Houston ◽  
Marion C. Dickson ◽  
Valerie Ludbrook ◽  
Brian White ◽  
Jean-Luc Schwachtgen ◽  
...  
Keyword(s):  
Shear Stress ◽  
Tissue Factor ◽  
Fluid Shear Stress ◽  
Fluid Shear ◽  
Stress Induction

EFFECTS OF FLUID SHEAR STRESS AND CIGLITAZONE ON OSTEOBLASTS

2012 ◽  
Vol 12 (04) ◽  
pp. 1250076
Author(s):  
LIJUN SUN ◽  
HAOYU WANG ◽  
HAO XU ◽  
JINHONG WEI ◽  
LIANG SHI ◽  
...  
Keyword(s):  
Shear Stress ◽  
Mrna Expression ◽  
Fluid Shear Stress ◽  
Nuclear Factor Κb ◽  
Nuclear Factor ◽  
Fluid Shear ◽  
Proliferation And Differentiation ◽  
Cox 2

Long-term use of thiazolidinedione (TZD) antidiabetic agents in patients with type 2 diabetes mellitus has been shown to increase the incidence of osteoporosis. Mechanical loading can enhance bone mass by promoting bone formation and suppressing bone resorption, which may be beneficial to patients with TZD-induced osteoporosis. In this study, we examined the cooperative effect of fluid shear stress (FSS) and ciglitazone (CIG), a type of TZD, on osteoblasts. The proliferation, osteoblast differentiation-related mRNA expression and translocation of nuclear factor κB (NFκB) of osteoblasts were assessed. The results show that CIG significantly decreased the proliferation of osteoblasts, inhibited the translocation of NFκB to the nucleus and reduced the mRNA expression of COX-2, IGF, Runx2 and OCN. At the same time, CIG also increased the mRNA expression of PPARγ. Conversely, FSS significantly increased the proliferation of osteoblasts, promoted the translocation of NFκB to the nucleus and increased the mRNA expression of COX-2, IGF, Runx2 and OCN but decreased the mRNA expression of PPARγ. When FSS and CIG were combined, FSS counteracted the effects of CIG on osteoblasts. Taken together, the current results suggest that FSS is able to arrest the effects of CIG on the proliferation and differentiation of osteoblasts.

scholarly journals Fluid shear stress induces upregulation of COX-2 and PGI2 release in endothelial cells via a pathway involving PECAM-1, PI3K, FAK, and p38

2017 ◽  
Vol 312 (3) ◽  
pp. H485-H500 ◽  
Author(s):  
Sparkle Russell-Puleri ◽  
Nathaniel G. dela Paz ◽  
Diana Adams ◽  
Mitali Chattopadhyay ◽  
Limary Cancel ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Cell Adhesion Molecule ◽  
Fluid Shear Stress ◽  
Wild Type ◽  
Fluid Shear ◽  
Platelet Endothelial Cell Adhesion ◽  
Cox 2 ◽  
Cell Adhesion Molecule 1 ◽  
Endothelial Cell Adhesion

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 PGI2 have 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/cm2 for 5 h to examine shear stress-induced induction of COX-2/PGI2. Our 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 PGI2 release. Knockdown of PECAM-1 (small interference RNA) expression inhibited FSS-induced activation of α5β1-integrin, upregulation of COX-2, and release of PGI2 in 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 PGI2 in 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 PGI2 levels compared with wild-type mice, as well as complete inhibition of acute flow-induced PGI2 release compared with wild-type animals. NEW & NOTEWORTHY In 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/PGI2 mechanotransduction is mediated by the mechanosensor platelet endothelial cell adhesion molecule-1 (PECAM-1).

Role of p120-catenin in the morphological changes of endothelial cells exposed to fluid shear stress

2010 ◽  
Vol 398 (3) ◽  
pp. 426-432 ◽  
Author(s):  
Naoya Sakamoto ◽  
Kei Segawa ◽  
Makoto Kanzaki ◽  
Toshiro Ohashi ◽  
Masaaki Sato
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Fluid Shear Stress ◽  
Morphological Changes ◽  
Fluid Shear ◽  
P120 Catenin

ROLE OF CELL-CELL JUNCTIONS IN MEDIATING ENDOTHELIAL CELL RESPONSES TO FLUID SHEAR STRESS

2004 ◽  
Vol 13 (3) ◽  
pp. 41
Author(s):  
Eleni Tzima ◽  
Mohamed Irani-Tehrani ◽  
Elizabetta Dejana ◽  
Martin Schwartz
Keyword(s):  
Shear Stress ◽  
Endothelial Cell ◽  
Fluid Shear Stress ◽  
Cell Junctions ◽  
Fluid Shear ◽  
Cell Responses ◽  
Cell Cell
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