Differential cytotoxic actions of Shiga toxin 1 and Shiga toxin 2 on microvascular and macrovascular endothelial cells

2011 ◽  
Vol 105 (03) ◽  
pp. 515-528 ◽  
Author(s):  
Andreas Bauwens ◽  
Martina Bielaszewska ◽  
Björn Kemper ◽  
Patrik Langehanenberg ◽  
Gert von Bally ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Shiga Toxin ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Single Cells ◽  
Digital Holographic Microscopy ◽  
Vascular Endothelial ◽  
Enterohaemorrhagic Escherichia Coli ◽  
Shiga Toxin 2 ◽  
Comprehensive Comparison

SummaryShiga toxin (Stx)-mediated injury to vascular endothelial cells in the kidneys, brain and other organs underlies the pathogenesis of haemolytic uraemic syndrome (HUS) caused by enterohaemorrhagic Escherichia coli (EHEC). We present a direct and comprehensive comparison of cellular injury induced by the two major Stx types, Stx1 and Stx2, in human brain microvascular endothelial cells (HBMECs) and EA.hy 926 macro-vascular endothelial cells. Scanning electron microscopy of microcarrier-based cell cultures, digital holographic microscopy of living single cells, and quantitative apoptosis/necrosis assays demonstrate that Stx1 causes both necrosis and apoptosis, whereas Stx2 induces almost exclusively apoptosis in both cell lines. Moreover, microvascular and macrovascular endothelial cells have different susceptibilities to the toxins: EA.hy 926 cells are slightly, but significantly (~ 10 times) more susceptible to Stx1, whereas HBMECs are strikingly (≥ 1,000 times) more susceptible to Stx2. These findings have implications in the pathogenesis of HUS, and suggest the existence of yet to be delineated Stx type-specific mechanisms of endothelial cell injury beyond inhibition of protein bio-synthesis.

scholarly journals Pathogenic Mechanism of Mouse Brain Damage Caused by Oral Infection with Shiga Toxin-Producing Escherichia coliO157:H7

2000 ◽  
Vol 68 (3) ◽  
pp. 1207-1214 ◽  
Author(s):  
Eiji Kita ◽  
Yoshihisa Yunou ◽  
Takaaki Kurioka ◽  
Hiroko Harada ◽  
Shinji Yoshikawa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Brain Damage ◽  
Shiga Toxin ◽  
Vascular Endothelial Cells ◽  
Oral Infection ◽  
Target Cells ◽  
Vascular Endothelial ◽  
Short Term Exposure ◽  
Tnf Α ◽  
The Brain

ABSTRACT In a previous study, we showed that infection with Shiga toxin (Stx)-producing Escherichia coli O157:H7 (strain SmrN-9) caused neurologic symptoms in malnourished mice with positive immunoreactions of Stx2 in brain tissues. The present study explores the mechanism of how Stx injures the vascular endothelium to enter the central nervous system in mice. Oral infection with strain SmrN-9 elicited a tumor necrosis factor alpha (TNF-α) response in the blood as early as 2 days after infection, while Stx was first detected at 3 days postinfection. In the brain, TNF-α was detected at day 3, and its quantity was increased over the next 3 days. Frozen sections of the brains from moribound mice contained high numbers of apoptotic cells. Glycolipids recognized by an anti-Gb3 monoclonal antibody were extracted from the brain, and purified Stx2 was able to bind to the glycolipids. In human umbilical vascular endothelial cells (HUVEC) cultured with fluorescein-labeled Stx2 (100 ng/ml), TNF-α (20 U/ml) significantly facilitated the intracellular compartmentalization of fluorescence during 24 h of incubation, suggesting the enhanced intracellular processing of Stx2. Consequently, higher levels of apoptosis in HUVEC were found at 48 h. Short-term exposure of HUVEC to Stx2 abrogated their apoptotic response to subsequent incubation with TNF-α alone or TNF-α and Stx2. In contrast, primary exposure of HUVEC to TNF-α followed by exposure to Stx2 alone or TNF-α and Stx2 induced apoptosis at the same level as obtained after 48-h incubation with these two agents. These results suggest that the rapid production of circulating TNF-α after infection induces a state of competence in vascular endothelial cells to undergo apoptosis, which would be finally achieved by subsequent elevation of Stx in the blood. In this synergistic action, target cells must be first exposed to TNF-α. Such cell injury may be a prerequisite to brain damage after infection with Stx-producing E. coliO157:H7.

scholarly journals Metabolic Reprogramming of Vascular Endothelial Cells: Basic Research and Clinical Applications

2021 ◽  
Vol 9 ◽  
Author(s):  
Hanlin Peng ◽  
Xiuli Wang ◽  
Junbao Du ◽  
Qinghua Cui ◽  
Yaqian Huang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Vascular Function ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Basic Research ◽  
Initial Response ◽  
Vascular Wall ◽  
Metabolic Reprogramming ◽  
Vascular Endothelial ◽  
Endocrine Organ

Vascular endothelial cells (VECs) build a barrier separating the blood from the vascular wall. The vascular endothelium is the largest endocrine organ, and is well-known for its crucial role in the regulation of vascular function. The initial response to endothelial cell injury can lead to the activation of VECs. However, excessive activation leads to metabolic pathway disruption, VEC dysfunction, and angiogenesis. The pathways related to VEC metabolic reprogramming recently have been considered as key modulators of VEC function in processes such as angiogenesis, inflammation, and barrier maintenance. In this review, we focus on the changes of VEC metabolism under physiological and pathophysiological conditions.

Fructus corni Attenuates Oxidative Stress in Macrophages and Endothelial Cells

1998 ◽  
Vol 26 (03n04) ◽  
pp. 291-300 ◽  
Author(s):  
Qiaoling Peng ◽  
Zhihua Wei ◽  
Benjamin H. S. Lau
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cell Viability ◽  
Oxidative Burst ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Thiobarbituric Acid ◽  
Vascular Endothelial ◽  
Thiobarbituric Acid Reactive Substances ◽  
Chinese Medicinal Herb

The antioxidant effect of a Chinese medicinal herb, Fructus corni extract (FCE), was investigated using models of oxidative stress in macrophages and vascular endothelial cells. Murine macrophages (J774) were incubated with FCE at 37°C and 5% CO2 for 1 hr. Oxidative burst was triggered by zymosan and measured with a fluorescent probe. FCE exhibited a concentration- dependent suppression of oxidative burst. Confluent monolayers of bovine pulmonary artery endothelial cells (PAEC) were preincubated with FCE for 20 hrs, washed, and then exposed to an organic oxidant t-butyl hydroperoxide (tBHP) for 2 hrs. Cell viability was assessed by methylthiazol tetrazolium (MTT) assay, and cell injury by the release of intracellular lactate dehydrogenase (LDH). Lipid peroxidation products of PAEC were determined by measuring thiobarbituric acid-reactive substances (TBARS). Exposure of PAEC to tBHP resulted in decreased cell viability, increased LDH release, and elevated TBARS. Preincubation of PAEC with FCE significantly reversed these changes. Our results demonstrated that FCE can protect vascular endothelial cells from oxidant injury. The data thus suggest that Fructus corni may be useful for the prevention and/or treatment of disorders associated with oxidative damage.

Apoptosis during macrophage-dependent ocular tissue remodelling

Development ◽  
1994 ◽  
Vol 120 (12) ◽  
pp. 3395-3403 ◽  
Author(s):  
R. Lang ◽  
M. Lustig ◽  
F. Francois ◽  
M. Sellinger ◽  
H. Plesken
Keyword(s):  
Endothelial Cells ◽  
Cell Death ◽  
Vascular Endothelial Cells ◽  
Apoptotic Cell ◽  
Single Cells ◽  
Ocular Tissue ◽  
Fragmentation Pattern ◽  
Vascular Endothelial ◽  
Tissue Remodelling ◽  
Cellular Components

We have characterized the nature and pattern of cell death during regression of the pupillary membrane, a developmentally transient capillary network found in the anterior chamber of the eye. This analysis has revealed that the cellular components of the pupillary membrane include vascular endothelial cells in an intricate network of fine capillaries as well as attendant macrophages. The capillaries are situated on the anterior surface of the lens and held in relative position by a cobweb-like meshwork of extracellular matrix fibres that regress along with the cellular components of this structure. Cell death during regression of the pupillary membrane is characteristic of apoptosis. Specifically, apoptotic bodies containing condensed chromatin can be observed in vascular endothelial cells and genomic DNA isolated from the pupillary membrane shows the nucleosomal fragmentation pattern typical of apoptotic cells. Using a method for labelling fragmented DNA in tissue preparations (TUNEL), we have assessed the overall pattern of apoptotic cell death during pupillary membrane regression. We find that apoptosis occurs either in single cells in healthy vessels or synchronously along the entire length of a capillary segment. Both morphological and TUNEL analysis indicate that capillary regression occurs from junction to junction one segment at a time. We propose a model to explain the pattern of capillary regression observed and conclude from these and previous experiments (Lang and Bishop (1993) Cell 74, 453–462), that during regression of the pupillary membrane, the macrophage elicits target cell death by inducing apoptosis.

scholarly journals Characterization of nicardipine hydrochloride-induced cell injury in human vascular endothelial cells

2015 ◽  
Vol 40 (1) ◽  
pp. 71-76 ◽  
Author(s):  
Masanori Ochi ◽  
Yoshiko Kawai ◽  
Yoshiyuki Tanaka ◽  
Hiromu Toyoda
Keyword(s):  
Endothelial Cells ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Vascular Endothelial

Oxidative-stress response in vascular endothelial cells exposed to acellular hemoglobin solutions

1995 ◽  
Vol 269 (2) ◽  
pp. H648-H655 ◽  
Author(s):  
R. Motterlini ◽  
R. Foresti ◽  
K. Vandegriff ◽  
M. Intaglietta ◽  
R. M. Winslow
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Stress Protein ◽  
Vascular Endothelial ◽  
Aortic Endothelial Cells ◽  
Control Value ◽  
Methemoglobin Formation ◽  
Porcine Aortic Endothelial Cells

We investigated the effect of different hemoglobins on the activation of endothelial heme oxygenase (HO), an inducible "stress" protein, which is responsible for heme catabolism, and we determined whether the propensity of hemoglobins to autoxidize correlates with endothelial heme uptake and cell injury. Porcine aortic endothelial cells were incubated for 6 h in the presence of 60 microM unmodified hemoglobin A0 (HbA0), hemoglobin cross-linked between the alpha-chains with bis-(3,5-dibromosalicyl)fumarate (alpha alpha Hb), or cyanomet-alpha alpha-hemoglobin (CNmet alpha alpha Hb). Endothelial HO activity augmented 4.1-fold in the presence of alpha alpha Hb, 2.7-fold with HbA0, and 1.8-fold with CNmet alpha alpha Hb over the control value. Deferoxamine, but not catalase or dimethylthiourea, partially attenuated the HO induction produced by alpha alpha Hb. The rates of methemoglobin formation exhibited a linear relationship over the time of incubation (r = 0.94), and the apparent rate constant was 1.8-fold higher for alpha alpha Hb (0.023 h-1) than for HbA0 (0.013 h-1). Endothelial heme content and lactate dehydrogenase (LDH) release, an index of cell injury, were also higher in alpha alpha Hb compared with HbA0 and CNmet alpha alpha Hb groups (P < 0.05). Deferoxamine but not catalase markedly reduced the release of LDH induced by alpha alpha Hb, whereas dimethylthiourea provided only a partial cytoprotection. These studies suggest that 1) the higher rate of oxidation of alpha alpha Hb contributes to the augmented endothelial HO activity, and 2) both heme release and iron-mediated oxygen radical formation are major contributors to endothelial oxidative stress and cytotoxicity generated by the cross-linked hemoglobin.

Abstract P246: Soluble (Pro)renin Receptor Induces Endothelial Cell Injury via Activation of Nox4/NF-κB Pathway

Hypertension ◽  
2017 ◽  
Vol 70 (suppl_1) ◽  
Author(s):  
Ziwei Fu ◽  
Jiajia Hu ◽  
Fei Wang ◽  
Jiahui Su ◽  
Xiaohan Lu ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Injury ◽  
Vascular Endothelial Cells ◽  
Apoptotic Cell ◽  
Umbilical Vein ◽  
Fold Increase ◽  
Cell Number ◽  
Nuclear Fraction ◽  
Protein Abundance ◽  
Vascular Endothelial

Circulating soluble (pro)renin receptor (sPRR), the cleavage product of the extracellular domain of PRR, is elevated in patients with cardiovascular diseases, highlighting its value as a disease biomarker. We explored a potential biological effect of sPRR in vascular endothelial cells. In primary human umbilical vein endothelial cells (HUVECs), a 2-h treatment with a recombinant histidine-tagged sPRR (sPRR-His) at 50 nM decreased IκBα protein by 55%, associated with 1.5-fold increase in nuclear fraction protein abundance of NF-κB p65 as assessed by immunoblotting. By immunostaining, the increased p65 was localized to the nucleus. The NF-κB p65 transcription factor activity assay on the isolated nuclear fractions showed that the activity increased 1.9-fold after 2-h sPRR-His treatment. At 3 h of sPRR-His treatment, mRNA expression was increased 3.8-fold for IL-6, 30.8-fold for IL-8, 17.3-fold for VCAM-1, and 4.2-fold for ICAM-1 as assessed by qRT-PCR; ELISA detected a 2.6-fold increase in medium IL-6 and 3.7-fold increase in medium IL-8. Moreover, enhanced apoptosis was evidenced by a 2.9-fold increase of cleaved caspase 3 protein and a 4-fold increase in the apoptotic cell number, as assessed by immunoblotting and annexin V-FITC/PI double staining flow cytometry, respectively. In addition, sPRR-His induced a 69% decrease in phospho-eNOS (Ser1177) protein abundance. At 2 h, sPRR-His induced a 2.0-fold increase in Nox4 protein and a 2.8-fold increase in medium H2O2 as assessed by immunoblotting and ROS-Glo H2O2 assay, respectively. A Nox1/4 inhibitor GKT137892 and NADPH oxidase inhibitor apocynin completely abolished sPRR-His-induced NF-κB activation, cytokine production, and apoptosis, similar to the effect of NF-κB inhibition with PDTC. Overall, the present study for the first time reports that sPRR serves as a pro-inflammatory and pro-apoptotic mediator in vascular endothelial cells through activation of Nox4/NF-κB. These findings support PRR/sPRR as a potential target for treatment of cardiovascular disease.

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