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.

Detection of oxidative stress induced by calcium phosphate bions in human arterial endothelial cells

2021 ◽  
pp. 70-78
Author(s):  
А.Г. Кутихин ◽  
Д.К. Шишкова ◽  
Р.А. Мухамадияров ◽  
Е.А. Великанова
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Cell Death ◽  
Superoxide Dismutase ◽  
Calcium Phosphate ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Bafilomycin A1 ◽  
Arterial Endothelial Cells

Введение. Кальций-фосфатные бионы (КФБ) формируются в организме человека при перенасыщении сыворотки ионами кальция и фосфора и вызывают дисфункцию эндотелия, однако молекулярные механизмы нарушения функционирования эндотелия при воздействии КФБ не ясны. Цель исследования - выяснение роли кальций-фосфатных бионов различной формы в развитии окислительного стресса в артериальных эндотелиальных клетках (ЭК) человека. Методика. Для детекции окислительного стресса к конфлюэнтным культурам первичных ЭК коронарной и внутренней грудной артерии человека добавляли равные концентрации КФБ сферической или игольчатой формы (СКФБ и ИКФБ соответственно) с последующим культивированием в течение 1 и 4 ч, добавлением флюоресцентных индикаторов окислительного стресса MitoSOX Red и CellROX Green и конфокальной микроскопией. Измеряли концентрацию продуктов перекисного окисления липидов в культуральной жидкости через 24 ч экспозиции эндотелиальных клеток КФБ. Анализ нейтрализации цитотоксических эффектов перекисного окисления липидов проводили путем добавления к ЭК супероксиддисмутазы и каталазы на 4 или 24 ч (одновременно с КФБ). Для сравнения механизмов клеточной гибели при воздействии СКФБ и ИКФБ анализировали цитотоксичность обоих типов бионов при одновременном воздействии лизосомального ингибитора бафиломицина А1. Результаты. Значимого увеличения генерации активных форм кислорода (АФК) в результате экспозиции СКФБ (независимо от линии ЭК и продолжительности экспозиции) не было выявлено. В то же время наблюдалось повышение генерации супероксида через 4 ч, а иных свободных радикалов через 1 ч после добавления ИКФБ к ЭК. Предварительная нейтрализация АФК супероксиддисмутазой и каталазой частично защищала ЭК от индуцируемой ИКФБ гибели. При этом добавление бафиломицина А1 к ЭК частично защищало их от гибели только при воздействии СКФБ, но не ИКФБ. Заключение. Гибель ЭК при воздействии СКФБ происходит в результате первичного повреждения лизосом, а при воздействии ИКФБ - в первую очередь вследствие окислительного стресса. Background. Calcium phosphate bions (CPB) form in the human blood upon its supersaturation with calcium and phosphate and provoke endothelial dysfunction; however, the molecular mechanisms of these pathological processes remain unclear. Aim. To elucidate the role of differently shaped CPBs in induction of oxidative stress in human arterial endothelial cells (Ecs). Methods. For detection of oxidative stress, equal concentrations of spherical CPB (CPB-S) or needle-shaped CPB (CPB-N) were added to confluent cultures of primary human coronary artery and internal thoracic artery ECs for 1 and 4 h; this was followed by MitoSOX Red and CellROX Green staining and subsequent confocal microscopy. Concentration of thiobarbituric acid-reactive substances was measured in the EC culture supernatant at 24 h of the CPB exposure. The lipid peroxidation cytotoxicity was neutralized by adding superoxide dismutase and catalase to ECs for 4 or 24 h. To compare cell death subroutines induced by CPB-S and CPB-N, the effect of bafilomycin A1, a lysosomal inhibitor, on CRB cytotoxicity was studied. Results. No increase in reactive oxygen species generation was observed in the CPB-S exposure, regardless of the EC line and exposure duration. However, addition of CPB-N to ECs increased the production of superoxide and other free radicals after four- and one-hour exposure, respectively. Prior neutralization of reactive oxygen species with superoxide dismutase and catalase partially protected ECs from CPB-N- but not CPB-S-induced death while bafilomycin A1, vice versa, protected ECs from CPB-S- but not CPB-N-induced death. Conclusion. CPB-S cause cell death due to primary damage of lysosomes whereas CPB-N induce apoptosis due to oxidative stress.

HO-2 provides endogenous protection against oxidative stress and apoptosis caused by TNF-α in cerebral vascular endothelial cells

2006 ◽  
Vol 291 (5) ◽  
pp. C897-C908 ◽  
Author(s):  
Shyamali Basuroy ◽  
Sujoy Bhattacharya ◽  
Dilyara Tcheranova ◽  
Yan Qu ◽  
Raymond F. Regan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Reactive Oxygen Species Generation ◽  
Reactive Oxygen ◽  
Serum Deprivation ◽  
Oxygen Species ◽  
Tnf Α ◽  
Endogenous Protection ◽  
Cerebral Vascular

Tumor necrosis factor-α (TNF-α) causes oxidative stress and apoptosis in a variety of cell types. Heme oxygenase (HO) degrades heme to bilirubin, an antioxidant, and carbon monoxide (CO), a cell cycle modulator, and a vasodilator. Newborn pig cerebral microvascular endothelial cells (CMVEC) highly express constitutive HO-2. We investigated the role of HO-2 in protection against TNF-α-induced apoptosis in cerebral vascular endothelium. In CMVEC from mice and newborn pigs, 15 ng/ml TNF-α alone, or with 10 μg/ml cycloheximide (CHX) caused apoptosis detected by nuclear translocation of p65 NF-κB, caspase-3 activation, DNA fragmentation, cell-cell contact destabilization, and cell detachment. TNF-α did not induce HO-1 expression in CMVEC. CMVEC from HO-2 knockout mice showed greater sensitivity to apoptosis caused by serum deprivation and TNF-α than did wild-type mice. TNF-α increased reactive oxygen species generation, including hydrogen peroxide and superoxide radicals, as detected by dihydrorhodamine-123 and dihydroethidium. The TNF-α response was inhibited by superoxide dismutase and catalase suggesting apoptosis is oxidative stress related. Inhibition of endogenous HO-2 in newborn pig CMVEC increased oxidative stress and exaggerated apoptosis caused by serum deprivation and TNF-α. In HO-1-overexpressing CMVEC (HO-1 selective induction by cobalt portophyrin), TNF-α did not cause apoptosis. A CO-releasing compound, CORM-A1, and bilirubin blocked TNF-α-induced reactive oxygen species accumulation and apoptosis consistent with the antioxidant and antiapoptotic roles of the end products of HO activity. We conclude that HO-2 is critical for protection of cerebrovascular endothelium against apoptotic changes induced by oxidative stress and cytokine-mediated inflammation.

Increased reactive oxygen species production with antisense oligonucleotides directed against uncoupling protein 2 in murine endothelial cells

2002 ◽  
Vol 80 (6) ◽  
pp. 757-764 ◽  
Author(s):  
Carine Duval ◽  
Anne Nègre-Salvayre ◽  
Alain Doglio ◽  
Robert Salvayre ◽  
Luc Pénicaud ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Antisense Oligonucleotides ◽  
Uncoupling Protein ◽  
Reactive Oxygen ◽  
Ldl Oxidation ◽  
Uncoupling Protein 2 ◽  
Thiobarbituric Acid Reactive Substance ◽  
Oxygen Species

Uncoupling protein 2 (UCP-2) belongs to the mitochondrial anion carrier family. It is ubiquitously expressed but is most abdundant in the reticuloendothelial system. In addition to uncoupling function, UCP-2 modulates the production of reactive oxygen species (ROS) by isolated mitochondria. Using an antisense oligonucleotide strategy, we investigated whether a defect in UCP-2 expression modulates ROS in intact endothelial cells. Murine endothelial cells (CRL 2181) pretreated by antisense oligonucleotides directed against UCP-2 mRNA exhibited a significant and specific increase in membrane potential and intracellular ROS level compared with control scrambled or anti-UCP-1 and -UCP-3 antisense oligonucleotides. These specific changes induced by UCP-2 antisense oligonucleotides were correlated with a rise in extracellular superoxide anion production and oxidative stress assessed by thiobarbituric acid reactive substance values. Taken together, these data suggest a role for UCP-2 in control of ROS production and subsequent oxidation of surrounding compounds mediating oxidative stress of endothelial cells. These data also support the notion that manipulations of UCP-2 at the genetic level could control ROS metabolism at the cellular level.Key words: UCP-2, reactive oxygen species, LDL oxidation, oxidative stress, mitochondria, endothelial cells.

Abstract 3754: Homocysteine Induces Alternations Of Tight Junction Proteins In Brain Endothelial Cells.

Stroke ◽  
2012 ◽  
Vol 43 (suppl_1) ◽  
Author(s):  
Neetu Tyagi ◽  
Natia Qipshidze ◽  
Srikanth Givvimani ◽  
Paras K Mishra ◽  
David Lominadze ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Tight Junction ◽  
Kinase Inhibitors ◽  
Mitogen Activated Protein Kinase ◽  
High Dose ◽  
Tight Junction Proteins ◽  
Filamentous Actin ◽  
Mek Kinase ◽  
Junction Proteins

Hyperhomocysteinmia (HHcy) is associated with neurological disorders (Stroke, Alzheimer, Parkinson etc) and causes blood brain barrier (BBB) dysfunction. We previously showed that an elevated level of homocysteine (Hcy) increased formation of filamentous actin and enhanced endothelial layer permeability. In the present work we tested the hypothesis that Hcy induces oxidative stress and binding to endothelial cells (ECs) alters expression of endothelial tight junction proteins (TJP). In this study mouse brain microvascular endothelial cells (bEND3) were grown in gold plated chambers of an electrical cell-substrate impedance system, 8-well chambered. Confluent bEND3 were treated with different doses of Hcy with mitogen-activated protein kinase (MEK) kinase inhibitors (PD98059 or U0126) or H 2 O 2 (oxidant), or medium alone for 24 h. Reactive oxygen species (ROS) was detected using DCFH-DA assay. Hcy induced a dose-dependent decrease in EC junction integrity as determined by transendothelial electrical resistance (TEER). Our results show that high dose of Hcy induces oxidative stress, which cause down regulation of the TJPs contents occludin, zona occluden-1 (ZO-1), and zona occluden-2 (ZO-2) in bEND3s. Hcy-induced decreases in contents of the TJPs were blocked by PD98059, U0126. While BQ788 inhibited endothelin-1-induced decrease in TEER, it did not affect Hcy-induced decrease in TEER. These data suggest that Hcy increases EC layer permeability via the MEK kinase signaling pathway by affecting TJPs, which are bound to actin filaments. Therefore, increased binding of Hcy with ECs during cerebo-vascular diseases may increase microvascular permeability by altering the content and possibly subcellular localization of endothelial TJPs.

scholarly journals Influence of oxidative stress on disease development

2013 ◽  
Vol 67 (1-2) ◽  
pp. 75-85
Author(s):  
Tatjana Bozic ◽  
Jelka Stevanovic ◽  
Suncica Borozan ◽  
Slavoljub Jovic ◽  
Blagoje Dimitrijevic ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Diabetes Mellitus ◽  
Heart Failure ◽  
Reactive Oxygen Species ◽  
Endothelial Cells ◽  
Proinflammatory Cytokines ◽  
Reactive Oxygen ◽  
Primary Role ◽  
Oxygen Species ◽  
Small Density

There is ever increasing data indicating the vmast contribution of oxidative stress to the pathogenesis of numerous diseases (atherosclerosis, hypertension, heart failure, diabetes mellitus, stroke, rheumatoid arthritis, and others). Thus, in the pathogenesis of atherosclerosis the primary role is held by reactive oxygen species that are synthetized by endothelial cells of arterial blood vessels, leukocytes and macrophages. Furthermore, native particles of lipoproteins of small density become atherogenic through oxidation caused by reactive oxygen species. The oxidation of small-density lipoproteins stimulates the inflammatory process, and it in turn steps up adhesion and the inflow of monocytes and affects the synthesis and release of numerous proinflammatory cytokines involved in the further course of the process. One of the reasons for the development of arterial hypertension is the simultaneous activation of NAD(P)H oxidase and 12/15-lipoxygenase, since it results in the stepped up production of reactive oxygen species. These stimulate the production of matrix metalloproteinase 2, which lead to vascular remodelling and to increased apoptosis of heart muscle cells. Stepped up apoptosis is linked with myocardial infarction, cardiomyopathies and the development of heart failure. The sensitivity of ?-cells of the endocrine part of the pancreas to reactive oxygen species favor the naturally low concentrations of the collectors of free radicals in them, as well as an increase in the concentration of proinflammatory cytokines, glucosis and lipids that induce a reduction in the mass and function of ?-cells. Hyperglycemia in diabetes mellitus causes tissue damage through non-enzyme glycosylation of intracellular and extracellular proteins, which results in: reduced enzyme activity, damaged nucleic acid, disrupted natural decomposition of proteins, and activation of cytotoxic pathways. These processes are the basis of the pathogenesis of numerous complications of diabetes mellitus. Since inducible nitrogen-oxide synthesis launches processes that stimulate apoptosis of cerebral endothelial cells, and superoxide-anion radicals, hypochloric acid and hydrogen peroxide damage the parenchyma of an ischemic brain and biomacromolecules (causing lipid peroxidation, oxidation of proteins and deoxyribonucleic acid), brain damage occurs during cerebral ischemia and reperfusion.

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