Physiologic Shear Stress Suppresses Endothelin-Converting Enzyme-1 Expression in Vascular Endothelial Cells

1998 ◽  
Vol 31 ◽  
pp. S42-S45 ◽  
Author(s):  
Ken Masatsugu ◽  
Hiroshi Itoh ◽  
Tae-Hwa Chun ◽  
Yoshihiro Ogawa ◽  
Naoshita Tamura ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial ◽  
Converting Enzyme ◽  
Endothelin Converting Enzyme

scholarly journals Localization of rat endothelin-converting enzyme to vascular endothelial cells and some secretory cells

1995 ◽  
Vol 311 (2) ◽  
pp. 657-665 ◽  
Author(s):  
M Takahashi ◽  
K Fukuda ◽  
K Shimada ◽  
K Barnes ◽  
A J Turner ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Plasma Membrane ◽  
Vascular Endothelial Cells ◽  
Simian Virus 40 ◽  
Secretory Cells ◽  
Rat Tissues ◽  
Vascular Endothelial ◽  
Converting Enzyme ◽  
Reducing Conditions ◽  
Endothelin Converting Enzyme

Endothelin is a potent vasoconstrictive peptide that is produced by vascular endothelial cells; it is formed from its precursor, big endothelin, by endothelin-converting enzyme (ECE). In this work, ECE was studied using specific monoclonal antibodies. In immunoblotting, ECE was estimated to be a 300 kDa protein on SDS/PAGE under non-reducing conditions, and 130 kDa under reducing conditions. Cross-linking experiments revealed that ECE is composed of two disulphide-linked subunits. Localization of ECE was studied at the cellular and subcellular levels in various rat tissues and cells. High-level expression of ECE was observed in membrane fractions of simian virus 40-transformed rat endothelial cells by immunoblotting, but the immunoreactive band was absent form aortic smooth muscle cells and cytosolic fractions of endothelial cells. In immunohistochemical analysis, ECE was found to be localized in the endothelial cells of the aorta, lung, kidney, liver and heart. Confocal immunofluorescent microscopy showed that most of the ECE in endothelial cells and cells transfected with ECE cDNA was clustered along the plasma membrane. Intact COS or CHO cells transfected with ECE cDNA rapidly and efficiently cleaved big endothelin-1 added to the culture medium. Thus endothelial cells express ECE on the plasma membrane and the active site of the enzyme faces outside the cells, i.e. it is an ectoenzyme. Other than endothelial cells, ECE was also present in some secretory cells. The enzyme was abundant in the adrenal gland, and localized in chromaffin cells. ECE was also highly condensed in pancreatic islet beta cells. It is concluded that ECE and endothelin may be involved in the regulated secretion of hormones.

scholarly journals Shear stress augments mitochondrial ATP generation that triggers ATP release and Ca2+ signaling in vascular endothelial cells

2018 ◽  
Vol 315 (5) ◽  
pp. H1477-H1485 ◽  
Author(s):  
Kimiko Yamamoto ◽  
Hiromi Imamura ◽  
Joji Ando
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Vascular Endothelial Cells ◽  
Critical Role ◽  
Atp Release ◽  
Vascular Endothelial ◽  
The Novel ◽  
Caveolin 1 ◽  
Atp Generation

Vascular endothelial cells (ECs) sense and transduce hemodynamic shear stress into intracellular biochemical signals, and Ca2+ signaling plays a critical role in this mechanotransduction, i.e., ECs release ATP in the caveolae in response to shear stress and, in turn, the released ATP activates P2 purinoceptors, which results in an influx into the cells of extracellular Ca2+. However, the mechanism by which the shear stress evokes ATP release remains unclear. Here, we demonstrated that cellular mitochondria play a critical role in this process. Cultured human pulmonary artery ECs were exposed to controlled levels of shear stress in a flow-loading device, and changes in the mitochondrial ATP levels were examined by real-time imaging using a fluorescence resonance energy transfer-based ATP biosensor. Immediately upon exposure of the cells to flow, mitochondrial ATP levels increased, which was both reversible and dependent on the intensity of shear stress. Inhibitors of the mitochondrial electron transport chain and ATP synthase as well as knockdown of caveolin-1, a major structural protein of the caveolae, abolished the shear stress-induced mitochondrial ATP generation, resulting in the loss of ATP release and influx of Ca2+ into the cells. These results suggest the novel role of mitochondria in transducing shear stress into ATP generation: ATP generation leads to ATP release in the caveolae, triggering purinergic Ca2+ signaling. Thus, exposure of ECs to shear stress seems to activate mitochondrial ATP generation through caveola- or caveolin-1-mediated mechanisms. NEW & NOTEWORTHY The mechanism of how vascular endothelial cells sense shear stress generated by blood flow and transduce it into functional responses remains unclear. Real-time imaging of mitochondrial ATP demonstrated the novel role of endothelial mitochondria as mechanosignaling organelles that are able to transduce shear stress into ATP generation, triggering ATP release and purinoceptor-mediated Ca2+ signaling within the cells.

scholarly journals Low Shear Stress Upregulates CX3CR1 Expression by Inducing VCAM-1 via the NF-κB Pathway in Vascular Endothelial Cells

2020 ◽  
Vol 78 (3) ◽  
pp. 383-389 ◽  
Author(s):  
Yiwei Zhao ◽  
Peile Ren ◽  
Qiufang Li ◽  
Shafiu Adam Umar ◽  
Tan Yang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shear Stress ◽  
Protein Expression ◽  
Vascular Endothelial Cells ◽  
Critical Role ◽  
Mrna Levels ◽  
Vascular Endothelial ◽  
Low Shear Stress ◽  
Low Shear ◽  
Cx3cr1 Expression

Abstract Atherosclerosis is a significant cause of mortality and morbidity. Studies suggest that the chemokine receptor CX3CR1 plays a critical role in atherogenesis. Shear stress is an important mechanical force that affects blood vessel function. In this study, we investigated the effect of shear stress on CX3CR1 expression in vascular endothelial cells (VECs). First, cells were exposed to different shear stress and then CX3CR1 mRNA and protein were measured by quantitative RT-PCR and western blot analysis, respectively. CX3CR1 gene silencing was used to analyze the molecular mechanisms underlying shear stress-mediated effects on CX3CR1 expression. CX3CR1 mRNA and protein expression were significantly increased with 4.14 dyne/cm2 of shear stress compared with other tested levels of shear stress. We observed a significant increase in CX3CR1 mRNA levels at 2 h and CX3CR1 protein expression at 4 h. CX3CR1-induced VCAM-1 expression in response to low shear stress by activating NF-κB signaling pathway in VECs. Our findings demonstrate that low shear stress increases CX3CR1 expression, which increases VCAM-1 expression due to elevated NF-κB activation. The current study provides evidence of the correlation between shear stress and atherosclerosis mediated by CX3CR1.

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