scholarly journals Lipoic acid antagonizes paraquat-induced vascular endothelial dysfunction by suppressing mitochondrial reactive oxidative stress

2019 ◽  
Vol 8 (6) ◽  
pp. 918-927 ◽  
Author(s):  
Li Pang ◽  
Ping Deng ◽  
Yi-dan Liang ◽  
Jing-yu Qian ◽  
Li-Chuan Wu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Nitric Oxide ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Lipoic Acid ◽  
Microvascular Endothelial Cells ◽  
Ros Generation ◽  
Protective Effects ◽  
Migration Ability ◽  
Microvascular Endothelial

Abstract Paraquat (PQ) is a widely used herbicide in the agricultural field. The lack of an effective antidote is the significant cause of high mortality in PQ poisoning. Here, we investigate the antagonistic effects of alpha lipoic acid (α-LA), a naturally existing antioxidant, on PQ toxicity in human microvascular endothelial cells (HMEC-1). All the doses of 250, 500 and 1000 μM α-LA significantly inhibited 1000 μM PQ-induced cytotoxicity in HMEC-1 cells. α-LA pretreatment remarkably diminished the damage to cell migration ability, recovered the declined levels of the vasodilator factor nitric oxide (NO), elevated the expression level of endothelial nitric oxide synthases (eNOS), and inhibited the upregulated expression of vasoconstrictor factor endothelin-1 (ET-1). Moreover, α-LA pretreatment inhibited reactive oxygen species (ROS) generation, suppressed the damage to the mitochondrial membrane potential (ΔΨm) and mitigated the inhibition of adenosine triphosphate (ATP) production in HMEC-1 cells. These results suggested that α-LA could alleviate PQ-induced endothelial dysfunction by suppressing oxidative stress. In summary, our present study provides novel insight into the protective effects and pharmacological potential of α-LA against PQ toxicity in microvascular endothelial cells.

scholarly journals Exosomal circHIPK3 Released from Hypoxia-Pretreated Cardiomyocytes Regulates Oxidative Damage in Cardiac Microvascular Endothelial Cells via the miR-29a/IGF-1 Pathway

2019 ◽  
Vol 2019 ◽  
pp. 1-28 ◽  
Author(s):  
Yan Wang ◽  
Ranzun Zhao ◽  
Weiwei Liu ◽  
Zhenglong Wang ◽  
Jidong Rong ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Ectopic Expression ◽  
Bioactive Molecules ◽  
Microvascular Endothelial Cells ◽  
Circular Rnas ◽  
Protective Effects ◽  
Microvascular Endothelial ◽  
Cardiac Microvascular Endothelial Cells

Background/Aims. Circular RNAs (circRNAs) are a class of endogenous noncoding RNAs that regulate gene expression in eukaryotes. Recently, exosomes from cardiomyocytes (CMs) have been found to facilitate cell proliferation and survival by transporting various bioactive molecules, including circRNA. However, the functions of exosomal circRNAs are not clear. The present research is aimed at determining whether circHIPK3 released from hypoxia-pretreated CMs is transferred into cardiac microvascular endothelial cells (CMVECs) by exosomes and becomes functionally active in the CMVECs under oxidative stress conditions. Methods. Quantitative polymerase chain reactions were conducted to detect the expression pattern of circHIPK3 in CMVECs under oxidative stress. Annexin V-FITC/propidium iodide (PI) staining assays, TUNEL assays, ROS assays, and Western blot analysis were conducted to detect the role of exosomal circHIPK3 in CMVEC function in vitro. Luciferase activity assays and RNA immunoprecipitation studies were conducted in vitro to reveal the mechanism of circHIPK3-mediated CMVEC function. Results. circHIPK3 expression was significantly upregulated in hypoxic exosomes (HPC-exos) compared with normoxic exosomes (Nor-exos). Moreover, HPC-exos induced stronger antioxidant effects than Nor-exos. The silencing or overexpression of circHIPK3 changed CMVEC survival under oxidative conditions in vitro. Furthermore, circHIPK3 silencing in HPC-exos abrogated the protective effects of HPC-exos in CMVECs, as shown by increased levels of apoptosis, ROS, MDA, and proapoptotic proteins. circHIPK3 acted as an endogenous miR-29a sponge to sequester and inhibit miR-29a activity, which led to increased IGF-1 expression. The ectopic expression of miR-29a mimicked the effect of circHIPK3 silencing in CMVECs in vitro. Conclusions. circHIPK3 in HPC-exos plays a role in CMVECs under oxidative conditions through miR-29a-mediated IGF-1 expression, leading to a decrease in oxidative stress-induced CMVECs dysfunction. These data suggest that the exosomal circRNA in CMs is a potential target to control CMVECs dysfunction under oxidative conditions.

Abstract 283: Angiotensin II Induces Oxidative Stress Through ADP-ribose-Transient Receptor Potential Melastatin 2-Dependent Mechanisms In Human Microvascular Endothelial Cells: Role Of AT2 Receptor.

Hypertension ◽  
2014 ◽  
Vol 64 (suppl_1) ◽  
Author(s):  
Maria G Dulak-Lis ◽  
Aurelie D Nguyen ◽  
Carol J Jenkins ◽  
Augusto C Montezano ◽  
Rhian M Touyz
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Calcium Channel ◽  
Superoxide Production ◽  
Microvascular Endothelial Cells ◽  
Ros Generation ◽  
H2o2 Production ◽  
Ang Ii ◽  
Calcium Dependent ◽  
Microvascular Endothelial

Endothelial dysfunction is associated with oxidative stress and dysregulation of calcium signalling. We previously demonstrated that calcium dependent Nox5 is regulated by Ang II and may be implicated in vascular damage in hypertension. Elevation of intracellular free calcium concentration ([Ca2+]i) influences oxidative stress, which may be related to activation of redox sensitive calcium channel TRPM2. Here, we postulated that in human microvascular endothelial cells (HMEC), Ang II induces ROS generation through TRPM2-dependent processes. HMECs were stimulated with either Ang II (100 nM) or H2O2 (1 mM). ROS production was measured by lucigenin (superoxide) and amplex red (H2O2); redox sensitive MAPKs/eNOS activation by immunoblotting; and AT1R/AT2R mRNA by Q PCR. In some experiments, the following inhibitors were used: aminoethoxydiphenyl borate (APB, TRPM2/SERCA/IP3R inhibitor), N (p amylcinnamoyl)anthranilic acid (ACA, TRPM2/PLA2 inhibitor), 8-bromo-cADP-ribose (8 Br-cADPR, ADPR antagonist), 3,4-Dihydro-5[4-(1-piperindinyl)butoxy]-1(2H)-isoquinoline (DPQ, poly-ADPR polymerase inhibitor) and PD123319 (AT2R antagonist). In hmECs, Ang II increased superoxide levels (1.9±0.2 fold, p<0.05 vs. vehicle), an effect blocked by APB, ACA, 8-Br-cADPR, DPQ and PD123319. In addition, Ang II-induced increase in H2O2 production (1.6±0.21 fold, p<0.05 vs. vehicle) was inhibited by AT2R antagonism. Ang II stimulation increased ERK1/2 activation (185%), but not p38, through AT2R-dependent mechanisms (p<0.05). AT2R, but not AT1R was expressed in HMECs. H2O2, an activator of TRPM2, decreased superoxide production (25%) and increased MAPKs (p38: 82%; ERK1/2: 40%; JNK: 36%), as well as, eNOS (24%) activation, p<0.05. In addition, ROS formation by Ang II was measured in the presence of L-type calcium channel blocker diltiazem, which also blocked Ang II effects on superoxide production. In conclusion, our data demonstrate that Ang II-induced oxidative stress and redox-sensitive MAPK activation in hmEC cells may involve TRPM2 and calcium-dependent signalling, which are mediated via AT2R. Our findings identify a novel signalling pathways whereby Ang II/AT2R regulates endothelial cell ROS generation through TRPM2.

Stimulation of Tetrahydrobiopterin Synthesis by 17β-Estradiol in Brain Microvascular Endothelial Cells

Pteridines ◽  
2000 ◽  
Vol 11 (4) ◽  
pp. 129-132
Author(s):  
Kazuhiro Shiota ◽  
Masakazu Ishii ◽  
Toshinori Yamamoto ◽  
Shunichi Shimizu ◽  
Yuji Kiuchi
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Vascular Endothelial Cells ◽  
Mrna Level ◽  
Microvascular Endothelial Cells ◽  
No Production ◽  
Brain Microvascular Endothelial Cells ◽  
Protective Effects ◽  
17Β Estradiol ◽  
Microvascular Endothelial

Abstract The purpose of this study was to examine whether 17β-estradiol stimulates the synthesis of tetrahydrobiopterin : BH4), which is one of the cofactors of nitric oxide (NO) synthase, in mouse brain microvascular endothelial cells. Addition of 17()-estradiol to endothelial cells time- and concentration-dependently increased intracellular BH4 level. 17β-Estradiol also stimulated the mRNA level of GTP-cyclohydrolase I (GTPCH), which is a rate-limiting enzyme of the de novo BH4 synthetic pathway. In addition, the 17β-estradiol-induced expression of GTPCH mRNA was strongly attenuated by treatment with an inhibitor of 17β-estradiol receptor 4-hydroxy-tamoxlfen. These results suggest that 17β-estradiol stimulates BH4 synthesis through the induction of GTPCH by tamoxifensensitive receptor in vascular endothelial cells. The 17β-estradiol-induced increase in BH4 level might be implicated in not only NO production, but also protective effects of 17β-estradiol against ischemic brain damage and atherosclerosis, since BH4 is an intracellular antioxidant.

Abstract MP30: Circulating Sars-cov-2 Spike Protein 1 Causes Microarteriolar Oxidative Stress, Endothelial Dysfunction And Enhanced Thromboxane And Endothelin Contractility That Are Prevented By Spironolactone.

Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Dan Wang ◽  
Christopher S Wilcox
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Fluorescence Microscopy ◽  
Vascular Dysfunction ◽  
Microvascular Complications ◽  
Spike Protein ◽  
Ros Generation ◽  
Intravenous Injections ◽  
Novel Model

Introduction and hypothesis: Following bodily entry, the SARS-CoV-2 virus undergoes pulmonary replication with release of circulating viral spike protein 1 (SP1) into the bloodstream. Uptake of SP1 by endothelial cells might provoke vascular dysfunction and thrombosis. We hypothesized that spironolactone could prevent microvascular complications from circulating SP1 in COVID-19. Methods: male C57Bl/6 mice received spironolactone (100 mg · kg -1 · d -1 PO x 3d) or vehicle and intravenous injections of recombinant full-length human SP1 (10 μg per mouse) or vehicle. They were euthanized after 3 days. Mesenteric resistant arterioles (n=4 per group) were dissected and mounted on isometric myographs. Acetylcholine-induced EDRF responses and L-NAME-inhibitable NO generation (DAF-FM fluorescence) were studied in pre-constricted vessels and contraction to endothelin 1 (ET1) or thromboxane (U-46, 619) and ET1-induced ROS (PEG-SOD inhibitable ethidium: dihydroethidium fluorescence) were studied by fluorescence microscopy in other vessels. Results: SP1 reduced acetylcholine-induced EDRF (17 ± 3 vs 27 ± 5 % mean ± sem; P < 0.05) and NO generation (0.21 ± 0.03 vs 0.36 ± 0.04, F 1 /F 0 ; P < 0.05) while increasing contraction to ET1 (10 -7 mol·l -1 : 124 ± 13 vs 89 ± 4 %; P < 0.05) and U-46, 619 (10 -6 mol·l -1 :114± 5 vs 87± 6 %; P < 0.05) and ET1-induced ROS generation(0.30± 0.08 vs 0.09± 0.03; P < 0.05). Spironolactone did not modify any of these responses in vessels from normal mice but prevented all the effects of SP1. Conclusion: these preliminary studies provide a novel model to study COVID-19 vasculopathy. They indicate that spironolactone can provide protection from microvascular oxidative stress, endothelial dysfunction and enhanced contractility and might thereby moderate COVID-19 complications.

Abstract 235: Hypoxia Enhanced Delivery of Mitochondria-Targeted Catalase Protects Choroid Retinal Microvascular Endothelial Cells from Oxidative Stress

Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Christopher J Dougherty ◽  
Howard Prentice ◽  
Kathleen Dorey ◽  
Keith A Webster ◽  
Janet C Blanks
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
High Glucose ◽  
Endothelial Permeability ◽  
Luciferase Assay ◽  
Expression Vectors ◽  
Microvascular Endothelial Cells ◽  
Tissue Specific ◽  
Microvascular Endothelial

Loss of pericytes is a critical event early in the progression of microvascular dysfunction in diabetic retinopathy. Pericyte loss may be linked to high glucose mediated reactive oxygen species generation, blocking N-cadherin trafficking to the endothelial cell surface preventing pericyte recruitment and vessel stabilization. Hydrogen peroxide has been identified as a major free radical produced during high glucose exposure in endothelial cells. The goal of this research is to determine if tissue-specific hypoxia-regulated expression of a mitochondria-targeted catalase can prevent or limit RF/6A microvascular endothelial cell apoptosis and decrease vascular permeability by limiting cellular oxidative stress. For the development of tissue-specific and hypoxia-enhanced expression vectors, promoters were constructed with nine tandem combinations of HREs. This 9x HRE oligomer enhancer was inserted together into a pGL3 firefly luciferase plasmid with the Tie2( short ) promoter for endothelial-specific expression. The 9xHRE-Tie2( sh ) promoter construct was highly selective for RF/6A cells producing a basal amount of mitochondria-targeted catalase equivalent to the Tie2( short ) promoter alone. In response to hypoxia ( pO 2 = 1% ), the 9xHRE-Tie2( short ) promoter showed a 21-fold hypoxia-inducible activation similar in strength to the CMV promoter , measured by dual luciferase assay. The hybrid promoters were incorporated into a replication deficient AAV delivery system for apoptosis and cell culture based endothelial permeability assays. In preliminary assays using RF/6A microvascular endothelial cells, apoptosis was reduced by 58% and permeability was reduced by 46%. The results suggest that mitochondria-targeted catalase protects RF/6A microvascular endothelial cells from apoptosis and reduces endothelial permeability in a high-glucose, low-oxygen environment.

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