scholarly journals Progerin-Expressing Endothelial Cells are Unable to Adapt to Shear Stress

2021 ◽  
Author(s):  
Brooke E Danielsson ◽  
Hannah C Peters ◽  
Kranthi Bathula ◽  
Lindsay M Spear ◽  
Natalie A Noll ◽  
...  

Hutchinson-Gilford Progeria Syndrome (HGPS) is a rare premature aging disease caused by a single-point mutation in the lamin A gene, resulting in a truncated and farnesylated form of lamin A. This mutant lamin A protein, known as progerin, accumulates at the periphery of the nuclear lamina, resulting in both an abnormal nuclear morphology and nuclear stiffening. HGPS patients experience rapid onset of atherosclerosis, with death from heart attack or stroke as teenagers. Progerin expression has been shown to cause dysfunction in both vascular smooth muscle cells and endothelial cells (ECs). In this study we examined how progerin-expressing ECs adapt to fluid shear stress, the principal mechanical force from blood flow. We compared the response to shear stress for progerin-expressing, wild-type lamin A overexpressing, and control ECs to physiological levels of fluid shear stress. Additionally, we also knocked down ZMPSTE24 in ECs, which results in increased farnesylation of lamin A and similar phenotypes to HGPS. Our results showed that ECs either expressing progerin or with ZMPSTE24 knockdown were unable to adapt to shear stress, experiencing significant cell loss at a longer duration of exposure to shear stress (3 days). ECs overexpressing wild-type lamin A also exhibited similar impairments in adaptation to shear stress, including similar levels of cell loss. Quantification of nuclear morphology showed that progerin-expressing ECs had similar nuclear abnormalities in both static and shear conditions. Treatment of progerin-expressing cells and ZMPSTE24 KD cells with lonafarnib and methystat, drugs previously shown to improve HGPS nuclear morphology, resulted in improvements in adaptation to shear stress. Additionally, pre-alignment of cells to shear stress prior to progerin-expression prevented cell loss. Our results demonstrate that changes in nuclear lamins can affect the ability of EC to properly adapt to shear stress.

2017 ◽  
Vol 312 (3) ◽  
pp. H485-H500 ◽  
Author(s):  
Sparkle Russell-Puleri ◽  
Nathaniel G. dela Paz ◽  
Diana Adams ◽  
Mitali Chattopadhyay ◽  
Limary Cancel ◽  
...  

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).


2015 ◽  
Vol 309 (11) ◽  
pp. C736-C746 ◽  
Author(s):  
Michael J. Mitchell ◽  
Celine Denais ◽  
Maxine F. Chan ◽  
Zhexiao Wang ◽  
Jan Lammerding ◽  
...  

Metastasis contributes to over 90% of cancer-related deaths and is initiated when cancer cells detach from the primary tumor, invade the basement membrane, and enter the circulation as circulating tumor cells (CTCs). While metastasis is viewed as an inefficient process with most CTCs dying within the bloodstream, it is evident that some CTCs are capable of resisting hemodynamic shear forces to form secondary tumors in distant tissues. We hypothesized that nuclear lamins A and C (A/C) act as key structural components within CTCs necessary to resist destruction from elevated shear forces of the bloodstream. Herein, we show that, compared with nonmalignant epithelial cells, tumor cells are resistant to elevated fluid shear forces in vitro that mimic those within the bloodstream, as evidenced by significant decreases in cellular apoptosis and necrosis. Knockdown of lamin A/C significantly reduced tumor cell resistance to fluid shear stress, with significantly increased cell death compared with parental tumor cell and nontargeting controls. Interestingly, lamin A/C knockdown increased shear stress-induced tumor cell apoptosis, but did not significantly affect cellular necrosis. These data demonstrate that lamin A/C is an important structural component that enables tumor cell resistance to fluid shear stress-mediated death in the bloodstream, and may thus facilitate survival and hematogenous metastasis of CTCs.


2020 ◽  
Vol 8 (2) ◽  
pp. 92
Author(s):  
Yoyon Arif ◽  
Erna Sulistiowati

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.


1997 ◽  
Vol 273 (5) ◽  
pp. H2396-H2405 ◽  
Author(s):  
Hans-Joachim Schnittler ◽  
Bernd Püschel ◽  
Detlev Drenckhahn

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.


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