scholarly journals Cathepsin L Acutely Alters Microvessel Integrity within the Neurovascular Unit during Focal Cerebral Ischemia

2015 ◽  
Vol 35 (11) ◽  
pp. 1888-1900 ◽  
Author(s):  
Yu-Huan Gu ◽  
Masato Kanazawa ◽  
Stephanie Y Hung ◽  
Xiaoyun Wang ◽  
Shunichi Fukuda ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cerebral Ischemia ◽  
Ex Vivo ◽  
Focal Cerebral Ischemia ◽  
Cathepsin L ◽  
Neurovascular Unit ◽  
Edema Formation ◽  
Ischemic Core ◽  
Neuron Injury

During focal cerebral ischemia, the degradation of microvessel basal lamina matrix occurs acutely and is associated with edema formation and microhemorrhage. These events have been attributed to matrix metalloproteinases (MMPs). However, both known protease generation and ligand specificities suggest other participants. Using cerebral tissues from a non-human primate focal ischemia model and primary murine brain endothelial cells, astrocytes, and microglia in culture, the effects of active cathepsin L have been defined. Within 2 hours of ischemia onset cathepsin L, but not cathepsin B, activity appears in the ischemic core, around microvessels, within regions of neuron injury and cathepsin L expression. In in vitro studies, cathepsin L activity is generated during experimental ischemia in microglia, but not astrocytes or endothelial cells. In the acidic ischemic core, cathepsin L release is significantly increased with time. A novel ex vivo assay showed that cathepsin L released from microglia during ischemia degrades microvessel matrix, and interacts with MMP activity. Hence, the loss of microvessel matrix during ischemia is explained by microglial cathepsin L release in the acidic core during injury evolution. The roles of cathepsin L and its interactions with specific MMP activities during ischemia are relevant to strategies to reduce microvessel injury and hemorrhage.

scholarly journals Regulator of G‐Protein Signaling 5 Maintains Brain Endothelial Cell Function in Focal Cerebral Ischemia

2020 ◽  
Vol 9 (18) ◽  
Author(s):  
Nikola Sladojevic ◽  
Brian Yu ◽  
James K. Liao
Keyword(s):  
Endothelial Cells ◽  
Cerebral Ischemia ◽  
G Protein ◽  
Blood Brain Barrier ◽  
Focal Cerebral Ischemia ◽  
Brain Barrier ◽  
Stroke Severity ◽  
Protein Signaling ◽  
Blood Brain

Background Regulator of G‐protein signaling 5 (RGS5) is a negative modulator of G‐protein–coupled receptors. The role of RGS5 in brain endothelial cells is not known. We hypothesized that RGS5 in brain microvascular endothelial cells may be an important mediator of blood‐brain barrier function and stroke severity after focal cerebral ischemia. Methods and Results Using a transient middle cerebral artery occlusion model, we found that mice with global and endothelial‐specific deletion of Rgs5 exhibited larger cerebral infarct size, greater neurological motor deficits, and increased brain edema. In our in vitro models, we observed increased G q activity and elevated intracellular Ca 2+ levels in brain endothelial cells. Furthermore, the loss of endothelial RGS5 leads to decreased endothelial NO synthase expression and phosphorylation, relocalization of endothelial tight junction proteins, and increased cell permeability. Indeed, RGS5 deficiency leads to increased Rho‐associated kinase and myosin light chain kinase activity, which were partially reversed in our in vitro model by pharmacological inhibition of G q , metabotropic glutamate receptor 1, and ligand‐gated ionotropic glutamate receptor. Conclusions Our findings indicate that endothelial RGS5 plays a novel neuroprotective role in focal cerebral ischemia. Loss of endothelial RGS5 leads to hyperresponsiveness to glutamate signaling pathways, enhanced Rho‐associated kinase– and myosin light chain kinase–mediated actin‐cytoskeleton reorganization, endothelial dysfunction, tight junction protein relocalization, increased blood‐brain barrier permeability, and greater stroke severity. These findings suggest that preservation of endothelial RGS5 may be an important therapeutic strategy for maintaining blood‐brain barrier integrity and limiting the severity of ischemic stroke.

scholarly journals Angiogenesis in the ischemic core: A potential treatment target?

2019 ◽  
Vol 39 (5) ◽  
pp. 753-769 ◽  
Author(s):  
Masato Kanazawa ◽  
Tetsuya Takahashi ◽  
Masanori Ishikawa ◽  
Osamu Onodera ◽  
Takayoshi Shimohata ◽  
...  
Keyword(s):  
Ischemic Stroke ◽  
Cerebral Ischemia ◽  
Tissue Injury ◽  
Focal Cerebral Ischemia ◽  
Neurovascular Unit ◽  
Focal Ischemia ◽  
Model Systems ◽  
Surrounding Tissue ◽  
Model Studies ◽  
Ischemic Core

The ischemic penumbra is both a concept in understanding the evolution of cerebral tissue injury outcome of focal ischemia and a potential therapeutic target for ischemic stroke. In this review, we examine the evidence that angiogenesis can contribute to beneficial outcomes following focal ischemia in model systems. Several studies have shown that, following cerebral ischemia, endothelial proliferation and subsequent angiogenesis can be detected beginning four days after cerebral ischemia in the border of the ischemic core, or in the ischemic periphery, in rodent and non-human primate models, although initial signals appear within hours of ischemia onset. Components of the neurovascular unit, its participation in new vessel formation, and the nature of the core and penumbra responses to experimental focal cerebral ischemia, are considered here. The potential co-localization of vascular remodeling and axonal outgrowth following focal cerebral ischemia based on the definition of tissue remodeling and the processes that follow ischemic stroke are also considered. The region of angiogenesis in the ischemic core and its surrounding tissue (ischemic periphery) may be a novel target for treatment. We summarize issues that are relevant to model studies of focal cerebral ischemia looking ahead to potential treatments.

Beneficial effect of dipyridyl, a liposoluble iron chelator against focal cerebral ischemia: In vivo and in vitro evidence of protection of cerebral endothelial cells

2008 ◽  
Vol 1193 ◽  
pp. 136-142 ◽  
Author(s):  
Delphine Méthy ◽  
Nathalie Bertrand ◽  
Anne Prigent-Tessier ◽  
Claude Mossiat ◽  
Danica Stanimirovic ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cerebral Ischemia ◽  
Beneficial Effect ◽  
Focal Cerebral Ischemia ◽  
Iron Chelator ◽  
Cerebral Endothelial Cells

Antiangiogenic effects of phospholipase A2 Lys49 BnSP-7 from Bothrops pauloensis snake venom on endothelial cells: An in vitro and ex vivo approach

2021 ◽  
Vol 72 ◽  
pp. 105099
Author(s):  
Lorena Polloni ◽  
Fernanda Van Petten Vasconcelos Azevedo ◽  
Samuel Cota Teixeira ◽  
Eloá Moura ◽  
Tassia Rafaela Costa ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Phospholipase A2 ◽  
Snake Venom ◽  
Ex Vivo ◽  
Ex Vivo Approach

scholarly journals Neutrophil extracellular traps induce MCP-1 release from endothelial cells at the plaque rupture site in acute myocardial infarction

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
A Ondracek ◽  
T.M Hofbauer ◽  
A Mangold ◽  
T Scherz ◽  
V Seidl ◽  
...  
Keyword(s):  
Myocardial Infarction ◽  
Acute Myocardial Infarction ◽  
Endothelial Cells ◽  
Plaque Rupture ◽  
Ex Vivo ◽  
Coronary Intervention ◽  
Neutrophil Extracellular Traps ◽  
Funding Source ◽  
Extracellular Traps

Abstract Introduction Leukocyte-mediated inflammation is crucial in acute myocardial infarction (AMI). We recently observed that neutrophil extracellular traps (NETs) are increased at the culprit site, promoting activation and differentiation of fibrocytes, cells with mesenchymal and leukocytic properties. Fibrocyte migration is mediated by monocyte chemoattractant protein (MCP)-1 and C-C chemokine receptor type 2 (CCR2). We investigated the interplay between NETs, fibrocyte function, and MCP-1 in AMI. Methods Culprit site and femoral blood of AMI patients was drawn during percutaneous coronary intervention. We characterized CCR2 expression of fibrocytes by flow cytometry. MCP-1 and the NET marker citrullinated histone H3 (citH3) were measured by ELISA. Fibrocytes were treated in vitro with MCP-1. Human coronary arterial endothelial cells (hCAECs) were stimulated with isolated NETs, and MCP-1 was measured by ELISA and qPCR. The influence of MCP-1 on NET formation in vitro was assessed using isolated neutrophils. Results We have included 50 consecutive AMI patients into the study. NETs and concentrations of MCP-1 were increased at the CLS. NET stimulation of hCAECs induced MCP-1 on mRNA and protein level. Increasing MCP-1 gradient was associated with fibrocyte accumulation at the site of occlusion. In the presence of higher MCP-1 these fibrocytes expressed proportionally less CCR2 than peripheral fibrocytes. In vitro, MCP-1 dose-dependently decreased fibrocyte CCR2 and reduced ex vivo NET release of healthy donor neutrophils. Conclusions NETs induce endothelial MCP-1 release, presumably promoting a chemotactic gradient for leukocyte and fibrocyte migration. MCP-1 mediated inhibition of NET formation could point to a negative feedback loop. These data will shed light on vascular healing. Funding Acknowledgement Type of funding source: Public grant(s) – National budget only. Main funding source(s): Austrian Science Fund

scholarly journals Can Be miR-126-3p a Biomarker of Premature Aging? An Ex Vivo and In Vitro Study in Fabry Disease

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 356 ◽  
Author(s):  
Alessia Lo Curto ◽  
Simona Taverna ◽  
Maria Assunta Costa ◽  
Rosa Passantino ◽  
Giuseppa Augello ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Fabry Disease ◽  
Healthy Subjects ◽  
Aging Process ◽  
Replicative Senescence ◽  
Ex Vivo ◽  
Umbilical Vein ◽  
Quantitative Polymerase Chain Reaction ◽  
Premature Aging

Fabry disease (FD) is a lysosomal storage disorder (LSD) characterized by lysosomal accumulation of glycosphingolipids in a wide variety of cytotypes, including endothelial cells (ECs). FD patients experience a significantly reduced life expectancy compared to the general population; therefore, the association with a premature aging process would be plausible. To assess this hypothesis, miR-126-3p, a senescence-associated microRNA (SA-miRNAs), was considered as an aging biomarker. The levels of miR-126-3p contained in small extracellular vesicles (sEVs), with about 130 nm of diameter, were measured in FD patients and healthy subjects divided into age classes, in vitro, in human umbilical vein endothelial cells (HUVECs) “young” and undergoing replicative senescence, through a quantitative polymerase chain reaction (qPCR) approach. We confirmed that, in vivo, circulating miR-126 levels physiologically increase with age. In vitro, miR-126 augments in HUVECs underwent replicative senescence. We observed that FD patients are characterized by higher miR-126-3p levels in sEVs, compared to age-matched healthy subjects. We also explored, in vitro, the effect on ECs of glycosphingolipids that are typically accumulated in FD patients. We observed that FD storage substances induced in HUVECs premature senescence and increased of miR-126-3p levels. This study reinforces the hypothesis that FD may aggravate the normal aging process.

scholarly journals A tumor-promoting role for soluble TβRIII in glioblastoma

2021 ◽  
Author(s):  
Isabel Burghardt ◽  
Judith Johanna Schroeder ◽  
Tobias Weiss ◽  
Dorothee Gramatzki ◽  
Michael Weller
Keyword(s):  
Endothelial Cells ◽  
Ex Vivo ◽  
Microvascular Endothelial Cells ◽  
Smad2 Phosphorylation ◽  
Cell Gene Expression ◽  
Microvascular Endothelial ◽  
Cell Gene ◽  
Mouse Glioma

Abstract Purpose Members of the transforming growth factor (TGF)-β superfamily play a key role in the regulation of the malignant phenotype of glioblastoma by promoting invasiveness, angiogenesis, immunosuppression, and maintaining stem cell-like properties. Betaglycan, a TGF-β coreceptor also known as TGF-β receptor III (TβRIII), interacts with members of the TGF-β superfamily and acts as membrane-associated or shed molecule. Shed, soluble TβRIII (sTβRIII) is produced upon ectodomain cleavage of the membrane-bound form. Elucidating the role of TβRIII may improve our understanding of TGF-β pathway activity in glioblastoma Methods Protein levels of TβRIII were determined by immunohistochemical analyses and ex vivo single-cell gene expression profiling of glioblastoma tissue respectively. In vitro, TβRIII levels were assessed investigating long-term glioma cell lines (LTCs), cultured human brain-derived microvascular endothelial cells (hCMECs), glioblastoma-derived microvascular endothelial cells, and glioma-initiating cell lines (GICs). The impact of TβRIII on TGF-β signaling was investigated, and results were validated in a xenograft mouse glioma model Results Immunohistochemistry and ex vivo single-cell gene expression profiling of glioblastoma tissue showed that TβRIII was expressed in the tumor tissue, predominantly in the vascular compartment. We confirmed this pattern of TβRIII expression in vitro. Specifically, we detected sTβRIII in glioblastoma-derived microvascular endothelial cells. STβRIII facilitated TGF-β-induced Smad2 phosphorylation in vitro and overexpression of sTβRIII in a xenograft mouse glioma model led to increased levels of Smad2 phosphorylation, increased tumor volume, and decreased survival Conclusions These data shed light on the potential tumor-promoting role of extracellular shed TβRIII which may be released by glioblastoma endothelium with high sTβRIII levels.

scholarly journals Profiling of Cytokines Secreted by Conventional Aqueous Outflow Pathway Endothelial Cells Activated In Vitro and Ex Vivo With Laser Irradiation

2015 ◽  
Vol 56 (12) ◽  
pp. 7100 ◽  
Author(s):  
Jorge A. Alvarado ◽  
Phuonglan Chau ◽  
Jianfeng Wu ◽  
Richard Juster ◽  
Amde Selassie Shifera ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Laser Irradiation ◽  
Ex Vivo ◽  
Outflow Pathway ◽  
Aqueous Outflow

scholarly journals Characterization of human fetal brain endothelial cells reveals barrier properties suitable for in vitro modeling of the BBB with syngenic co-cultures

2017 ◽  
Vol 38 (5) ◽  
pp. 888-903 ◽  
Author(s):  
Allison M Andrews ◽  
Evan M Lutton ◽  
Lee A Cannella ◽  
Nancy Reichenbach ◽  
Roshanak Razmpour ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Neurovascular Unit ◽  
Fetal Brain ◽  
Barrier Properties ◽  
Endothelial Activation ◽  
Fetal Tissue ◽  
In Vitro Models ◽  
Adult Brain ◽  
Alternative Source

Endothelial cells (ECs) form the basis of the blood–brain barrier (BBB), a physical barrier that selectively restricts transport into the brain. In vitro models can provide significant insight into BBB physiology, mechanisms of human disease pathology, toxicology, and drug delivery. Given the limited availability of primary human adult brain microvascular ECs ( aBMVECs), human fetal tissue offers a plausible alternative source for multiple donors and the opportunity to build syngenic tri-cultures from the same host. Previous efforts to culture fetal brain microvascular ECs ( fBMVECs) have not been successful in establishing mature barrier properties. Using optimal gestational age for isolation and flow cytometry cell sorting, we show for the first time that fBMVECs demonstrate mature barrier properties. fBMVECs exhibited similar functional phenotypes when compared to aBMVECs for barrier integrity, endothelial activation, and gene/protein expression of tight junction proteins and transporters. Importantly, we show that tissue used to culture fBMVECs can also be used to generate a syngenic co-culture, creating a microfluidic BBB on a chip. The findings presented provide a means to overcome previous challenges that limited successful barrier formation by fBMVECs. Furthermore, the source is advantageous for autologous reconstitution of the neurovascular unit for next generation in vitro BBB modeling.

scholarly journals Neuroprotection by Brazilian Green Propolis againstIn vitroandIn vivoIschemic Neuronal Damage

2005 ◽  
Vol 2 (2) ◽  
pp. 201-207 ◽  
Author(s):  
Masamitsu Shimazawa ◽  
Satomi Chikamatsu ◽  
Nobutaka Morimoto ◽  
Satoshi Mishima ◽  
Hiroichi Nagai ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cerebral Ischemia ◽  
Neuronal Damage ◽  
Focal Cerebral Ischemia ◽  
Brain Infarction ◽  
Folk Medicine ◽  
Neuroprotective Function ◽  
Brazilian Green Propolis

We examined whether Brazilian green propolis, a widely used folk medicine, has a neuroprotective functionin vitroand/orin vivo.In vitro, propolis significantly inhibited neurotoxicity induced in neuronally differentiated PC12 cell cultures by either 24 h hydrogen peroxide (H2O2) exposure or 48 h serum deprivation. Regarding the possible underlying mechanism, propolis protected against oxidative stress (lipid peroxidation) in mouse forebrain homogenates and scavenged free radicals [induced by diphenyl-p-picrylhydrazyl (DPPH). In micein vivo, propolis [30 or 100 mg/kg; intraperitoneally administered four times (at 2 days, 1 day and 60 min before, and at 4 h after induction of focal cerebral ischemia by permanent middle cerebral artery occlusion)] reduced brain infarction at 24 h after the occlusion. Thus, a propolis-induced inhibition of oxidative stress may be partly responsible for its neuroprotective function againstin vitrocell death andin vivofocal cerebral ischemia.

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