scholarly journals Ischemia-induced stimulation of cerebral microvascular endothelial cell Na-K-Cl cotransport involves p38 and JNK MAP kinases

2012 ◽  
Vol 302 (3) ◽  
pp. C505-C517 ◽  
Author(s):  
Breanna K. Wallace ◽  
Karen A. Jelks ◽  
Martha E. O'Donnell
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Endothelial Cell ◽  
Map Kinases ◽  
Artery Occlusion ◽  
Microvascular Endothelial Cell ◽  
Microvascular Endothelial ◽  
Cerebral Artery Occlusion ◽  
Sb 239063 ◽  
Stimulation Of

Previous studies have provided evidence that, in the early hours of ischemic stroke, a luminal membrane blood-brain barrier (BBB) Na-K-Cl cotransporter (NKCC) participates in ischemia-induced cerebral edema formation. Inhibition of BBB NKCC activity by intravenous bumetanide significantly reduces edema and infarct in the rat permanent middle cerebral artery occlusion model of ischemic stroke. We demonstrated previously that the BBB cotransporter is stimulated by hypoxia, aglycemia, and AVP, factors present during cerebral ischemia. However, the underlying mechanisms have not been known. Ischemic conditions have been shown to activate p38 and JNK MAP kinases (MAPKs) in brain, and the p38 and JNK inhibitors SB-239063 and SP-600125, respectively, have been found to reduce brain damage following middle cerebral artery occlusion and subarachnoid hemorrhage, respectively. The present study was conducted to determine whether one or both of these MAPKs participates in ischemic factor stimulation of BBB NKCC activity. Cultured cerebral microvascular endothelial cell NKCC activity was evaluated as bumetanide-sensitive86Rb influx. Activities of p38 and JNK were assessed by Western blot and immunofluorescence methods using antibodies that detect total vs. phosphorylated (activated) p38 or JNK. We report that p38 and JNK are present in cultured cerebral microvascular endothelial cells and in BBB endothelial cells in situ and that hypoxia (7% O2and 2% O2), aglycemia, AVP, and O2-glucose deprivation (5- to 120-min exposures) all rapidly activate p38 and JNK in the cells. We also provide evidence that SB-239063 and SP-600125 reduce or abolish ischemic factor stimulation of BBB NKCC activity. These findings support the hypothesis that ischemic factor stimulation of the BBB NKCC involves activation of p38 and JNK MAPKs.

scholarly journals Cerebral microvascular endothelial cell Na/H exchange: evidence for the presence of NHE1 and NHE2 isoforms and regulation by arginine vasopressin

2009 ◽  
Vol 297 (2) ◽  
pp. C278-C289 ◽  
Author(s):  
Tina I. Lam ◽  
Phyllis M. Wise ◽  
Martha E. O'Donnell
Keyword(s):  
Endothelial Cells ◽  
Artery Occlusion ◽  
Protein Isoforms ◽  
Microvascular Endothelial Cell ◽  
Edema Formation ◽  
Intracellular Ca ◽  
Microvascular Endothelial ◽  
Cerebral Artery Occlusion ◽  
Brain Water ◽  
Exchange Activity

Blood-brain barrier (BBB) Na transporters are essential for brain water and electrolyte homeostasis. However, they also contribute to edema formation during the early hours of ischemic stroke by increased transport of Na from blood into brain across an intact BBB. We previously showed that a luminal BBB Na-K-Cl cotransporter is stimulated by hypoxia, aglycemia, and AVP and that inhibition of the cotransporter by intravenous bumetanide significantly reduces edema and infarct in the rat middle cerebral artery occlusion (MCAO) model of stroke. More recently, we found evidence that intravenous cariporide (HOE-642), a highly potent Na/H exchange inhibitor, also reduces brain edema after MCAO. The present study was conducted to investigate which Na/H exchange protein isoforms are present in BBB endothelial cells and to evaluate the effects of ischemic factors on BBB Na/H exchange activity. Western blot analysis of bovine cerebral microvascular endothelial cells (CMEC) and immunoelectron microscopy of perfusion-fixed rat brain revealed that Na/H exchanger isoforms 1 and 2 (NHE1 and NHE2) are present in BBB endothelial cells. Using microspectrofluorometry and the pH-sensitive dye BCECF, we found that hypoxia (2% O2, 30 min), aglycemia (30 min), and AVP (1–200 nM, 5 min) significantly increased CMEC Na/H exchange activity, assessed as Na-dependent, HOE-642-sensitive H+ flux. We found that AVP stimulation of CMEC Na/H exchange activity is dependent on intracellular Ca concentration and is blocked by V1, but not V2, vasopressin receptor antagonists. Our findings support the hypothesis that a BBB Na/H exchanger, possibly NHE1 and/or NHE2, is stimulated during ischemia to participate in cerebral edema formation.

scholarly journals Ischemia-induced stimulation of Na-K-Cl cotransport in cerebral microvascular endothelial cells involves AMP kinase

2011 ◽  
Vol 301 (2) ◽  
pp. C316-C326 ◽  
Author(s):  
Breanna K. Wallace ◽  
Shahin Foroutan ◽  
Martha E. O'Donnell
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Brain Slices ◽  
Glucose Deprivation ◽  
Artery Occlusion ◽  
Microvascular Endothelial Cells ◽  
Edema Formation ◽  
Compound C ◽  
Microvascular Endothelial ◽  
Stimulation Of

Increased blood-brain barrier (BBB) Na-K-Cl cotransporter activity appears to contribute to cerebral edema formation during ischemic stroke. We have shown previously that inhibition of BBB Na-K-Cl cotransporter activity reduces edema and infarct in the rat middle cerebral artery occlusion (MCAO) model of ischemic stroke. We have also shown that the BBB cotransporter is stimulated by the ischemic factors hypoxia, aglycemia, and arginine vasopressin (AVP), although the mechanisms responsible are not well understood. AMP-activated protein kinase (AMPK), a key mediator of cell responses to stress, can be activated by a variety of stresses, including ischemia, hypoxia, and aglycemia. Previous studies have shown that the AMPK inhibitor Compound C significantly reduces infarct in mouse MCAO. The present study was conducted to evaluate the possibility that AMPK participates in ischemic factor-induced stimulation of the BBB Na-K-Cl cotransporter. Cerebral microvascular endothelial cells (CMEC) were assessed for Na-K-Cl cotransporter activity as bumetanide-sensitive86Rb influx. AMPK activity was assessed by Western blot analysis and immunofluorescence methods using antibodies that detect total versus phosphorylated (activated) AMPK. We found that hypoxia (7% and 2% O2), aglycemia, AVP, and oxygen-glucose deprivation (5- to 120-min exposures) increase activation of AMPK. We also found that Compound C inhibition of AMPK reduces hypoxia-, aglycemia-, and AVP-induced stimulation of CMEC Na-K-Cl cotransporter activity. Confocal immunofluorescence of perfusion-fixed rat brain slices revealed the presence of AMPK, both total and phosphorylated kinase, in BBB in situ of both control and ischemic brain. These findings suggest that ischemic factor stimulation of the BBB Na-K-Cl cotransporter involves activation of AMPK.

A Porcine Model for Adipose Tissue-Derived Endothelial Cell Transplantation

1992 ◽  
Vol 1 (4) ◽  
pp. 293-298 ◽  
Author(s):  
Carlton Young ◽  
Bruce E. Jarrell ◽  
James B. Hoying ◽  
Stuart K. Williams
Keyword(s):  
Endothelial Cells ◽  
Adipose Tissue ◽  
Endothelial Cell ◽  
Cell Transplantation ◽  
Animal Studies ◽  
Porcine Model ◽  
Cell Isolation ◽  
Microvascular Endothelial Cell ◽  
Microvascular Endothelium ◽  
Microvascular Endothelial

The transplantation of endothelial cells represents a technology which has been suggested for applications ranging from improvement in function of implanted vascular devices to genetic therapy. The use of microvascular endothelial cell transplantation has seen increased use both in animal studies as well as clinical use. This report describes our techniques for the isolation and establishment of initial cultures of microvascular endothelial cells derived from porcine fat. A variety of anatomic sites within the pig were evaluated to determine the appropriateness of different sources of fat for endothelial cell isolation. The properitoneal fat was determined to be optimal due to the predominance of endothelium in this tissue and the ease of isolation of microvascular endothelium following collagenase digestion. The study of endothelial cell transplantation in the porcine model is now possible using the methods described for adipose tissue-derived micro vessel endothelial cell isolation.

Abstract 166: Endothelial Overexpression of LOX-1 Increases Stroke Size in vivo

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Alexander Akhmedov ◽  
Remo D Spescha ◽  
Francesco Paneni ◽  
Giovani G Camici ◽  
Thomas F Luescher
Keyword(s):  
Endothelial Cells ◽  
Ischemic Stroke ◽  
Endothelial Dysfunction ◽  
Middle Cerebral Artery ◽  
Middle Cerebral Artery Occlusion ◽  
Cerebral Artery ◽  
Oxidized Ldl ◽  
Artery Occlusion ◽  
Cerebral Artery Occlusion ◽  
The Brain

Background— Stroke is one of the most common causes of death and long term disability worldwide primarily affecting the elderly population. Lectin-like oxidized LDL receptor 1 (LOX-1) is the receptor for oxidized LDL identified in endothelial cells. Binding of OxLDL to LOX-1 induces several cellular events in endothelial cells, such as activation of transcription factor NF-kB, upregulation of MCP-1, and reduction in intracellular NO. Accumulating evidence suggests that LOX-1 is involved in endothelial dysfunction, inflammation, atherogenesis, myocardial infarction, and intimal thickening after balloon catheter injury. Interestingly, a recent study demonstrated that acetylsalicylic acid (aspirin), which could prevent ischemic stroke, inhibited Ox-LDL-mediated LOX-1 expression in human coronary endothelial cells. The expression of LOX-1 was increased at a transient ischemic core site in the rat middle cerebral artery occlusion model. These data suggest that LOX-1 expression induces atherosclerosis in the brain and is the precipitating cause of ischemic stroke. Therefore, the goal of the present study was to investigate the role of endothelial LOX-1 in stroke using experimental mouse model. Methods and Results— 12-week-old male LOX-1TG generated recently in our group and wild-type (WT) mice were applied for a transient middle cerebral artery occlusion (MCAO) model to induce ischemia/reperfusion (I/R) brain injury. LOX-1TG mice developed 24h post-MCAO significantly larger infarcts in the brain compared to WT (81.51±8.84 vs. 46.41±10.13, n=7, p < 0.05) as assessed morphologically using Triphenyltetrazolium chloride (TTC) staining. Moreover, LOX-1TG showed higher neurological deficit in RotaRod (35.57±8.92 vs. 66.14±10.63, n=7, p < 0.05) and Bederson tests (2.22±0.14 vs. 1.25±0.30, n=9-12, p < 0.05) - two experimental physiological tests for neurological function. Conclusions— Thus, our data suggest that LOX-1 plays a critical role in the ischemic stroke when expressed at unphysiological levels. Such LOX-1 -associated phenotype could be due to the endothelial dysfunction. Therefore, LOX-1 may represent novel therapeutic targets for preventing ischemic stroke.

scholarly journals Brucella abortus-Stimulated Platelets Activate Brain Microvascular Endothelial Cells Increasing Cell Transmigration through the Erk1/2 Pathway

Pathogens ◽  
2020 ◽  
Vol 9 (9) ◽  
pp. 708
Author(s):  
Ana María Rodríguez ◽  
Aldana Trotta ◽  
Agustina P. Melnyczajko ◽  
M. Cruz Miraglia ◽  
Kwang Sik Kim ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Brucella Abortus ◽  
Cell Activation ◽  
Transendothelial Migration ◽  
Endothelial Activation ◽  
Microvascular Endothelial Cell ◽  
Inflammatory Disorder ◽  
Endothelial Cell Activation ◽  
Microvascular Endothelial

Central nervous system invasion by bacteria of the genus Brucella results in an inflammatory disorder called neurobrucellosis. A common feature associated with this pathology is blood–brain barrier (BBB) activation. However, the underlying mechanisms involved with such BBB activation remain unknown. The aim of this work was to investigate the role of Brucella abortus-stimulated platelets on human brain microvascular endothelial cell (HBMEC) activation. Platelets enhanced HBMEC activation in response to B. abortus infection. Furthermore, supernatants from B. abortus-stimulated platelets also activated brain endothelial cells, inducing increased secretion of IL-6, IL-8, CCL-2 as well as ICAM-1 and CD40 upregulation on HBMEC compared with supernatants from unstimulated platelets. Outer membrane protein 19, a B. abortus lipoprotein, recapitulated B. abortus-mediated activation of HBMECs by platelets. In addition, supernatants from B. abortus-activated platelets promoted transendothelial migration of neutrophils and monocytes. Finally, using a pharmacological inhibitor, we demonstrated that the Erk1/2 pathway is involved in the endothelial activation induced by B. abortus-stimulated platelets and also in transendothelial migration of neutrophils. These results describe a mechanism whereby B. abortus-stimulated platelets induce endothelial cell activation, promoting neutrophils and monocytes to traverse the BBB probably contributing to the inflammatory pathology of neurobrucellosis.

scholarly journals Interleukin 15 Induces Endothelial Hyaluronan Expression in Vitro and Promotes Activated T Cell Extravasation through a Cd44-Dependent Pathway in Vivo

1999 ◽  
Vol 190 (1) ◽  
pp. 9-20 ◽  
Author(s):  
Pila Estess ◽  
Animesh Nandi ◽  
Mansour Mohamadzadeh ◽  
Mark H. Siegelman
Keyword(s):  
T Cells ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
T Cell ◽  
Microvascular Endothelial Cell ◽  
Dependent Manner ◽  
Cell Recruitment ◽  
Microvascular Endothelial ◽  
Dependent Pathway

T cell recruitment to extralymphoid tissues is fundamental to the initiation and perpetuation of the inflammatory state during immune and autoimmune responses. Interleukin (IL)-15 is a proinflammatory cytokine whose described functions largely overlap with those of IL-2. The latter is attributable in large part to its binding of the heterotrimeric receptor that contains the β and γ chains of the IL-2R in combination with an unique IL-15Rα chain. However, unlike IL-2, IL-15 and its receptor have a wide tissue and cell type distribution, including endothelial cells. Here, we examine the effect of IL-15 on hyaluronan expression by endothelial cells, and investigate its role in vivo in promoting the extravasation of antigen-activated T cells through a CD44-dependent pathway. The expression of hyaluronan on primary endothelial cells and microvascular endothelial cell lines is induced by IL-15, whereas IL-2 has no such activity. Moreover, intraperitoneal administration of IL-15 or TNF-α in the absence of other exogenous proinflammatory stimuli allows the extravasation of superantigen-stimulated T cells into this site in vivo in a CD44-dependent manner. T cell recruitment induced by IL-15 requires expression of an intact IL-2Rβ chain, indicating that IL-15 operates in this context through the traditional IL-15R. The results suggest that IL-15 can regulate endothelial cell function and thereby enables a CD44-initiated adhesion pathway that facilitates entry of activated T lymphocytes into inflammatory sites. They further demonstrate a novel role for IL-15 (distinct from any of IL-2) in regulating microvascular endothelial cell adhesive function, help to understand the role of IL-15R expression on endothelium, and further support a central position for this cytokine in orchestrating multiple sequential aspects of T cell effector function and therefore chronic inflammatory processes.

scholarly journals Vasculotide, an Angiopoietin-1 mimetic, reduces acute skin ionizing radiation damage in a preclinical mouse model

2021 ◽  
Author(s):  
Elina Korpela ◽  
Darren Yohan ◽  
Lee CL Chin ◽  
Anthony Kim ◽  
Xiaoyong Huang ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Ionizing Radiation ◽  
Radiation Damage ◽  
Microvascular Endothelial Cell ◽  
Skin Damage ◽  
Cancer Radiotherapy ◽  
Microvascular Endothelial ◽  
Angiopoietin 1

Background Most cancer patients are treated with radiotherapy, but the treatment can also damage the surrounding normal tissue. Acute skin damage from cancer radiotherapy diminishes patients’ quality of life, yet effective biological interventions for this damage are lacking. Protecting microvascular endothelial cells from irradiation-induced perturbations is emerging as a targeted damage-reduction strategy. Since Angiopoetin-1 signaling through the Tie2 receptor on endothelial cells opposes microvascular perturbations in other disease contexts, we used a preclinical Angiopoietin-1 mimic called Vasculotide to investigate its effect on skin radiation toxicity using a preclinical model. Methods Athymic mice were treated intraperitoneally with saline or Vasculotide and their flank skin was irradiated with a single large dose of ionizing radiation. Acute cutaneous damage and wound healing were evaluated by clinical skin grading, histology and immunostaining. Diffuse reflectance optical spectroscopy, myeloperoxidase-dependent bioluminescence imaging of neutrophils and a serum cytokine array were used to assess inflammation. Microvascular endothelial cell response to radiation was tested with in vitro clonogenic and Matrigel tubule formation assays. Tumour xenograft growth delay experiments were also performed. Appreciable differences between treatment groups were assessed mainly using parametric and non-parametric statistical tests comparing areas under curves, followed by post-hoc comparisons. Results In vivo, different schedules of Vasculotide treatment reduced the size of the irradiation-induced wound. Although skin damage scores remained similar on individual days, Vasculotide administered post irradiation resulted in less skin damage overall. Vasculotide alleviated irradiation-induced inflammation in the form of reduced levels of oxygenated hemoglobin, myeloperoxidase bioluminescence and chemokine MIP-2. Surprisingly, Vasculotide-treated animals also had higher microvascular endothelial cell density in wound granulation tissue. In vitro, Vasculotide enhanced the survival and function of irradiated endothelial cells. Conclusions Vasculotide administration reduces acute skin radiation damage in mice, and may do so by affecting several biological processes. This radiation protection approach may have clinical impact for cancer radiotherapy patients by reducing the severity of their acute skin radiation damage.

scholarly journals Bovine Organospecific Microvascular Endothelial Cell Lines as New and Relevant In Vitro Models to Study Viral Infections

2020 ◽  
Vol 21 (15) ◽  
pp. 5249 ◽  
Author(s):  
Anne-Claire Lagrée ◽  
Fabienne Fasani ◽  
Clotilde Rouxel ◽  
Marine Pivet ◽  
Marie Pourcelot ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Lines ◽  
T Antigen ◽  
In Vitro Studies ◽  
Microvascular Endothelial Cell ◽  
Target Cells ◽  
Microvascular Endothelial

Microvascular endothelial cells constitute potential targets for exogenous microorganisms, in particular for vector-borne pathogens. Their phenotypic and functional variations according to the organs they are coming from provide an explanation of the organ selectivity expressed in vivo by pathogens. In order to make available relevant tools for in vitro studies of infection mechanisms, our aim was to immortalize bovine organospecific endothelial cells but also to assess their permissivity to viral infection. Using transfection with SV40 large T antigen, six bovine microvascular endothelial cell lines from various organs and one macrovascular cell line from an umbilical cord were established. They display their own panel of endothelial progenitor/mature markers, as assessed by flow cytometry and RT-qPCR, as well as the typical angiogenesis capacity. Using both Bluetongue and foot-and-mouth disease viruses, we demonstrate that some cell lines are preferentially infected. In addition, they can be transfected and are able to express viral proteins such as BTV8-NS3. Such microvascular endothelial cell lines bring innovative tools for in vitro studies of infection by viruses or bacteria, allowing for the study of host-pathogen interaction mechanisms with the actual in vivo target cells. They are also suitable for applications linked to microvascularization, such as anti-angiogenic and anti-tumor research, growing fields in veterinary medicine.

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