scholarly journals Uptake of oxidative stress-mediated extracellular vesicles by vascular endothelial cells under low magnitude shear stress

2022 ◽  
Vol 9 ◽  
pp. 397-410
Author(s):  
Xian Qin ◽  
Kun Zhang ◽  
Juhui Qiu ◽  
Nan Wang ◽  
Kai Qu ◽  
...  
2006 ◽  
Vol 290 (5) ◽  
pp. C1399-C1410 ◽  
Author(s):  
Helena Parfenova ◽  
Shyamali Basuroy ◽  
Sujoy Bhattacharya ◽  
Dilyara Tcheranova ◽  
Yan Qu ◽  
...  

In cerebral circulation, epileptic seizures associated with excessive release of the excitatory neurotransmitter glutamate cause endothelial injury. Heme oxygenase (HO), which metabolizes heme to a vasodilator, carbon monoxide (CO), and antioxidants, biliverdin/bilirubin, is highly expressed in cerebral microvessels as a constitutive isoform, HO-2, whereas the inducible form, HO-1, is not detectable. Using cerebral vascular endothelial cells from newborn pigs and HO-2-knockout mice, we addressed the hypotheses that 1) glutamate induces oxidative stress-related endothelial death by apoptosis, and 2) HO-1 and HO-2 are protective against glutamate cytotoxicity. In cerebral endothelial cells, glutamate (0.1–2.0 mM) increased formation of reactive oxygen species, including superoxide radicals, and induced major keystone events of apoptosis, such as NF-κB nuclear translocation, caspase-3 activation, DNA fragmentation, and cell detachment. Glutamate-induced apoptosis was greatly exacerbated in HO-2 gene-deleted murine cerebrovascular endothelial cells and in porcine cells with pharmacologically inhibited HO-2 activity. Glutamate toxicity was prevented by superoxide dismutase, suggesting apoptotic changes are oxidative stress related. When HO-1 was pharmacologically upregulated by cobalt protoporphyrin, apoptotic effects of glutamate in cerebral endothelial cells were completely prevented. Glutamate-induced reactive oxygen species production and apoptosis were blocked by a CO-releasing compound, CORM-A1 (50 μM), and by bilirubin (1 μM), consistent with the antioxidant and cytoprotective roles of the end products of HO activity. We conclude that both HO-1 and HO-2 have anti-apoptotic effects against oxidative stress-related glutamate toxicity in cerebral vascular endothelium. Although HO-1, when induced, provides powerful protection, HO-2 is an essential endogenous anti-apoptotic factor against glutamate toxicity in the cerebral vascular endothelium.


Phytomedicine ◽  
2019 ◽  
Vol 52 ◽  
pp. 206-215 ◽  
Author(s):  
Weirong Wang ◽  
Chenxu Shang ◽  
Wei Zhang ◽  
Zhen Jin ◽  
Feng Yao ◽  
...  

2016 ◽  
Vol 11 (5) ◽  
pp. 383 ◽  
Author(s):  
Leila Safaeian ◽  
SeyyedEbrahim Sajjadi ◽  
ShaghayeghHaghjooy Javanmard ◽  
Hossein Montazeri ◽  
Fariba Samani

2018 ◽  
Vol 315 (5) ◽  
pp. H1477-H1485 ◽  
Author(s):  
Kimiko Yamamoto ◽  
Hiromi Imamura ◽  
Joji Ando

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.


1993 ◽  
Vol 264 (3) ◽  
pp. C715-C722 ◽  
Author(s):  
D. Lu ◽  
N. Maulik ◽  
I. I. Moraru ◽  
D. L. Kreutzer ◽  
D. K. Das

Cellular organisms respond at the cellular and molecular level when confronted with sudden changes in environment, and molecular adaptation represents the ability of the cells to acclimate themselves to their new environment. In this study we examined the response of bovine vascular endothelial cells (VEC) to the oxidative stress by exposing the cultured cells to two different concentrations of H2O2, 0.04 or 0.08 mM, for 18-24 h. H2O2-exposed VEC displayed good viability (85-90% for 0.04 mM H2O2; 75-80% for 0.08 mM H2O2) and exhibited normal morphology. H2O2 treatment of the VEC was associated with the expression of a number of new proteins, as demonstrated by two-dimensional gel electrophoresis of total cell lysate. Cells exposed to 0.04 mM H2O2 expressed 25 new proteins, whereas 19 newly expressed proteins were detected when the cells were exposed to 0.08 mM H2O2. Western blot analysis of H2O2-treated VEC using specific antibodies to heat-shock proteins (HSP) identified one of these proteins as a member of the HSP 70 family. In addition, H2O2 induced an increase in antioxidative enzyme activities in the VEC, including superoxide dismutase, catalase, and glutathione peroxidase. Moreover, these changes were a truly adaptive phenomenon because challenging the VEC with brief exposure to toxic levels of H2O2 (1 mM for 30 min) showed increased viability (by Trypan blue exclusion test) and decreased injury (by lactate dehydrogenase supernatant-to-cellular ratio determination) in adapted cells (preexposed to 0.04 or 0.08 mM H2O2) compared with control cells.(ABSTRACT TRUNCATED AT 250 WORDS)


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