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

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.

Download Full-text

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

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00035.2016 ◽

2017 ◽

Vol 312 (3) ◽

pp. H485-H500 ◽

Cited By ~ 35

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).

Download Full-text

Lepasnya Sel Endotel Dan Vascular Endothelial Cadherin (Ve-Cadherin) Pada Huvecs Dengan Glukosa Tinggi Dan Fluid Shear Stress

Jurnal Kesehatan Islam : Islamic Health Journal ◽

10.33474/jki.v8i2.8890 ◽

2020 ◽

Vol 8 (2) ◽

pp. 92

Author(s):

Yoyon Arif ◽

Erna Sulistiowati

Keyword(s):

Endothelial Cells ◽

Shear Stress ◽

Fluid Shear Stress ◽

Vascular Endothelial ◽

Fluid Shear ◽

Vascular Endothelial Cadherin

Sel endotel melapisi lumen pembuluh darah sehingga menyebabkan paparan langsung aliran darah dan timbul gaya hemodinamik shear stress. Vascular Endothelial (VE) Cadherin merupakan salah satu struktur penghubung antar sel yang berperan mencegah terlepasnya sel endotel dari membran dasar. Paparan glukosa tinggi menyebabkan stress oksidatif sehingga sel endotel mengalami apoptosis dan nekrosis dan terlepas. Penelitian ini bertujuan mempelajari efek paparan glukosa tinggi dan fluid shear stress terhadap morfologi, struktur VE-Cadherin dan densitas sel endotel pada kultur sel endotel HUVECs (Human Vein Endothelial Cells Culture).Metode Penelitian eksperimental laboratorium dengan metode HUVECs yang dipapar d-glukosa 22 mM selama 7 hari. Shear stress dibangkitkan dengan alat cone and plate 10 dyne/cm2 selama 5, 8, 12 dan 15 menit. Pulasan VE-Cadherin dengan imunohistokimia. Data dianalisis dengan metode statistik. Signifikan pada p<0,05.Hasil Shear stress selama 15 menit menyebabkan perubahan bentuk sel endotel menjadi lebih panjang dan inti sel lebih pipih. Paparan glukosa tinggi dan fluid shear stress menyebabkan penurunan skor VE-Cadherin dan densitas sel endotel secara signifikan Penurunan skor VE-Cadherin berpengaruh langsung terhadap penurunan densitas sel endotel.Kesimpulan. Paparan glukosa tinggi dan fluid shear stress menyebabkan kerusakan struktur VE-Cadherin sehingga terjadi peningkatan apoptosis dan nekrosis sel endotel.

Download Full-text