Hyperoxia Elevates Cu,Zn-Superoxide Dismutase of Endothelial Cells as Detected by a Sensitive ELISA

Enzyme ◽  
1992 ◽  
Vol 46 (4-5) ◽  
pp. 188-195 ◽  
Author(s):  
Shishir K. Das ◽  
Barry L. Fanburg
Keyword(s):  
Endothelial Cells ◽  
Superoxide Dismutase

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.

scholarly journals Hypoxic human umbilical vein endothelial cells induce activation of adherent polymorphonuclear leukocytes

Blood ◽  
1994 ◽  
Vol 83 (12) ◽  
pp. 3705-3716 ◽  
Author(s):  
T Arnould ◽  
C Michiels ◽  
J Remacle
Keyword(s):  
Endothelial Cells ◽  
Superoxide Dismutase ◽  
Superoxide Anion ◽  
Calcium Concentration ◽  
Molecular Mechanisms ◽  
Umbilical Vein ◽  
Superoxide Anion Production ◽  
Elastase Inhibitor ◽  
Human Umbilical Vein ◽  
Umbilical Vein Endothelial Cells

Abstract Several pieces of evidence are reported for the accumulation of activated neutrophils in ischemic and reperfused tissues leading to the transformation of the ischemic tissue into an inflammatory territory and to an enhancement of tissue damages during reoxygenation. However, the molecular mechanisms responsible for these observations and the precise role played by endothelial cells in this process are still poorly understood. In this study, an in vitro model that mimics this situation was used to investigate the effects of hypoxia-incubated human umbilical vein endothelial cells (HUVEC) on polymorphonuclear leukocyte (PMN) functions. A strong PMN activation characterized by an increase in intracellular calcium concentration as well as by superoxide anion release and leukotriene B4 production was observed when these cells were coincubated with hypoxic HUVEC. On the other hand, conditioned medium from hypoxia-incubated HUVEC failed to activate PMN, as determined by the lack of PMN calcium concentration increase, the failure of superoxide anion production enhancement, as well as the absence of effects on the integrin CD18, CD11a, and CD11b expression. These results indicate that the presence of hypoxia- incubated HUVEC is necessary to obtain an activation of the PMN, probably via the adherence process. Once activated by coincubation with hypoxic HUVEC, PMN became cytotoxic, as evidenced by 51Cr released from prelabeled HUVEC. This cytotoxic effect of activated PMN for hypoxic endothelial cells could be prevented by a combination of superoxide dismutase and catalase (94% inhibition), whereas superoxide dismutase alone was inefficient. Antiprotease (alpha 2-macroglobulin) and a specific elastase inhibitor (MAAPV-CMK) were also inefficient. These results correlate very well with the fact that no increase in elastase release could be observed in supernatants from PMN coincubated with hypoxic HUVEC. Furthermore, when adherence process was blocked by oleic acid or by anti-ICAM-1 monoclonal antibodies, protection was, respectively, 90% and 72%. We thus evidenced that free radicals but not elastase released from activated PMN coincubated with hypoxic HUVEC are involved in HUVEC injury. We conclude from these results that PMN activation is initiated by PMN adherence to hypoxic HUVEC. These observations indicate that hypoxic HUVEC may be partly responsible for neutrophil activation observed in ischemic tissues, which is part of the amplification process of tissue damage.

Pulmonary reduction of an intravascular redox polymer

2001 ◽  
Vol 280 (6) ◽  
pp. L1290-L1299 ◽  
Author(s):  
Said H. Audi ◽  
Robert D. Bongard ◽  
Yoshiyuki Okamoto ◽  
Marilyn P. Merker ◽  
David L. Roerig ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Superoxide Dismutase ◽  
Electron Transport ◽  
Kinetic Model ◽  
Electron Acceptors ◽  
Redox Polymer ◽  
Pulmonary Endothelial Cells ◽  
Equilibrium Level ◽  
A Cell

Pulmonary endothelial cells in culture reduce external electron acceptors via transplasma membrane electron transport (TPMET). In studying endothelial TPMET in intact lungs, it is difficult to exclude intracellular reduction and reducing agents released by the lung. Therefore, we evaluated the role of endothelial TPMET in the reduction of a cell-impermeant redox polymer, toluidine blue O polyacrylamide (TBOP+), in intact rat lungs. When added to the perfusate recirculating through the lungs, the venous effluent TBOP+concentration decreased to an equilibrium level reflecting TBOP+ reduction and autooxidation of its reduced (TBOPH) form. Adding superoxide dismutase (SOD) to the perfusate increased the equilibrium TBOP+ concentration. Kinetic analysis indicated that the SOD effect could be attributed to elimination of the superoxide product of TBOPH autooxidation rather than of superoxide released by the lungs, and experiments with lung-conditioned perfusate excluded release of other TBOP+ reductants in sufficient quantities to cause significant TBOP+ reduction. Thus the results indicate that TBOP+ reduction is via TPMET and support the utility of TBOP+ and the kinetic model for investigating TPMET mechanisms and their adaptations to physiological and pathophysiological stresses in the intact lung.

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