scholarly journals Total flavonoids from Astragalus alleviate endothelial dysfunction by activating the Akt/eNOS pathway

2017 ◽  
Vol 46 (6) ◽  
pp. 2096-2103 ◽  
Author(s):  
Qian Liu ◽  
Ling Zhang ◽  
Qiyuan Shan ◽  
Yuxia Ding ◽  
Zhaocai Zhang ◽  
...  

Objective To investigate the vasodilative and endothelial-protective effects and the underlying mechanisms of total flavonoids from Astragalus (TFA). Methods The vasodilative activities of TFA were measured with a myograph ex vivo using rat superior mesenteric arterial rings. The primary human umbilical vein endothelial cell (HUVEC) viabilities were assayed using the cell counting kit-8 after hypoxia or normoxia treatment with or without TFA. Akt, P-Akt, eNOS, P-eNOS, Erk, P-Erk, Bcl-2 and Bax expression were analyzed using western blotting. Results TFA showed concentration-dependent vasodilative effects on rat superior mesenteric arterial rings, but had no effects on normal or potassium chloride precontracted arterial rings. TFA did not affect HUVEC viabilities in normoxia, but dramatically promoted cell proliferation in the concentration range of 1 to 30 µg/mL under hypoxia. Moreover, TFA significantly increased the ratios of P-Akt/Akt and P-eNOS/eNOS in vascular endothelial cells under hypoxic conditions, but did not change the P-Erk/Erk or Bcl-2/Bax ratios. Conclusions TFA might exhibit vasorelaxant and endothelial-protective effects via the Akt/eNOS signaling pathway.

2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Qiyun Wang ◽  
Xinyuan Zhang ◽  
Kaiyue Wang ◽  
Ling Zhu ◽  
Bingjie Qiu ◽  
...  

Background. Diabetic retinopathy (DR) is a leading cause of blindness in working-age populations. Proper in vitro DR models are crucial for exploring pathophysiology and identifying novel therapeutic targets. This study establishes a rational in vitro diabetic retinal neuronal-endothelial dysfunction model and a comprehensive downstream validation system. Methods. Human retinal vascular endothelial cells (HRMECs) and retinal ganglion cells (RGCs) were treated with different glucose concentrations with mannitol as matched osmotic controls. Cell proliferation and viability were evaluated by the Cell Counting Kit-8. Cell migration was measured using a transwell migration assay. Cell sprouting was assessed by a tube formation assay. The VEGF expression was assessed by ELISA. RGCs were labeled by neurons and RGC markers TUJ1 and BRN3A for quantitative and morphological analysis. Apoptosis was detected using PI/Hoechst staining and TUNEL assay and quantified by ImageJ. Results. Cell proliferation and migration in HRMECs were significantly higher in the 25 mM glucose-treated group ( p < 0.001 ) but lower in the 50 mM and 100 mM groups ( p < 0.001 ). The permeability and the apoptotic index in HRMECs were statistically higher in the 25 mM, 50 mM, and 100 mM groups ( p < 0.05 ). The tube formation assay found that all the parameters were significantly higher in the 25 mM and 50 mM groups ( p < 0.001 ) concomitant with the elevated VEGFA expression in HRMECs ( p = 0.016 ). Cell viability was significantly lower in the 50 mM, 100 mM, and 150 mM groups in RGCs ( p 50 mM = 0.013 , p 100 mM = 0.019 , and p 150 mM = 0.002 ). Apoptosis was significantly elevated, but the proportion of RGCs with neurite extension was significantly lower in the 50 mM, 100 mM, and 150 mM groups ( p 50 mM < 0.001 , p 100 m M < 0.001 , and p 150 mM < 0.001 ). Conclusions. We have optimized glucose concentrations to model diabetic retinal endothelial (25-50 mM) or neuronal (50-100 mM) dysfunction in vitro, which have a wide range of downstream applications.


Endocrinology ◽  
2004 ◽  
Vol 145 (12) ◽  
pp. 5532-5539 ◽  
Author(s):  
Dongmin Liu ◽  
Laurie L. Homan ◽  
Joseph S. Dillon

Abstract Genistein may improve vascular function, but the mechanism of this effect is unclear. We tested the hypothesis that genistein directly regulates vascular function through stimulation of endothelial nitric oxide synthesis. Genistein activated endothelial nitric oxide synthase (eNOS) in intact bovine aortic endothelial cells and human umbilical vein endothelial cells over an incubation period of 10 min. The maximal eNOS activity was at 1 μm genistein. Consistent with this activation pattern, 1 μm genistein maximally stimulated the phosphorylation of eNOS at serine 1179 at 10 min of incubation. The rapid activation of eNOS by genistein was not dependent on RNA transcription or new protein synthesis and was not blocked by a specific estrogen receptor antagonist. In addition, inhibition of MAPK or phosphatidylinositol 3-OH kinase/Akt kinase had no affect on eNOS activation by genistein. Furthermore, the genistein effect on eNOS was also independent of tyrosine kinase inhibition. However, inhibition of cAMP-dependent kinase [protein kinase A (PKA)] by H89 completely abolished the genistein-stimulated eNOS activation and phosphorylation, suggesting that genistein acted through a PKA-dependent pathway. These findings demonstrated that genistein had direct nongenomic effects on eNOS activity in vascular endothelial cells, leading to eNOS activation and nitric oxide synthesis. These effects were mediated by PKA and were unrelated to an estrogenic effect. This cellular mechanism may underlie some of the cardiovascular protective effects proposed for soy phytoestrogens.


2013 ◽  
Vol 2013 ◽  
pp. 1-7 ◽  
Author(s):  
Purum Kang ◽  
Seung Ho Han ◽  
Hea Kyung Moon ◽  
Jeong-Min Lee ◽  
Hyo-Keun Kim ◽  
...  

The purpose of the present study is to examine the effects of essential oil ofCitrus bergamiaRisso (bergamot, BEO) on intracellular Ca2+in human umbilical vein endothelial cells. Fura-2 fluorescence was used to examine changes in intracellular Ca2+concentration[Ca2+]i. In the presence of extracellular Ca2+, BEO increased[Ca2+]i, which was partially inhibited by a nonselective Ca2+channel blocker La3+. In Ca2+-free extracellular solutions, BEO increased[Ca2+]iin a concentration-dependent manner, suggesting that BEO mobilizes intracellular Ca2+. BEO-induced[Ca2+]iincrease was partially inhibited by a Ca2+-induced Ca2+release inhibitor dantrolene, a phospholipase C inhibitor U73122, and an inositol 1,4,5-triphosphate (IP3)-gated Ca2+channel blocker, 2-aminoethoxydiphenyl borane (2-APB). BEO also increased[Ca2+]iin the presence of carbonyl cyanide m-chlorophenylhydrazone, an inhibitor of mitochondrial Ca2+uptake. In addition, store-operated Ca2+entry (SOC) was potentiated by BEO. These results suggest that BEO mobilizes Ca2+from primary intracellular stores via Ca2+-induced and IP3-mediated Ca2+release and affect promotion of Ca2+influx, likely via an SOC mechanism.


Nutrients ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 3990
Author(s):  
Maria Annunziata Carluccio ◽  
Rosanna Martinelli ◽  
Marika Massaro ◽  
Nadia Calabriso ◽  
Egeria Scoditti ◽  
...  

Hydroxytyrosol (HT), a peculiar olive and olive oil phenolic antioxidant, plays a significant role in the endothelial and cardiovascular protection associated with olive oil consumption. However, studies examining the effects of HT on the whole-genome expression of endothelial cells, which are prominent targets for vasculo-protective effects of olive oil polyphenols, have been lacking. This study aims to comprehensively evaluate the genomic effects exerted by HT, at the transcriptional level, in endothelial cells under resting or proinflammatory conditions. Human umbilical vein endothelial cells (HUVECs) were treated with 10 µmol/L HT for 1 h and then stimulated with 5 ng/mL interleukin (IL)-1β for 3 h. Total RNA was extracted, and gene expression profile assessed with microarray analysis. Functional enrichment analysis and pathway analysis were performed by Ingenuity Pathways Analysis. Microarray data were validated by qRT-PCR. Fixing a significance threshold at 1.5-fold change, HT affected the expression of 708 and 599 genes, respectively, in HUVECs under resting and IL-1β-stimulated conditions; among these, 190 were common to both conditions. Unfolded protein response (UPR) and endoplasmic reticulum stress resulted from the two top canonical pathways common between HT and HT-IL-1β affected genes. IL-17F/A signaling was found in the top canonical pathways of HT modified genes under resting unstimulated conditions, whereas cardiac hypertrophy signaling was identified among the pathways affected by HT-IL-1β. The transcriptomic analysis allowed pinpointing immunological, inflammatory, proliferative, and metabolic-related pathways as the most affected by HT in endothelial cells. It also revealed previously unsuspected genes and related gene pathways affected by HT, thus broadening our knowledge of its biological properties. The unbiased identification of novel genes regulated by HT improves our understanding of mechanisms by which olive oil prevents or attenuates inflammatory diseases and identifies new genes to be enquired as potential contributors to the inter-individual variation in response to functional food consumption.


2000 ◽  
Vol 113 (17) ◽  
pp. 3117-3123 ◽  
Author(s):  
C. Wadham ◽  
J.R. Gamble ◽  
M.A. Vadas ◽  
Y. Khew-Goodall

Pez is a non-transmembrane tyrosine phosphatase with homology to the FERM (4.1, ezrin, radixin, moesin) family of proteins. The subcellular localisation of Pez in endothelial cells was found to be regulated by cell density and serum concentration. In confluent monolayers Pez was cytoplasmic, but in cells cultured at low density Pez was nuclear, suggesting that it is a nuclear protein in proliferating cells. This notion is supported by the loss of nuclear Pez when cells are serum-starved to induce quiescence, and the rapid return of Pez to the nucleus upon refeeding with serum to induce proliferation. Vascular endothelial cells normally exist as a quiescent confluent monolayer but become proliferative during angiogenesis or upon vascular injury. Using a ‘wound’ assay to mimic these events in vitro, Pez was found to be nuclear in the cells that had migrated and were proliferative at the ‘wound’ edge. TGFbeta, which inhibits cell proliferation but not migration, inhibited the translocation of Pez to the nucleus in the cells at the ‘wound’ edge, further strengthening the argument that Pez plays a role in the nucleus during cell proliferation. Together, the data presented indicate that Pez is a nuclear tyrosine phosphatase that may play a role in cell proliferation.


Viruses ◽  
2018 ◽  
Vol 10 (10) ◽  
pp. 563 ◽  
Author(s):  
Aleksandra Drelich ◽  
Barbara Judy ◽  
Xi He ◽  
Qing Chang ◽  
Shangyi Yu ◽  
...  

Members of the family Filoviridae, including Ebola virus (EBOV) and Marburg virus (MARV), cause severe hemorrhagic fever in humans and nonhuman primates. Given their high lethality, a comprehensive understanding of filoviral pathogenesis is urgently needed. In the present studies, we revealed that the exchange protein directly activated by cAMP 1 (EPAC1) gene deletion protects vasculature in ex vivo explants from EBOV infection. Importantly, pharmacological inhibition of EPAC1 using EPAC-specific inhibitors (ESIs) mimicked the EPAC1 knockout phenotype in the ex vivo model. ESI treatment dramatically decreased EBOV infectivity in both ex vivo vasculature and in vitro vascular endothelial cells (ECs). Furthermore, postexposure protection of ECs against EBOV infection was conferred using ESIs. Protective efficacy of ESIs in ECs was observed also in MARV infection. Additional studies using a vesicular stomatitis virus pseudotype that expresses EBOV glycoprotein (EGP-VSV) confirmed that ESIs reduced infection in ECs. Ultrastructural studies suggested that ESIs blocked EGP-VSV internalization via inhibition of macropinocytosis. The inactivation of EPAC1 affects the early stage of viral entry after viral binding to the cell surface, but before early endosome formation, in a phosphatidylinositol-4,5-bisphosphate 3-kinase (PI3K)-dependent manner. Our study delineated a new critical role of EPAC1 during EBOV uptake into ECs.


1987 ◽  
Vol 242 (2) ◽  
pp. 347-352 ◽  
Author(s):  
D M L Morgan

The responses of human umbilical-vein vascular endothelial cells in culture to the naturally occurring polyamines spermine, spermidine and putrescine, their acetyl derivatives and oxidation products were examined. In the absence of human polyamine oxidase, exposure of cells to polyamines (up to 160 microM) had no adverse effects. In the presence of polyamine oxidase, spermine and spermidine were cytotoxic, but putrescine was not. Acetylation of the aminopropyl group of spermidine or both aminopropyl groups of spermine prevented this cytotoxicity. The amino acids corresponding to the polyamines, representing a further stage of oxidation, were also without effect. The cytotoxic effects were irreversible. Use of bovine serum amine oxidase in place of the human enzyme gave qualitatively similar results.


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