scholarly journals Hydroxysafflor Yellow A Blocks HIF-1α Induction of NOX2 and Protects ZO-1 Protein in Cerebral Microvascular Endothelium

Author(s):  
Yi Li ◽  
Xiaotian Liu ◽  
Peilin Zhang ◽  
Yuchen Li ◽  
Mengru Sun ◽  
...  

Abstract Background: Zonula occludens-1 (ZO-1) protein ensures cerebrovascular integrity against brain ischemic injury. Hydroxysafflor yellow A (HSYA) is a major ingredient of safflower (Carthamus tinctorius L.) with anti-oxidative activity. Because conventional ROS scavengers display poor reactivity with endogenous ROS, this study investigated whether HSYA protected ZO-1 by targeting the enzymes responsible for ROS generation.Methords: Photothrombotic stroke model was prepared in mice to evaluate the protective effect of HSYA on cerebrovascular endothelium. The molecular regulation was investigated in cultured cerebral microvascular endothelial cells (bEnd.3 cells).Results: Oral administration of HSYA (50 mg/kg) reduced cerebral vascular leakage with ZO-1 protection in mice after stroke, largely due to suppression of ROS-associated inflammation. In LPS-stimulated bEnd.3 cells, HSYA increased the ratio of NAD+/NADH to restore Sirt1 induction, which bound to Von Hippel-Lindau (VHL) to ensure HIF-1α protein degradation. Although both NOX1 and NOX2 isoforms were inducible in endothelial cells, we identified NOX2 as the driving force of ROS production. Chromatin immunoprecipitation and luciferase report gene assay revealed that HIF-1α transcriptionally regulated p47phox and Nox2 subunits for the assembly of NOX2 complex, which was blocked by HSYA treatment, largely by reducing HIF-1α accumulation. Inflammation-associated lipid peroxidation impaired ZO-1 protein, but HSYA treatment attenuated carbonyl modification and thus prevented ZO-1 protein from 20S proteasome-mediated degradation, eventually protecting endothelial integrity. In microvascular ZO-1 deficient mice, we further confirmed that HSYA protected cerebrovascular integrity and attenuated ischemic injury dependent on ZO-1 protection. Conclusions: HSYA blocked HIF-1α/NOX2 signaling cascades to protect ZO-1 from proteasomal degradation, suggesting that targeting NOX2 in endothelium is a potential therapeutic strategy to protect against ischemic brain injury.

2021 ◽  
Vol 65 (3) ◽  
Author(s):  
Cheng Chen ◽  
Yan Huang ◽  
Pingping Xia ◽  
Fan Zhang ◽  
Longyan Li ◽  
...  

Individuals with diabetes are exposed to a higher risk of perioperative stroke than non-diabetics mainly due to persistent hyperglycemia. LncRNA Meg3 has been considered as an important mediator in regulating ischemic stroke. However, the functional and regulatory roles of Meg3 in diabetic brain ischemic injury remain unclear. In this study, rat brain microvascular endothelial cells (RBMVECs) were exposed to 6 h of oxygen and glucose deprivation (OGD), and subsequent reperfusion via incubating cells with glucose of various high concentrations for 24 h to imitate in vitro diabetic brain ischemic injury. It was shown that the marker events of ferroptosis and increased Meg3 expression occurred after the injury induced by OGD combined with hyperglycemia. However, all ferroptotic events were reversed with the treatment of Meg3-siRNA. Moreover, in this in vitro model, p53 was also characterized as a downstream target of Meg3. Furthermore, p53 knockdown protected RBMVECs against OGD + hyperglycemic reperfusion-induced ferroptosis, while the overexpression of p53 exerted opposite effects, implying that p53 served as a positive regulator of ferroptosis. Additionally, the overexpression or knockdown of p53 significantly modulated GPX4 expression in RBMVECs exposed to the injury induced by OGD combined with hyperglycemic treatment. Furthermore, GPX4 expression was suppressed again after the reintroduction of p53 into cells silenced by Meg3. Finally, chromatin immunoprecipitation assay uncovered that p53 was bound to GPX4 promoter. Altogether, these data revealed that, by modulating GPX4 transcription and expression, the Meg3-p53 signaling pathway mediated the ferroptosis of RBMVECs upon injury induced by OGD combined with hyperglycemic reperfusion.


2020 ◽  
Author(s):  
Cheng Chen ◽  
Yan Huang ◽  
Pingping Xia ◽  
Fan Zhang ◽  
Longyan Li ◽  
...  

Abstract Background Individuals with diabetes are exposed to a higher risk of perioperative stroke than non-diabetics mainly due to persistent hyperglycemia. lncRNA-MEG3 (long non-coding RNA maternally expressed gene 3) has been considered as an important mediator in regulating ischemic stroke. However, the functional and regulatory roles of lncRNA-MEG3 in diabetic brain ischemic injury remain unclear. Results In this study, RBMVECs (the rat brain microvascular endothelial cells) were exposed to 6 h of OGD (oxygen and glucose deprivation), and subsequent reperfusion via incubating cells with glucose of various high concentrations for 24 h to imitate in vitro diabetic brain ischemic injury. It was shown that the marker events of ferroptosis and increased lncRNA-MEG3 expression occurred after the injury induced by OGD combined with hyperglycemic treatment. However, all ferroptotic events were reversed with the treatment of MEG3-siRNA. Moreover, in this in vitro model, p53 was also characterized as a downstream target of lncRNA-MEG3. Furthermore, p53 knockdown protected RBMVECs against OGD + hyperglycemic reperfusion-induced ferroptosis, while the overexpression of p53 exerted opposite effects, implying that p53 served as a positive regulator of ferroptosis. Additionally, the overexpression or knockdown of p53 significantly modulated GPX4 expression in RBMVECs exposed to the injury induced by OGD combined with hyperglycemic treatment. Furthermore, GPX4 expression was suppressed again after the introduction of p53 into cells silenced by lncRNA-MEG3. Finally, ChIP assay uncovered that p53 was bound to GPX4 promoter. Conclusions Altogether, these data revealed that, by modulating GPX4 transcription and expression, the lncRNA-MEG3-p53 signaling pathway mediated the ferroptosis of RBMVECs upon injury induced by OGD combined with hyperglycemic treatment.


1992 ◽  
Vol 1 (4) ◽  
pp. 293-298 ◽  
Author(s):  
Carlton Young ◽  
Bruce E. Jarrell ◽  
James B. Hoying ◽  
Stuart K. Williams

The transplantation of endothelial cells represents a technology which has been suggested for applications ranging from improvement in function of implanted vascular devices to genetic therapy. The use of microvascular endothelial cell transplantation has seen increased use both in animal studies as well as clinical use. This report describes our techniques for the isolation and establishment of initial cultures of microvascular endothelial cells derived from porcine fat. A variety of anatomic sites within the pig were evaluated to determine the appropriateness of different sources of fat for endothelial cell isolation. The properitoneal fat was determined to be optimal due to the predominance of endothelium in this tissue and the ease of isolation of microvascular endothelium following collagenase digestion. The study of endothelial cell transplantation in the porcine model is now possible using the methods described for adipose tissue-derived micro vessel endothelial cell isolation.


1993 ◽  
Vol 264 (2) ◽  
pp. H639-H652 ◽  
Author(s):  
M. Nishida ◽  
W. W. Carley ◽  
M. E. Gerritsen ◽  
O. Ellingsen ◽  
R. A. Kelly ◽  
...  

Although reciprocal intercellular signaling may occur between endocardial or microvascular endothelium and cardiac myocytes, suitable in vitro models have not been well characterized. In this report, we describe the isolation and primary culture of cardiac microvascular endothelial cells (CMEC) from both adult rat and human ventricular tissue. Differential uptake of fluorescently labeled acetylated low-density lipoprotein (Ac-LDL) indicated that primary isolates of rat CMEC were quite homogeneous, unlike primary isolates of human ventricular tissue, which required cell sorting based on Ac-LDL uptake to create endothelial cell-enriched primary cultures. The endothelial phenotype of both primary isolates and postsort subcultured CMEC and their microvascular origin were determined by characteristic histochemical staining for a number of endothelial cell-specific markers, by the absence of cells with fibroblast or pericyte-specific cell surface antigens, and by rapid tube formation on purified basement membrane preparations. Importantly, [3H]-thymidine uptake was increased 2.3-fold in subconfluent rat microvascular endothelial cells 3 days after coculture with adult rat ventricular myocytes because of release of an endothelial cell mitogen(s) into the extracellular matrix, resulting in a 68% increase in cell number compared with CMEC in monoculture. Thus biologically relevant cell-to-cell interactions can be modeled with this in vitro system.


2021 ◽  
Vol 18 ◽  
Author(s):  
Juxuan Ruan ◽  
Lei Wang ◽  
Jiheng Dai ◽  
Jing Li ◽  
Ning Wang ◽  
...  

Objective: Angiogenesis led by brain microvascular endothelial cells (BMECs) contributes to the remission of brain injury after brain ischemia reperfusion. In this study, we investigated the effects of hydroxysafflor yellow A(HSYA) on angiogenesis of BMECs injured by OGD/R via SIRT1-HIF-1α-VEGFA signaling pathway. Methods: The OGD/R model of BMECs was established in vitro by OGD for 2h and reoxygenation for 24h. At first, the concentrations of vascular endothelial growth factor (VEGF), Angiopoietin (ang) and platelet-derived growth factor (PDGF) in supernatant were detected by ELISA, and the proteins expression of VEGFA, Ang-2 and PDGFB in BMECs were tested by western blot; the proliferation, adhesion, migration (scratch healing and transwell) and tube formation experiment of BMECs; the expression of CD31 and CD34 were tested by immunofluorescence staining. The levels of sirtuin1(SIRT1), hypoxia-inducible factor-1α (HIF-1α), VEGFA mRNA and protein were tested. Results: HSYA up-regulated the levels of VEGF, Ang and PDGF in the supernatant of BMECs under OGD/R, and the protein expression of VEGFA, Ang-2 and PDGFB were increased; HSYA could significantly alleviate the decrease of cell proliferation, adhesion, migration and tube formation ability of BMECs during OGD/R; HSYA enhanced the fluorescence intensity of CD31 and CD34 of BMECs during OGD/R; HSYA remarkably up-regulated the expression of SIRT1, HIF-1α, VEGFA mRNA and protein after OGD/R, and these increase decreased after SIRT1 was inhibited. Conclusion: SIRT1-HIF-1α-VEGFA signaling pathway is involved in HSYA improves angiogenesis of BMECs injured by OGD/R.


Hypertension ◽  
2021 ◽  
Vol 78 (Suppl_1) ◽  
Author(s):  
Dan Wang ◽  
Christopher S Wilcox

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.


Molecules ◽  
2018 ◽  
Vol 23 (12) ◽  
pp. 3372 ◽  
Author(s):  
Yan-Hui Shen ◽  
Li-Ying Wang ◽  
Bao-Bao Zhang ◽  
Qi-Ming Hu ◽  
Pu Wang ◽  
...  

Ethyl rosmarinate (RAE) is one of the active constituents from Clinopodium chinense (Benth.) O. Kuntze, which is used for diabetic treatment in Chinese folk medicine. In this study, we investigated the protective effect of RAE on high glucose-induced injury in endothelial cells and explored its underlying mechanisms. Our results showed that both RAE and rosmarinic acid (RA) increased cell viability, decreased the production of reactive oxygen species (ROS), and attenuated high glucose-induced endothelial cells apoptosis in a dose-dependent manner, as evidenced by Hochest staining, Annexin V–FITC/PI double staining, and caspase-3 activity. RAE and RA both elevated Bcl-2 expression and reduced Bax expression, according to Western blot. We also found that LY294002 (phosphatidylinositol 3-kinase, or PI3K inhibitor) weakened the protective effect of RAE. In addition, PDTC (nuclear factor-κB, or NF-κB inhibitor) and SP600125 (c-Jun N-terminal kinase, or JNK inhibitor) could inhibit the apoptosis in endothelial cells caused by high glucose. Further, we demonstrated that RAE activated Akt, and the molecular docking analysis predicted that RAE showed more affinity with Akt than RA. Moreover, we found that RAE inhibited the activation of NF-κB and JNK. These results suggested that RAE protected endothelial cells from high glucose-induced apoptosis by alleviating reactive oxygen species (ROS) generation, and regulating the PI3K/Akt/Bcl-2 pathway, the NF-κB pathway, and the JNK pathway. In general, RAE showed greater potency than RA equivalent.


2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Qing Zhao ◽  
Futian Tang ◽  
Limei Shan ◽  
Inga Cepinskas ◽  
Gedas Cepinskas ◽  
...  

Objectives: Elevated levels of reactive oxygen species (ROS) are the initial source of endothelial dysfunction in diabetes. Calpain has been implicated in diabetic vascular complications. The present study was to investigate the role of calpain in mitochondrial ROS generation in endothelial cells and vascular dysfunction in diabetic mice. Methods: Endothelial cells cultured from human umbilical vein (HUVEC) were stimulated with high glucose. Calpain activity and protein were determined in mitochondria of HUVEC. Intracellular and mitochondrial ROS generation as well as apoptosis were measured. Type I diabetic OVE 26 mice and type II diabetic db/db mice with calpastatin over-expression (OVE26/CAST and db/db-CAST) were generated, respectively. Type I diabetes was also induced in both wild-type and Tg-CAST mice by injection of streptozocin (STZ). The endothelium-dependent relaxation of aortic ring was measured. Results: High glucose significantly increased calpain-1 protein, calpain activity and ROS generation in mitochondria of HUVEC. Pharmacological inhibition of calpain or over-expression of calpastatin abrogated high glucose-induced intracellular ROS production, mitochondrial ROS generation and apoptosis in HUVEC. Incubation of isolated mitochondria with calpain-1 protein significantly induced its ROS generation and the membrane potential. In diabetic mice, calpain activity was induced in aortic vessels, which correlated with an increase in ROS production and protein tyrosine nitration. Over-expression of calpastatin prevented calpain activity, reduced ROS production and inhibited protein tyrosine nitration in diabetic mice. Aortic ring segments from diabetic mice exhibited a significant reduction in vascular relaxation to acetylcholine, which was reversed by over-expression of calpastatin in Tg-CAST, OVE26/CAST and db/db-CAST mice. Conclusions: This study has demonstrated a novel role of calpain in mitochondrial ROS generation, which contributes to apoptosis in endothelial cells during hyperglycemia. Thus, over-expression of calpastatin inhibits reduces ROS production and ameliorates endothelium-dependent vascular dysfunction in mouse models of diabetes.


1990 ◽  
Vol 96 (2) ◽  
pp. 257-262
Author(s):  
C.J. Jackson ◽  
P.K. Garbett ◽  
B. Nissen ◽  
L. Schrieber

A major problem encountered when isolating human microvascular endothelium is the presence of contaminating cells such as fibroblasts that rapidly over-grow the endothelial cells. We describe here a simple, rapid technique for purifying endothelial cells derived from the microvasculature of neonatal foreskin and osteoarthritic and rheumatoid arthritic synovium. This technique is based on the selective binding of the lectin Ulex europaeus I (UEA I) to the endothelial cell surface via fucose residues. Initially UEA I was covalently bound to tosyl-activated super-paramagnetic polystyrene beads (Dynabeads) by incubation for 24 h at room temperature. Cells were isolated by extracting microvascular segments from enzyme-treated (trypsin and Pronase) cubes of tissue. The mixed population of cells obtained were purified by incubating them at 4 degrees C for 10 min with the UEA I-coated Dynabeads. Endothelium bound to the beads whilst contaminating cells were removed by five washes with HBSS using a magnetic particle concentrator. The endothelial cells thus obtained grew to confluence as a cobblestone-like monolayer and expressed von Willebrand factor antigen. The cells were released from the Dynabeads by the competitive binding of fucose (10 min at 4 degrees C). This new method is simple and reproducible and allows pure human microvascular endothelial cells to be cultured within 2 h of obtaining a specimen.


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