scholarly journals Autocrine Effects of Brain Endothelial Cell-Produced Human Apolipoprotein E on Metabolism and Inflammation in vitro

2021 ◽  
Vol 9 ◽  
Author(s):  
Felecia M. Marottoli ◽  
Troy N. Trevino ◽  
Xue Geng ◽  
Zarema Arbieva ◽  
Pinal Kanabar ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Apolipoprotein E ◽  
Paracellular Permeability ◽  
Mitochondrial Activity ◽  
Oxygen Species ◽  
Brain Endothelial Cell ◽  
Brain Endothelial Cells ◽  
Lps Treatment

Reports of APOE4-associated neurovascular dysfunction during aging and in neurodegenerative disorders has led to ongoing research to identify underlying mechanisms. In this study, we focused on whether the APOE genotype of brain endothelial cells modulates their own phenotype. We utilized a modified primary mouse brain endothelial cell isolation protocol that enabled us to perform experiments without subculture. Through initial characterization we found, that compared to APOE3, APOE4 brain endothelial cells produce less apolipoprotein E (apoE) and have altered metabolic and inflammatory gene expression profiles. Further analysis revealed APOE4 brain endothelial cultures have higher preference for oxidative phosphorylation over glycolysis and, accordingly, higher markers of mitochondrial activity. Mitochondrial activity generates reactive oxygen species, and, with APOE4, there were higher mitochondrial superoxide levels, lower levels of antioxidants related to heme and glutathione and higher markers/outcomes of oxidative damage to proteins and lipids. In parallel, or resulting from reactive oxygen species, there was greater inflammation in APOE4 brain endothelial cells including higher chemokine levels and immune cell adhesion under basal conditions and after low-dose lipopolysaccharide (LPS) treatment. In addition, paracellular permeability was higher in APOE4 brain endothelial cells in basal conditions and after high-dose LPS treatment. Finally, we found that a nuclear receptor Rev-Erb agonist, SR9009, improved functional metabolic markers, lowered inflammation and modulated paracellular permeability at baseline and following LPS treatment in APOE4 brain endothelial cells. Together, our data suggest that autocrine signaling of apoE in brain endothelial cells represents a novel cellular mechanism for how APOE regulates neurovascular function.

Reactive oxygen species mediate Rac-induced loss of cell-cell adhesion in primary human endothelial cells

2002 ◽  
Vol 115 (9) ◽  
pp. 1837-1846 ◽  
Author(s):  
Sandra van Wetering ◽  
Jaap D. van Buul ◽  
Safira Quik ◽  
Frederik P. J. Mul ◽  
Eloise C. Anthony ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Cell Adhesion ◽  
Endothelial Cell ◽  
Reactive Oxygen ◽  
Small Gtpases ◽  
Endothelial Cell Migration ◽  
Oxygen Species ◽  
Cell Cell

The integrity of the endothelium is dependent on cell-cell adhesion, which is mediated by vascular-endothelial (VE)-cadherin. Proper VE-cadherin-mediated homotypic adhesion is, in turn, dependent on the connection between VE-cadherin and the cortical actin cytoskeleton. Rho-like small GTPases are key molecular switches that control cytoskeletal dynamics and cadherin function in epithelial as well as endothelial cells. We show here that a cell-penetrating, constitutively active form of Rac (Tat-RacV12) induces a rapid loss of VE-cadherin-mediated cell-cell adhesion in endothelial cells from primary human umbilical veins (pHUVEC). This effect is accompanied by the formation of actin stress fibers and is dependent on Rho activity. However,transduction of pHUVEC with Tat-RhoV14, which induces pronounced stress fiber and focal adhesion formation, did not result in a redistribution of VE-cadherin or an overall loss of cell-cell adhesion. In line with this observation, endothelial permeability was more efficiently increased by Tat-RacV12 than by Tat-RhoV14. The loss of cell-cell adhesion, which is induced by Tat-RacV12, occurred in parallel to and was dependent upon the intracellular production of reactive oxygen species (ROS). Moreover, Tat-RacV12 induced an increase in tyrosine phosphorylation of a component the VE-cadherin-catenin complex, which was identified as α-catenin. The functional relevance of this signaling pathway was further underscored by the observation that endothelial cell migration, which requires a transient reduction of cell-cell adhesion, was blocked when signaling through ROS was inhibited. In conclusion, Rac-mediated production of ROS represents a previously unrecognized means of regulating VE-cadherin function and may play an important role in the (patho)physiology associated with inflammation and endothelial damage as well as with endothelial cell migration and angiogenesis.

scholarly journals Kallistatin attenuates endothelial apoptosis through inhibition of oxidative stress and activation of Akt-eNOS signaling

2010 ◽  
Vol 299 (5) ◽  
pp. H1419-H1427 ◽  
Author(s):  
Bo Shen ◽  
Lin Gao ◽  
Yi-Te Hsu ◽  
Grant Bledsoe ◽  
Makato Hagiwara ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Oxygen Species ◽  
Phosphatidylinositol 3 Kinase ◽  
Reactive Oxygen Species Formation ◽  
Endothelial Apoptosis ◽  
Species Formation ◽  
Tnf Α

Kallistatin is a regulator of vascular homeostasis capable of controlling a wide spectrum of biological actions in the cardiovascular and renal systems. We previously reported that kallistatin inhibited intracellular reactive oxygen species formation in cultured cardiac and renal cells. The present study was aimed to investigate the role and mechanisms of kallistatin in protection against oxidative stress-induced vascular injury and endothelial cell apoptosis. We found that kallistatin gene delivery significantly attenuated aortic superoxide formation and glomerular capillary loss in hypertensive DOCA-salt rats. In cultured endothelial cells, kallistatin suppressed TNF-α-induced cellular apoptosis, and the effect was blocked by the pharmacological inhibition of phosphatidylinositol 3-kinase and nitric oxide synthase (NOS) and by the knockdown of endothelial NOS (eNOS) expression. The transduction of endothelial cells with adenovirus expressing dominant-negative Akt abolished the protective effect of kallistatin on endothelial apoptosis and caspase activity. In addition, kallistatin inhibited TNF-α-induced reactive oxygen species formation and NADPH oxidase activity, and these effects were attenuated by phosphatidylinositol 3-kinase and NOS inhibition. Kallistatin also prevented the induction of Bim protein and mRNA expression by oxidative stress. Moreover, the downregulation of forkhead box O 1 (FOXO1) and Bim expression suppressed TNF-α-mediated endothelial cell death. Furthermore, the antiapoptotic actions of kallistatin were accompanied by Akt-mediated FOXO1 and eNOS phosphorylation, as well as increased NOS activity. These findings indicate a novel role of kallistatin in the protection against vascular injury and oxidative stress-induced endothelial apoptosis via the activation of Akt-dependent eNOS signaling.

scholarly journals Methylglyoxal-Induced Dysfunction in Brain Endothelial Cells via the Suppression of Akt/HIF-1α Pathway and Activation of Mitophagy Associated with Increased Reactive Oxygen Species

Antioxidants ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 820 ◽  
Author(s):  
Donghyun Kim ◽  
Kyeong-A Kim ◽  
Jeong-Hyeon Kim ◽  
Eun-Hye Kim ◽  
Ok-Nam Bae
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Tight Junction ◽  
Reactive Oxygen ◽  
Mitochondrial Damage ◽  
Oxygen Species ◽  
Brain Endothelial Cells ◽  
Tight Junction Proteins ◽  
Junction Proteins

Methylglyoxal (MG) is a dicarbonyl compound, the level of which is increased in the blood of diabetes patients. MG is reported to be involved in the development of cerebrovascular complications in diabetes, but the exact mechanisms need to be elucidated. Here, we investigated the possible roles of oxidative stress and mitophagy in MG-induced functional damage in brain endothelial cells (ECs). Treatment of MG significantly altered metabolic stress as observed by the oxygen-consumption rate and barrier-integrity as found in impaired trans-endothelial electrical resistance in brain ECs. The accumulation of MG adducts and the disturbance of the glyoxalase system, which are major detoxification enzymes of MG, occurred concurrently. Reactive oxygen species (ROS)-triggered oxidative damage was observed with increased mitochondrial ROS production and the suppressed Akt/hypoxia-inducible factor 1 alpha (HIF-1α) pathway. Along with the disturbance of mitochondrial bioenergetic function, parkin-1-mediated mitophagy was increased by MG. Treatment of N-acetyl cysteine significantly reversed mitochondrial damage and mitophagy. Notably, MG induced dysregulation of tight junction proteins including occludin, claudin-5, and zonula occluden-1 in brain ECs. Here, we propose that diabetic metabolite MG-associated oxidative stress may contribute to mitochondrial damage and autophagy in brain ECs, resulting in the dysregulation of tight junction proteins and the impairment of permeability.

SIRT3 interactions with FOXO3 acetylation, phosphorylation and ubiquitinylation mediate endothelial cell responses to hypoxia

2014 ◽  
Vol 464 (1) ◽  
pp. 157-168 ◽  
Author(s):  
Anne H.-H. Tseng ◽  
Li-Hong Wu ◽  
Shyan-Shu Shieh ◽  
Danny Ling Wang
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Antioxidant Enzymes ◽  
Endothelial Cell ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Cell Responses ◽  
Cellular Capacity

This article reports that hypoxia elicits SIRT3 to deacetylate FOXO3 in endothelial cells. This drives an increase in the expression of mitochondrial antioxidant enzymes, reduces accumulation of reactive oxygen species in mitochondria and thereby confers cellular capacity to adapt to hypoxia.

Prostaglandin E2 Stimulates Human Brain Endothelial Cell Migration Via a Signaling Pathway Involving Activation of Rho-Kinase II

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 3729-3729
Author(s):  
Gausal Khan ◽  
Maria Theresa Rizzo
Keyword(s):  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Human Brain ◽  
Prostaglandin E2 ◽  
Rho Kinase ◽  
Endothelial Cell Migration ◽  
Brain Endothelial Cell ◽  
Brain Endothelial Cells ◽  
Migratory Response

Abstract Prostaglandin E2 (PGE2) plays a crucial role in angiogenesis as well as in ischemic and inflammatory disorders of the brain associated with breakdown of the blood-brain barrier. However, the effects of PGE2 on brain endothelial cell migration, a key process in the angiogenic response and blood-brain barrier stability, are not well defined. Exposure of human brain endothelial cells (HBECs) to PGE2 elicited a chemotactic response in a time- and dose-dependent manner. The maximum migratory response was detected following 8 hours exposure of HBECs to PGE2 (100 nM). Migration of HBECs in response to PGE2 was accompanied by profound changes in the reorganization of actin filaments. Fluorescence microscopy examination of NBD-phallacidin-labeled endothelial cells showed increased formation of stress fibers, lamellipodia and podosomes after treatment with PGE2 (100 nM) compared to control. Based on these results, we hypothesized that Rho-kinase (ROCK), an enzyme involved in regulation of actin dynamics and cell migration, mediated the effects of PGE2 on HBEC migration. Western blot analyses revealed that ROCK II (type alpha), but not ROCK I (type beta), was expressed in HBECs. To examine ROCK II activation, we performed immunocomplex kinase assays using myosin light chain (MLC) as a substrate. PGE2 (100 nM) induced a 2-fold increase of 32P-incorporation into MLC indicating activation of ROCK II. Pretreatment of HBECs with the selective ROCK inhibitor, Y27632 (150 nM), blunted HBEC migration in response to PGE2 but had no effect on migration induced by fetal bovine serum (10%). Knockdown of ROCK II by siRNA also abrogated the migratory response of HBECs to PGE2. In contrast, similar treatment had no effect of HBEC migration stimulated by hepatocyte growth factor. Taken together, these results are consistent with the hypothesis that stimulation of HBECs with PGE2 leads to activation of ROCK II, reorganization of the actin cytoskeleton and ultimately migration. A better characterization of the molecular events that regulate migration of brain endothelial cells is critical for the development of novel strategies to treat cerebrovascular diseases associated with deregulated angiogenesis.

scholarly journals Regulation of VEGF-induced endothelial cell migration by mitochondrial reactive oxygen species

2011 ◽  
Vol 301 (3) ◽  
pp. C695-C704 ◽  
Author(s):  
Youxue Wang ◽  
Qun S. Zang ◽  
Zijuan Liu ◽  
Qian Wu ◽  
David Maass ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Cell Migration ◽  
Endothelial Cell ◽  
Reactive Oxygen ◽  
Mitochondrial Metabolism ◽  
Endothelial Cell Migration ◽  
Antioxidant Vitamin ◽  
Oxygen Species ◽  
Endothelial Migration

Endothelial migration is a crucial aspect of a variety of physiologic and pathologic conditions including atherosclerosis and vascular repair. Reactive oxygen species (ROS) function as second messengers during endothelial migration. Multiple intracellular sources of ROS are regulated by cellular context, external stimulus, and the microenvironment. However, the predominant source of ROS during endothelial cell (EC) migration and the mechanisms by which ROS regulate cell migration are incompletely understood. In this study, we tested the hypothesis that mitochondria-derived ROS (mtROS) regulate EC migration. In cultured human umbilical vein endothelial cells, VEGF increased mitochondrial metabolism, promoted mtROS production, and induced cell migration. Either the targeted mitochondrial delivery of the antioxidant, vitamin E (Mito-Vit-E), or the depletion of mitochondrial DNA abrogated VEGF-mediated mtROS production. Overexpression of mitochondrial catalase also inhibited VEGF-induced mitochondrial metabolism, Rac activation, and cell migration. Furthermore, these interventions suppressed VEGF-stimulated EC migration and blocked Rac1 activation in endothelial cells. Constitutively active Rac1 reversed Mito-Vit-E-induced inhibition of EC migration. Mito-Vit-E also attenuated carotid artery reendothelialization in vivo. These results provide strong evidence that mtROS regulate EC migration through Rac-1.

Sign in / Sign up

Export Citation Format

Share Document