Abstract 665: Activation of Histone Deacetylase 2: A Novel Strategy for Reversing Vascular Dysfunction in Atherogenesis

2014 ◽  
Vol 34 (suppl_1) ◽  
Author(s):  
Deepesh Pandey ◽  
Gautam Sikka ◽  
Yehudis Bergman ◽  
Jae H Kim ◽  
Sungwoo Ryoo ◽  
...  
Keyword(s):  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Cell Activation ◽  
Vascular Dysfunction ◽  
Hdac Inhibitors ◽  
Ros Production ◽  
Promoter Regions ◽  
Endothelial Cell Activation ◽  
Novel Therapy ◽  
Histone Deacetylase 2

Arginase 2 is a critical target in atherosclerosis as it regulates both endothelial NO, fibrosis and inflammation. The increase in Arg2 activity with endothelial cell activation is dependent on both early post-translational dependent mechanisms as well as a later increase in Arg 2 expression. The regulators of Arg2 transcription in the endothelium have not been characterized. The goal of current study is to determine the role of specific HDACs in the regulation of endothelial Arg2 transcription and thereby endothelial function. The global HDAC inhibitor, trichostatin (TSA) both time and concentration-dependently increased Arg2 mRNA, protein levels and activity in both HAECs and mouse aortic rings, a process that leads to Arg2-dependent endothelial dysfunction. TSA and atherogenic stimulus enhances activity of common promoter regions of Arg 2. All non-selective Class I HDAC inhibitors (TSA, Scriptaid, varinostat) enhanced Arg2 expression, while only the, the HDCA 1 and 2 selective inhibitor, mocetinostat (MGCD) enhances Arg2 expression. Overexpression of HDAC 2, 3 or 8 in HAECs have no effect on Arg 2 expression while HDAC2 cDNA overexpression concentration-dependently suppresses Arg2 expression. Conversely, siRNA knockdown of HDAC2 enhances Arg2 expression. Additionally like TSA, mouse aortic rings pre-incubated with MGCD resulted in endothelial dysfunction. Finally HDAC inhibition with TSA decreased endothelial NO and increased ROS production in an arginase-inhibitable manner. In conclusion, HDAC2 is critical regulator of Arg2 expression thereby regulating endothelial NO and ROS production, and consequently endothelial function. Overexpression or activation of HDAC2 thus represents a novel therapy for the prevention and treatment of endothelial dysfunction and atherosclerosis.

scholarly journals Age-associated pro-inflammatory adaptations of the mouse thoracic aorta

2013 ◽  
Vol 110 (10) ◽  
pp. 785-794 ◽  
Author(s):  
Bianca Hemmeryckx ◽  
Marc F. Hoylaerts ◽  
Eveline Deloose ◽  
Cor E. Van Hove ◽  
Paul Fransen ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Thoracic Aorta ◽  
Cell Activation ◽  
Aortic Ring ◽  
Ros Production ◽  
Endothelial Protein C Receptor ◽  
Endothelial Cell Activation ◽  
Nadph Oxidase 4 ◽  
Inflammatory State ◽  
Factor Α

SummaryArterial ageing may be associated with a reduction in vasodilation due to increased reactive oxygen species (ROS) production, whereas endothelial cell activation induces procoagulant changes. However, little is known on the effect of ageing on expression of anticoagulant endothelial markers such as endothelial protein C receptor (EPCR). To study age-associated alterations in smooth muscle cell (SMC) and endothelial cell (EC) structure and function, the aorta was isolated from 10-week-and 12– and 24-month-old C57BL/6J mice and analysed for its expression of genes involved in senescence, oxidative stress production, coagulation and matrix remodelling. In addition, vasorelaxation experiments were performed using 10-week-and 24-month-old thoracic aortic ring segments in organ chamber baths. The media thickness of the thoracic aorta progressively increased with age, associated with hypertrophy of vascular SMCs. Basal nitric oxide production and sensitivity to acetylcholine-mediated vasodilation in thoracic aorta rings was reduced with age, whereas no significant differences in ROS production could be demonstrated. Gene expression of tissue factor, EPCR and von Willebrand factor was not affected by ageing of the aorta, whereas that of thrombomodulin was mildly reduced and that of xanthine dehydrogenase, NADPH oxidase 4, tumour necrosis factor-α and vascular cell adhesion molecule-1 significantly enhanced. In conclusion, a reduction in endothelial cell-mediated vasodilation in aged thoracic aortas of C57BL/6J mice was accompanied by a shift towards a pro-inflammatory state of the endothelium.

CD14+CD16++ “nonclassical” monocytes are associated with endothelial dysfunction in patients with coronary artery disease

2017 ◽  
Vol 117 (05) ◽  
pp. 971-980 ◽  
Author(s):  
Karol Urbanski ◽  
Dominik Ludew ◽  
Grzegorz Filip ◽  
Magdalena Filip ◽  
Agnieszka Sagan ◽  
...  
Keyword(s):  
Coronary Artery Disease ◽  
Coronary Artery ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Mononuclear Cells ◽  
Vascular Dysfunction ◽  
Activation Markers ◽  
Mammary Arteries ◽  
No Bioavailability ◽  
Artery Disease

SummaryEndothelial dysfunction and inflammation are key mechanisms of vascular disease. We hypothesised that heterogeneity of monocyte subpopulations may be related to the development of vascular dysfunction in coronary artery disease (CAD). Therefore, we examined the relationships between monocyte subsets (CD14++CD16– “classical – Mon1”, CD14++CD16+ “intermediate – Mon2” and CD14+CD16++ “nonclassical – Mon3”), endothelial function and risk factor profiles in 130 patients with CAD undergoing coronary artery bypass grafting. This allowed for direct nitric oxide (NO) bioavailability assessment using isometric tension studies ex vivo (acetylcholine; ACh- and sodium- nitropruside; SNP-dependent) in segments of internal mammary arteries. The expression of CD14 and CD16 antigens and activation markers were determined in peripheral blood mononuclear cells using flow cytometry. Patients with high CD14+CD16++ “nonclassical” and low CD14++CD16- “classical” monocytes presented impaired endothelial function. High frequency of CD14+CD16++ “nonclassical” monocytes was associated with increased vascular superoxide production. Furthermore, endothelial dysfunction was associated with higher expression of activation marker CD11c selectively on CD14+CD16++ monocytes. Nonclassical and classical monocyte frequencies remained independent predictors of endothelial dysfunction when major risk factors for atherosclerosis were taken into account (β =0.18 p=0.04 and β =-0.19 p=0.03, respectively). In summary, our data indicate that CD14+CD16++ “nonclassical” monocytes are associated with more advanced vascular dysfunction measured as NO-bioavailability and vascular reactive oxygen species production.

Abstract 66: The Role of the Viral Nef Protein as a Mediator of HIV-1--Induced Endothelial Dysfunction

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Ting Wang
Keyword(s):  
Cardiovascular Disease ◽  
T Cells ◽  
Endothelial Cells ◽  
Endothelial Cell ◽  
Endothelial Dysfunction ◽  
Binding Site ◽  
Cell Activation ◽  
Endothelial Activation ◽  
Endothelial Cell Activation ◽  
Hiv 1

With the prevalence of antiviral therapy in the developed world, many HIV-1-infected people die of diseases other than AIDS. One of the emerging major causes is cardiovascular disease, leading to the prediction that the majority of HIV-1 patients are expected to develop cardiovascular complications. Endothelial dysfunction is thought to be a key event in the development of cardiovascular diseases, particularly atherosclerosis. Assays testing the effect of HIV-1 on endothelial activation shows that direct contact with HIV-1 infected T cells enhance endothelial cell activation to a greater extent than HIV-1 alone, suggesting an intracellular HIV-1 protein is responsible for endothelial activation. The HIV-1 viral protein Nef, which is responsible for T cell activation and maintenance of high viral loads in vivo , has been shown to mediate its own transfer to bystander cells. We demonstrate here for the first time that Nef induces nanotube-like conduits connecting T cells and endothelial cells. We also show that Nef is transferred from T cells to endothelial cells via these nanotubes, and is necessary and sufficient for endothelial cell activation. Moreover, we show that SIV-infected macaques exhibit endothelial Nef expression in coronary arteries. Nef expression in endothelial cells causes endothelial apoptosis, ROS and MCP-1 production. Interestingly, a Nef SH3 binding site mutant abolishes Nef-induced apoptosis and ROS formation and reduces MCP-1 production in endothelial cells, suggesting that the Nef SH3 binding site is critical for Nef effects on endothelial cells. Nef induces apoptosis of endothelial cells through an NADPH oxidase- and ROS-dependent mechanism, while Nef-induced MCP-1 production is NF-kB dependent. Taken together, these data suggest that Nef can mediate its transfer from T cells to endothelial cells through nanotubes to enhance endothelial dysfunction.Thus, Nef is a promising new therapeutic target for reducing the risk for cardiovascular disease in the HIV-1 positive population.

scholarly journals The Role of Endothelial Microparticle in Coronary Heart Disease as The Complications of Diabetes Mellitus

2019 ◽  
Vol 4 (1) ◽  
pp. 31-39
Author(s):  
Eka Fithra Elfi ◽  
Yose Ramda Ilhami ◽  
Eryati Darwin
Keyword(s):  
Nitric Oxide ◽  
Diabetes Mellitus ◽  
Coronary Heart Disease ◽  
Heart Disease ◽  
Endothelial Dysfunction ◽  
Cell Activation ◽  
Inflammatory Factors ◽  
Endothelial Cell Activation ◽  
Complications Of Diabetes

  Coronary heart disease (CHD) is caused by obstruction of coronary blood flow due to endothelial dysfunction triggered by various genetic and non-genetic risk factors such as hyperlipidemia, hypertension, hyperglycemia and obesity. Endothelial cell activation due to hyperglycaemia in diabetes mellitus induces production of pro-inflammatory factors that damage the cell membrane triggering the formation of membrane particles called microparticles. Endothe-lial microparticles contain proteins including endothelial nitric oxide synthase (eNOS) which plays a role in the production of nitric oxide (NO). To determine the role of microparticles in the occurrence of coro-nary heart disease in diabetes mellitus due to endothelial dysfunction, a study was conducted by comparing the levels of eNOS and NO in DM patients who had CHD with DM patients who had no CHD. Blood samples from 20 DM patients who had CHD and 20 DM patients who had no CHD of the outpatients in Cardiology Department and Inter-nal Medicine department of regional public hospital were included in this study. All patients were fulfilled inclusion and exclusion criteria and diagnosed by the appropriate specialist. The eNOS and NO lev-els were measured using the ELISA method. The results of this study show that eNOS levels in the group of DM patients who had CHD (21,292±12,415 ng/ml) were significantly lower (p <0.05) than those in the group of DM patients who had no CHD (29,721±11,952 ng/ml). Nitric oxide levels in DM patients who had CHD (0,053±0,021 nmol/ μl) were not statistically different to the levels in DM patients who had no CHD (0,047±0,032 nmol/μl). From the results of this study we concluded that endothelial microparticle protein eNOS plays a role in the occurrence of CHD due to the complications of diabetes mellitus 

scholarly journals Endothelial Dysfunction: Is There a Hyperglycemia-Induced Imbalance of NOX and NOS?

2019 ◽  
Vol 20 (15) ◽  
pp. 3775 ◽  
Author(s):  
Cesar A. Meza ◽  
Justin D. La Favor ◽  
Do-Houn Kim ◽  
Robert C. Hickner
Keyword(s):  
Type 2 Diabetes ◽  
Cardiovascular Disease ◽  
Blood Flow ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Vascular Dysfunction ◽  
Vascular Complications ◽  
Enzymatic Production

NADPH oxidases (NOX) are enzyme complexes that have received much attention as key molecules in the development of vascular dysfunction. NOX have the primary function of generating reactive oxygen species (ROS), and are considered the main source of ROS production in endothelial cells. The endothelium is a thin monolayer that lines the inner surface of blood vessels, acting as a secretory organ to maintain homeostasis of blood flow. The enzymatic production of nitric oxide (NO) by endothelial NO synthase (eNOS) is critical in mediating endothelial function, and oxidative stress can cause dysregulation of eNOS and endothelial dysfunction. Insulin is a stimulus for increases in blood flow and endothelium-dependent vasodilation. However, cardiovascular disease and type 2 diabetes are characterized by poor control of the endothelial cell redox environment, with a shift toward overproduction of ROS by NOX. Studies in models of type 2 diabetes demonstrate that aberrant NOX activation contributes to uncoupling of eNOS and endothelial dysfunction. It is well-established that endothelial dysfunction precedes the onset of cardiovascular disease, therefore NOX are important molecular links between type 2 diabetes and vascular complications. The aim of the current review is to describe the normal, healthy physiological mechanisms involved in endothelial function, and highlight the central role of NOX in mediating endothelial dysfunction when glucose homeostasis is impaired.

Polynitroxyl Albumin Prevents Vaso-Occlusion in Transgenic Sickle Mice.

Blood ◽  
2004 ◽  
Vol 104 (11) ◽  
pp. 366-366 ◽  
Author(s):  
Hemchandra Mahaseth ◽  
John D. Belcher ◽  
Thomas E. Welch ◽  
Khalid M. Sonbol ◽  
Paul R. Bowlin ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Sickle Cell ◽  
Adhesion Molecule ◽  
Vascular Endothelium ◽  
Cell Activation ◽  
Ros Production ◽  
Dorsal Skin ◽  
Cell Disease ◽  
Endothelial Cell Activation ◽  
Hypoxia Reoxygenation

Abstract Sickle cell disease is characterized by excessive oxidative stress. Sickle patients have enhanced rates of endogenous reactive oxygen species (ROS) production and impaired antioxidant defense mechanisms. We hypothesize that excessive production of ROS promotes activation of vascular endothelium and vaso-occlusion in sickle cell disease. Intravascular ROS production has been shown to trigger the activation of vascular endothelium and increase leukocyte-endothelium interactions. We investigated whether inhibition of intravascular ROS production by treatment with polynitroxyl albumin (PNA), a superoxide dismutase and catalase mimetic agent, could modulate endothelial cell activation and vaso-occlusion in S+S Antilles transgenic sickle mice after hypoxia-reoxygenation. Nuclear factor-kappa B (NF-kB), an oxidant sensitive transcription factor critical for endothelial cell activation, was elevated in lungs and livers of sickle mice and was reduced 2.5 (p=0.043) and 1.5 (p=0.043) fold respectively, by treatment with PNA after hypoxia-reoxygenation. Similarly, vascular cell adhesion molecule-1 (VCAM-1) and intercellular adhesion molecule-1 (ICAM-1) were elevated 3 to 4.7 fold in the same organs (p<0.05). After treatment with PNA, VCAM-1 expression was reduced 2.3 fold in lungs (p=0.014) and 1.5 fold in livers (p=0.006), ICAM-1 expression decreased 1.7 fold in lungs (p=0.014) and 2 fold in livers (p=0.007). Control studies using human serum albumin had no effect on NF-kB activation or adhesion molecule expression in sickle mice. These anti-inflammatory effects of PNA on endothelium corresponded with changes in blood flow in dorsal skin venules. Intravital microscopy revealed that PNA significantly inhibited hypoxia-reoxygenation-induced leukocyte rolling (3.8 fold inhibition, p<0.001) and completely inhibited vaso-occlusion (p<0.001) in venules in the dorsal skin of transgenic sickle mice. We speculate that therapies that reduce ROS will result in improved organ perfusion in sickle cell disease.

Gas6 Regulates Thrombin-Induced of VCAM-1 Expression by a FoxO1 Dependent Mechanism

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 5192-5192
Author(s):  
Richard Robins ◽  
Catherine A. Lemarie ◽  
Mark D. Blostein
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Venous Thrombosis ◽  
Cell Biology ◽  
Cell Activation ◽  
Conflicts Of Interest ◽  
Vascular Dysfunction ◽  
Soluble Form ◽  
Endothelial Cell Activation

Abstract Abstract 5192 Forkhead proteins play a broad role in endothelial cell biology. These factors mediate cell adhesion to extracellular matrix, regulate the expression of pro-inflammatory and pro-thrombotic genes, and participate in cell repair, proliferation and apoptosis. FoxOs are known downstream targets of the PI3K/Akt signaling pathway. Phosphorylation of FoxO transcription factors results in their translocation from the nucleus to the cytoplasm, thereby inhibiting their transcriptional activity. It has recently been shown that the deletion of the three FoxO isoforms in endothelial cells protects mice from vascular dysfunction. Gas6, a member of the vitamin K-dependent family of proteins, has been shown to protect endothelial cells from apoptosis and promote endothelial cell activation in vivo. It has been shown that the expression of ICAM-1 and VCAM-1 were blunted in the absence of gas6. Interestingly, a role for VCAM-1 in the pathogenesis of venous thrombosis has been proposed. Elevated levels of the soluble form of VCAM-1 have been detected in the serum of patients with venous thrombosis. We previously demonstrated that the anti-apoptotic effect of gas6 was mediated partially through FoxO1, but overall, the signalling mechanisms occurring downstream of gas6 remain largely unknown. We hypothesize that gas6 promotes thrombin-induced VCAM-1 expression through the regulation of FoxO1 in endothelial cells. Western blot analysis demonstrated that thrombin induced time dependent phosphorylation of FoxO1 with a maximum at 30 minutes in WT (p<0. 05) but not in gas6 deficient (−/−) cells. In addition, thrombin reduced the nuclear content of FoxO in WT (p<0. 05) but not in gas6−/− endothelial cells. Using qPCR, we found that mRNA expression of VCAM-1 was increased after 30 minutes of stimulation with thrombin in WT cells (p<0. 05). More importantly, thrombin-mediated induction of VCAM-1 was blunted in gas6−/− endothelial cells. We found that FoxO1 siRNA increased basal VCAM-1 expression in WT endothelial cells. Taken together, our data demonstrate that gas6 is a crucial mediator of FoxO1 that regulates thrombin-induced VCAM-1 expression. This pathway may explain the pro-thrombotic and pro-inflammatory role of gas6. Disclosures: No relevant conflicts of interest to declare.

scholarly journals Antioxidant Treatment Reverts Increased Arterial Basal Tone and Oxidative Stress in Nephrectomized (5/6) Hypertensive Rats

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Rodrigo O. Marañón ◽  
Claudio Joo Turoni ◽  
Maria Sofia Karbiner ◽  
Nicolas Salas ◽  
Maria Peral de Bruno
Keyword(s):  
Oxidative Stress ◽  
Endothelial Dysfunction ◽  
Endothelial Function ◽  
Vascular Dysfunction ◽  
Sprague Dawley ◽  
Sprague Dawley Rats ◽  
Basal Tone ◽  
No Bioavailability

Nonischemic 5/6 nephrectomized rat (NefR) is a model of chronic kidney disease. However, little is known about vascular dysfunction and its relation with hypertension in NefR.Aims. To evaluate possible alterations of endothelial function, NO-bioavailability, and basal tone in aorta from NefR and the role of oxidative stress. Sprague Dawley rats were divided into sham rats (SR), NefR, and NefR treated with tempol (NefR-T). Mean arterial pressure (MAP) and renal function were determined. In isolated aortic rings the following was measured: 1-endothelial function, 2-basal tone, 3-NO levels, 4-membrane potential (MP), and 5-oxidative stress. NefR increased MAP (SR: 119 ± 4 mmHg;n=7; NefR: 169 ± 6;n=8;P<0.001). Tempol did not modify MAP (NefR-T: 168 ± 10;n=6;P<0.001). NefR showed endothelial dysfunction, increased basal tone and decreased NO levels (SR: 32 ± 2 nA;n=7, NefR: 10 ± 2;n=8;P<0.001). In both in vitro and in vivo tempol improves basal tone, NO levels, and MP. Oxidative stress in NefR was reverted in NefR-T. We described, for the first time, that aorta from NefR presented increased basal tone related to endothelial dysfunction and decreased NO-bioavailability. The fact that tempol improves NO-contents and basal tone, without decrease MAP, indicates that oxidative stress could be implicated early and independently to hypertension, in the vascular alterations.

THE ROLE OF INFLAMMATION AND ENDOTHELIAL CELL ACTIVATION IN HYPERTENSIVE CHILDREN WITH ENDOTHELIAL DYSFUNCTION

2011 ◽  
Vol 29 ◽  
pp. e337
Author(s):  
M. Andor ◽  
O. Margineanu ◽  
M. Tomescu ◽  
D. Lighezan ◽  
R. Christodorescu ◽  
...  
Keyword(s):  
Endothelial Cell ◽  
Endothelial Dysfunction ◽  
Cell Activation ◽  
Endothelial Cell Activation
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