scholarly journals The Role of SOD2 in Maintaining Endothelial Cell Function in SCD

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 3563-3563
Author(s):  
Atinuke Dosunmu-Ogunbi ◽  
Yingze Zhang ◽  
Seyed Mehdi Nouraie ◽  
Adam Straub
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Barrier Function ◽  
Cell Permeability ◽  
Clinical Parameters ◽  
Cell Disease ◽  
Endothelial Cell Permeability

Sickle cell disease (SCD) is characterized by increased oxidative stress. Sources of oxidative stress include (1) intermittent vascular occlusion resulting in hypoxia-reoxygenation induced activation of prooxidant enzymes such as xanthine oxidase and NADPH oxidase, (2) increased fragility of red blood cell membranes causing hemolysis and release of free hemoglobin and heme which produce reactive oxygen species (ROS) through Fenton chemistry, and (3) respiratory chain leaked electrons reacting with oxygen to form superoxide. In SCD, the antioxidant defense system has been shown to be insufficient in its response to increased ROS production. In particular, peripheral blood expression of the mitochondrial targeted antioxidant superoxide dismutase 2 (SOD2) is decreased in SCD patients relative to non-sickle controls. We hypothesize that depletion of SOD2 may modify the progression of sickle pathology. In order to test our hypothesis we (Aim 1) genotyped 410 SCD patients from the Treatment of Pulmonary Hypertension and Sickle Cell Disease with Sildenafil Therapy (walk-PHaSST) study for a common polymorphism of SOD2 (rs4880), valine to alanine on the 16thamino acid (V16A), and investigated whether or not the polymorphism is associated with clinical indicators of endothelial dysfunction. (Aim 2) In primary human pulmonary arterial endothelial cells (hPAECs) we utilized an siRNA mediated knockdown of SOD2 (SOD2 KD) in order to examine its role in maintaining endothelial cell permeability. Permeability was measured by using electric-cell substrate impedance sensing (ECIS). In Aim 1, among the 410 SC anemia patients 129 (31%), 64 (16%) and 217 (53%) were homozygotes for the common valine allele (TT), homozygotes for the variant alanine allele (CC) and heterozygotes (TC), respectively. We examined association of each genotype with the following clinical parameters: history of pulmonary embolism, systolic blood pressure (SBP), pulse blood pressure, hemoglobin, mean corpuscular value, reticulocyte count, white blood cell count, platelet count, tricuspid regurgitant velocity (TRV), left mass index, right atrial area, left ventricle, right ventricular area at systolic, creatinine, six minute walk distance (6MWD). We found that homozygotes of alanine variant (CC) had higher systolic blood pressure (p=0.011), higher TRV (p=0.004), larger right ventricular area at systolic (p=0.023), as well as shorter 6MWD (p=0.006). All four of these clinical parameters are strong indicators of vasculopathy and endothelial damage. Based on our clinical findings, we extended our studies to isolated endothelial cells to define the role of SOD2 in endothelial cell permeability. In Aim 2, we used ECIS in order to measure resistance in SOD2 KD hPAECs. Decreased resistance as measured by ECIS has been shown to be an indicator of increased permeability. We found that SOD2 KD hPAECs had decreased baseline resistance as compared to hPAECs treated with a non-targeting siRNA sequence (siNT). This data supports that SOD2 plays a role in maintaining endothelial cell barrier function. We also, investigated whether free hemin would further accentuate endothelial barrier dysfunction in SOD2 KD cells. We serum starved siNT and siSOD2 KD hPAECs for four hours before treating with 2 mM hemin and measuring resistance. We found that after four hours of 2 mM hemin treatment, there was no further reduction of resistance in SOD2 KD hPAECs as compared to siNT hPAECs. In conclusion, we have found that in SCD patients SOD2 V16A is associated with clinically significant indicators of endothelial dysfunction and SOD2 is essential for the maintenance of endothelial cell barriers in hPAECs. Future directions will be aimed at further investigating the SOD2 V16A polymorphism, specifically we are interested in whether the polymorphism plays a role in barrier function. We will also investigate the pathways by which SOD2 depletion mediates endothelial cell barrier function. Taken together, our preliminary findings suggest that SOD2 functions as an essential mediator of endothelial function in SCD and thus can be used as a target for future SCD therapeutics. Disclosures Straub: Bayer Pharmaceuticals: Research Funding.

Signal transduction and regulation of lung endothelial cell permeability. Interaction between calcium and cAMP

1998 ◽  
Vol 275 (2) ◽  
pp. L203-L222 ◽  
Author(s):  
Timothy M. Moore ◽  
Paul M. Chetham ◽  
John J. Kelly ◽  
Troy Stevens
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Intracellular Signaling ◽  
Endothelial Permeability ◽  
Cell Permeability ◽  
Gap Formation ◽  
Pulmonary Endothelium ◽  
Intracellular Signals ◽  
Endothelial Cell Permeability ◽  
Cell Cell

Pulmonary endothelium forms a semiselective barrier that regulates fluid balance and leukocyte trafficking. During the course of lung inflammation, neurohumoral mediators and oxidants act on endothelial cells to induce intercellular gaps permissive for transudation of proteinaceous fluid from blood into the interstitium. Intracellular signals activated by neurohumoral mediators and oxidants that evoke intercellular gap formation are incompletely understood. Cytosolic Ca2+ concentration ([Ca2+]i) and cAMP are two signals that importantly dictate cell-cell apposition. Although increased [Ca2+]ipromotes disruption of the macrovascular endothelial cell barrier, increased cAMP enhances endothelial barrier function. Furthermore, during the course of inflammation, elevated endothelial cell [Ca2+]idecreases cAMP to facilitate intercellular gap formation. Given the significance of both [Ca2+]iand cAMP in mediating cell-cell apposition, this review addresses potential sites of cross talk between these two intracellular signaling pathways. Emerging data also indicate that endothelial cells derived from different vascular sites within the pulmonary circulation exhibit distinct sensitivities to permeability-inducing stimuli; that is, elevated [Ca2+]ipromotes macrovascular but not microvascular barrier disruption. Thus this review also considers the roles of [Ca2+]iand cAMP in mediating site-specific alterations in endothelial permeability.

scholarly journals Role of ADAMs in Endothelial Cell Permeability

2008 ◽  
Vol 102 (10) ◽  
pp. 1139-1142 ◽  
Author(s):  
Bharathy Ponnuchamy ◽  
Raouf A. Khalil
Keyword(s):  
Endothelial Cell ◽  
Cell Permeability ◽  
Endothelial Cell Permeability

scholarly journals Essential Role of a Ca 2+ -Selective, Store-Operated Current ( I SOC ) in Endothelial Cell Permeability

2005 ◽  
Vol 96 (8) ◽  
pp. 856-863 ◽  
Author(s):  
Songwei Wu ◽  
Eugene A. Cioffi ◽  
Diego Alvarez ◽  
Sarah L. Sayner ◽  
Hairu Chen ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Essential Role ◽  
Cell Permeability ◽  
Endothelial Cell Permeability

Endothelial cell P-selectin mediates a proinflammatory and prothrombogenic phenotype in cerebral venules of sickle cell transgenic mice

2004 ◽  
Vol 286 (5) ◽  
pp. H1608-H1614 ◽  
Author(s):  
Katherine C. Wood ◽  
Robert P. Hebbel ◽  
D. Neil Granger
Keyword(s):  
Bone Marrow ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Sickle Cell ◽  
Leukocyte Adhesion ◽  
Chimeric Mice ◽  
Wild Type ◽  
Cell Disease ◽  
Adhesion Of Platelets

Whereas the adhesion of leukocytes and erythrocytes to vascular endothelium has been implicated in the vasooclusive events associated with sickle cell disease, the role of platelet-vessel wall interactions in this process remains undefined. The objectives of this study were to: 1) determine whether the adhesion of platelets and leukocytes in cerebral venules differs between sickle cell transgenic (βS) mice and their wild-type (WT) counterparts (C57Bl/6) under both resting and posthypoxic conditions, and 2) define the contributions of P-selectin to these adhesion processes. Animals were anesthetized, and platelet and leukocyte interactions with endothelial cells of cerebral postcapillary venules were monitored and quantified using intravital fluorescence microscopy in WT, βS, and chimeric mice produced by transplanting bone marrow from WT or βSmice into WT or P-selectin-deficient (P-sel–/–) mice. Platelet and leukocyte adhesion to endothelial cells in both unstimulated and posthypoxic βSmice were significantly elevated over WT levels. Chimeric mice involving bone marrow transfer from βSmice to P-sel–/–mice exhibited a profound attenuation of both platelet and leukocyte adhesion compared with βSbone marrow transfer to WT mice. These findings indicate that βSmice assume both an inflammatory and prothrombogenic phenotype, with endothelial cell P-selectin playing a major role in mediating these microvascular responses.

scholarly journals Pathogenic Hantaviruses Andes Virus and Hantaan Virus Induce Adherens Junction Disassembly by Directing Vascular Endothelial Cadherin Internalization in Human Endothelial Cells

2010 ◽  
Vol 84 (14) ◽  
pp. 7405-7411 ◽  
Author(s):  
Elena Gorbunova ◽  
Irina N. Gavrilovskaya ◽  
Erich R. Mackow
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Adherens Junctions ◽  
Paracellular Permeability ◽  
Cell Permeability ◽  
Hantaan Virus ◽  
Vascular Endothelial ◽  
Vascular Endothelial Cadherin ◽  
Andes Virus ◽  
Endothelial Cell Permeability

ABSTRACT Hantaviruses infect endothelial cells and cause 2 vascular permeability-based diseases. Pathogenic hantaviruses enhance the permeability of endothelial cells in response to vascular endothelial growth factor (VEGF). However, the mechanism by which hantaviruses hyperpermeabilize endothelial cells has not been defined. The paracellular permeability of endothelial cells is uniquely determined by the homophilic assembly of vascular endothelial cadherin (VE-cadherin) within adherens junctions, which is regulated by VEGF receptor-2 (VEGFR2) responses. Here, we investigated VEGFR2 phosphorylation and the internalization of VE-cadherin within endothelial cells infected by pathogenic Andes virus (ANDV) and Hantaan virus (HTNV) and nonpathogenic Tula virus (TULV) hantaviruses. We found that VEGF addition to ANDV- and HTNV-infected endothelial cells results in the hyperphosphorylation of VEGFR2, while TULV infection failed to increase VEGFR2 phosphorylation. Concomitant with the VEGFR2 hyperphosphorylation, VE-cadherin was internalized to intracellular vesicles within ANDV- or HTNV-, but not TULV-, infected endothelial cells. Addition of angiopoietin-1 (Ang-1) or sphingosine-1-phosphate (S1P) to ANDV- or HTNV-infected cells blocked VE-cadherin internalization in response to VEGF. These findings are consistent with the ability of Ang-1 and S1P to inhibit hantavirus-induced endothelial cell permeability. Our results suggest that pathogenic hantaviruses disrupt fluid barrier properties of endothelial cell adherens junctions by enhancing VEGFR2-VE-cadherin pathway responses which increase paracellular permeability. These results provide a pathway-specific mechanism for the enhanced permeability of hantavirus-infected endothelial cells and suggest that stabilizing VE-cadherin within adherens junctions is a primary target for regulating endothelial cell permeability during pathogenic hantavirus infection.

Role of Macrophage Stimulating Protein 1 (MSP1) in the Development of Glomerulopathy in Sickle Cell Disease

Blood ◽  
2015 ◽  
Vol 126 (23) ◽  
pp. 4583-4583
Author(s):  
Marina Jerebtsova ◽  
Elena Afia Adjei ◽  
Alfia Khaibullina ◽  
Zena Quezado ◽  
Sergei A. Nekhai
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Ischemia Reperfusion ◽  
Cell Disease ◽  
Macrophage Stimulating Protein ◽  
Capillary Formation ◽  
Glomerular Lesions

Abstract Background More than 50% patients with sickle cell disease (SCD) develop renal glomerular disease. Its pathophysiology is likely to be multifactorial, being affected by hyperfiltration, glomerular hypertension, ischemia-reperfusion injury, oxidative stress, and endothelial dysfunction. Ischemia-reperfusion is associated with significant recruitment of glomerular and interstitial macrophages. Recently, Macrophage Stimulating Protein 1 (MSP1) was shown to be involved in the development of anti-Thy1 glomerulonephritis in rat model that also associated with renal macrophages infiltration. MSP1 is produced by the liver and secreted into the circulation as a non-active protein. It is cleaved and activated locally by a macrophage membrane-associated proteinase. We hypothesesize that infiltrating macrophages in SCD activate MSP1 protein that accumulates in the renal glomeruli and induces endothelial cell and podocytes injury. Objective We analyzed MSP1 expression in vivo in SCD mouse model and the effect of recombinant MSP1 on cultured human podocytes and endothelial cells. Methods Transgenic SCD mice were obtained from Jackson Laboratory (B6;129-Hbatm1(HBA)Tow Hbbtm2(HBG1,HBB*)Tow/Hbbtm3(HBG1,HBB)Tow/J Townes strain). Townes mice produce approximately 94% human sickle (HbS), 6% human fetal hemoglobin (HbF), and no murine hemoglobin. Control animals are carrying two copies of the transgene encoding human α1-globin gene and two copies of the Hbbtm3(HBG1,HBB)Tow mutation (human hemoglobin gamma (Aγ) gene and the human wildtype hemoglobin beta (βA) gene). Townes mice spontaneously develop renal glomerular lesions. Kidneys were collected from 5 months old mice and immunohistochemistry (IHC) was carried to detect macrophages, endothelial cells (CD34), podocytes (WT-1) and MSP1. Human glomerular endothelial cell line (HGEC) and two human podocyte lines (PD1 and PD2) were treated with recombinant MCP1 and the cellular motility, permeability, growth and capillary formation were analyzed. Results SCD mice developed focal segmental glomerulosclerosis. It was associated with glomerular capillary aneurisms, loss of podocytes and increased macrophages infiltration. IHC demonstrated accumulation of MSP1 in the capillaries of affected glomeruli. In vitro, MSP1 treatment increased motility of both endothelial cells and podocytes. In addition, MSP1 significantly reduced podocytes growth and viability. MSP1 also inhibited capillary formation by endothelial cells on Matrigel. Conclusion Activated MSP1 is likely to be involved in the development of glomerular lesions in SCD which could be due to the modulation of endothelial cell and podocytes function. Further analysis is needed to elucidate the role of MSP1 in the development of glomerular disease in humans. Acknowledgments This work was supported by NIH Research Grants (1P50HL118006, 1R01HL125005 and 5G12MD007597). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health. Disclosures No relevant conflicts of interest to declare.

scholarly journals Hantaviruses Direct Endothelial Cell Permeability by Sensitizing Cells to the Vascular Permeability Factor VEGF, while Angiopoietin 1 and Sphingosine 1-Phosphate Inhibit Hantavirus-Directed Permeability

2008 ◽  
Vol 82 (12) ◽  
pp. 5797-5806 ◽  
Author(s):  
Irina N. Gavrilovskaya ◽  
Elena E. Gorbunova ◽  
Natalie A. Mackow ◽  
Erich R. Mackow
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Vascular Permeability ◽  
Cell Permeability ◽  
Hemorrhagic Disease ◽  
Αvβ3 Integrin ◽  
Endothelial Cell Permeability ◽  
Sphingosine 1 Phosphate ◽  
Permeability Assay ◽  
Angiopoietin 1

ABSTRACT Hantaviruses infect human endothelial cells and cause two vascular permeability-based diseases: hemorrhagic fever with renal syndrome and hantavirus pulmonary syndrome. Hantavirus infection alone does not permeabilize endothelial cell monolayers. However, pathogenic hantaviruses inhibit the function of αvβ3 integrins on endothelial cells, and hemorrhagic disease and vascular permeability deficits are consequences of dysfunctional β3 integrins that normally regulate permeabilizing vascular endothelial growth factor (VEGF) responses. Here we show that pathogenic Hantaan, Andes, and New York-1 hantaviruses dramatically enhance the permeability of endothelial cells in response to VEGF, while the nonpathogenic hantaviruses Prospect Hill and Tula have no effect on endothelial cell permeability. Pathogenic hantaviruses directed endothelial cell permeability 2 to 3 days postinfection, coincident with pathogenic hantavirus inhibition of αvβ3 integrin functions, and hantavirus-directed permeability was inhibited by antibodies to VEGF receptor 2 (VEGFR2). These studies demonstrate that pathogenic hantaviruses, similar to αvβ3 integrin-deficient cells, specifically enhance VEGF-directed permeabilizing responses. Using the hantavirus permeability assay we further demonstrate that the endothelial-cell-specific growth factor angiopoietin 1 (Ang-1) and the platelet-derived lipid mediator sphingosine 1-phosphate (S1P) inhibit hantavirus directed endothelial cell permeability at physiologic concentrations. These results demonstrate the utility of a hantavirus permeability assay and rationalize the testing of Ang-1, S1P, and antibodies to VEGFR2 as potential hantavirus therapeutics. The central importance of β3 integrins and VEGF responses in vascular leak and hemorrhagic disease further suggest that altering β3 or VEGF responses may be a common feature of additional viral hemorrhagic diseases. As a result, our findings provide a potential mechanism for vascular leakage after infection by pathogenic hantaviruses and the means to inhibit hantavirus-directed endothelial cell permeability that may be applicable to additional vascular leak syndromes.

rhAPC reduces the endothelial cell permeability via a decrease of contractile tensions induced by endothelial cells

2012 ◽  
Vol 114 (2) ◽  
pp. 212-219
Author(s):  
Eylem Kurulgan Demirci ◽  
Taylan Demirci ◽  
Peter Linder ◽  
Juergen Trzewik ◽  
Jessica Ricarda Gierkowski ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Permeability ◽  
Endothelial Cell Permeability

Abstract 347: Endothelin-1 Regulates Molecules of the Major Histocompatibility Complex: Role in Sickle Cell Disease

2016 ◽  
Vol 36 (suppl_1) ◽  
Author(s):  
Isamar Alicea ◽  
Daniel Gil de Lamadrid ◽  
Analaura Santiago ◽  
Joshua Cazares ◽  
Shirley Valentin ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Major Histocompatibility Complex ◽  
Endothelial Cell ◽  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Major Histocompatibility ◽  
Cell Disease ◽  
Endothelin 1 ◽  
Histocompatibility Complex

Sickle Cell Disease (SCD) is characterized, in part, by vascular endothelial cell activation, increased oxidative stress and sickle cell adhesion. Excess levels of the vasoconstrictor, endothelin-1 (ET-1), activate endothelial cells, induce oxidative stress and inflammation in the vascular wall and regulate erythrocyte homeostasis, in part, via activation of protein disulfide isomerase (PDI). We measured circulating ET-1, TGFβ1 and PDI activity in two sickle transgenic knockout mouse models expressing human sickle hemoglobin (Hb), BERK and βS Antilles . We observed significant increases in all three markers (n=6; p<0.01) when compared to either C57BL/J6 mice or knockout mice expressing normal human Hb A. We then intraperitoneally injected BERK mice for 14 days with ET-1 receptor antagonists and observed significant reductions in these circulating markers (n=6; p<0.05). These studies are important as PDI is proposed to control hemostasis, thrombosis and is reported to regulate the major histocompatibility complex (MHC). In addition, activated endothelial cells express PDI and MHC. However, the relationship between ET-1 and MHC in SCD remains unclear. We characterized the role of ET-1 on MHC expression in the endothelial cell line, EA.hy926. We observed dose-dependent increases in the expression of MHC class I (HLA-A2 4.8 ± 2.1 folds p<0.01 n=4), MHC class II (HLA-DR 4.4 ± 1.7 folds p<0.01 n=4) and MHC transcription factor (CIITA 3.5 ± 1.8 folds p<0.05 n=4) in EA.hy926 cells. Increased expression of MHC was significantly blocked by co-incubation of cells with 10μM BQ788, a selective blocker of ET-1 type B receptors. Chromatin immunoprecipitation studies showed that ET-1 incubation produced an increase in Histone H3 acetylation of the promoter in MHC molecules (HLA-A2 4.6 ± 1.4 folds, HLA-DRB 6.0 ± 0.7 folds, p<0.01, n=3) in these cells; an event that was likewise blocked by BQ788. In addition, ET-1 stimulated recruitment of CIITA to the promoter of HLA-A2 (1.9 ± 0.7 folds, p<0.05, n=3) and HLA-DRB (3.0 ± 0.6 folds, p<0.01, n=3). These results implicate ET-1 as a novel regulator of MHC promoter activity and suggest that ET-1 receptor blockade represents an important therapeutic approach to improve both the inflammatory and vascular complications of SCD.

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