Risk factors for increased immune reconstitution in response to Mycobacterium tuberculosis antigens in tuberculosis HIV-infected, antiretroviral-naïve patients.

PubMed

da Silva, Tatiana Pereira; Giacoia-Gripp, Carmem Beatriz Wagner; Schmaltz, Carolina A; Sant'Anna, Flavia Marinho; Saad, Maria Helena; Matos, Juliana Arruda de; de Lima E Silva, Julio Castro Alves; Rolla, Valeria Cavalcanti; Morgado, Mariza Gonçalves

2017-09-06

Little is known regarding the restoration of the specific immune response after combined antiretroviral therapy (cART) and anti-tuberculosis (TB) therapy introduction among TB-HIV patients. In this study, we examined the immune response of TB-HIV patients to Mycobacterium tuberculosis (Mtb) antigens to evaluate the response dynamics to different antigens over time. Moreover, we also evaluated the influence of two different doses of efavirenz and the factors associated with immune reconstitution. This is a longitudinal study nested in a clinical trial, where cART was initiated during the baseline visit (D0), which occurred 30 ± 10 days after the introduction of anti-TB therapy. Follow-up visits were performed at 30, 60, 90 and 180 days after cART initiation. The production of IFN-γ upon in vitro stimulation with Mtb antigens purified protein derivative (PPD), ESAT-6 and 38 kDa/CFP-10 using ELISpot was examined at baseline and follow-up visits. Sixty-one patients, all ART-naïve, were selected and included in the immune reconstitution analysis; seven (11.5%) developed Immune Reconstitution Inflammatory Syndrome (IRIS). The Mtb specific immune response was higher for the PPD antigen followed by 38 kDa/CFP-10 and increased in the first 60 days after cART initiation. In multivariate analysis, the variables independently associated with increased IFN-γ production in response to PPD antigen were CD4 + T cell counts <200 cells/mm 3 at baseline, age, site of tuberculosis, 800 mg efavirenz dose and follow-up CD4 + T cell counts. Moreover, the factors associated with the production of IFN-γ in response to 38 kDa/CFP-10 were detectable HIV viral load (VL) and CD4 + T cell counts at follow-up visits of ≥200 cells/mm 3 . These findings highlight the differences in immune response according to the specificity of the Mtb antigen, which contributes to a better understanding of TB-HIV immunopathogenesis. IFN-γ production elicited by PPD and 38 kDa/CFP-10 antigens

Interleukin-6 and vascular endothelial growth factor release by renal cell carcinoma cells impedes lymphocyte-dendritic cell cross-talk.

PubMed

Cabillic, F; Bouet-Toussaint, F; Toutirais, O; Rioux-Leclercq, N; Fergelot, P; de la Pintière, C Thomas; Genetet, N; Patard, J-J; Catros-Quemener, V

2006-12-01

Anti-tumour T cell response requires antigen presentation via efficient immunological synapse between antigen presenting cells, e.g. dendritic cells (DC), and specific T cells in an adapted Th1 cytokine context. Nine renal cell carcinoma (RCC) primary culture cells were used as sources of tumour antigens which were loaded on DC (DC-Tu) for autologous T cell activation assays. Cytotoxic activity of lymphocytes stimulated with DC-Tu was evaluated against autologous tumour cells. Assays were performed with 75 grays irradiated tumour cells (Tu irr) and with hydrogen peroxide +/- heat shock (Tu H(2)O(2) +/- HS) treated cells. DC-Tu irr failed to enhance cytotoxic activity of autologous lymphocytes in seven of 13 assays. In all these defective assays, irradiated tumour cells displayed high interleukin (IL)-6 and vascular endothelial growth factor (VEGF) release. Conversely, when tumour cells released low IL-6 levels (n = 4), DC-Tu irr efficiently enhanced CTL activity. When assays were performed with the same RCC cells treated with H(2)O(2) + HS, DC-Tu stimulation resulted in improved CTL activity. H(2)O(2) + HS treatment induced post-apoptotic cell necrosis of tumour cells, totally abrogated their cytokine release [IL-6, VEGF, transforming growth factor (TGF)-beta1] and induced HSP70 expression. Taken together, data show that reduction in IL-6 and VEGF release in the environment of the tumour concomitantly to tumour cell HSP expression favours induction of a stronger anti-tumour CTL response.

Are there Race-Dependent Endothelial Cell Responses to Exercise?

PubMed Central

Brown, Michael D.; Feairheller, Deborah L.

2013-01-01

African Americans have endothelial dysfunction which likely contributes to their high prevalence of hypertension. Endothelial cell responses to stimuli could play a role in the development of endothelial dysfunction and hypertension. High physiological levels of vascular laminar shear stress can profoundly alter endothelial cell phenotype. It is not known whether there are race-dependent endothelial cell responses to laminar shear stress. PMID:23262464

Loss of endothelial barrier antigen immunoreactivity as a marker of Clostridium perfringens type D epsilon toxin-induced microvascular damage in rat brain.

PubMed

Finnie, J W; Manavis, J; Chidlow, G

2014-01-01

The epsilon toxin elaborated by Clostridium perfringens type D in the intestine of domestic livestock is principally responsible for the neurological disease produced after its absorption in excessive quantities into the systemic circulation. The fundamental basis of the cerebral damage induced by epsilon toxin appears to be microvascular injury with ensuing severe, diffuse vasogenic oedema. Endothelial barrier antigen (EBA), which is normally expressed by virtually all capillaries and venules in the rat brain, was used in this study as a marker of blood-brain barrier (BBB) integrity. After exposure to high levels of circulating epsilon toxin, there was substantial loss of EBA in many brain microvessels, attended by widespread plasma albumin extravasation. These results support microvascular injury and subsequent BBB breakdown as a key factor in the pathogenesis of epsilon toxin-induced neurological disease. Copyright © 2014 Elsevier Ltd. All rights reserved.

Induction of cytotoxic T lymphocyte response against Mycobacterial antigen using domain I of anthrax edema factor as antigen delivery system

DOE Office of Scientific and Technical Information (OSTI.GOV)

Chandra, Subhash; Kaur, Manpreet; Midha, Shuchi

2007-05-25

We have investigated the efficiency of N-terminal 1-260 residues of Edema factor (EFn) as a delivery system for ESAT-6, an antigenic protein of Mycobacterium tuberculosis H{sub 37}R{sub v}, into the cytosol of mammalian cells. The EFn.ESAT-6 recombinant protein was obtained by genetic fusion of EFn and ESAT-6 DNA. Our data shows that in the presence of PA, EFn.ESAT-6 fusion protein is internalized into the cytosol of antigen presenting cells, and the splenocytes produced both Th1 and Th2 cytokines in vitro. Further, EFn.ESAT-6 elicited effective cytotoxicT lymphocyte (CTL) response in an in vitro CTL assay. This study for the first timemore » demonstrates that EFn can be used as a vehicle to deliver heterologous proteins of therapeutic importance.« less

Detecting Tie2, an endothelial growth factor receptor, by using immunohistochemistry in mouse lungs.

PubMed

Guha, Prajna P; David, Sascha A; Ghosh, Chandra C

2014-01-01

Immunohistochemical (IHC) staining is an invaluable, sensitive, and effective method to detect the presence and localization of proteins in the cellular compartment in tissues. The basic concept of IHC is detecting the antigen in tissues by means of specific antibody binding, which is then demonstrated with a colored histochemical reaction that can be observed under a light microscope. The most challenging aspect of IHC techniques is optimizing the precise experimental conditions that are required to get a specific and a strong signal. The critical steps of IHC are specimen acquisition, fixation, permeabilization, detection system, and selection of the antigen specific antibody and its optimization. Here, we elaborate the technique using the endothelial growth factor binding receptor Tie2 in mouse lungs.

Rapid flow-induced responses in endothelial cells

NASA Technical Reports Server (NTRS)

Stamatas, G. N.; McIntire, L. V.

2001-01-01

Endothelial cells alter their morphology, growth rate, and metabolism in response to fluid shear stress. To study rapid flow-induced responses in the 3D endothelial cell morphology and calcium distribution, coupled fluorescence microscopy with optical sectioning, digital imaging, and numerical deconvolution techniques have been utilized. Results demonstrate that within the first minutes of flow application nuclear calcium is increasing. In the same time frame whole cell height and nuclear height are reduced by about 1 microm. Whole cell height changes may facilitate reduction of shear stress gradients on the luminal surface, whereas nuclear structural changes may be important for modulating endothelial growth rate and metabolism. To study the role of the cytoskeleton in these responses, endothelial cells have been treated with specific disrupters (acrylamide, cytochalasin D, and colchicine) of each of the cytoskeleton elements (intermediate filaments, microfilaments, and microtubules, respectively). None of these compounds had any effect on the shear-induced calcium response. Cytochalasin D and acrylamide did not affect the shear-induced nuclear morphology changes. Colchicine, however, completely abrogated the response, indicating that microtubules may be implicated in force transmission from the plasma membrane to the nucleus. A pedagogical model based on tensegrity theory principles is presented that is consistent with the results on the 3D endothelial morphology.

Growth factor-induced morphological, physiological and molecular characteristics in cerebral endothelial cells.

PubMed

Krizbai, I A; Bauer, H; Amberger, A; Hennig, B; Szabó, H; Fuchs, R; Bauer, H C

2000-09-01

The capacity of vascular endothelial cells to modulate their phenotype in response to changes in environmental conditions is one of the most important characteristics of this cell type. Since different growth factors may play an important signalling role in this adaptive process we have investigated the effect of endothelial cell growth factor (ECGF) on morphological, physiological and molecular characteristics of cerebral endothelial cells (CECs). CECs grown in the presence of ECGF and its cofactor heparin exhibit an epithelial-like morphology (type I CECs). Upon removal of growth factors, CECs develop an elongated spindle-like shape (type II CECs) which is accompanied by the reorganization of actin filaments and the induction of alpha-actin expression. Since one of the most important functions of CECs is the creation of a selective diffusion barrier between the blood and the central nervous system (CNS), we have studied the expression of junction-related proteins in both cell types. We have found that removal of growth factors from endothelial cultures leads to the downregulation of cadherin and occludin protein levels. The loss of junctional proteins was accompanied by a significant increase in the migratory activity and an altered protease activity profile of the cells. TGF-beta1 suppressed endothelial migration in all experiments. Our data provide evidence to suggest that particular endothelial functions are largely controlled by the presence of growth factors. The differences in adhesiveness and migration may play a role in important physiological and pathological processes of endothelial cells such as vasculogenesis or tumor progression.

Improvement of insulin sensitivity in response to exercise training in type 2 diabetes mellitus is associated with vascular endothelial growth factor A expression.

PubMed

Wagner, Henrik; Fischer, Helene; Degerblad, Marie; Alvarsson, Michael; Gustafsson, Thomas

2016-09-01

Insulin sensitivity changes in response to exercise training demonstrate a large variation. Vascular endothelial growth factor A could promote increased insulin sensitivity through angiogenesis. We investigated associations between changes in expression of key genes and insulin sensitivity, aerobic capacity and glycaemic control following exercise training in diabetes mellitus type 2. Subjects with diabetes mellitus type 2 underwent 12 weeks of structured exercise. Euglycaemic clamp, exercise test and HbA1c were performed. Muscle biopsies were obtained for mRNA expression. A total of 16 subjects completed the study. Change in vascular endothelial growth factor A expression was positively associated with an increase in insulin sensitivity (p = 0.004) and with a decrease in HbA1c (p = 0.034). Vascular endothelial growth factor A receptor-1 expression showed similar associations. The variation in physical adaptation to exercise training in diabetes mellitus type 2 was associated with changes in expression of vascular endothelial growth factor A in muscle. This difference in induced gene expression could contribute to the variation in exercise training effects on insulin sensitivity. Measures of capillary blood flow need to be assessed in future studies. © The Author(s) 2016.

Mechanisms of integrin-vascular endothelial growth factor receptor cross-activation in angiogenesis.

PubMed

Mahabeleshwar, Ganapati H; Feng, Weiyi; Reddy, Kumar; Plow, Edward F; Byzova, Tatiana V

2007-09-14

The functional responses of endothelial cells are dependent on signaling from peptide growth factors and the cellular adhesion receptors, integrins. These include cell adhesion, migration, and proliferation, which, in turn, are essential for more complex processes such as formation of the endothelial tube network during angiogenesis. This study identifies the molecular requirements for the cross-activation between beta3 integrin and tyrosine kinase receptor 2 for vascular endothelial growth factor (VEGF) receptor (VEGFR-2) on endothelium. The relationship between VEGFR-2 and beta3 integrin appears to be synergistic, because VEGFR-2 activation induces beta3 integrin tyrosine phosphorylation, which, in turn, is crucial for VEGF-induced tyrosine phosphorylation of VEGFR-2. We demonstrate here that adhesion- and growth factor-induced beta3 integrin tyrosine phosphorylation are directly mediated by c-Src. VEGF-stimulated recruitment and activation of c-Src and subsequent beta3 integrin tyrosine phosphorylation are critical for interaction between VEGFR-2 and beta3 integrin. Moreover, c-Src mediates growth factor-induced beta3 integrin activation, ligand binding, beta3 integrin-dependent cell adhesion, directional migration of endothelial cells, and initiation of angiogenic programming in endothelial cells. Thus, the present study determines the molecular mechanisms and consequences of the synergism between 2 cell surface receptor systems, growth factor receptor and integrins, and opens new avenues for the development of pro- and antiangiogenic strategies.

Human Herpesvirus-8-Transformed Endothelial Cells Have Functionally Activated Vascular Endothelial Growth Factor/Vascular Endothelial Growth Factor Receptor

PubMed Central

Masood, Rizwan; Cesarman, Ethel; Smith, D. Lynne; Gill, Parkash S.; Flore, Ornella

2002-01-01

Kaposi’s sarcoma is a vascular tumor commonly associated with human immunodeficiency virus (HIV)-1 and human herpesvirus (HHV-8) also known as Kaposi’s sarcoma-associated herpesvirus. The principal features of this tumor are abnormal proliferation of vascular structures lined with spindle-shaped endothelial cells. HHV-8 may transform a subpopulation of endothelial cells in vitro via viral and cellular gene expression. We hypothesized that among the cellular genes, vascular endothelial growth factors (VEGFs) and their cognate receptors may be involved in viral-mediated transformation. We have shown that HHV-8-transformed endothelial cells (EC-HHV-8) express higher levels of VEGF, VEGF-C, VEGF-D, and PlGF in addition to VEGF receptors-1, -2, and -3. Furthermore, antibodies to VEGF receptor-2 inhibited cell proliferation and viability. Similarly, inhibition of VEGF gene expression with antisense oligonucleotides inhibited EC-HHV-8 cell proliferation/viability. The growth and viability of primary endothelial cells and a fibroblast cell line however were unaffected by either the VEGF receptor-2 antibody or the VEGF antisense oligodeoxynucleotides. VEGF and VEGF receptors are thus induced in EC-HHV-8 and participate in the transformation. Inhibitors of VEGF may thus modulate the disease process during development and progression. PMID:11786394

Transforming growth factor-beta inhibits human antigen-specific CD4+ T cell proliferation without modulating the cytokine response.

PubMed

Tiemessen, Machteld M; Kunzmann, Steffen; Schmidt-Weber, Carsten B; Garssen, Johan; Bruijnzeel-Koomen, Carla A F M; Knol, Edward F; van Hoffen, Els

2003-12-01

Transforming growth factor (TGF)-beta has been demonstrated to play a key role in the regulation of the immune response, mainly by its suppressive function towards cells of the immune system. In humans, the effect of TGF-beta on antigen-specific established memory T cells has not been investigated yet. In this study antigen-specific CD4(+) T cell clones (TCC) were used to determine the effect of TGF-beta on antigen-specific proliferation, the activation status of the T cells and their cytokine production. This study demonstrates that TGF-beta is an adequate suppressor of antigen-specific T cell proliferation, by reducing the cell-cycle rate rather than induction of apoptosis. Addition of TGF-beta resulted in increased CD69 expression and decreased CD25 expression on T cells, indicating that TGF-beta is able to modulate the activation status of in vivo differentiated T cells. On the contrary, the antigen-specific cytokine production was not affected by TGF-beta. Although TGF-beta was suppressive towards the majority of the T cells, insensitivity of a few TCC towards TGF-beta was also observed. This could not be correlated to differential expression of TGF-beta signaling molecules such as Smad3, Smad7, SARA (Smad anchor for receptor activation) and Hgs (hepatocyte growth factor-regulated tyrosine kinase substrate). In summary, TGF-beta has a pronounced inhibitory effect on antigen-specific T cell proliferation without modulating their cytokine production.

Transcription factor fos-related antigen-2 induces progressive peripheral vasculopathy in mice closely resembling human systemic sclerosis.

PubMed

Maurer, Britta; Busch, Nicole; Jüngel, Astrid; Pileckyte, Margarita; Gay, Renate E; Michel, Beat A; Schett, Georg; Gay, Steffen; Distler, Jörg; Distler, Oliver

2009-12-08

Microvascular damage is one of the first pathological changes in systemic sclerosis. In this study, we investigated the role of Fos-related antigen-2 (Fra-2), a transcription factor of the activator protein-1 family, in the peripheral vasculopathy of systemic sclerosis and examined the underlying mechanisms. Expression of Fra-2 protein was significantly increased in skin biopsies of systemic sclerosis patients compared with healthy controls, especially in endothelial and vascular smooth muscle cells. Fra-2 transgenic mice developed a severe loss of small blood vessels in the skin that was paralleled by progressive skin fibrosis at 12 weeks of age. The reduction in capillary density was preceded by a significant increase in apoptosis in endothelial cells at week 9 as detected by immunohistochemistry. Similarly, suppression of Fra-2 by small interfering RNA prevented human microvascular endothelial cells from staurosporine-induced apoptosis and improved both the number of tubes and the cumulative tube lengths in the tube formation assay. In addition, cell migration in the scratch assay and vascular endothelial growth factor-dependent chemotaxis in a modified Boyden chamber assay were increased after transfection of human microvascular endothelial cells with Fra-2 small interfering RNA, whereas proliferation was not affected. Fra-2 is present in human systemic sclerosis and may contribute to the development of microvasculopathy by inducing endothelial cell apoptosis and by reducing endothelial cell migration and chemotaxis. Fra-2 transgenic mice are a promising preclinical model to study the mechanisms and therapeutic approaches of the peripheral vasculopathy in systemic sclerosis.

An evolving new paradigm: endothelial cells--conditional innate immune cells.

PubMed

Mai, Jietang; Virtue, Anthony; Shen, Jerry; Wang, Hong; Yang, Xiao-Feng

2013-08-22

Endothelial cells (ECs) are a heterogeneous population that fulfills many physiological processes. ECs also actively participate in both innate and adaptive immune responses. ECs are one of the first cell types to detect foreign pathogens and endogenous metabolite-related danger signals in the bloodstream, in which ECs function as danger signal sensors. Treatment with lipopolysaccharide activates ECs, causing the production of pro-inflammatory cytokines and chemokines, which amplify the immune response by recruiting immune cells. Thus, ECs function as immune/inflammation effectors and immune cell mobilizers. ECs also induce cytokine production by immune cells, in which ECs function as immune regulators either by activating or suppressing immune cell function. In addition, under certain conditions, ECs can serve as antigen presenting cells (antigen presenters) by expressing both MHC I and II molecules and presenting endothelial antigens to T cells. These facts along with the new concept of endothelial plasticity suggest that ECs are dynamic cells that respond to extracellular environmental changes and play a meaningful role in immune system function. Based on these novel EC functions, we propose a new paradigm that ECs are conditional innate immune cells. This paradigm provides a novel insight into the functions of ECs in inflammatory/immune pathologies.

Adaptive induction of NF-E2-related factor-2-driven antioxidant genes in endothelial cells in response to hyperglycemia.

PubMed

Ungvari, Zoltan; Bailey-Downs, Lora; Gautam, Tripti; Jimenez, Rosario; Losonczy, Gyorgy; Zhang, Cuihua; Ballabh, Praveen; Recchia, Fabio A; Wilkerson, Donald C; Sonntag, William E; Pearson, Kevin; de Cabo, Rafael; Csiszar, Anna

2011-04-01

Hyperglycemia in diabetes mellitus promotes oxidative stress in endothelial cells, which contributes to development of cardiovascular diseases. Nuclear factor erythroid 2-related factor-2 (Nrf2) is a transcription factor activated by oxidative stress that regulates expression of numerous reactive oxygen species (ROS) detoxifying and antioxidant genes. This study was designed to elucidate the homeostatic role of adaptive induction of Nrf2-driven free radical detoxification mechanisms in endothelial protection under diabetic conditions. Using a Nrf2/antioxidant response element (ARE)-driven luciferase reporter gene assay we found that in a cultured coronary arterial endothelial cell model hyperglycemia (10-30 mmol/l glucose) significantly increases transcriptional activity of Nrf2 and upregulates the expression of the Nrf2 target genes NQO1, GCLC, and HMOX1. These effects of high glucose were significantly attenuated by small interfering RNA (siRNA) downregulation of Nrf2 or overexpression of Keap-1, which inactivates Nrf2. High-glucose-induced upregulation of NQO1, GCLC, and HMOX1 was also prevented by pretreatment with polyethylene glycol (PEG)-catalase or N-acetylcysteine, whereas administration of H(2)O(2) mimicked the effect of high glucose. To test the effects of metabolic stress in vivo, Nrf2(+/+) and Nrf2(-/-) mice were fed a high-fat diet (HFD). HFD elicited significant increases in mRNA expression of Gclc and Hmox1 in aortas of Nrf2(+/+) mice, but not Nrf2(-/-) mice, compared with respective standard diet-fed control mice. Additionally, HFD-induced increases in vascular ROS levels were significantly greater in Nrf2(-/-) than Nrf2(+/+) mice. HFD-induced endothelial dysfunction was more severe in Nrf2(-/-) mice, as shown by the significantly diminished acetylcholine-induced relaxation of aorta of these animals compared with HFD-fed Nrf2(+/+) mice. Our results suggest that adaptive activation of the Nrf2/ARE pathway confers endothelial protection under

Immunohistochemical expression of vascular endothelial growth factor in canine oral squamous cell carcinomas.

PubMed

Martano, Manuela; Restucci, Brunella; Ceccarelli, Dora Maria; Lo Muzio, Lorenzo; Maiolino, Paola

2016-01-01

Angiogenesis is crucial for the growth and metastasis of malignant tumours, and various proangiogenic factors promote this process. One of these factors is vascular endothelial growth factor (VEGF), which appears to play a key role in tumour angiogenesis. The aim of the present study was to assess whether VEGF expression is associated with angiogenesis, disease progression and neoplastic proliferation in canine oral squamous cell carcinoma (OSCC) tissue. VEGF immunoreactivity was quantified by immunohistochemistry in 30 specimens, including normal oral mucosa and OSCC tissues graded as well, moderately or poorly differentiated. VEGF expression was correlated with tumour cell proliferation, as assessed using the proliferating cell nuclear antigen (PCNA) marker and microvessel density (data already published). The present results revealed that VEGF and PCNA expression increased significantly between normal oral tissue and neoplastic tissue, and between well and moderately/poorly differentiated tumours. In addition, VEGF expression was strongly correlated with PCNA expression and microvessel density. It was concluded that VEGF may promote angiogenesis through a paracrine pathway, stimulating endothelial cell proliferation and, similarly, may induce tumour cell proliferation through an autocrine pathway. The present results suggest that the evaluation of VEGF may be a useful additional criterion for estimating malignancy and growth potential in canine OSCCs.

The cellular response to vascular endothelial growth factors requires co-ordinated signal transduction, trafficking and proteolysis

PubMed Central

Smith, Gina A.; Fearnley, Gareth W.; Tomlinson, Darren C.; Harrison, Michael A.; Ponnambalam, Sreenivasan

2015-01-01

VEGFs (vascular endothelial growth factors) are a family of conserved disulfide-linked soluble secretory glycoproteins found in higher eukaryotes. VEGFs mediate a wide range of responses in different tissues including metabolic homoeostasis, cell proliferation, migration and tubulogenesis. Such responses are initiated by VEGF binding to soluble and membrane-bound VEGFRs (VEGF receptor tyrosine kinases) and co-receptors. VEGF and receptor splice isoform diversity further enhances complexity of membrane protein assembly and function in signal transduction pathways that control multiple cellular responses. Different signal transduction pathways are simultaneously activated by VEGFR–VEGF complexes with membrane trafficking along the endosome–lysosome network further modulating signal output from multiple enzymatic events associated with such pathways. Balancing VEGFR–VEGF signal transduction with trafficking and proteolysis is essential in controlling the intensity and duration of different intracellular signalling events. Dysfunction in VEGF-regulated signal transduction is important in chronic disease states including cancer, atherosclerosis and blindness. This family of growth factors and receptors is an important model system for understanding human disease pathology and developing new therapeutics for treating such ailments. PMID:26285805

Modification of tissue-factor mRNA and protein response to thrombin and interleukin 1 by high glucose in cultured human endothelial cells.

PubMed

Boeri, D; Almus, F E; Maiello, M; Cagliero, E; Rao, L V; Lorenzi, M

1989-02-01

Because diabetic vascular disease is accompanied by a state of hypercoagulability, manifested by increased thrombin activity and foci of intravascular coagulation, we investigated whether a specific procoagulant property of the endothelium--production and surface expression of tissue factor--is modified by elevated glucose concentrations. In unperturbed human vascular endothelial cells, tissue factor mRNA and expression of the functional protein were undetectable and were not induced by 10-12 days of exposure to 30 mM glucose. In thrombin-stimulated cultures, tissue-factor expression was related inversely to cellular density, with confluent cultures producing (per 10(5) cells) half the amount of tissue factor measured in sparse cultures. Cells exposed to high glucose and studied when cell number and thymidine incorporation were identical to control cells manifested increased tissue-factor mRNA level and functional protein production in response to thrombin (P = .002). This effect was not attributable to hypertonicity and was not observed after short exposure to high glucose. In contrast, the tissue-factor response to interleukin 1, a modulator of endothelial function in the context of host defense, was decreased in cells cultured in high glucose (P = .04). These findings indicate that exposure to high glucose can alter tissue-factor gene expression in perturbed vascular endothelium. The reciprocal effects of high glucose on the tissue-factor response to thrombin and interleukin 1 points to different pathways of tissue-factor stimulation by the two agents and suggests functional consequences pertinent to the increased thrombin activity and compromised host-defense mechanisms observed in diabetes.

An evolving new paradigm: endothelial cells – conditional innate immune cells

PubMed Central

2013-01-01

Endothelial cells (ECs) are a heterogeneous population that fulfills many physiological processes. ECs also actively participate in both innate and adaptive immune responses. ECs are one of the first cell types to detect foreign pathogens and endogenous metabolite-related danger signals in the bloodstream, in which ECs function as danger signal sensors. Treatment with lipopolysaccharide activates ECs, causing the production of pro-inflammatory cytokines and chemokines, which amplify the immune response by recruiting immune cells. Thus, ECs function as immune/inflammation effectors and immune cell mobilizers. ECs also induce cytokine production by immune cells, in which ECs function as immune regulators either by activating or suppressing immune cell function. In addition, under certain conditions, ECs can serve as antigen presenting cells (antigen presenters) by expressing both MHC I and II molecules and presenting endothelial antigens to T cells. These facts along with the new concept of endothelial plasticity suggest that ECs are dynamic cells that respond to extracellular environmental changes and play a meaningful role in immune system function. Based on these novel EC functions, we propose a new paradigm that ECs are conditional innate immune cells. This paradigm provides a novel insight into the functions of ECs in inflammatory/immune pathologies. PMID:23965413

Endothelial adhesion molecules and leukocyte integrins in preeclamptic patients.

PubMed

Haller, H; Ziegler, E M; Homuth, V; Drab, M; Eichhorn, J; Nagy, Z; Busjahn, A; Vetter, K; Luft, F C

1997-01-01

Endothelial cell activation is important in the pathogenesis of preeclampsia; however, the nature of the activation is unknown. We investigated 22 patients with preeclampsia. 29 normotensive pregnancies, and 18 nonpregnant women to test the hypothesis that serum from preeclamptic patients induces expression of intercellular adhesion molecule-1 (ICAM-1) and vascular adhesion molecule-1 (VCAM-1) and stimulates intracellular free calcium concentrations [Ca2+]i in cultured endothelial cells. We then asked whether the corresponding integrin adhesive counter receptors lymphocyte function-associated antigen-1 (CD11a/CD18), macrophage-1 antigen (CD11b/CD18), p150,95 (CD11c/CD18), and very late activation antigen-4 (CD49/CD29) are increased in patients with preeclampsia. In the pregnant women, the measurements were conducted both before and after delivery. Integrin expression was measured by fluorescent antibody cell sorting analysis using monoclonal antibodies. ICAM-1 and VCAM-1 were analyzed on endothelial cells by enzyme-linked immunosorbent assay. [Ca2+]i was measured with fura 2. Serum from preeclamptic patients increased endothelial cell ICAM-1 expression but not VCAM-1 expression. Preeclamptic patients' serum also increased [Ca2+]i in endothelial cells compared with serum from normal nonpregnant or normal pregnant women. Endothelial cell [Ca2+]i concentrations were correlated with the ICAM-1 expression in preeclamptic patients (r = .80, P < .001) before but not after delivery. Expression of the integrin counter receptors on leukocytes was similarly increased in preclampsia and normal pregnancy compared with the nonpregnant state. The expression decreased significantly after delivery in both groups. Our results demonstrate that serum from preeclamptic women induces increased ICAM-1 surface expression on endothelial cells, while the expression of the integrin counterreceptors was not different. The effect on endothelial cells may be related to an increase in [Ca2+]i

Vascular Endothelial Growth Factor (VEGF) and Platelet (PF-4) Factor 4 Inputs Modulate Human Microvascular Endothelial Signaling in a Three-Dimensional Matrix Migration Context*

PubMed Central

Hang, Ta-Chun; Tedford, Nathan C.; Reddy, Raven J.; Rimchala, Tharathorn; Wells, Alan; White, Forest M.; Kamm, Roger D.; Lauffenburger, Douglas A.

2013-01-01

The process of angiogenesis is under complex regulation in adult organisms, particularly as it often occurs in an inflammatory post-wound environment. As such, there are many impacting factors that will regulate the generation of new blood vessels which include not only pro-angiogenic growth factors such as vascular endothelial growth factor, but also angiostatic factors. During initial postwound hemostasis, a large initial bolus of platelet factor 4 is released into localized areas of damage before progression of wound healing toward tissue homeostasis. Because of its early presence and high concentration, the angiostatic chemokine platelet factor 4, which can induce endothelial anoikis, can strongly affect angiogenesis. In our work, we explored signaling crosstalk interactions between vascular endothelial growth factor and platelet factor 4 using phosphotyrosine-enriched mass spectrometry methods on human dermal microvascular endothelial cells cultured under conditions facilitating migratory sprouting into collagen gel matrices. We developed new methods to enable mass spectrometry-based phosphorylation analysis of primary cells cultured on collagen gels, and quantified signaling pathways over the first 48 h of treatment with vascular endothelial growth factor in the presence or absence of platelet factor 4. By observing early and late signaling dynamics in tandem with correlation network modeling, we found that platelet factor 4 has significant crosstalk with vascular endothelial growth factor by modulating cell migration and polarization pathways, centered around P38α MAPK, Src family kinases Fyn and Lyn, along with FAK. Interestingly, we found EphA2 correlational topology to strongly involve key migration-related signaling nodes after introduction of platelet factor 4, indicating an influence of the angiostatic factor on this ambiguous but generally angiogenic signal in this complex environment. PMID:24023389

Endothelial biomarkers in human sepsis: pathogenesis and prognosis for ARDS

PubMed Central

Hendrickson, Carolyn M.; Matthay, Michael A.

2018-01-01

Experimental models of sepsis in small and large animals and a variety of in vitro preparations have established several basic mechanisms that drive endothelial injury. This review is focused on what can be learned from the results of clinical studies of plasma biomarkers of endothelial injury and inflammation in patients with sepsis. There is excellent evidence that elevated plasma levels of several biomarkers of endothelial injury, including von Willebrand factor antigen (VWF), angiopoietin-2 (Ang-2), and soluble fms-like tyrosine kinase 1 (sFLT-1), and biomarkers of inflammation, especially interleukin-8 (IL-8) and soluble tumor necrosis factor receptor (sTNFr), identify sepsis patients with a higher mortality. There are also some data that elevated levels of endothelial biomarkers can identify which patients with non-pulmonary sepsis will develop acute respiratory distress syndrome (ARDS). If ARDS patients are divided among those with indirect versus direct lung injury, then there is an association of elevated levels of endothelial biomarkers in indirect injury and markers of inflammation and alveolar epithelial injury in patients with direct lung injury. New research suggests that the combination of biologic and clinical markers may make it possible to segregate patients with ARDS into hypo- versus hyper-inflammatory phenotypes that may have implications for therapeutic responses to fluid therapy. Taken together, the studies reviewed here support a primary role of the microcirculation in the pathogenesis and prognosis of ARDS after sepsis. Biological differences identified by molecular patterns could explain heterogeneity of treatment effects that are not explained by clinical factors alone. PMID:29575977

Lymphatic endothelial cell line (CH3) from a recurrent retroperitoneal lymphangioma.

PubMed

Way, D; Hendrix, M; Witte, M; Witte, C; Nagle, R; Davis, J

1987-09-01

An endothelial cell line derived from a massive recurrent chyle-containing retroperitoneal lymphangioma was isolated in monolayer culture. Scanning and transmission electron microscopy and immunohistochemistry confirmed a close resemblance to blood vascular endothelium with typical cobblestone morphology, positive immunofluorescence staining for endothelial marker Factor VIII-associated antigen and fibronectin, and prominent Weibel-Palade bodies. The endothelial cells also exhibited other ultrastructural features characteristic of lymphatic endothelium, including sparse microvillous surface projections, overlapping intercellular junctions, and abundant intermediate filaments. This endothelial cell line represents a new source of proliferating lymphatic endothelium for future study, including structural and functional comparison to blood vascular endothelium.

Roles of lymphatic endothelial cells expressing peripheral tissue antigens in CD4 T-cell tolerance induction.

PubMed

Rouhani, Sherin J; Eccles, Jacob D; Riccardi, Priscila; Peske, J David; Tewalt, Eric F; Cohen, Jarish N; Liblau, Roland; Mäkinen, Taija; Engelhard, Victor H

2015-04-10

Lymphatic endothelial cells (LECs) directly express peripheral tissue antigens and induce CD8 T-cell deletional tolerance. LECs express MHC-II molecules, suggesting they might also tolerize CD4 T cells. We demonstrate that when β-galactosidase (β-gal) is expressed in LECs, β-gal-specific CD8 T cells undergo deletion via the PD-1/PD-L1 and LAG-3/MHC-II pathways. In contrast, LECs do not present endogenous β-gal in the context of MHC-II molecules to β-gal-specific CD4 T cells. Lack of presentation is independent of antigen localization, as membrane-bound haemagglutinin and I-Eα are also not presented by MHC-II molecules. LECs express invariant chain and cathepsin L, but not H2-M, suggesting that they cannot load endogenous antigenic peptides onto MHC-II molecules. Importantly, LECs transfer β-gal to dendritic cells, which subsequently present it to induce CD4 T-cell anergy. Therefore, LECs serve as an antigen reservoir for CD4 T-cell tolerance, and MHC-II molecules on LECs are used to induce CD8 T-cell tolerance via LAG-3.

Roles of lymphatic endothelial cells expressing peripheral tissue antigens in CD4 T-cell tolerance induction

PubMed Central

Rouhani, Sherin J.; Eccles, Jacob D.; Riccardi, Priscila; Peske, J. David; Tewalt, Eric F.; Cohen, Jarish N.; Liblau, Roland; Mäkinen, Taija; Engelhard, Victor H.

2015-01-01

Lymphatic endothelial cells (LECs) directly express peripheral tissue antigens and induce CD8 T-cell deletional tolerance. LECs express MHC-II molecules, suggesting they might also tolerize CD4 T cells. We demonstrate that when β-galactosidase (β-gal) is expressed in LECs, β-gal-specific CD8 T cells undergo deletion via the PD-1/PD-L1 and LAG-3/MHC-II pathways. In contrast, LECs do not present endogenous β-gal in the context of MHC-II molecules to β-gal-specific CD4 T cells. Lack of presentation is independent of antigen localization, as membrane-bound haemagglutinin and I-Eα are also not presented by MHC-II molecules. LECs express invariant chain and cathepsin L, but not H2-M, suggesting that they cannot load endogenous antigenic peptides onto MHC-II molecules. Importantly, LECs transfer β-gal to dendritic cells, which subsequently present it to induce CD4 T-cell anergy. Therefore, LECs serve as an antigen reservoir for CD4 T-cell tolerance, and MHC-II molecules on LECs are used to induce CD8 T-cell tolerance via LAG-3. PMID:25857745

Endothelial Response to Glucocorticoids in Inflammatory Diseases

PubMed Central

Zielińska, Karolina A.; Van Moortel, Laura; Opdenakker, Ghislain; De Bosscher, Karolien; Van den Steen, Philippe E.

2016-01-01

The endothelium plays a crucial role in inflammation. A balanced control of inflammation requires the action of glucocorticoids (GCs), steroidal hormones with potent cell-specific anti-inflammatory properties. Besides the classic anti-inflammatory effects of GCs on leukocytes, recent studies confirm that endothelial cells also represent an important target for GCs. GCs regulate different aspects of endothelial physiology including expression of adhesion molecules, production of pro-inflammatory cytokines and chemokines, and maintenance of endothelial barrier integrity. However, the regulation of endothelial GC sensitivity remains incompletely understood. In this review, we specifically examine the endothelial response to GCs in various inflammatory diseases ranging from multiple sclerosis, stroke, sepsis, and vasculitis to atherosclerosis. Shedding more light on the cross talk between GCs and endothelium will help to improve existing therapeutic strategies and develop new therapies better tailored to the needs of patients. PMID:28018358

Inducible Knockdown of Endothelial Protein Tyrosine Phosphatase-1B Promotes Neointima Formation in Obese Mice by Enhancing Endothelial Senescence.

PubMed

Jäger, Marianne; Hubert, Astrid; Gogiraju, Rajinikanth; Bochenek, Magdalena L; Münzel, Thomas; Schäfer, Katrin

2018-02-01

Protein tyrosine phosphatase-1B (PTP1B) is a negative regulator of receptor tyrosine kinase signaling. In this study, we determined the importance of PTP1B expressed in endothelial cells for the vascular response to arterial injury in obesity. Morphometric analysis of vascular lesions generated by 10% ferric chloride (FeCl 3 ) revealed that tamoxifen-inducible endothelial PTP1B deletion (Tie2.ER T2 -Cre × PTP1B fl/fl ; End.PTP1B knockout, KO) significantly increased neointima formation, and reduced numbers of (endothelial lectin-positive) luminal cells in End.PTP1B-KO mice suggested impaired lesion re-endothelialization. Significantly higher numbers of proliferating cell nuclear antigen (PCNA)-positive proliferating cells as well as smooth muscle actin (SMA)-positive or vascular cell adhesion molecule-1 (VCAM1)-positive activated smooth muscle cells or vimentin-positive myofibroblasts were detected in neointimal lesions of End.PTP1B-KO mice, whereas F4/80-positive macrophage numbers did not differ. Activated receptor tyrosine kinase and transforming growth factor-beta (TGFβ) signaling and oxidative stress markers were also significantly more abundant in End.PTP1B-KO mouse lesions. Genetic knockdown or pharmacological inhibition of PTP1B in endothelial cells resulted in increased expression of caveolin-1 and oxidative stress, and distinct morphological changes, elevated numbers of senescence-associated β-galactosidase-positive cells, and increased expression of tumor suppressor protein 53 (p53) or the cell cycle inhibitor cyclin-dependent kinase inhibitor-2A (p16INK4A) suggested senescence, all of which could be attenuated by small interfering RNA (siRNA)-mediated downregulation of caveolin-1. In vitro, senescence could be prevented and impaired re-endothelialization restored by preincubation with the antioxidant Trolox. Our results reveal a previously unknown role of PTP1B in endothelial cells and provide mechanistic insights how PTP1B deletion or inhibition

High-density lipoproteins protect endothelial cells from tumor necrosis factor-alpha-induced apoptosis.

PubMed

Sugano, M; Tsuchida, K; Makino, N

2000-06-16

High-density lipoproteins (HDL) levels have been shown to be inversely correlated with coronary heart disease, but the mechanisms of the direct protective effect of HDL on endothelial cells are not fully understood. The apoptosis of endothelial cells induced by cytokines and/or oxidized low-density lipoproteins, etc. may provide a mechanistic clue to the "response-to-injury" hypothesis of atherogenesis. Here we report that HDL prevent the apoptosis of human umbilical venous endothelial cells (HUVECs) induced by tumor necrosis factor-alpha (TNF-alpha) via an inhibition of CPP32-like protease activity. The incubation of HUVECs with TNF-alpha significantly increased the CPP32-like protease activity, and induced apoptosis. Preincubation of HUVECs with HDL before incubation with TNF-alpha significantly suppressed the increase in the CPP32-like protease activity, preventing apoptosis in a concentration-dependent manner. These results suggest that HDL prevent the suicide pathway leading to apoptosis of endothelial cells by decreasing the CPP32-like protease activity and that HDL thus play a protective role against the "response-to-injury" hypothesis of atherogenesis. Copyright 2000 Academic Press.

Antigen expression level threshold tunes the fate of CD8 T cells during primary hepatic immune responses.

PubMed

Tay, Szun Szun; Wong, Yik Chun; McDonald, David M; Wood, Nicole A W; Roediger, Ben; Sierro, Frederic; Mcguffog, Claire; Alexander, Ian E; Bishop, G Alex; Gamble, Jennifer R; Weninger, Wolfgang; McCaughan, Geoffrey W; Bertolino, Patrick; Bowen, David G

2014-06-24

CD8 T-cell responses to liver-expressed antigens range from deletional tolerance to full effector differentiation resulting in overt hepatotoxicity. The reasons for these heterogeneous outcomes are not well understood. To identify factors that govern the fate of CD8 T cells activated by hepatocyte-expressed antigen, we exploited recombinant adenoassociated viral vectors that enabled us to vary potential parameters determining these outcomes in vivo. Our findings reveal a threshold of antigen expression within the liver as the dominant factor determining T-cell fate, irrespective of T-cell receptor affinity or antigen cross-presentation. Thus, when a low percentage of hepatocytes expressed cognate antigen, high-affinity T cells developed and maintained effector function, whereas, at a high percentage, they became functionally exhausted and silenced. Exhaustion was not irreversibly determined by initial activation, but was maintained by high intrahepatic antigen load during the early phase of the response; cytolytic function was restored when T cells primed under high antigen load conditions were transferred into an environment of low-level antigen expression. Our study reveals a hierarchy of factors dictating the fate of CD8 T cells during hepatic immune responses, and provides an explanation for the different immune outcomes observed in a variety of immune-mediated liver pathologic conditions.

Molecular pathways mediating differential responses to lipopolysaccharide between human and baboon arterial endothelial cells.

PubMed

Shi, Qiang; Cox, Laura A; Glenn, Jeremy; Tejero, Maria E; Hondara, Vida; Vandeberg, John L; Wang, Xing Li

2010-02-01

1. Vascular inflammation plays a critical role in atherogenesis. Previously, we showed that baboon arterial endothelial cells (BAEC) were hyporesponsive to lipopolysaccharide (LPS) compared with human arterial endothelial cells (HAEC). 2. In the present study, we investigated mechanisms underlying differential responses between HAEC and BAEC to tumour necrosis factor (TNF)-alpha and LPS. 3. Both HAEC and BAEC responded similarly to TNF-alpha. However, BAEC showed retarded responses to LPS in expression of E-selectin, intercellular adhesion molecule-1, monocyte chemotactic protein-1 and interleukin-8 (P < 0.05). These changes were confirmed at the mRNA level. Tumour necrosis factor-alpha activated nuclear factor-kappaB members such as p50, p52, p65, c-rel and RelB in both HAEC and BAEC. In contrast, LPS activated p50 and p65 only in HAEC. Using microarray assays, we found that TNF receptor-associated factor 2 (TRAF-2), TNF receptor superfamily, member 1A-associated via death domain (TRADD) and nuclear factors such as nuclear factor of kappa in B-cells inhibitor, alpha (NFKBIA) and nuclear factor of kappa in B-cells inhibitor, beta (NFKBIB) were upregulated by LPS only in HAEC. Although the baseline expression of Toll-like receptor (TLR) 4 was low in both HAEC and BAEC, TNF-alpha activated TLR4 expression in both cell types. Although LPS increased TLR4 expression only in HAEC, human and baboon peripheral blood mononuclear cells exhibited similar TLR4 expression and response to LPS. Transfecting BAEC with TLR4/myeloid differentiation protein-2 overexpression vector conferred BAEC responsiveness to LPS. 4. The findings of the present study indicate that an altered TLR4 system may be responsible for the resistance of baboon endothelial cells to LPS. Given the importance of TLR4 in human immune responses and vascular diseases, the natural resistance of baboons to LPS/TLR4-initiated inflammation could make the baboon a valuable animal model in which to study how

Original antigenic sin responses to influenza viruses.

PubMed

Kim, Jin Hyang; Skountzou, Ioanna; Compans, Richard; Jacob, Joshy

2009-09-01

Most immune responses follow Burnet's rule in that Ag recruits specific lymphocytes from a large repertoire and induces them to proliferate and differentiate into effector cells. However, the phenomenon of "original antigenic sin" stands out as a paradox to Burnet's rule of B cell engagement. Humans, upon infection with a novel influenza strain, produce Abs against older viral strains at the expense of responses to novel, protective antigenic determinants. This exacerbates the severity of the current infection. This blind spot of the immune system and the redirection of responses to the "original Ag" rather than to novel epitopes were described fifty years ago. Recent reports have questioned the existence of this phenomenon. Hence, we revisited this issue to determine the extent to which original antigenic sin is induced by variant influenza viruses. Using two related strains of influenza A virus, we show that original antigenic sin leads to a significant decrease in development of protective immunity and recall responses to the second virus. In addition, we show that sequential infection of mice with two live influenza virus strains leads to almost exclusive Ab responses to the first viral strain, suggesting that original antigenic sin could be a potential strategy by which variant influenza viruses subvert the immune system.

Screening Immunomodulators To Skew the Antigen-Specific Autoimmune Response.

PubMed

Northrup, Laura; Sullivan, Bradley P; Hartwell, Brittany L; Garza, Aaron; Berkland, Cory

2017-01-03

Current therapies to treat autoimmune diseases often result in side effects such as nonspecific immunosuppression. Therapies that can induce antigen-specific immune tolerance provide an opportunity to reverse autoimmunity and mitigate the risks associated with global immunosuppression. In an effort to induce antigen-specific immune tolerance, co-administration of immunomodulators with autoantigens has been investigated in an effort to reprogram autoimmunity. To date, identifying immunomodulators that may skew the antigen-specific immune response has been ad hoc at best. To address this need, we utilized splenocytes obtained from mice with experimental autoimmune encephalomyelitis (EAE) in order to determine if certain immunomodulators may induce markers of immune tolerance following antigen rechallenge. Of the immunomodulatory compounds investigated, only dexamethasone modified the antigen-specific immune response by skewing the cytokine response and decreasing T-cell populations at a concentration corresponding to a relevant in vivo dose. Thus, antigen-educated EAE splenocytes provide an ex vivo screen for investigating compounds capable of skewing the antigen-specific immune response, and this approach could be extrapolated to antigen-educated cells from other diseases or human tissues.

Vascular endothelial growth factor-A enhances indoleamine 2,3-dioxygenase expression by dendritic cells and subsequently impacts lymphocyte proliferation

PubMed Central

Marti, Luciana Cavalheiro; Pavon, Lorena; Severino, Patricia; Sibov, Tatiana; Guilhen, Daiane; Moreira-Filho, Carlos Alberto

2013-01-01

Dendritic cells (DCs) are antigen (Ag)-presenting cells that activate and stimulate effective immune responses by T cells, but can also act as negative regulators of these responses and thus play important roles in immune regulation. Pro-angiogenic vascular endothelial growth factor (VEGF) has been shown to cause defective DC differentiation and maturation. Previous studies have demonstrated that the addition of VEGF to DC cultures renders these cells weak stimulators of Ag-specific T cells due to the inhibitory effects mediated by VEGF receptor 1 (VEGFR1) and/or VEGFR2 signalling. As the enzyme indoleamine 2,3-dioxygenase (IDO) is recognised as an important negative regulator of immune responses, this study aimed to investigate whether VEGF affects the expression of IDO by DCs and whether VEGF-matured DCs acquire a suppressor phenotype. Our results are the first to demonstrate that VEGF increases the expression and activity of IDO in DCs, which has a suppressive effect on Ag-specific and mitogen-stimulated lymphocyte proliferation. These mechanisms have broad implications for the study of immunological responses and tolerance under conditions as diverse as cancer, graft rejection and autoimmunity. PMID:24141959

Hypercholesterolemia potentiates aortic endothelial response to inhaled diesel exhaust

PubMed Central

Maresh, J. Gregory; Campen, Matthew J.; Reed, Matthew D.; Darrow, April L.; Shohet, Ralph V.

2012-01-01

Background Inhalation of diesel exhaust induces vascular effects including impaired endothelial function and increased atherosclerosis. Objective To examine the in vivo effects of subchronic diesel exhaust exposure on endothelial cell transcriptional responses in the presence of hypercholesterolemia. Methods ApoE (−/−) and ApoE (+/+) mice inhaled diesel exhaust diluted to particulate matter levels of 300 or 1000 μg/m3 vs. filtered air. After 30 days, endothelial cells were harvested from dispersed aortic cells by fluorescent-activated cell sorting (FACS). Relative mRNA abundance was evaluated by microarray analysis to measure strain-specific transcriptional responses in mice exposed to dilute diesel exhaust vs. filtered air. Results Forty-nine transcripts were significantly dysregulated by >2.8-fold in the endothelium of ApoE (−/−) mice receiving diesel exhaust at 300 or 1000 μg/m3. These included transcripts with roles in plasminogen activation, endothelial permeability, inflammation, genomic stability, and atherosclerosis; similar responses were not observed in ApoE (+/+) mice. Conclusions The potentiation of diesel exhaust-related endothelial gene regulation by hypercholesterolemia helps to explain air pollution-induced vascular effects in animals and humans. The observed regulated transcripts implicate pathways important in the acceleration of atherosclerosis by air pollution. PMID:21222557

Targeting tumor antigens to secreted membrane vesicles in vivo induces efficient antitumor immune responses.

PubMed

Zeelenberg, Ingrid S; Ostrowski, Matias; Krumeich, Sophie; Bobrie, Angélique; Jancic, Carolina; Boissonnas, Alexandre; Delcayre, Alain; Le Pecq, Jean-Bernard; Combadière, Béhazine; Amigorena, Sebastian; Théry, Clotilde

2008-02-15

Expression of non-self antigens by tumors can induce activation of T cells in vivo, although this activation can lead to either immunity or tolerance. CD8+ T-cell activation can be direct (if the tumor expresses MHC class I molecules) or indirect (after the capture and cross-presentation of tumor antigens by dendritic cells). The modes of tumor antigen capture by dendritic cells in vivo remain unclear. Here we examine the immunogenicity of the same model antigen secreted by live tumors either in association with membrane vesicles (exosomes) or as a soluble protein. We have artificially addressed the antigen to secreted vesicles by coupling it to the factor VIII-like C1C2 domain of milk fat globule epidermal growth factor-factor VIII (MFG-E8)/lactadherin. We show that murine fibrosarcoma tumor cells that secrete vesicle-bound antigen grow slower than tumors that secrete soluble antigen in immunocompetent, but not in immunodeficient, host mice. This growth difference is due to the induction of a more potent antigen-specific antitumor immune response in vivo by the vesicle-bound than by the soluble antigen. Finally, in vivo secretion of the vesicle-bound antigen either by tumors or by vaccination with naked DNA protects against soluble antigen-secreting tumors. We conclude that the mode of secretion can determine the immunogenicity of tumor antigens and that manipulation of the mode of antigen secretion may be used to optimize antitumor vaccination protocols.

Geraniol Suppresses Angiogenesis by Downregulating Vascular Endothelial Growth Factor (VEGF)/VEGFR-2 Signaling.

PubMed

Wittig, Christine; Scheuer, Claudia; Parakenings, Julia; Menger, Michael D; Laschke, Matthias W

2015-01-01

Geraniol exerts several direct pharmacological effects on tumor cells and, thus, has been suggested as a promising anti-cancer compound. Because vascularization is a major precondition for tumor growth, we analyzed in this study the anti-angiogenic action of geraniol. In vitro, geraniol reduced the migratory activity of endothelial-like eEND2 cells. Western blot analyses further revealed that geraniol downregulates proliferating cell nuclear antigen (PCNA) and upregulates cleaved caspase-3 (Casp-3) expression in eEND2 cells. Moreover, geraniol blocked vascular endothelial growth factor (VEGF)/VEGFR-2 signal transduction, resulting in a suppression of downstream AKT and ERK signaling pathways. In addition, geraniol significantly reduced vascular sprout formation in a rat aortic ring assay. In vivo, geraniol inhibited the vascularization of CT26 tumors in dorsal skinfold chambers of BALB/c mice, which was associated with a smaller tumor size when compared to vehicle-treated controls. Immunohistochemical analyses confirmed a decreased number of Ki67-positive cells and CD31-positive microvessels with reduced VEGFR-2 expression within geraniol-treated tumors. Taken together, these findings indicate that geraniol targets multiple angiogenic mechanisms and, therefore, is an attractive candidate for the anti-angiogenic treatment of tumors.

Isolation and characterization of human umbilical cord-derived endothelial colony-forming cells

PubMed Central

Zhang, Hao; Tao, Yanling; Ren, Saisai; Liu, Haihui; Zhou, Hui; Hu, Jiangwei; Tang, Yongyong; Zhang, Bin; Chen, Hu

2017-01-01

Endothelial colony-forming cells (ECFCs) are a population of endothelial progenitor cells (EPCs) that display robust proliferative potential and vessel-forming capability. Previous studies have demonstrated that a limited number of ECFCs may be obtained from adult bone marrow, peripheral blood and umbilical cord (UC) blood. The present study describes an effective method for isolating ECFCs from human UC. The ECFCs derived from human UC displayed the full properties of EPCs. Analysis of the growth kinetics, cell cycle and colony-forming ability of the isolated human UC-ECFCs indicated that the cells demonstrated properties of stem cells, including relative stability and rapid proliferation in vitro. Gene expression of Fms related tyrosine kinase 1, kinase insert domain receptor, vascular endothelial cadherin, cluster of differentiation (CD)31, CD34, epidermal growth factor homology domains-2, von Willebrand factor and endothelial nitric oxide synthase was assessed by reverse transcription-polymerase chain reaction. The cells were positive for CD34, CD31, CD73, CD105 and vascular endothelial growth factor receptor-2, and negative for CD45, CD90 and human leukocyte antigen-antigen D related protein according to flow cytometry. 1,1′-dioctadecyl-3,3,3′,3′-tetra-methyl-indocarbocyanine perchlorate-labeled acetylated low-density lipoprotein and fluorescein isothiocyanate-Ulex europaeus-l were used to verify the identity of the UC-ECFCs. Matrigel was used to investigate tube formation capability. The results demonstrated that the reported technique is a valuable method for isolating human UC-ECFCs, which have potential for use in vascular regeneration. PMID:29067104

ACE/DD genotype is associated with hemostasis balance disturbances reflecting hypercoagulability and endothelial dysfunction in patients with untreated hypertension.

PubMed

Makris, T K; Stavroulakis, G A; Dafni, U G; Gialeraki, A E; Krespi, P G; Hatzizacharias, A N; Tsoukala, C G; Vythoulkas, J S; Kyriakidis, M K

2000-11-01

Angiotensin-converting enzyme (ACE) gene polymorphism has been associated with an increased incidence of myocardial infarction. Recent studies have investigated a potential influence of ACE gene polymorphism on fibrinolysis or endothelial function. It has been previously established that essential hypertension is accompanied by endothelial dysfunction and fibrinolytic balance disorders. The aim of our study was to study the relation between ACE gene polymorphism and fibrinolytic/hemostatic factors as well as endothelial cell damage markers in patients with hypertension. The following parameters were evaluated in 104 patients with previously untreated hypertension: plasminogen activator inhibitor-1 (PAI-1), tissue plasminogen activator (tPA) antigen, fibrinogen, D-dimer, and von Willebrand factor (vWF). The genotype of the ACE gene was also determined (by the polymerase chain reaction method), and patients were characterized according to the observed alleles as deletion/deletion (DD), insertion/insertion (II), or insertion/deletion (ID). Those with DD genotype (n = 42) had significantly higher plasma levels of PAI-1 antigen (P =. 012), tPA antigen (P =.0001), fibrinogen (P =.0002), D-dimer (P =. 0001) and vWF (P =.0004) compared with ID (n = 30) or II (n = 32) genotypes. The ACE gene genotypes appeared to be significant predictors for plasma PAI-1 antigen, tPA antigen, fibrinogen, D -dimer, and vWF even after adjustment for age, sex, body mass index, triglyceride and cholesterol levels, and blood pressure. Our findings suggest that the ACE/DD genotype is associated with hemostasis balance disturbances reflecting hypercoagulability and endothelial damage in patients with untreated hypertension.

In Vitro Endothelialization Test of Biomaterials Using Immortalized Endothelial Cells.

PubMed

Kono, Ken; Hiruma, Hitomi; Kobayashi, Shingo; Sato, Yoji; Tanaka, Masaru; Sawada, Rumi; Niimi, Shingo

2016-01-01

Functionalizing biomaterials with peptides or polymers that enhance recruitment of endothelial cells (ECs) can reduce blood coagulation and thrombosis. To assess endothelialization of materials in vitro, primary ECs are generally used, although the characteristics of these cells vary among the donors and change with time in culture. Recently, primary cell lines immortalized by transduction of simian vacuolating virus 40 large T antigen or human telomerase reverse transcriptase have been developed. To determine whether immortalized ECs can substitute for primary ECs in material testing, we investigated endothelialization on biocompatible polymers using three lots of primary human umbilical vein endothelial cells (HUVEC) and immortalized microvascular ECs, TIME-GFP. Attachment to and growth on polymer surfaces were comparable between cell types, but results were more consistent with TIME-GFP. Our findings indicate that TIME-GFP is more suitable for in vitro endothelialization testing of biomaterials.

Healthy human T-Cell Responses to Aspergillus fumigatus antigens.

PubMed

Chaudhary, Neelkamal; Staab, Janet F; Marr, Kieren A

2010-02-17

Aspergillus fumigatus is associated with both invasive and allergic pulmonary diseases, in different hosts. The organism is inhaled as a spore, which, if not cleared from the airway, germinates into hyphal morphotypes that are responsible for tissue invasion and resultant inflammation. Hyphae secrete multiple products that function as antigens, evoking both a protective (T(H)1-T(H)17) and destructive allergic (T(H)2) immunity. How Aspergillus allergens (Asp f proteins) participate in the development of allergic sensitization is unknown. To determine whether Asp f proteins are strictly associated with T(H)2 responses, or represent soluble hyphal products recognized by healthy hosts, human T cell responses to crude and recombinant products were characterized by ELISPOT. While responses (number of spots producing IFN-gamma, IL-4 or IL-17) to crude hyphal antigen preparations were weak, responses to recombinant Asp f proteins were higher. Recombinant allergens stimulated cells to produce IFN-gamma more so than IL-4 or IL-17. Volunteers exhibited a diverse CD4+ and CD8+ T cell antigen recognition profile, with prominent CD4 T(H)1-responses to Asp f3 (a putative peroxismal membrane protein), Asp f9/16 (cell wall glucanase), Asp f11 (cyclophilin type peptidyl-prolyl isomerase) and Asp f22 (enolase). Strong IFN-gamma responses were reproduced in most subjects tested over 6 month intervals. Products secreted after conidial germination into hyphae are differentially recognized by protective T cells in healthy, non-atopic individuals. Defining the specificity of the human T cell repertoire, and identifying factors that govern early responses may allow for development of novel diagnostics and therapeutics for both invasive and allergic Aspergillus diseases.

OPTICAL COHERENCE TOMOGRAPHY BASELINE PREDICTORS FOR INITIAL BEST-CORRECTED VISUAL ACUITY RESPONSE TO INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR TREATMENT IN EYES WITH DIABETIC MACULAR EDEMA: The CHARTRES Study.

PubMed

Santos, Ana R; Costa, Miguel Â; Schwartz, Christian; Alves, Dalila; Figueira, João; Silva, Rufino; Cunha-Vaz, Jose G

2018-06-01

To identify baseline optical coherence tomography morphologic characteristics predicting the visual response to anti-vascular endothelial growth factor therapy in diabetic macular edema. Sixty-seven patients with diabetic macular edema completed a prospective, observational study (NCT01947881-CHARTRES). All patients received monthly intravitreal injections of Lucentis for 3 months followed by PRN treatment and underwent best-corrected visual acuity measurements and spectral domain optical coherence tomography at Baseline, Months 1, 2, 3, and 6. Visual treatment response was characterized as good (≥10 letters), moderate (5-10 letters), and poor (<5 or letters loss). Spectral domain optical coherence tomography images were graded before and after treatment by a certified Reading Center. One month after loading dose, 26 patients (38.80%) were identified as good responders, 19 (28.35%) as Moderate and 22 (32.83%) as poor responders. There were no significant best-corrected visual acuity and central retinal thickness differences at baseline (P = 0.176; P = 0.573, respectively). Ellipsoid zone disruption and disorganization of retinal inner layers were good predictors for treatment response, representing a significant risk for poor visual recovery to anti-vascular endothelial growth factor therapy (odds ratio = 10.96; P < 0.001 for ellipsoid zone disruption and odds ratio = 7.05; P = 0.034 for disorganization of retinal inner layers). Damage of ellipsoid zone, higher values of disorganization of retinal inner layers, and central retinal thickness decrease are good predictors of best-corrected visual acuity response to anti-vascular endothelial growth factor therapy.

Onchocerciasis modulates the immune response to mycobacterial antigens

PubMed Central

Stewart, G R; Boussinesq, M; Coulson, T; Elson, L; Nutman, T; Bradley, J E

1999-01-01

Chronic helminth infection induces a type-2 cellular immune response. In contrast to this, mycobacterial infections commonly induce a type-1 immune response which is considered protective. Type-2 responses and diminished type-1 responses to mycobacteria have been previously correlated with active infection states such as pulmonary tuberculosis and lepromatous leprosy. The present study examines the immune responses of children exposed to both the helminth parasite Onchocerca volvulus and the mycobacterial infections, Mycobacterium tuberculosis and M. leprae. Proliferation of peripheral blood mononuclear cells (PBMC) and production of IL-4 in response to both helminth and mycobacterial antigen (PPD) decreased dramatically with increasing microfilarial (MF) density. Although interferon-gamma (IFN-γ) production strongly correlated with cellular proliferation, it was surprisingly not related to MF density for either antigen. IL-4 production in response to helminth antigen and PPD increased with ascending children's age. IFN-γ and cellular proliferation to PPD were not related to age, but in response to helminth antigen were significantly higher in children of age 9–12 years than children of either the younger age group (5–8 years) or the older group (13–16 years). Thus, there was a MF density-related down-regulation of cellular responsiveness and age-related skewing toward type 2 which was paralleled in response to both the helminth antigen and PPD. This parasite-induced immunomodulation of the response to mycobacteria correlates with a previous report of doubled incidence of lepromatous leprosy in onchocerciasis hyperendemic regions. Moreover, this demonstration that helminth infection in humans can modulate the immune response to a concurrent infection or immunological challenge is of critical importance to future vaccination strategies. PMID:10469056

Endothelial markers in malignant vascular tumours of the liver: superiority of QB-END/10 over von Willebrand factor and Ulex europaeus agglutinin 1.

PubMed

Anthony, P P; Ramani, P

1991-01-01

A new monoclonal antibody, QB-END/10, raised against the CD34 antigen in human endothelial cell membranes and haemopoietic progenitor cells, was studied for its usefulness as a marker of neoplastic vascular cells in 21 angiosarcomas and seven malignant haemangioendotheliomas of the liver. QB-END/10 was both more sensitive and more specific than Von Willebrand factor (VWF) and Ulex europaeus 1 agglutinin (UEA-1) in labelling endothelial cells and it did not cross react with epithelia as UEA-1 often does. Staining was uniformly strong and clear in all histological variants of these two tumours. QB-END/10 should prove particularly useful in the differential diagnosis of malignant vascular tumours of the liver.

Endothelial markers in malignant vascular tumours of the liver: superiority of QB-END/10 over von Willebrand factor and Ulex europaeus agglutinin 1.

PubMed Central

Anthony, P P; Ramani, P

1991-01-01

A new monoclonal antibody, QB-END/10, raised against the CD34 antigen in human endothelial cell membranes and haemopoietic progenitor cells, was studied for its usefulness as a marker of neoplastic vascular cells in 21 angiosarcomas and seven malignant haemangioendotheliomas of the liver. QB-END/10 was both more sensitive and more specific than Von Willebrand factor (VWF) and Ulex europaeus 1 agglutinin (UEA-1) in labelling endothelial cells and it did not cross react with epithelia as UEA-1 often does. Staining was uniformly strong and clear in all histological variants of these two tumours. QB-END/10 should prove particularly useful in the differential diagnosis of malignant vascular tumours of the liver. Images PMID:1705261

Breast Angiosarcoma: Case Series and Expression of Vascular Endothelial Growth Factor

PubMed Central

Brar, Rondeep; West, Robert; Witten, Daniela; Raman, Bhargav; Jacobs, Charlotte; Ganjoo, Kristen

2009-01-01

Purpose Angiosarcoma of the breast is a rare, malignant tumor for which little is known regarding prognostic indicators and optimal therapeutic regimens. To address this issue, we performed a retrospective analysis of breast angiosarcoma cases seen at Stanford University along with immunohistochemical analysis for markers of angiogenesis. Methods Breast angiosarcoma cases seen between 1980 and 2008 were examined. Viable tissue blocks were analyzed for expression of vascular endothelial growth factor and its receptors. Results A total of 16 cases were identified. Data was collected regarding epidemiology, treatment, response rates, disease-free survival, and the use of various imaging modalities. Five tissue blocks remained viable for immunohistochemical analysis. Vascular endothelial growth factor-A was positively expressed in 3 of these samples. Conclusion Angiosarcoma of the breast is an aggressive malignancy with a propensity for both local recurrence and distant metastases. Angiogenesis inhibition may represent a novel therapeutic modality in this rare, vascular malignancy. PMID:20737044

Use of routine histopathology and factor VIII-related antigen/von Willebrand factor immunohistochemistry to differentiate primary hemangiosarcoma of bone from telangiectatic osteosarcoma in 54 dogs.

PubMed

Giuffrida, M A; Bacon, N J; Kamstock, D A

2017-12-01

Hemangiosarcoma (HSA) of bone and telangiectatic osteosarcoma (tOSA) can appear similar histologically, but differ in histogenesis (malignant endothelial cells versus osteoblasts), and may warrant different treatments. Immunohistochemistry (IHC) for endothelial cell marker factor VIII-related antigen/von Willebrand factor (FVIII-RAg/vWF) is a well-documented ancillary test to confirm HSA diagnoses in soft tissues, but its use in osseous HSA is rarely described. Archived samples of 54 primary appendicular bone tumours previously diagnosed as HSA or tOSA were evaluated using combination routine histopathology (RHP) and IHC. Approximately 20% of tumours were reclassified on the basis of FVIII-RAg/vWF immunoreactivity, typically from an original diagnosis of tOSA to a reclassified diagnosis of HSA. No sample with tumour osteoid clearly identified on RHP was immunopositive for FVIII-RAg/vWF. RHP alone was specific but not sensitive for diagnosis of HSA, compared with combination RHP and IHC. Routine histopathological evaluation in combination with FVIII-RAg/vWF IHC can help differentiate canine primary appendicular HSA from tOSA. © 2016 John Wiley & Sons Ltd.

Vascular endothelial growth factor is upregulated by l-dopa in the parkinsonian brain: implications for the development of dyskinesia

PubMed Central

Francardo, Veronica; Lindgren, Hanna S.; Sillivan, Stephanie E.; O’Sullivan, Sean S.; Luksik, Andrew S.; Vassoler, Fair M.; Lees, Andrew J.; Konradi, Christine

2011-01-01

Angiogenesis and increased permeability of the blood–brain barrier have been reported to occur in animal models of Parkinson’s disease and l-dopa-induced dyskinesia, but the significance of these phenomena has remained unclear. Using a validated rat model of l-dopa-induced dyskinesia, this study demonstrates that chronic treatment with l-dopa dose dependently induces the expression of vascular endothelial growth factor in the basal ganglia nuclei. Vascular endothelial growth factor was abundantly expressed in astrocytes and astrocytic processes in the proximity of blood vessels. When co-administered with l-dopa, a small molecule inhibitor of vascular endothelial growth factor signalling significantly attenuated the development of dyskinesia and completely blocked the angiogenic response and associated increase in blood–brain barrier permeability induced by the treatment. The occurrence of angiogenesis and vascular endothelial growth factor upregulation was verified in post-mortem basal ganglia tissue from patients with Parkinson’s disease with a history of dyskinesia, who exhibited increased microvascular density, microvascular nestin expression and an upregulation of vascular endothelial growth factor messenger ribonucleic acid. These congruent findings in the rat model and human patients indicate that vascular endothelial growth factor is implicated in the pathophysiology of l-dopa-induced dyskinesia and emphasize an involvement of the microvascular compartment in the adverse effects of l-dopa pharmacotherapy in Parkinson’s disease. PMID:21771855

Role of the Antigen Capture Pathway in the Induction of a Neutralizing Antibody Response to Anthrax Protective Antigen.

PubMed

Verma, Anita; Ngundi, Miriam M; Price, Gregory A; Takeda, Kazuyo; Yu, James; Burns, Drusilla L

2018-02-27

Toxin neutralizing antibodies represent the major mode of protective immunity against a number of toxin-mediated bacterial diseases, including anthrax; however, the cellular mechanisms that lead to optimal neutralizing antibody responses remain ill defined. Here we show that the cellular binding pathway of anthrax protective antigen (PA), the binding component of anthrax toxin, determines the toxin neutralizing antibody response to this antigen. PA, which binds cellular receptors and efficiently enters antigen-presenting cells by receptor-mediated endocytosis, was found to elicit robust anti-PA IgG and toxin neutralizing antibody responses. In contrast, a receptor binding-deficient mutant of PA, which does not bind receptors and only inefficiently enters antigen-presenting cells by macropinocytosis, elicited very poor antibody responses. A chimeric protein consisting of the receptor binding-deficient PA mutant tethered to the binding subunit of cholera toxin, which efficiently enters cells using the cholera toxin receptor rather than the PA receptor, elicited an anti-PA IgG antibody response similar to that elicited by wild-type PA; however, the chimeric protein elicited a poor toxin neutralizing antibody response. Taken together, our results demonstrate that the antigen capture pathway can dictate the magnitudes of the total IgG and toxin neutralizing antibody responses to PA as well as the ratio of the two responses. IMPORTANCE Neutralizing antibodies provide protection against a number of toxin-mediated bacterial diseases by inhibiting toxin action. Therefore, many bacterial vaccines are designed to induce a toxin neutralizing antibody response. We have used protective antigen (PA), the binding component of anthrax toxin, as a model antigen to investigate immune mechanisms important for the induction of robust toxin neutralizing antibody responses. We found that the pathway used by antigen-presenting cells to capture PA dictates the robustness of the

Capture of endothelial cells under flow using immobilized vascular endothelial growth factor

PubMed Central

Smith, Randall J.; Koobatian, Maxwell T.; Shahini, Aref; Swartz, Daniel D.; Andreadis, Stelios T.

2015-01-01

We demonstrate the ability of immobilized vascular endothelial growth factor (VEGF) to capture endothelial cells (EC) with high specificity under fluid flow. To this end, we engineered a surface consisting of heparin bound to poly-L-lysine to permit immobilization of VEGF through the C-terminal heparin-binding domain. The immobilized growth factor retained its biological activity as shown by proliferation of EC and prolonged activation of KDR signaling. Using a microfluidic device we assessed the ability to capture EC under a range of shear stresses from low (0.5 dyne/cm2) to physiological (15 dyne/cm2). Capture was significant for all shear stresses tested. Immobilized VEGF was highly selective for EC as evidenced by significant capture of human umbilical vein and ovine pulmonary artery EC but no capture of human dermal fibroblasts, human hair follicle derived mesenchymal stem cells, or mouse fibroblasts. Further, VEGF could capture EC from mixtures with non-EC under low and high shear conditions as well as from complex fluids like whole human blood under high shear. Our findings may have far reaching implications, as they suggest that VEGF could be used to promote endothelialization of vascular grafts or neovascularization of implanted tissues by rare but continuously circulating EC. PMID:25771020

Endothelial Snail Regulates Capillary Branching Morphogenesis via Vascular Endothelial Growth Factor Receptor 3 Expression

PubMed Central

Park, Jeong Ae; Kim, Dong Young; Kim, Young-Myeong; Kwon, Young-Guen

2015-01-01

Vascular branching morphogenesis is activated and maintained by several signaling pathways. Among them, vascular endothelial growth factor receptor 2 (VEGFR2) signaling is largely presented in arteries, and VEGFR3 signaling is in veins and capillaries. Recent reports have documented that Snail, a well-known epithelial-to-mesenchymal transition protein, is expressed in endothelial cells, where it regulates sprouting angiogenesis and embryonic vascular development. Here, we identified Snail as a regulator of VEGFR3 expression during capillary branching morphogenesis. Snail was dramatically upregulated in sprouting vessels in the developing retinal vasculature, including the leading-edged vessels and vertical sprouting vessels for capillary extension toward the deep retina. Results from in vitro functional studies demonstrate that Snail expression colocalized with VEGFR3 and upregulated VEGFR3 mRNA by directly binding to the VEGFR3 promoter via cooperating with early growth response protein-1. Snail knockdown in postnatal mice attenuated the formation of the deep capillary plexus, not only by impairing vertical sprouting vessels but also by downregulating VEGFR3 expression. Collectively, these data suggest that the Snail-VEGFR3 axis controls capillary extension, especially in vessels expressing VEGFR2 at low levels. PMID:26147525

Endothelial microparticles interact with and support the proliferation of T cells

PubMed Central

Wheway, Julie; Latham, Sharissa L; Combes, Valery; Grau, Georges ER

2014-01-01

Endothelial cells (EC) closely interact with circulating lymphocytes. Aggression or activation of the endothelium leads to an increased shedding of EC microparticles (MP). Endothelial MP (EMP) are found in high plasma levels in numerous immunoinflammatory diseases, e.g. atherosclerosis, sepsis, multiple sclerosis and cerebral malaria, supporting their role as effectors and markers of vascular dysfunction. Given our recently described role for human brain microvascular endothelial cells (HBEC) in modulating immune responses we investigated how HBEC-derived MP could interact with and support the proliferation of T cells. Like their mother cells, EMP expressed molecules important for antigen presentation and T cell co-stimulation, i.e., β2-microglobulin, MHC II, CD40 and ICOSL. HBEC were able to take up fluorescently labeled antigens with EMP also containing fluorescent antigens suggestive of antigen carryover from HBEC to EMP. In co-cultures, fluorescently labeled EMP from resting or cytokine-stimulated HBEC formed conjugates with both CD4+ and CD8+ subsets, with higher proportions of T cells binding EMP from cytokine stimulated cells. The increased binding of EMP from cytokine stimulated HBEC to T cells was VCAM-1 and ICAM-1-dependent. Finally, in CFSE T cell proliferation assays using anti-CD3 mAb or T cell mitogens, EMP promoted the proliferation of CD4+ T cells and that of CD8+ T cells in the absence of exogenous stimuli and in the T cell mitogenic stimulation. Our findings provide novel evidence that EMP can enhance T cell activation and potentially ensuing antigen presentation, thereby pointing towards a novel role for MP in neuro-immunological complications of infectious diseases. PMID:25187656

Rac regulates vascular endothelial growth factor stimulated motility.

PubMed

Soga, N; Connolly, J O; Chellaiah, M; Kawamura, J; Hruska, K A

2001-01-01

During angiogenesis endothelial cells migrate towards a chemotactic stimulus. Understanding the mechanism of endothelial cell migration is critical to the therapeutic manipulation of angiogenesis and ultimately cancer prevention. Vascular endothelial growth factor (VEGF) is a potent chemotactic stimulus of endothelial cells during angiogenesis. The endothelial cell signal transduction pathway of VEGF represents a potential target for cancer therapy, but the mechanisms of post-receptor signal transduction including the roles of rho family GTPases in regulating the cytoskeletal effects of VEGF in endothelial cells are not understood. Here we analyze the mechanisms of cell migration in the mouse brain endothelial cell line (bEND3). Stable transfectants containing a tetracycline repressible expression vector were used to induce expression of Rac mutants. Endothelial cell haptotaxis was stimulated by constitutively active V12Rac on collagen and vitronectin coated supports, and chemotaxis was further stimulated by VEGF. Osteopontin coated supports were the most stimulatory to bEND3 haptotaxis, but VEGF was not effective in further increasing migration on osteopontin coated supports. Haptotaxis on support coated with collagen, vitronectin, and to a lesser degree osteopontin was inhibited by N17 Rac. N17 Rac expression blocked stimulation of endothelial cell chemotaxis by VEGF. As part of the chemotactic stimulation, VEGF caused a loss of actin organization at areas of cell-cell contact and increased stress fiber expression in endothelial cells which were directed towards pores in the transwell membrane. N17 Rac prevented the stimulation of cell-cell contact disruption and the stress fiber stimulation by VEGF. These data demonstrate two pathways of regulating endothelial cell motility, one in which Rac is activated by matrix/integrin stimulation and is a crucial modulator of endothelial cell haptotaxis. The other pathway, in the presence of osteopontin, is Rac independent

Geraniol Suppresses Angiogenesis by Downregulating Vascular Endothelial Growth Factor (VEGF)/VEGFR-2 Signaling

PubMed Central

Wittig, Christine; Scheuer, Claudia; Parakenings, Julia; Menger, Michael D.; Laschke, Matthias W.

2015-01-01

Geraniol exerts several direct pharmacological effects on tumor cells and, thus, has been suggested as a promising anti-cancer compound. Because vascularization is a major precondition for tumor growth, we analyzed in this study the anti-angiogenic action of geraniol. In vitro, geraniol reduced the migratory activity of endothelial-like eEND2 cells. Western blot analyses further revealed that geraniol downregulates proliferating cell nuclear antigen (PCNA) and upregulates cleaved caspase-3 (Casp-3) expression in eEND2 cells. Moreover, geraniol blocked vascular endothelial growth factor (VEGF)/VEGFR-2 signal transduction, resulting in a suppression of downstream AKT and ERK signaling pathways. In addition, geraniol significantly reduced vascular sprout formation in a rat aortic ring assay. In vivo, geraniol inhibited the vascularization of CT26 tumors in dorsal skinfold chambers of BALB/c mice, which was associated with a smaller tumor size when compared to vehicle-treated controls. Immunohistochemical analyses confirmed a decreased number of Ki67-positive cells and CD31-positive microvessels with reduced VEGFR-2 expression within geraniol-treated tumors. Taken together, these findings indicate that geraniol targets multiple angiogenic mechanisms and, therefore, is an attractive candidate for the anti-angiogenic treatment of tumors. PMID:26154255

Neuropilin2 expressed in gastric cancer endothelial cells increases the proliferation and migration of endothelial cells in response to VEGF

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Woo Ho; Lee, Sun Hee; Jung, Myung Hwan

2009-08-01

The structure and characteristics of the tumor vasculature are known to be different from those of normal vessels. Neuropilin2 (Nrp2), which is expressed in non-endothelial cell types, such as neuronal or cancer cells, functions as a receptor for both semaphorin and vascular endothelial growth factor (VEGF). After isolating tumor and normal endothelial cells from advanced gastric cancer tissue and normal gastric mucosa tissues, respectively, we identified genes that were differentially expressed in gastric tumor endothelial (TEC) and normal endothelial cells (NEC) using DNA oligomer chips. Using reverse transcriptase-PCR, we confirmed the chip results by showing that Nrp2 gene expression ismore » significantly up-regulated in TEC. Genes that were found to be up-regulated in TEC were also observed to be up-regulated in human umbilical vein endothelial cells (HUVECs) that were co-cultured with gastric cancer cells. In addition, HUVECs co-cultured with gastric cancer cells showed an increased reactivity to VEGF-induced proliferation and migration. Moreover, overexpression of Nrp2 in HUVECs significantly enhanced the proliferation and migration induced by VEGF. Observation of an immunohistochemical analysis of various human tumor tissue arrays revealed that Nrp2 is highly expressed in the tumor vessel lining and to a lesser extent in normal tissue microvessels. From these results, we suggest that Nrp2 may function to increase the response to VEGF, which is more significant in TEC than in NEC given the differential expression, leading to gastric TEC with aggressive angiogenesis phenotypes.« less

Titanium dioxide nanoparticles increase inflammatory responses in vascular endothelial cells

PubMed Central

Han, Sung Gu; Newsome, Bradley; Hennig, Bernhard

2013-01-01

Atherosclerosis is a chronic inflammatory disease that remains the leading cause of death in the United States. Numerous risk factors for endothelial cell inflammation and the development of atherosclerosis have been identified, including inhalation of ultrafine particles. Recently, engineered nanoparticles (NPs) such as titanium (TiO2) NPs have attracted much attention due to their wide range of applications. However, there are also great concerns surrounding potential adverse health effects in vascular systems. Although TiO2 NPs are known to induce oxidative stress and inflammation, the associated signaling pathways have not been well studied. The focus of this work, therefore, deals with examination of the cellular signaling pathways responsible for TiO2 NP-induced endothelial oxidative stress and inflammation. In this study, primary vascular endothelial cells were treated with TiO2 NPs for 2–16 h at concentrations of 0–50 µg/mL. TiO2 NP exposure increased cellular oxidative stress and DNA binding of NF-κB. Further, phosphorylation of Akt, ERK, JNK and p38 was increased in cells exposed to TiO2 NPs. TiO2 NPs also significantly increased induction of mRNA and protein levels of vascular cell adhesion molecule-1 (VCAM-1) and mRNA levels of monocyte chemoattractant protein-1 (MCP-1). Pretreatment with inhibitors for NF-κB (pyrrolidine dithiocarbamate), oxidative stress (epigallocatechin gallate and apocynin), Akt (LY294002), ERK (PD98059), JNK (SP600125) and p38 (SB203580) significantly attenuated TiO2 NP-induced MCP-1 and VCAM-1 gene expression, as well as activation of NF-κB. These data indicate that TiO2 NPs can induce endothelial inflammatory responses via redox-sensitive cellular signaling pathways. PMID:23380242

Glucocorticoid Induction of Occludin Expression and Endothelial Barrier Requires Transcription Factor p54 NONO

PubMed Central

Keil, Jason M.; Liu, Xuwen; Antonetti, David A.

2013-01-01

Purpose. Glucocorticoids (GCs) effectively reduce retinal edema and induce vascular barrier properties but possess unwanted side effects. Understanding GC induction of barrier properties may lead to more effective and specific therapies. Previous work identified the occludin enhancer element (OEE) as a GC-responsive cis-element in the promoters of multiple junctional genes, including occludin, claudin-5, and cadherin-9. Here, we identify two OEE-binding factors and determine their contribution to GC induction of tight junction (TJ) gene expression and endothelial barrier properties. Methods. OEE-binding factors were isolated from human retinal endothelial cells (HREC) using DNA affinity purification followed by MALDI-TOF MS/MS. Chromatin immunoprecipitation (ChIP) assays determined in situ binding. siRNA was used to evaluate the role of trans-acting factors in transcription of TJ genes in response to GC stimulation. Paracellular permeability was determined by quantifying flux through a cell monolayer, whereas transendothelial electrical resistance (TER) was measured using the ECIS system. Results. MS/MS analysis of HREC nuclear extracts identified the heterodimer of transcription factors p54/NONO (p54) and polypyrimidine tract-binding protein-associated splicing factor (PSF) as OEE-binding factors, which was confirmed by ChIP assay from GC-treated endothelial cells and rat retina. siRNA knockdown of p54 demonstrated that this factor is necessary for GC induction of occludin and claudin-5 expression. Further, p54 knockdown ablated the pro-barrier effects of GC treatment. Conclusions. p54 is essential for GC-mediated expression of occludin, claudin-5, and barrier induction, and the p54/PSF heterodimer may contribute to normal blood-retinal barrier (BRB) induction in vivo. Understanding the mechanism of GC induction of BRB properties may provide novel therapies for macular edema. PMID:23640037

Glucocorticoid induction of occludin expression and endothelial barrier requires transcription factor p54 NONO.

PubMed

Keil, Jason M; Liu, Xuwen; Antonetti, David A

2013-06-12

Glucocorticoids (GCs) effectively reduce retinal edema and induce vascular barrier properties but possess unwanted side effects. Understanding GC induction of barrier properties may lead to more effective and specific therapies. Previous work identified the occludin enhancer element (OEE) as a GC-responsive cis-element in the promoters of multiple junctional genes, including occludin, claudin-5, and cadherin-9. Here, we identify two OEE-binding factors and determine their contribution to GC induction of tight junction (TJ) gene expression and endothelial barrier properties. OEE-binding factors were isolated from human retinal endothelial cells (HREC) using DNA affinity purification followed by MALDI-TOF MS/MS. Chromatin immunoprecipitation (ChIP) assays determined in situ binding. siRNA was used to evaluate the role of trans-acting factors in transcription of TJ genes in response to GC stimulation. Paracellular permeability was determined by quantifying flux through a cell monolayer, whereas transendothelial electrical resistance (TER) was measured using the ECIS system. MS/MS analysis of HREC nuclear extracts identified the heterodimer of transcription factors p54/NONO (p54) and polypyrimidine tract-binding protein-associated splicing factor (PSF) as OEE-binding factors, which was confirmed by ChIP assay from GC-treated endothelial cells and rat retina. siRNA knockdown of p54 demonstrated that this factor is necessary for GC induction of occludin and claudin-5 expression. Further, p54 knockdown ablated the pro-barrier effects of GC treatment. p54 is essential for GC-mediated expression of occludin, claudin-5, and barrier induction, and the p54/PSF heterodimer may contribute to normal blood-retinal barrier (BRB) induction in vivo. Understanding the mechanism of GC induction of BRB properties may provide novel therapies for macular edema.

Induction of endothelial cell proliferation by angiogenic factors released by activated monocytes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pakala, Rajbabu; Watanabe, Takuya; Benedict, Claude R

2002-06-01

Introduction: Cell-cell interaction is an essential component of atherosclerotic plaque development. Activated monocytes appear to play a central role in the development of atherosclerosis, not only through foam cell formation but also via the production of various growth factors that induce proliferation of different cell types that are involved in the plaque development. Using serum free co-culture method, we determined the effect of monocytes on endothelial cell proliferation. Methods: Endothelial cell proliferation is determined by the amount of [{sup 3}H]thymidine incorporated in to the DNA. Basic fibroblast growth factor (b-FGF), vascular endothelial growth factor (VEGF) and interleukin-8 (IL-8) levels inmore » the conditioned medium were determined by ELISA. Results: Conditioned medium from unactivated monocytes partially inhibited endothelial cell proliferation, whereas conditioned medium from activated monocytes promoted endothelial cell proliferation. The mitogenic effect of conditioned medium derived from activated monocytes is due to the presence of b-FGF, VEGF and IL-8. Neutralizing antibodies against b-FGF, VEGF and IL-8 partially reversed the mitogenic effect of conditioned medium derived from activated monocytes. When b-FGF, VEGF and IL-8 were immunoprecipitated from conditioned medium derived from activated monocytes, it is less mitogenic to endothelial cells. Conclusion: Activated monocytes may play an important role in the development of atherosclerotic plaque by producing endothelial cell growth factors.« less

Serodiagnosis of Tuberculosis: Comparison of Immunoglobulin A (IgA) Response to Sulfolipid I with IgG and IgM Responses to 2,3-Diacyltrehalose, 2,3,6-Triacyltrehalose, and Cord Factor Antigens

PubMed Central

Julián, Esther; Matas, Lurdes; Pérez, Andrés; Alcaide, José; Lanéelle, Marie-Antoinette; Luquin, Marina

2002-01-01

Nonpeptidic antigens from the Mycobacterium tuberculosis cell wall are the focus of extensive studies to determine their potential role as protective antigens or serological markers of tuberculous disease. Regarding this latter role and using an enzyme-linked immunosorbent assay, we have made a comparative study of the immunoglobulin G (IgG), IgM, and IgA antibody responses to four trehalose-containing glycolipids purified from M. tuberculosis: diacyltrehaloses, triacyltrehaloses, cord factor, and sulfolipid I (SL-I). Sera from 92 tuberculosis patients (taken before starting antituberculosis treatment) and a wide group of control individuals (84 sera from healthy donors, including purified protein derivative-negative, -positive, healed, and vaccinated individuals, and 52 sera from nontuberculous pneumonia patients), all from Spain, were studied. The results indicated a significantly elevated IgG and IgA antibody response in tuberculosis patients, compared with controls, with all the antigens used. SL-I was the best antigen studied, showing test sensitivities and specificities for IgG of 81 and 77.6%, respectively, and of 66 and 87.5% for IgA. Using this antigen and combining IgA and IgG antibody detection, high test specificity was achieved (93.7%) with a sensitivity of 67.5%. Currently, it is widely accepted that it is not possible to achieve sensitivities above 80% in tuberculosis serodiagnosis when using one antigen alone. Thus, we conclude that SL-I, in combination with other antigenic molecules, could be a useful antigen for tuberculosis serodiagnosis. PMID:12354881

Dexamethasone enhances agonist induction of tissue factor in monocytes but not in endothelial cells.

PubMed

Bottles, K D; Morrissey, J H

1993-06-01

Stimulation of monocytic cells by inflammatory agents such as bacterial lipopolysaccharide or tumour necrosis factor-alpha leads to the rapid and transient expression of tissue factor, the major cellular initiator of the extrinsic coagulation cascade in both haemostasis and tissue inflammation. In this study we investigated whether the synthetic anti-inflammatory glucocorticoid, dexamethasone, would inhibit agonist induction of tissue factor expression in both monocytes and endothelial cells. Surprisingly, dexamethasone significantly enhanced the induction of tissue factor expression by peripheral blood mononuclear cells and an established monocytic cell line, THP-1, in response to lipopolysaccharide or tumour necrosis factor-alpha. However, unlike monocytic cells, dexamethasone did not enhance agonist induction of tissue factor in endothelial cells. Synergistic enhancement of tissue factor expression by dexamethasone was also reflected in tissue factor mRNA levels in THP-1 cells, but was not the result of improved TF mRNA stability. Synergism between bacterial lipopolysaccharide and glucocorticoid in the induction of monocyte effector function is extremely unusual and may help to explain the variable outcome of glucocorticoid treatment of septic shock.

Impaired antibody response against T-dependent antigens in rhino mice.

PubMed

Takaoki, M; Kawaji, H

1980-05-01

The antibody response in rhino mice, which carry a mutant gene hrrh, to thymus-dependent (TD) or thymus-independent (TI) antigens was compared with that of phenotypically normal littermates. The magnitude of antibody response to TD antigens in rhino mice decreased as they grew up, whereas the antibody response to TI antigens in rhino mice was indistinguishable from that of littermates. A transfer of thymus cells from littermates to rhino mice resulted in the partial restoration of the responsiveness to TD antigens. The experiments employing adoptive transfer of spleen cells from rhino mice to the irradiated normal mice suggested that the hyporesponsiveness of TD antigens of adult rhino mice was mainly due to the defect in the T helper cell activities rather than either the increase of the suppressor cells or defects in other cell types.

STATs MEDIATE FIBROBLAST GROWTH FACTOR INDUCED VASCULAR ENDOTHELIAL MORPHOGENESIS

PubMed Central

Yang, Xinhai; Qiao, Dianhua; Meyer, Kristy; Friedl, Andreas

2009-01-01

The fibroblast growth factors (FGFs) play diverse roles in development, wound healing and angiogenesis. The intracellular signal transduction pathways which mediate these pleiotropic activities remain incompletely understood. We show here that the proangiogenic factors FGF2 and FGF8b can activate signal transducers and activators of transcription (STATs) in mouse microvascular endothelial cells. Both FGF2 and FGF8b activate STAT5 and to a lesser extent STAT1, but not STAT3. The FGF2-dependent activation of endothelial STAT5 was confirmed in vivo with the matrigel plug angiogenesis assay. In tissue samples of human gliomas, a tumor type where FGF-induced angiogenesis is important, STAT5 is detected in tumor vessel endothelial cell nuclei, consistent with STAT5 activation. By forced expression of constitutively active or dominant-negative mutant STAT5A in mouse brain endothelial cells, we further show that STAT5 activation is both necessary and sufficient for FGF-induced cell migration, invasion and tube formation, which are key events in vascular endothelial morphogenesis and angiogenesis. In contrast, STAT5 is not required for brain endothelial cell mitogenesis. The cytoplasmic tyrosine kinases Src and Janus kinase 2 (Jak2) both appear to be involved in the activation of STAT5, as their inhibition reduces FGF2 and FGF8b induced STAT5 phosphorylation and endothelial cell tube formation. Constitutively active STAT5A partially restores tube formation in the presence of Src or Jak2 inhibitors. These observations demonstrate that FGFs utilize distinct signaling pathways to induce angiogenic phenotypes. Together, our findings implicate the FGF-Jak2/Src-STAT5 cascade as a critical angiogenic FGF signaling pathway. PMID:19176400

MicroRNA-210 Modulates Endothelial Cell Response to Hypoxia and Inhibits the Receptor Tyrosine Kinase Ligand Ephrin-A3*S⃞

PubMed Central

Fasanaro, Pasquale; D'Alessandra, Yuri; Di Stefano, Valeria; Melchionna, Roberta; Romani, Sveva; Pompilio, Giulio; Capogrossi, Maurizio C.; Martelli, Fabio

2008-01-01

MicroRNAs (miRNAs) are small non-protein-coding RNAs that function as negative gene expression regulators. In the present study, we investigated miRNAs role in endothelial cell response to hypoxia. We found that the expression of miR-210 progressively increased upon exposure to hypoxia. miR-210 overexpression in normoxic endothelial cells stimulated the formation of capillary-like structures on Matrigel and vascular endothelial growth factor-driven cell migration. Conversely, miR-210 blockade via anti-miRNA transfection inhibited the formation of capillary-like structures stimulated by hypoxia and decreased cell migration in response to vascular endothelial growth factor. miR-210 overexpression did not affect endothelial cell growth in both normoxia and hypoxia. However, anti-miR-210 transfection inhibited cell growth and induced apoptosis, in both normoxia and hypoxia. We determined that one relevant target of miR-210 in hypoxia was Ephrin-A3 since miR-210 was necessary and sufficient to down-modulate its expression. Moreover, luciferase reporter assays showed that Ephrin-A3 was a direct target of miR-210. Ephrin-A3 modulation by miR-210 had significant functional consequences; indeed, the expression of an Ephrin-A3 allele that is not targeted by miR-210 prevented miR-210-mediated stimulation of both tubulogenesis and chemotaxis. We conclude that miR-210 up-regulation is a crucial element of endothelial cell response to hypoxia, affecting cell survival, migration, and differentiation. PMID:18417479

A small population of liver endothelial cells undergoes endothelial-to-mesenchymal transition in response to chronic liver injury.

PubMed

Ribera, Jordi; Pauta, Montse; Melgar-Lesmes, Pedro; Córdoba, Bernat; Bosch, Anna; Calvo, Maria; Rodrigo-Torres, Daniel; Sancho-Bru, Pau; Mira, Aurea; Jiménez, Wladimiro; Morales-Ruiz, Manuel

2017-11-01

Rising evidence points to endothelial-to-mesenchymal transition (EndMT) as a significant source of the mesenchymal cell population in fibrotic diseases. In this context, we hypothesized that liver endothelial cells undergo EndMT during fibrosis progression. Cirrhosis in mice was induced by CCl 4 A transgenic mouse expressing a red fluorescent protein reporter under the control of Tie2 promoter (Tie2-tdTomato) was used to trace the acquisition of EndMT. Sinusoidal vascular connectivity was evaluated by intravital microscopy and high-resolution three-dimensional confocal microscopy. A modest but significant fraction of liver endothelial cells from both cirrhotic patients and CCl 4 -treated Tie2-tdTomato mice acquired an EndMT phenotype characterized by the coexpression of CD31 and α-smooth muscle actin, compared with noncirrhotic livers. Bone morphogenetic protein-7 (BMP-7) inhibited the acquisition of EndMT induced by transforming growth factor-β1 (TGF-β1) treatment in cultured primary mouse liver endothelial cells from control mice. EndMT was also reduced significantly in vivo in cirrhotic Tie2-tdTomato mice treated intraperitoneally with BMP-7 compared with untreated mice (1.9 ± 0.2 vs. 3.8 ± 0.3%, respectively; P < 0.05). The decrease of EndMT in cirrhotic livers correlated with a significant decrease in liver fibrosis ( P < 0.05) and an improvement in the vascular disorganization rate ( P < 0.05). We demonstrated the acquisition of the EndMT phenotype by a subpopulation of endothelial cells from cirrhotic livers in both animal models and patients. BMP-7 treatment decreases the occurrence of the EndMT phenotype and has a positive impact on the severity of disease by reducing fibrosis and sinusoidal vascular disorganization. NEW & NOTEWORTHY A subpopulation of liver endothelial cells from cirrhotic patients and mice with liver fibrosis undergoes endothelial-to-mesenchymal transition. Liver endothelial cells from healthy mice could transition into a

Selective effect of irradiation on responses to thymus-independent antigen.

PubMed

Lee, S K; Woodland, R T

1985-02-01

Low doses of ionizing radiation have a selective immunosuppressive effect on in vivo B cell responses to thymus-independent (TI) antigens. The B cell response, assayed as direct anti-trinitrophenyl (TNP)-specific plaque-forming cells (PFC), induced by type 2, TI antigens (TNP-Ficoll or TNP-Dextran), was reduced, on the average, by 10-fold in animals exposed to 200 rad of ionizing radiation 24 hr before antigen challenge. In contrast, PFC responses to type 1, TI antigens (TNP-lipopolysaccharide or TNP-Brucella abortus) are unaffected in mice exposed to the same dose of radiation. Adoptive transfers showed that this selective immunosuppression is a result of the specific inactivation of the B cell subpopulation responding to type 2, TI antigens. These experiments suggest that physiologic differences exist in the B cell subpopulations of normal mice which respond to type 1, or type 2, TI antigens.

Factors Released from Endothelial Cells Exposed to Flow Impact Adhesion, Proliferation, and Fate Choice in the Adult Neural Stem Cell Lineage.

PubMed

Dumont, Courtney M; Piselli, Jennifer M; Kazi, Nadeem; Bowman, Evan; Li, Guoyun; Linhardt, Robert J; Temple, Sally; Dai, Guohao; Thompson, Deanna M

2017-08-15

The microvasculature within the neural stem cell (NSC) niche promotes self-renewal and regulates lineage progression. Previous work identified endothelial-produced soluble factors as key regulators of neural progenitor cell (NPC) fate and proliferation; however, endothelial cells (ECs) are sensitive to local hemodynamics, and the effect of this key physiological process has not been defined. In this study, we evaluated adult mouse NPC response to soluble factors isolated from static or dynamic (flow) EC cultures. Endothelial factors generated under dynamic conditions significantly increased neuronal differentiation, while those released under static conditions stimulated oligodendrocyte differentiation. Flow increases EC release of neurogenic factors and of heparin sulfate glycosaminoglycans that increase their bioactivity, likely underlying the enhanced neuronal differentiation. Additionally, endothelial factors, especially from static conditions, promoted adherent growth. Together, our data suggest that blood flow may impact proliferation, adhesion, and the neuron-glial fate choice of adult NPCs, with implications for diseases and aging that reduce flow.

Inhibition of Epidermal Growth Factor Receptor and Vascular Endothelial Growth Factor Receptor Phosphorylation on Tumor-Associated Endothelial Cells Leads to Treatment of Orthotopic Human Colon Cancer in Nude Mice1

PubMed Central

Sasaki, Takamitsu; Kitadai, Yasuhiko; Nakamura, Toru; Kim, Jang-Seong; Tsan, Rachel Z; Kuwai, Toshio; Langley, Robert R; Fan, Dominic; Kim, Sun-Jin; Fidler, Isaiah J

2007-01-01

The purpose of our study was to determine whether the dual inhibition of epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) signaling pathways in tumor-associated endothelial cells can inhibit the progressive growth of human colon carcinoma in the cecum of nude mice. SW620CE2 human colon cancer cells growing in culture and orthotopically in the cecum of nude mice expressed a high level of transforming growth factor alpha (TGF-α) and vascular endothelial growth factor (VEGF) but were negative for EGFR, human epidermal growth factor receptor 2 (HER2), and VEGFR. Double immunofluorescence staining revealed that tumor-associated endothelial cells expressed EGFR, VEGFR2, phosphorylated EGFR (pEGFR), and phosphorylated VEGFR (pVEGFR). Treatment of mice with either 7H-pyrrolo [2,3-d]-pyrimidine lead scaffold (AEE788; an inhibitor of EGFR and VEGFR tyrosine kinase) or CPT-11 as single agents significantly inhibited the growth of cecal tumors (P < .01); this decrease was even more pronounced with AEE788 combined with CPT-11 (P < .001). AEE788 alone or combined with CPT-11 also inhibited the expression of pEGFR and pVEGFR on tumor-associated endothelial cells, significantly decreased vascularization and tumor cell proliferation, and increased the level of apoptosis in both tumor-associated endothelial cells and tumor cells. These data demonstrate that targeting EGFR and VEGFR signaling on tumor-associated endothelial cells provides a viable approach for the treatment of colon cancer. PMID:18084614

Fibroblast Growth Factor Signaling Mediates Pulmonary Endothelial Glycocalyx Reconstitution

PubMed Central

Yang, Yimu; Haeger, Sarah M.; Suflita, Matthew A.; Zhang, Fuming; Dailey, Kyrie L.; Colbert, James F.; Ford, Joshay A.; Picon, Mario A.; Stearman, Robert S.; Lin, Lei; Liu, Xinyue; Han, Xiaorui; Linhardt, Robert J.

2017-01-01

The endothelial glycocalyx is a heparan sulfate (HS)–rich endovascular structure critical to endothelial function. Accordingly, endothelial glycocalyx degradation during sepsis contributes to tissue edema and organ injury. We determined the endogenous mechanisms governing pulmonary endothelial glycocalyx reconstitution, and if these reparative mechanisms are impaired during sepsis. We performed intravital microscopy of wild-type and transgenic mice to determine the rapidity of pulmonary endothelial glycocalyx reconstitution after nonseptic (heparinase-III mediated) or septic (cecal ligation and puncture mediated) endothelial glycocalyx degradation. We used mass spectrometry, surface plasmon resonance, and in vitro studies of human and mouse samples to determine the structure of HS fragments released during glycocalyx degradation and their impact on fibroblast growth factor receptor (FGFR) 1 signaling, a mediator of endothelial repair. Homeostatic pulmonary endothelial glycocalyx reconstitution occurred rapidly after nonseptic degradation and was associated with induction of the HS biosynthetic enzyme, exostosin (EXT)-1. In contrast, sepsis was characterized by loss of pulmonary EXT1 expression and delayed glycocalyx reconstitution. Rapid glycocalyx recovery after nonseptic degradation was dependent upon induction of FGFR1 expression and was augmented by FGF-promoting effects of circulating HS fragments released during glycocalyx degradation. Although sepsis-released HS fragments maintained this ability to activate FGFR1, sepsis was associated with the downstream absence of reparative pulmonary endothelial FGFR1 induction. Sepsis may cause vascular injury not only via glycocalyx degradation, but also by impairing FGFR1/EXT1–mediated glycocalyx reconstitution. PMID:28187268

Blockade of vascular endothelial growth factor receptor and epidermal growth factor receptor signaling for therapy of metastatic human pancreatic cancer.

PubMed

Baker, Cheryl H; Solorzano, Carmen C; Fidler, Isaiah J

2002-04-01

We determined whether concurrent blockage of vascular endothelial growth factor (VEGF) receptor and epidermal growth factor (EGF) receptor signaling by two novel tyrosine kinase inhibitors, PTK 787 and PKI 166, respectively, can inhibit angiogenesis and, hence, the growth and metastasis of human pancreatic carcinoma in nude mice. Highly metastatic human pancreatic carcinoma L3.6pl cells were injected into the pancreas of nude mice. Seven days later, groups of mice began receiving oral doses of PTK 787 and PKI 166 three times weekly. Some groups of mice also received i.p. injections of gemcitabine twice a week. The mice were necropsied when the control mice became moribund. Treatment with PTK 787 and PKI 166, with gemcitabine alone, or with the combination of PTK 787, PKI 166, and gemcitabine produced 69, 50, and 97% reduction in the volume of pancreatic tumors, respectively. Administration of protein tyrosine kinase inhibitors and gemcitabine also significantly decreased the incidence of lymph node and liver metastasis. The therapeutic efficacy directly correlated with a decrease in circulating proangiogenic molecules (VEGF, interleukin-8), a decrease in microvessel density, a decrease in proliferating cell nuclear antigen staining, and an increase in apoptosis of tumor cells and endothelial cells. Therapies produced by combining gemcitabine with either PKI 166 or PTK 787 were similar to those produced by combining gemcitabine with both PKI 166 and PTK 787. These results suggest that blockade of either epidermal growth factor receptor or VEGF receptor signaling combined with chemotherapy provides an effective approach to the therapy of pancreatic cancer.

Endothelial gaps and adherent leukocytes in allergen-induced early- and late-phase plasma leakage in rat airways.

PubMed Central

Baluk, P.; Bolton, P.; Hirata, A.; Thurston, G.; McDonald, D. M.

1998-01-01

Exposure of sensitized individuals to antigen can induce allergic responses in the respiratory tract, manifested by early and late phases of vasodilatation, plasma leakage, leukocyte influx, and bronchoconstriction. Similar responses can occur in the skin, eye, and gastrointestinal tract. The early-phase response involves mast cell mediators and the late-phase response is leukocyte dependent, but the mechanism of leakage is not understood. We sought to identify the leaky blood vessels, to determine whether these vessels contained endothelial gaps, and to analyze the relationship of the gaps to adherent leukocytes, using biotinylated lectins or silver nitrate to stain the cells in situ and Monastral blue as a tracer to quantify plasma leakage. Most of the leakage occurred in postcapillary venules (< 40-microns diameter), whereas most of the leukocyte migration (predominantly neutrophils) occurred in collecting venules. Capillaries and arterioles did not leak. Endothelial gaps were found in the leaky venules, both by silver nitrate staining and by scanning electron microscopy, and 94% of the gaps were distinct from sites of leukocyte adhesion or migration. We conclude that endothelial gaps contribute to both early and late phases of plasma leakage induced by antigen, but most leakage occurs upstream to sites of leukocyte adhesion. Images Figure 3 Figure 5 Figure 6 Figure 7 PMID:9626051

Defenders and Challengers of Endothelial Barrier Function

PubMed Central

Rahimi, Nader

2017-01-01

Regulated vascular permeability is an essential feature of normal physiology and its dysfunction is associated with major human diseases ranging from cancer to inflammation and ischemic heart diseases. Integrity of endothelial cells also play a prominent role in the outcome of surgical procedures and organ transplant. Endothelial barrier function and integrity are regulated by a plethora of highly specialized transmembrane receptors, including claudin family proteins, occludin, junctional adhesion molecules (JAMs), vascular endothelial (VE)-cadherin, and the newly identified immunoglobulin (Ig) and proline-rich receptor-1 (IGPR-1) through various distinct mechanisms and signaling. On the other hand, vascular endothelial growth factor (VEGF) and its tyrosine kinase receptor, VEGF receptor-2, play a central role in the destabilization of endothelial barrier function. While claudins and occludin regulate cell–cell junction via recruitment of zonula occludens (ZO), cadherins via catenin proteins, and JAMs via ZO and afadin, IGPR-1 recruits bullous pemphigoid antigen 1 [also called dystonin (DST) and SH3 protein interacting with Nck90/WISH (SH3 protein interacting with Nck)]. Endothelial barrier function is moderated by the function of transmembrane receptors and signaling events that act to defend or destabilize it. Here, I highlight recent advances that have provided new insights into endothelial barrier function and mechanisms involved. Further investigation of these mechanisms could lead to the discovery of novel therapeutic targets for human diseases associated with endothelial dysfunction. PMID:29326721

CD144+ endothelial microparticles as a marker of endothelial injury in neonatal ABO blood group incompatibility.

PubMed

Awad, Hisham A E; Tantawy, Azza A G; El-Farrash, Rania A; Ismail, Eman A; Youssif, Noha M

2014-04-01

ABO antigens are expressed on the surfaces of red blood cells and the vascular endothelium. We studied circulating endothelial microparticles (EMP) in ABO haemolytic disease of the newborn (ABO HDN) as a marker of endothelial activation to test a hypothesis of possible endothelial injury in neonates with ABO HDN, and its relation with the occurrence and severity of haemolysis. Forty-five neonates with ABO HDN were compared with 20 neonates with Rhesus incompatibility (Rh HDN; haemolytic controls) and 20 healthy neonates with matched mother and infant blood groups (healthy controls). Laboratory investigations were done for markers of haemolysis and von Willebrand factor antigen (vWF Ag). EMP (CD144(+)) levels were measured before and after therapy (exchange transfusion and/or phototherapy). vWF Ag and pre-therapy EMP levels were higher in infants with ABO HDN or Rh HDN than in healthy controls, and were significantly higher in babies with ABO HDN than in those with Rh HDN (p<0.05). In ABO HDN, pre-therapy EMP levels were higher in patients with severe hyperbilirubinaemia than in those with mild and moderate disease or those with Rh HDN (p<0.001). Post-therapy EMP levels were lower than pre-therapy levels in both the ABO HDN and Rh HDN groups; however, the decline in EMP levels was particularly evident after exchange transfusion in ABO neonates with severe hyperbilirubinaemia (p<0.001). Multiple regression analysis revealed that the concentrations of haemoglobin, lactate dehydrogenase and indirect bilirubin were independently correlated with pre-therapy EMP levels in ABO HDN. Elevated EMP levels in ABO HDN may reflect an IgG-mediated endothelial injury parallel to the IgG-mediated erythrocyte destruction and could serve as a surrogate marker of vascular dysfunction and disease severity in neonates with this condition.

Vascular endothelial growth factor c/vascular endothelial growth factor receptor 3 signaling regulates chemokine gradients and lymphocyte migration from tissues to lymphatics.

PubMed

Iwami, Daiki; Brinkman, C Colin; Bromberg, Jonathan S

2015-04-01

Circulation of leukocytes via blood, tissue and lymph is integral to adaptive immunity. Afferent lymphatics form CCL21 gradients to guide dendritic cells and T cells to lymphatics and then to draining lymph nodes (dLN). Vascular endothelial growth factor C and vascular endothelial growth factor receptor 3 (VEGFR-3) are the major lymphatic growth factor and receptor. We hypothesized these molecules also regulate chemokine gradients and lymphatic migration. CD4 T cells were injected into the foot pad or ear pinnae, and migration to afferent lymphatics and dLN quantified by flow cytometry or whole mount immunohistochemistry. Vascular endothelial growth factor receptor 3 or its signaling or downstream actions were modified with blocking monoclonal antibodies (mAbs) or other reagents. Anti-VEGFR-3 prevented migration of CD4 T cells into lymphatic lumen and significantly decreased the number that migrated to dLN. Anti-VEGFR-3 abolished CCL21 gradients around lymphatics, although CCL21 production was not inhibited. Heparan sulfate (HS), critical to establish CCL21 gradients, was down-regulated around lymphatics by anti-VEGFR-3 and this was dependent on heparanase-mediated degradation. Moreover, a Phosphoinositide 3-kinase (PI3K)α inhibitor disrupted HS and CCL21 gradients, whereas a PI3K activator prevented the effects of anti-VEGFR-3. During contact hypersensitivity, VEGFR-3, CCL21, and HS expression were all attenuated, and anti-heparanase or PI3K activator reversed these effects. Vascular endothelial growth factor C/VEGFR-3 signaling through PI3Kα regulates the activity of heparanase, which modifies HS and CCL21 gradients around lymphatics. The functional and physical linkages of these molecules regulate lymphatic migration from tissues to dLN. These represent new therapeutic targets to influence immunity and inflammation.

Screening and Characterization of Drugs That Protect Corneal Endothelial Cells Against Unfolded Protein Response and Oxidative Stress.

PubMed

Kim, Eun Chul; Toyono, Tetsuya; Berlinicke, Cynthia A; Zack, Donald J; Jurkunas, Ula; Usui, Tomohiko; Jun, Albert S

2017-02-01

To screen for and characterize compounds that protect corneal endothelial cells against unfolded protein response (UPR) and oxidative stress. Bovine corneal endothelial cells (BCECs) were treated for 48 hours with 640 compounds from a Food and Drug Administration (FDA)-approved drug library and then challenged with thapsigargin or H2O2 to induce UPR or oxidative stress, respectively. Cell viability was measured using the CellTiter-Glo survival assay. Selected "hits" were subjected to further dose-response testing, and their ability to modulate expression of UPR and oxidative stress markers was assessed by RT-PCR, Western blot, and measurement of protein carbonyl and 8-hydroxydeoxyguanosine (8-OHdG) adducts in immortalized human corneal endothelial cells (iHCECs). Forty-one drugs at 20 μM and 55 drugs at 100 μM increased survival of H2O2-challenged cells, and 8 drugs at 20 μM and 2 drugs at 100 μM increased survival of thapsigargin-challenged cells, compared with untreated control cells. Nicergoline, ergothioneine, nimesulide, oxotremorine, and mefenamic acid increased survival of both H2O2- and thapsigargin-challenged cells. Oxotremorine altered DNA damage inducible 3 (CHOP) gene expression, glucose-regulated protein 78 kDa (GRP78) and activating transcription factor 4 (ATF4) protein expression, and protein carbonyl and 8-OHdG levels. Mefenamic acid altered GRP78 protein expression and protein carbonyl and 8-OHdG levels. Oxotremorine and mefenamic acid are potential survival factors for corneal endothelial cells under UPR and oxidative stress. The described assay can be further expanded to screen additional drugs for potential therapeutic effect in corneal endothelial diseases such as Fuchs' endothelial corneal dystrophy.

Glutathione regulation of redox-sensitive signals in tumor necrosis factor-{alpha}-induced vascular endothelial dysfunction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tsou, T.-C.; Yeh, S.C.; Tsai, F.-Y.

2007-06-01

We investigated the regulatory role of glutathione in tumor necrosis factor-alpha (TNF-{alpha})-induced vascular endothelial dysfunction as evaluated by using vascular endothelial adhesion molecule expression and monocyte-endothelial monolayer binding. Since TNF-{alpha} induces various biological effects on vascular cells, TNF-{alpha} dosage could be a determinant factor directing vascular cells into different biological fates. Based on the adhesion molecule expression patterns responding to different TNF-{alpha} concentrations, we adopted the lower TNF-{alpha} (0.2 ng/ml) to rule out the possible involvement of other TNF-{alpha}-induced biological effects. Inhibition of glutathione synthesis by L-buthionine-(S,R)-sulfoximine (BSO) resulted in down-regulations of the TNF-{alpha}-induced adhesion molecule expression and monocyte-endothelial monolayermore » binding. BSO attenuated the TNF-{alpha}-induced nuclear factor-kappaB (NF-{kappa}B) activation, however, with no detectable effect on AP-1 and its related mitogen-activated protein kinases (MAPKs). Deletion of an AP-1 binding site in intercellular adhesion molecule-1 (ICAM-1) promoter totally abolished its constitutive promoter activity and its responsiveness to TNF-{alpha}. Inhibition of ERK, JNK, or NF-{kappa}B attenuates TNF-{alpha}-induced ICAM-1 promoter activation and monocyte-endothelial monolayer binding. Our study indicates that TNF-{alpha} induces adhesion molecule expression and monocyte-endothelial monolayer binding mainly via activation of NF-{kappa}B in a glutathione-sensitive manner. We also demonstrated that intracellular glutathione does not modulate the activation of MAPKs and/or their downstream AP-1 induced by lower TNF-{alpha}. Although AP-1 activation by the lower TNF-{alpha} was not detected in our systems, we could not rule out the possible involvement of transiently activated MAPKs/AP-1 in the regulation of TNF-{alpha}-induced adhesion molecule expression.« less

Food antigen-induced immune responses in Crohn's disease patients and experimental colitis mice.

PubMed

Kawaguchi, Takaaki; Mori, Maiko; Saito, Keiko; Suga, Yasuyo; Hashimoto, Masaki; Sako, Minako; Yoshimura, Naoki; Uo, Michihide; Danjo, Keiko; Ikenoue, Yuka; Oomura, Kaori; Shinozaki, Junko; Mitsui, Akira; Kajiura, Takayuki; Suzuki, Manabu; Takazoe, Masakazu

2015-04-01

In Crohn's disease (CD), the involvement of food antigens in immune responses remains unclear. The objective of this study was to detect immune responses against food antigens in CD patients and examine the mechanism in a mouse model of colitis. We enrolled 98 CD patients, 50 ulcerative colitis patients, and 52 healthy controls (HCs) to compare the levels of serum immunoglobulin (Ig)Gs against 88 foods. The presence of serum IgGs against foods was also examined in interleukin (IL)-10 knockout (KO) mice in which CD4(+) T cell activation by antigenic food protein was assessed. Mice transferred with IL-10 KO cells received diets with or without food antigens, and the development of colitis was evaluated. The prevalence of IgGs against various foods, especially vegetables, grains, and nuts, was significantly higher in CD patients than in HCs. Similarly, the prevalence of IgGs against food proteins was higher in IL-10 KO mice than in BALB/c mice. Beta-conglycinin, identified as an antigenic food proteins in IL-10 KO mice, induced CD4(+) T cell production of interferon-γ and IL-17 through dendritic cell antigen presentation. Elimination of the food antigens ameliorated the development of colitis in mice without altering the composition of their intestinal microbiota. In CD colitis mice, intestinal inflammation via CD4(+) T cell hyperactivation was induced by food antigens associated with high serum IgG levels and was ameliorated by the elimination of food antigens. This disrupted immunological tolerance to food antigen, which might act as an exacerbating factor, remains to be elucidated in CD patients.

Association of immune response to endothelial cell growth factor with early disseminated and late manifestations of Lyme disease but not posttreatment Lyme disease syndrome.

PubMed

Tang, Kevin S; Klempner, Mark S; Wormser, Gary P; Marques, Adriana R; Alaedini, Armin

2015-12-01

Endothelial cell growth factor has been recently proposed as a potential autoantigen in manifestations of Lyme disease that are thought to involve immune-mediated mechanisms. Our findings indicate that a humoral immune response to this protein is not associated with posttreatment Lyme disease syndrome. © The Author 2015. Published by Oxford University Press on behalf of the Infectious Diseases Society of America. All rights reserved. For Permissions, please e-mail: journals.permissions@oup.com.

Manipulating the antigen-specific immune response by the hydrophobicity of amphiphilic poly(γ-glutamic acid) nanoparticles.

PubMed

Shima, Fumiaki; Akagi, Takami; Uto, Tomofumi; Akashi, Mitsuru

2013-12-01

The new generation vaccines are safe but poorly immunogenic, and thus they require the use of adjuvants. However, conventional vaccine adjuvants fail to induce potent cellular immunity, and their toxicity and side-effects hinder the clinical use. Therefore, a vaccine adjuvant which is safe and can induce an antigen-specific cellular immunity-biased immune response is urgently required. In the development of nanoparticle-based vaccine adjuvants, the hydrophobicity is one of the most important factors. It could control the interaction between the encapsulated antigens and/or nanoparticles with immune cells. In this study, nanoparticles (NPs) composed of amphiphilic poly(γ-glutamic acid)-graft-L-phenylalanine ethyl ester (γ-PGA-Phe) with various grafting degrees of hydrophobic side chains were prepared to evaluate the effect of hydrophobicity of vaccine carriers on the antigen encapsulation behavior, cellular uptake, activation of dendritic cells (DCs), and induction of antigen-specific cellular immunity-biased immune responses. These NPs could efficiently encapsulate antigens, and the uptake amount of the encapsulated antigen by DCs was dependent on the hydrophobicity of γ-PGA-Phe NPs. Moreover, the activation potential of the DCs and the induction of antigen-specific cellular immunity were correlated with the hydrophobicity of γ-PGA-Phe NPs. By controlling the hydrophobicity of antigen-encapsulated γ-PGA-Phe NPs, the activation potential of DCs was able to manipulate about 5 to 30-hold than the conventional vaccine, and the cellular immunity was about 10 to 40-hold. These results suggest that the hydrophobicity of NPs is a key factor for changing the interaction between NPs and immune cells, and thus the induction of cellular immunity-biased immune response could be achieved by controlling the hydrophobicity of them. Copyright © 2013 Elsevier Ltd. All rights reserved.

Vascular endothelial growth factor-C enhances radiosensitivity of lymphatic endothelial cells

PubMed Central

Kesler, Cristina T.; Kuo, Angera; Wong, Hon-Kit; Masuck, David J.; Shah, Jennifer L.; Kozak, Kevin; Held, Kathryn D.; Padera, Timothy P.

2013-01-01

Radiation therapy after lymph node dissection increases the risk of developing painful and incurable lymphedema in breast cancer patients. Lymphedema occurs when lymphatic vessels become unable to maintain proper fluid balance. The sensitivity of lymphatic endothelial cells (LECs) to ionizing radiation has not been reported to date. Here, the radiosensitivity of LECs in vitro has been determined using clonogenic survival assays. The ability of various growth factors to alter LEC radiosensitivity was also examined. Vascular endothelial growth factor (VEGF)-C enhanced radiosensitivity when LECs were treated prior to radiation. VEGF-C-treated LECs exhibited higher levels of entry into the cell cycle at the time of radiation, with a greater number of cells in the S and G2/M phases. These LECs showed higher levels of H2A.X—an indicator of DNA damage—after radiation. VEGF-C did not increase cell death as a result of radiation. Instead, it increased the relative number of quiescent LECs. These data suggest that abundant VEGF-C or lymphangiogenesis may predispose patients to radiation-induced lymphedema by impairing lymphatic vessel repair through induction of LEC quiescence. PMID:24201897

Antigen specific T-cell responses against tumor antigens are controlled by regulatory T cells in patients with prostate cancer.

PubMed

Hadaschik, Boris; Su, Yun; Huter, Eva; Ge, Yingzi; Hohenfellner, Markus; Beckhove, Philipp

2012-04-01

Immunotherapy is a promising approach in an effort to control castration resistant prostate cancer. We characterized tumor antigen reactive T cells in patients with prostate cancer and analyzed the suppression of antitumor responses by regulatory T cells. Peripheral blood samples were collected from 57 patients with histologically confirmed prostate cancer, 8 patients with benign prostatic hyperplasia and 16 healthy donors. Peripheral blood mononuclear cells were isolated and antigen specific interferon-γ secretion of isolated T cells was analyzed by enzyme-linked immunospot assay. T cells were functionally characterized and T-cell responses before and after regulatory T-cell depletion were compared. As test tumor antigens, a panel of 11 long synthetic peptides derived from a total of 8 tumor antigens was used, including prostate specific antigen and prostatic acid phosphatase. In patients with prostate cancer we noted a 74.5% effector T-cell response rate compared with only 25% in patients with benign prostatic hyperplasia and 31% in healthy donors. In most patients 2 or 3 tumor antigens were recognized. Comparing various disease stages there was a clear increase in the immune response against prostate specific antigens from intermediate to high risk tumors and castration resistant disease. Regulatory T-cell depletion led to a significant boost in effector T-cell responses against prostate specific antigen and prostatic acid phosphatase. Tumor specific effector T cells were detected in most patients with prostate cancer, especially those with castration resistant prostate cancer. Since effector T-cell responses against prostate specific antigens strongly increased after regulatory T-cell depletion, our results indicate that immunotherapy efficacy could be enhanced by decreasing regulatory T cells. Copyright © 2012 American Urological Association Education and Research, Inc. Published by Elsevier Inc. All rights reserved.

Membrane Type 1–Matrix Metalloproteinase/Akt Signaling Axis Modulates TNF-α-Induced Procoagulant Activity and Apoptosis in Endothelial Cells

PubMed Central

Ohkawara, Hiroshi; Ishibashi, Toshiyuki; Sugimoto, Koichi; Ikeda, Kazuhiko; Ogawa, Kazuei; Takeishi, Yasuchika

2014-01-01

Membrane type 1–matrix metalloproteinase (MT1-MMP) functions as a signaling molecule in addition to a proteolytic enzyme. Our hypothesis was that MT1-MMP cooperates with protein kinase B (Akt) in tumor necrosis factor (TNF)-α-induced signaling pathways of vascular responses, including tissue factor (TF) procoagulant activity and endothelial apoptosis, in cultured human aortic endothelial cells (ECs). TNF-α (10 ng/mL) induced a decrease in Akt phosphorylation within 60 minutes in ECs. A chemical inhibitor of MMP, TIMP-2 and selective small interfering RNA (siRNA)-mediated suppression of MT1-MMP reversed TNF-α-triggered transient decrease of Akt phosphorylation within 60 minutes, suggesting that MT1-MMP may be a key regulator of Akt phosphorylation in TNF-α-stimulated ECs. In the downstream events, TNF-α increased TF antigen and activity, and suppressed the expression of thrombomodulin (TM) antigen. Inhibition of Akt markedly enhanced TNF-α-induced expression of TF antigen and activity, and further reduced the expression of TM antigen. Silencing of MT1-MMP by siRNA also reversed the changed expression of TF and TM induced by TNF-α. Moreover, TNF-α induced apoptosis of ECs through Akt- and forkhead box protein O1 (FoxO1)-dependent signaling pathway and nuclear factor-kB (NF-kB) activation. Knockdown of MT1-MMP by siRNA reversed apoptosis of ECs by inhibiting TNF-α-induced Akt-dependent regulation of FoxO1 in TNF-α-stimulated ECs. Immunoprecipitation demonstrated that TNF-α induced the changes in the associations between the cytoplasmic fraction of MT1-MMP and Akt in ECs. In conclusion, we show new evidence that MT1-MMP/Akt signaling axis is a key modifier for TNF-α-induced signaling pathways for modulation of procoagulant activity and apoptosis of ECs. PMID:25162582

Carcinoembryonic antigen-stimulated THP-1 macrophages activate endothelial cells and increase cell-cell adhesion of colorectal cancer cells.

PubMed

Aarons, Cary B; Bajenova, Olga; Andrews, Charles; Heydrick, Stanley; Bushell, Kristen N; Reed, Karen L; Thomas, Peter; Becker, James M; Stucchi, Arthur F

2007-01-01

The liver is the most common site for metastasis by colorectal cancer, and numerous studies have shown a relationship between serum carcinoembryonic antigen (CEA) levels and metastasis to this site. CEA activates hepatic macrophages or Kupffer cells via binding to the CEA receptor (CEA-R), which results in the production of cytokines and the up-regulation of endothelial adhesion molecules, both of which are implicated in hepatic metastasis. Since tissue macrophages implicated in the metastatic process can often be difficult to isolate, the aim of this study was to develop an in vitro model system to study the complex mechanisms of CEA-induced macrophage activation and metastasis. Undifferentiated, human monocytic THP-1 (U-THP) cells were differentiated (D-THP) to macrophages by exposure to 200 ng/ml phorbol myristate acetate (PMA) for 18 h. Immunohistochemistry showed two CEA-R isoforms present in both U- and D-THP cells. The receptors were localized primarily to the nucleus in U-THP cells, while a significant cell-surface presence was observed following PMA-differentiation. Incubation of D-THP-1 cells with CEA resulted in a significant increase in tumor necrosis factor-alpha (TNF-alpha) release over 24 h compared to untreated D-THP-1 or U-THP controls confirming the functionality of these cell surface receptors. U-THP cells were unresponsive to CEA. Attachment of HT-29 cells to human umbilical vein endothelial cells significantly increased at 1 h after incubation with both recombinant TNF-alpha and conditioned media from CEA stimulated D-THP cells by six and eightfold, respectively. This study establishes an in vitro system utilizing a human macrophage cell line expressing functional CEA-Rs to study activation and signaling mechanisms of CEA that facilitate tumor cell attachment to activated endothelial cells. Utilization of this in vitro system may lead to a more complete understanding of the expression and function of CEA-R and facilitate the design of anti

Aging and vascular endothelial function in humans

PubMed Central

SEALS, Douglas R.; JABLONSKI, Kristen L.; DONATO, Anthony J.

2012-01-01

Advancing age is the major risk factor for the development of CVD (cardiovascular diseases). This is attributable, in part, to the development of vascular endothelial dysfunction, as indicated by reduced peripheral artery EDD (endothelium-dependent dilation) in response to chemical [typically ACh (acetylcholine)] or mechanical (intravascular shear) stimuli. Reduced bioavailability of the endothelium-synthesized dilating molecule NO (nitric oxide) as a result of oxidative stress is the key mechanism mediating reduced EDD with aging. Vascular oxidative stress increases with age as a consequence of greater production of reactive oxygen species (e.g. superoxide) without a compensatory increase in antioxidant defences. Sources of increased superoxide production include up-regulation of the oxidant enzyme NADPH oxidase, uncoupling of the normally NO-producing enzyme, eNOS (endothelial NO synthase) (due to reduced availability of the cofactor tetrahydrobiopterin) and increased mitochondrial synthesis during oxidative phosphorylation. Increased bioactivity of the potent endothelial-derived constricting factor ET-1 (endothelin-1), reduced endothelial production of/responsiveness to dilatory prostaglandins, the development of vascular inflammation, formation of AGEs (advanced glycation end-products), an increased rate of endothelial apoptosis and reduced expression of oestrogen receptor α (in postmenopausal females) also probably contribute to impaired EDD with aging. Several lifestyle and biological factors modulate vascular endothelial function with aging, including regular aerobic exercise, dietary factors (e.g. processed compared with non-processed foods), body weight/fatness, vitamin D status, menopause/oestrogen deficiency and a number of conventional and non-conventional risk factors for CVD. Given the number of older adults now and in the future, more information is needed on effective strategies for the prevention and treatment of vascular endothelial aging. PMID

Bone marrow vascular endothelial growth factor level per platelet count might be a significant predictor for the treatment outcomes of patients with diffuse large B-cell lymphomas.

PubMed

Kim, Jung Sun; Gang, Ga Won; Lee, Se Ryun; Sung, Hwa Jung; Park, Young; Kim, Dae Sik; Choi, Chul Won; Kim, Byung Soo

2015-10-01

Developing a parameter to predict bone marrow invasion by non-Hodgkin's lymphoma is an important unmet medical need for treatment decisions. This study aimed to confirm the validity of the hypothesis that bone marrow plasma vascular endothelial growth factor level might be correlated with the risk of bone marrow involvement and the prognosis of patients with diffuse large B-cell non-Hodgkin's lymphoma. Forty-nine diffuse large B-cell lymphoma patients treated with rituximab, cyclophosphamide, daunorubicin, vincristine and prednisolone regimen were enrolled. Vascular endothelial growth factor level was measured with enzyme-linked immunosorbent assay. The validity of bone marrow plasma vascular endothelial growth factor level and bone marrow vascular endothelial growth factor level per platelet count for predicting treatment response and survival after initial rituximab, cyclophosphamide, daunorubicin, vincristine and prednisolone combined chemotherapy was assessed. Bone marrow plasma vascular endothelial growth factor level per platelet count was significantly associated with old age (≥ 65 years), poor performance score (≥ 2), high International prognosis index (≥ 3) and bone marrow invasion. The patients with high bone marrow plasma vascular endothelial growth factor level per platelet count (≥ 3.01) showed a significantly lower complete response rate than the others. On Kaplan-Meier survival curves, the patients with high bone marrow plasma vascular endothelial growth factor levels (≥ 655 pg/ml) or high bone marrow plasma vascular endothelial growth factor level per platelet count (≥ 3.01) demonstrated a significantly shorter overall survival and progression-free survival than the others. In the patients without bone marrow involvement, bone marrow plasma vascular endothelial growth factor level per platelet count had a significant relationship with overall survival and progression-free survival. Multivariate analysis revealed that the patients without

Screening and Characterization of Drugs That Protect Corneal Endothelial Cells Against Unfolded Protein Response and Oxidative Stress

PubMed Central

Kim, Eun Chul; Toyono, Tetsuya; Berlinicke, Cynthia A.; Zack, Donald J.; Jurkunas, Ula; Usui, Tomohiko; Jun, Albert S.

2017-01-01

Purpose To screen for and characterize compounds that protect corneal endothelial cells against unfolded protein response (UPR) and oxidative stress. Methods Bovine corneal endothelial cells (BCECs) were treated for 48 hours with 640 compounds from a Food and Drug Administration (FDA)-approved drug library and then challenged with thapsigargin or H2O2 to induce UPR or oxidative stress, respectively. Cell viability was measured using the CellTiter-Glo survival assay. Selected “hits” were subjected to further dose-response testing, and their ability to modulate expression of UPR and oxidative stress markers was assessed by RT-PCR, Western blot, and measurement of protein carbonyl and 8-hydroxydeoxyguanosine (8-OHdG) adducts in immortalized human corneal endothelial cells (iHCECs). Results Forty-one drugs at 20 μM and 55 drugs at 100 μM increased survival of H2O2-challenged cells, and 8 drugs at 20 μM and 2 drugs at 100 μM increased survival of thapsigargin-challenged cells, compared with untreated control cells. Nicergoline, ergothioneine, nimesulide, oxotremorine, and mefenamic acid increased survival of both H2O2- and thapsigargin-challenged cells. Oxotremorine altered DNA damage inducible 3 (CHOP) gene expression, glucose-regulated protein 78 kDa (GRP78) and activating transcription factor 4 (ATF4) protein expression, and protein carbonyl and 8-OHdG levels. Mefenamic acid altered GRP78 protein expression and protein carbonyl and 8-OHdG levels. Conclusions Oxotremorine and mefenamic acid are potential survival factors for corneal endothelial cells under UPR and oxidative stress. The described assay can be further expanded to screen additional drugs for potential therapeutic effect in corneal endothelial diseases such as Fuchs' endothelial corneal dystrophy. PMID:28159976

Relationship of ovarian stimulation response with vascular endothelial growth factor and degree of granulosa cell apoptosis.

PubMed

Quintana, R; Kopcow, L; Marconi, G; Sueldo, C; Speranza, G; Barañao, R I

2001-09-01

The aim of this study was to evaluate the concentration of vascular endothelial growth factor (VEGF) in follicular fluid and in granulosa cell cultures in relation to the degree of apoptosis in granulosa cells from patients with different types of ovarian response to controlled ovarian hyperstimulation. We studied 30 women who underwent controlled ovarian hyperstimulation and oocyte retrieval. Group A comprised patients with 1-4 follicles (n = 10), group B patients with 5-14 follicles (n = 10) and group C patients with >15 follicles (n = 10). Mean (+/-SD) VEGF concentrations in follicular fluid were 1232 +/- 209, 813 +/- 198 and 396 +/- 103 pg/ml for groups A, B and C respectively (P > 0.01). Concentrations of VEGF in granulosa cell supernatant were 684 +/- 316, 1101 +/- 295 and 1596 +/- 227 pg/ml respectively (P < 0.05). Percentages of apoptotic cells in granulosa cells culture was 55.02 +/- 7.5, 23.98 +/- 4.4 and 14.2 +/- 2.3% respectively (A versus B, P < 0.01, A versus C, P < 0.006, B versus C, NS). Our findings showed that in patients with decreased ovarian response to controlled ovarian hyperstimulation, follicular fluid VEGF concentration is elevated, the concentration from granulosa cells culture supernatant is decreased and the percentage of apoptotic granulosa cells is increased, while opposite findings occurred in patients with normal or hyper-responses.

Resistive-Pulse Measurements with Nanopipettes: Detection of Vascular Endothelial Growth Factor C (VEGF-C) Using Antibody-Decorated Nanoparticles.

PubMed

Cai, Huijing; Wang, Yixian; Yu, Yun; Mirkin, Michael V; Bhakta, Snehasis; Bishop, Gregory W; Joshi, Amit A; Rusling, James F

2015-06-16

Quartz nanopipettes have recently been employed for resistive-pulse sensing of Au nanoparticles (AuNP) and nanoparticles with bound antibodies. The analytical signal in such experiments is the change in ionic current caused by the nanoparticle translocation through the pipette orifice. This paper describes resistive-pulse detection of cancer biomarker (Vascular Endothelial Growth Factor-C, VEGF-C) through the use of antibody-modified AuNPs and nanopipettes. The main challenge was to differentiate between AuNPs with attached antibodies for VEGF-C and antigen-conjugated particles. The zeta-potentials of these types of particles are not very different, and, therefore, carefully chosen pipettes with well-characterized geometry were necessary for selective detection of VEGF-C.

Resistive-Pulse Measurements with Nanopipettes: Detection of Vascular Endothelial Growth Factor C (VEGF-C) Using Antibody-Decorated Nanoparticles

PubMed Central

Cai, Huijing; Wang, Yixian; Yu, Yun; Mirkin, Michael V.; Bhakta, Snehasis; Bishop, Gregory W.; Joshi, Amit A.; Rusling, James F.

2015-01-01

Quartz nanopipettes have recently been employed for resistive-pulse sensing of Au nanoparticles (AuNP) and nanoparticles with bound antibodies. The analytical signal in such experiments is the change in ionic current caused by the nanoparticle translocation through the pipette orifice. This paper describes resistive-pulse detection of cancer biomarker (Vascular Endothelial Growth Factor-C, VEGF-C) through the use of antibody-modified AuNPs and nanopipettes. The main challenge was to differentiate between AuNPs with attached antibodies for VEGF-C and antigen-conjugated particles. The zeta-potentials of these types of particles are not very different, and, therefore, carefully chosen pipettes with well-characterized geometry were necessary for selective detection of VEGF-C. PMID:26040997

Adenoviral modification of mouse brain derived endothelial cells, bEnd3, to induce apoptosis by vascular endothelial growth factor.

PubMed

Mitsuuchi, Y; Powell, D R; Gallo, J M

2006-02-09

A second generation genetically-engineered cell-based drug delivery system, referred to as apoptotic-induced drug delivery (AIDD), was developed using endothelial cells (ECs) that undergo apoptosis upon binding of vascular endothelial growth factor (VEGF) to a Flk-1:Fas fusion protein (FF). This new AIDD was redesigned using mouse brain derived ECs, bEnd3 cells, and an adenovirus vector in order to enhance and control the expression of FF. The FF was tagged with a HA epitope (FFHA) and designed to be coexpressed with green fluorescence protein (GFP) by the regulation of cytomegalovirus promoters in the adenovirus vector. bEnd3 cells showed favorable coexpression of FFHA and GFP consistent with the multiplicity of infection of the adenovirus. Immunofluorescence analysis demonstrated that FFHA was localized at the plasma membrane, whereas GFP was predominantly located in the cytoplasm of ECs. Cell death was induced by VEGF, but not by platelet derived growth factor or fibroblast growth factor in a dose-dependent manner (range 2-20 ng/ml), and revealed caspase-dependent apoptotic profiles. The FFHA expressing bEnd3 cells underwent apoptosis when cocultured with a glioma cell (SF188V+) line able to overexpress VEGF. The combined data indicated that the FFHA adenovirus system can induce apoptotic signaling in ECs in response to VEGF, and thus, is an instrumental modification to the development of AIDD.

[Endothelial microparticles (EMP) in physiology and pathology].

PubMed

Sierko, Ewa; Sokół, Monika; Wojtukiewicz, Marek Z

2015-08-18

Endothelial microparticles (EMP) are released from endothelial cells (ECs) in the process of activation and/or apoptosis. They harbor adhesive molecules, enzymes, receptors and cytoplasmic structures and express a wide range of various constitutive antigens, typical for ECs, at their surface. Under physiological conditions the concentration of EMP in the blood is clinically insignificant. However, it was reported that under pathological conditions EMP concentration in the blood might slightly increase and contribute to blood coagulation, angiogenesis and inflammation. It has been shown that EMP directly and indirectly contribute to the activation of blood coagulation. Endothelial microparticles directly participate in blood coagulation through their surface tissue factor (TF) - a major initiator of blood coagulation. Furthermore, EMP exhibit procoagulant potential via expression of negatively charged phospholipids at their surface, which may promote assembly of coagulation enzymes (TF/VII, tenases and prothrombinase complexes), leading to thrombus formation. In addition, they provide a binding surface for coagulation factors: IXa, VIII, Va and IIa. Moreover, it is possible that EMP transfer TF from TF-bearing EMP to activated platelets and monocytes by binding them through adhesion molecules. Also, EMP express von Willebrand factor, which may facilitate platelet aggregation. Apart from their procoagulant properties, it was demonstrated that EMP may express adhesive molecules and metalloproteinases (MMP-2, MMP-9) at their surface and release growth factors, which may contribute to angiogenesis. Additionally, surface presence of C3 and C4 - components of the classical pathway - suggests pro-inflammatory properties of these structures. This article contains a summary of available data on the biology and pathophysiology of endothelial microparticles and their potential role in blood coagulation, angiogenesis and inflammation.

Aging impairs transcriptional regulation of vascular endothelial growth factor in human microvascular endothelial cells: implications for angiogenesis and cell survival.

PubMed

Ahluwalia, A; Jones, M K; Szabo, S; Tarnawski, A S

2014-04-01

In some tissues, aging impairs angiogenesis and reduces expression of vascular endothelial growth factor A (VEGF), a fundamental regulator of angiogenesis. We previously examined angiogenesis in aging and young gastric mucosa in vivo and in vitro and showed that an imbalance between expressions of VEGF (pro-angiogenic factor) and endostatin (anti-angiogenic protein) results in an aging-related impairment of angiogenesis in rats. However, the human relevance of these findings, and whether these mechanisms apply to endothelial cells derived from other tissues, is not clear. Since P-STAT3 and P-CREB are transcription factors that, in association with HIF-1α, can activate VEGF gene expression in some cells (e.g., liver cancer cells, vascular smooth muscle cells), we examined the expression of these two proteins in human dermal microvascular endothelial cells (HMVECs) derived from aging and neonatal individuals. We examined and quantified in vitro angiogenesis, expression of VEGF, P-STAT3, P-CREB and importin-α in HMVECs isolated from neonates (neonatal) and a 66 year old subject (aging). We also examined the effects of treatment with exogenous VEGF and endostatin on in vitro angiogenesis in these cells. Endothelial cells isolated from aging individuals had impaired angiogenesis (vs. neonatal endothelial cells) and reduced expression of VEGF mRNA and protein. Aged HMVECs also had reduced importin-α expression, and reduced expression and nuclear translocation of P-STAT3 and P-CREB. Reduced VEGF gene expression in aged HMVECs strongly correlated with the decreased levels of P-STAT3, P-CREB and importin-α in these cells. Our study clearly demonstrates that endothelial cells from aging individuals have impaired angiogenesis and reduced expression of VEGF likely due to impaired nuclear transport of P-STAT3 and P-CREB transcription factors in these cells.

ISCHEMIC CENTRAL RETINAL VEIN OCCLUSION IN THE ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR ERA.

PubMed

Tam, Emily K; Golchet, Pamela; Yung, Madeline; DeCroos, Francis C; Spirn, Marc; Lehmann-Clarke, Lydia; Ambresin, Aude; Tsui, Irena

2018-02-01

Anti-vascular endothelial growth factor therapy has improved the prognosis for patients with central retinal vein occlusion (CRVO). However, most studies published to date exclude ischemic CRVO. The purpose of this study was to describe the outcome in eyes with ischemic CRVO treated with anti-vascular endothelial growth factor therapy. Thirty-seven patients with ischemic CRVO from 3 centers were followed for at least 6 months. Data on patient demographic, vision status, and anti-vascular endothelial growth factor treatments were collected. Average number of injections during the study period was 5. Younger age was associated with improved vision (P = 0.006). Patients with improved visual outcomes tended to have macular edema as the primary indication for treatment, whereas patients with worse outcomes tended to have neovascularization as the primary indication for treatment. This study highlights significant variability in the use of anti-vascular endothelial growth factor therapy for ischemic CRVO and underscores that eyes with neovascularization tend to have worse visual outcomes.

Molecular expression in transfected corneal endothelial cells

NASA Astrophysics Data System (ADS)

Wang, Fan; Miao, Zhuang; Lu, Chengwei; Hao, Jilong

2017-10-01

To investigate the capability of human corneal endothelial cells serving as immunological cells. Expression of HLA-DP, -DQ, -DR, CD40, CD80, and CD86 was determined by immunohistochemical methods. Meanwhile, purified peripheral blood mononuclear cells were cocultured with human corneal endothelial cells which were pre-treated with and without -IFN respectively, activation of lymphocytes was determined by FACS analysis. In coculture system, T lymphocyte was activated by corneal endothelial cells, HLA-DP, -DQ, -DR and CD40 expression were increased by - IFN induction. Costimulatory molecular CD80 was shown on the endothelial cells. Human corneal endothelial cells were assumed to be involved in the corneal transplantation rejection process as potential antigen presenting cells.

Antigen-specific T cell responses to BK polyomavirus antigens identify functional anti-viral immunity and may help to guide immunosuppression following renal transplantation

PubMed Central

Chakera, A; Bennett, S; Lawrence, S; Morteau, O; Mason, P D; O'Callaghan, C A; Cornall, R J

2011-01-01

Infection with the polyoma virus BK (BKV) is a major cause of morbidity following renal transplantation. Limited understanding of the anti-viral immune response has prevented the design of a strategy that balances treatment with the preservation of graft function. The proven utility of interferon-gamma enzyme-linked immunospot (ELISPOT) assays to measure T cell responses in immunocompetent hosts was the basis for trying to develop a rational approach to the management of BKV following renal transplantation. In a sample of transplant recipients and healthy controls, comparisons were made between T cell responses to the complete panel of BKV antigens, the Epstein–Barr virus (EBV) antigens, BZLF1 and EBNA1, and the mitogen phytohaemagglutinin (PHA). Correlations between responses to individual antigens and immunosuppressive regimens were also analysed. Antigen-specific T cell responses were a specific indicator of recent or ongoing recovery from BKV infection (P < 0·05), with responses to different BKV antigens being highly heterogeneous. Significant BKV immunity was undetectable in transplant patients with persistent viral replication or no history of BKV reactivation. Responses to EBV antigens and mitogen were reduced in patients with BKV reactivation, but these differences were not statistically significant. The T cell response to BKV antigens is a useful and specific guide to recovery from BKV reactivation in renal transplant recipients, provided that the full range of antigenic responses is measured. PMID:21671906

Association of Vascular Endothelial Growth Factor Expression with Tumor Angiogenesis and with Early Relapse in Primary Breast Cancer

PubMed Central

Hoshina, Seigo; Takayanagi, Toshiaki; Tominaga, Takeshi

1994-01-01

Angiogenesis is an independent prognostic indicator in breast cancer. In this report, the relationship between expression of vascular endothclial growth factor (VEGF; a selective mitogen for endothelial cells) and the microvessel density was examined in 103 primary breast cancers. The expression of VEGF was evaluated by immunocytochemical staining using anti‐VEGF antibody. The microvessel density, which was determined by immunostaining for factor VIII antigen, in VEGF‐rich tumors was clearly higher than that in VEGF‐poor tumors (P<0.01). There was a good correlation between VEGF expression and the increment of microvessel density. Furthermore, postoperative survey demonstrated that the relapse‐free survival rate of VEGF‐rich tumors was significantly worse than that of VEGF‐poor tumors. It was suggested that the expression of VEGF is closely associated with the promotion of angiogenesis and with early relapse in primary breast cancer. PMID:7525523

Arachidonic acid metabolites and endothelial dysfunction of portal hypertension.

PubMed

Sacerdoti, David; Pesce, Paola; Di Pascoli, Marco; Brocco, Silvia; Cecchetto, Lara; Bolognesi, Massimo

2015-07-01

Increased resistance to portal flow and increased portal inflow due to mesenteric vasodilatation represent the main factors causing portal hypertension in cirrhosis. Endothelial cell dysfunction, defined as an imbalance between the synthesis, release, and effect of endothelial mediators of vascular tone, inflammation, thrombosis, and angiogenesis, plays a major role in the increase of resistance in portal circulation, in the decrease in the mesenteric one, in the development of collateral circulation. Reduced response to vasodilators in liver sinusoids and increased response in the mesenteric arterioles, and, viceversa, increased response to vasoconstrictors in the portal-sinusoidal circulation and decreased response in the mesenteric arterioles are also relevant to the pathophysiology of portal hypertension. Arachidonic acid (AA) metabolites through the three pathways, cyclooxygenase (COX), lipoxygenase, and cytochrome P450 monooxygenase and epoxygenase, are involved in endothelial dysfunction of portal hypertension. Increased thromboxane-A2 production by liver sinusoidal endothelial cells (LSECs) via increased COX-1 activity/expression, increased leukotriens, increased epoxyeicosatrienoic acids (EETs) (dilators of the peripheral arterial circulation, but vasoconstrictors of the portal-sinusoidal circulation), represent a major component in the increased portal resistance, in the decreased portal response to vasodilators and in the hyper-response to vasoconstrictors. Increased prostacyclin (PGI2) via COX-1 and COX-2 overexpression, and increased EETs/heme-oxygenase-1/K channels/gap junctions (endothelial derived hyperpolarizing factor system) play a major role in mesenteric vasodilatation, hyporeactivity to vasoconstrictors, and hyper-response to vasodilators. EETs, mediators of liver regeneration after hepatectomy and of angiogenesis, may play a role in the development of regenerative nodules and collateral circulation, through stimulation of vascular endothelial

Role of vascular endothelial cell growth factor in Ovarian Hyperstimulation Syndrome.

PubMed Central

Levin, E R; Rosen, G F; Cassidenti, D L; Yee, B; Meldrum, D; Wisot, A; Pedram, A

1998-01-01

Controlled ovarian hyperstimulation with gonadotropins is followed by Ovarian Hyperstimulation Syndrome (OHSS) in some women. An unidentified capillary permeability factor from the ovary has been implicated, and vascular endothelial cell growth/permeability factor (VEGF) is a candidate protein. Follicular fluids (FF) from 80 women who received hormonal induction for infertility were studied. FFs were grouped according to oocyte production, from group I (0-7 oocytes) through group IV (23-31 oocytes). Group IV was comprised of four women with the most severe symptoms of OHSS. Endothelial cell (EC) permeability induced by the individual FF was highly correlated to oocytes produced (r2 = 0.73, P < 0.001). Group IV FF stimulated a 63+/-4% greater permeability than FF from group I patients (P < 0. 01), reversed 98% by anti-VEGF antibody. Group IV fluids contained the VEGF165 isoform and significantly greater concentrations of VEGF as compared with group I (1,105+/-87 pg/ml vs. 353+/-28 pg/ml, P < 0. 05). Significant cytoskeletal rearrangement of F-actin into stress fibers and a destruction of ZO-1 tight junction protein alignment was caused by group IV FF, mediated in part by nitric oxide. These mechanisms, which lead to increased EC permeability, were reversed by the VEGF antibody. Our results indicate that VEGF is the FF factor responsible for increased vascular permeability, thereby contributing to the pathogenesis of OHSS. PMID:9835623

Biophysical Properties and Motility of Human Mature Dendritic Cells Deteriorated by Vascular Endothelial Growth Factor through Cytoskeleton Remodeling

PubMed Central

Hu, Zu-Quan; Xue, Hui; Long, Jin-Hua; Wang, Yun; Jia, Yi; Qiu, Wei; Zhou, Jing; Wen, Zong-Yao; Yao, Wei-Juan; Zeng, Zhu

2016-01-01

Dendritic cells (DCs), the most potent antigen-presenting cells, play a central role in the initiation, regulation, and maintenance of the immune responses. Vascular endothelial growth factor (VEGF) is one of the important cytokines in the tumor microenvironment (TME) and can inhibit the differentiation and functional maturation of DCs. To elucidate the potential mechanisms of DC dysfunction induced by VEGF, the effects of VEGF on the biophysical characteristics and motility of human mature DCs (mDCs) were investigated. The results showed that VEGF had a negative influence on the biophysical properties, including electrophoretic mobility, osmotic fragility, viscoelasticity, and transmigration. Further cytoskeleton structure analysis by confocal microscope and gene expression profile analyses by gene microarray and real-time PCR indicated that the abnormal remodeling of F-actin cytoskeleton may be the main reason for the deterioration of biophysical properties, motility, and stimulatory capability of VEGF-treated mDCs. This is significant for understanding the biological behavior of DCs and the immune escape mechanism of tumors. Simultaneously, the therapeutic efficacies may be improved by blocking the signaling pathway of VEGF in an appropriate manner before the deployment of DC-based vaccinations against tumors. PMID:27809226

Vascular Endothelial Growth Factor Receptor-2 Couples Cyclo-Oxygenase-2 with Pro-Angiogenic Actions of Leptin on Human Endothelial Cells

PubMed Central

Garonna, Elena; Botham, Kathleen M.; Birdsey, Graeme M.; Randi, Anna M.; Gonzalez-Perez, Ruben R.; Wheeler-Jones, Caroline P. D.

2011-01-01

Background The adipocyte-derived hormone leptin influences the behaviour of a wide range of cell types and is now recognised as a pro-angiogenic and pro-inflammatory factor. In the vasculature, these effects are mediated in part through its direct leptin receptor (ObRb)-driven actions on endothelial cells (ECs) but the mechanisms responsible for these activities have not been established. In this study we sought to more fully define the molecular links between inflammatory and angiogenic responses of leptin-stimulated human ECs. Methodology/Principal Findings Immunoblotting studies showed that leptin increased cyclo-oxygenase-2 (COX-2) expression (but not COX-1) in cultured human umbilical vein ECs (HUVEC) through pathways that depend upon activation of both p38 mitogen-activated protein kinase (p38MAPK) and Akt, and stimulated rapid phosphorylation of vascular endothelial growth factor receptor 2 (VEGFR2) on Tyr1175. Phosphorylation of VEGFR2, p38MAPK and Akt, and COX-2 induction in cells challenged with leptin were blocked by a specific leptin peptide receptor antagonist. Pharmacological inhibitors of COX-2, the phosphatidylinositol 3-kinase (PI3K)/Akt pathway and p38MAPK abrogated leptin-induced EC proliferation (assessed by quantifying 5-bromo-2′-deoxyuridine incorporation, calcein fluorescence and propidium iodide staining), slowed the increased migration rate of leptin-stimulated cells (in vitro wound healing assay) and inhibited leptin-induced capillary-like tube formation by HUVEC on Matrigel. Inhibition of VEGFR2 tyrosine kinase activity reduced leptin-stimulated p38MAPK and Akt activation, COX-2 induction, and pro-angiogenic EC responses, and blockade of VEGFR2 or COX-2 activities abolished leptin-driven neo-angiogenesis in a chick chorioallantoic membrane vascularisation assay in vivo. Conclusions/Significance We conclude that a functional endothelial p38MAPK/Akt/COX-2 signalling axis is required for leptin's pro-angiogenic actions and that this is

Synthetic MUC1 Antitumor Vaccine with Incorporated 2,3-Sialyl-T Carbohydrate Antigen Inducing Strong Immune Responses with Isotype Specificity.

PubMed

Straßburger, David; Glaffig, Markus; Stergiou, Natascha; Bialas, Sabrina; Besenius, Pol; Schmitt, Edgar; Kunz, Horst

2018-04-06

The endothelial glycoprotein MUC1 is known to underlie alterations in cancer by means of aberrant glycosylation accompanied by changes in morphology. The heavily shortened glycans induce a collapse of the peptide backbone and enable accessibility of the latter to immune cells, rendering it a tumor-associated antigen. Synthetic vaccines based on MUC1 tandem repeat motifs, comprising tumor-associated 2,3-sialyl-T antigen, conjugated to the immunostimulating tetanus toxoid, are reported herein. Immunization with these vaccines in a simple water/oil emulsion produced a strong immune response in mice to which stimulation with complete Freund's adjuvant (CFA) was not superior. In both cases, high levels of IgG1 and IgG2a/b were induced in C57BL/6 mice. Additional glycosylation in the immunodominant PDTRP domain led to improved binding of the induced antisera to MCF-7 breast tumor cells, compared with that of the monoglycosylated peptide vaccine. © 2018 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

In smokers, Sonic hedgehog modulates pulmonary endothelial function through vascular endothelial growth factor.

PubMed

Henno, Priscilla; Grassin-Delyle, Stanislas; Belle, Emeline; Brollo, Marion; Naline, Emmanuel; Sage, Edouard; Devillier, Philippe; Israël-Biet, Dominique

2017-05-23

Tobacco-induced pulmonary vascular disease is partly driven by endothelial dysfunction. The Sonic hedgehog (SHH) pathway is involved in vascular physiology. We sought to establish whether the SHH pathway has a role in pulmonary endothelial dysfunction in smokers. The ex vivo endothelium-dependent relaxation of pulmonary artery rings in response to acetylcholine (Ach) was compared in 34 current or ex-smokers and 8 never-smokers. The results were expressed as a percentage of the contraction with phenylephrine. We tested the effects of SHH inhibitors (GANT61 and cyclopamine), an SHH activator (SAG) and recombinant VEGF on the Ach-induced relaxation. The level of VEGF protein in the pulmonary artery ring was measured in an ELISA. SHH pathway gene expression was quantified in reverse transcriptase-quantitative polymerase chain reactions. Ach-induced relaxation was much less intense in smokers than in never-smokers (respectively 24 ± 6% and 50 ± 7% with 10 -4 M Ach; p = 0.028). All SHH pathway genes were expressed in pulmonary artery rings from smokers. SHH inhibition by GANT61 reduced Ach-induced relaxation and VEGF gene expression in the pulmonary artery ring. Recombinant VEGF restored the ring's endothelial function. VEGF gene and protein expression levels in the pulmonary artery rings were positively correlated with the degree of Ach-induced relaxation and negatively correlated with the number of pack-years. SHH pathway genes and proteins are expressed in pulmonary artery rings from smokers, where they modulate endothelial function through VEGF.

Inhibition of intimal thickening after vascular injury with a cocktail of vascular endothelial growth factor and cyclic Arg-Gly-Asp peptide.

PubMed

Li, Yue; McRobb, Lucinda S; Khachigian, Levon M

2016-10-01

Percutaneous coronary intervention is widely used for the treatment of coronary artery disease; however, significant challenges such as restenosis remain. Key to solving these problems is to inhibit smooth muscle cell activation while enhancing re-endothelialization. Early growth response-1 (Egr-1) is a transcription factor that regulates vascular smooth muscle cell (SMC) proliferation and migration through its control of an array of downstream genes. A "cocktail" of vascular endothelial growth factor (VEGF)-A, VEGF-D and cyclic RGD was tested for its ability to inhibit neointima formation and accelerate re-endothelialization following balloon injury to carotid arteries of rats. In vitro, the cocktail stimulated endothelial cell growth yet inhibited smooth muscle cell growth. In vivo, cocktail-treated injured arteries exhibited reduced intimal thickening by >50% (P<0.05). It increased both re-endothelialization and endothelial nitric oxide synthase (NOS) expression. Cocktail reduced Egr-1 expression, an effect blocked by the NOS inhibitor L-N(G)-nitroarginine methyl ester (L-NAME) that also prevented cocktail inhibition of neointima inhibition. This combination may potentially be useful for the treatment of restenosis with concomitant stimulation of revascularization. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

Engineering a prostate-specific membrane antigen-activated tumor endothelial cell prodrug for cancer therapy.

PubMed

Denmeade, Samuel R; Mhaka, Annastasiah M; Rosen, D Marc; Brennen, W Nathaniel; Dalrymple, Susan; Dach, Ingrid; Olesen, Claus; Gurel, Bora; Demarzo, Angelo M; Wilding, George; Carducci, Michael A; Dionne, Craig A; Møller, Jesper V; Nissen, Poul; Christensen, S Brøgger; Isaacs, John T

2012-06-27

Heterogeneous expression of drug target proteins within tumor sites is a major mechanism of resistance to anticancer therapies. We describe a strategy to selectively inhibit, within tumor sites, the function of a critical intracellular protein, the sarcoplasmic/endoplasmic reticulum calcium adenosine triphosphatase (SERCA) pump, whose proper function is required by all cell types for viability. To achieve targeted inhibition, we took advantage of the unique expression of the carboxypeptidase prostate-specific membrane antigen (PSMA) by tumor endothelial cells within the microenvironment of solid tumors. We generated a prodrug, G202, consisting of a PSMA-specific peptide coupled to an analog of the potent SERCA pump inhibitor thapsigargin. G202 produced substantial tumor regression against a panel of human cancer xenografts in vivo at doses that were minimally toxic to the host. On the basis of these data, a phase 1 dose-escalation clinical trial has been initiated with G202 in patients with advanced cancer.

[Undifferentiated cutaneous angiosarcoma of the head: identification by the endothelial marker Ulex europaeus agglutinin I].

PubMed

Bork, K; Fries, J; Hoede, N; Korting, G W; Dienes, P

1985-06-01

Cutaneous angiosarcoma of the head is a rare tumor of the elderly and can occur in an undifferentiated form without any clinical or histological signs of the vascular origin of this tumor. In these cases, the tumor can be identified by using endothelial cell markers, such as factor-VIII-related antigen and ulex europaeus agglutinin I, in an immunofluorescence technique or a peroxidase-antiperoxidase method. A 78-year-old patient is described who died within 18 months from such a tumor, which was diagnosed using the endothelial cell marker, ulex europaeus agglutinin I.

Responses of brain and non-brain endothelial cells to meningitis-causing Escherichia coli K1.

PubMed

Paul-Satyaseela, Maneesh; Xie, Yi; Di Cello, Francescopaolo; Kim, Kwang Sik

2006-03-31

Bacterial interaction with specific host tissue may contribute to its propensity to cause an infection in a particular site. In this study, we examined whether meningitis-causing Escherichia coli K1 interaction with human brain microvascular endothelial cells, which constitute the blood-brain barrier, differed from its interaction with non-brain endothelial cells derived from skin and umbilical cord. We showed that E. coli K1 association was significantly greater with human brain microvascular endothelial cells than with non-brain endothelial cells. In addition, human brain microvascular endothelial cells maintained their morphology and intercellular junctional resistance in response to E. coli K1. In contrast, non-brain endothelial cells exhibited decreased transendothelial electrical resistance and detachment from the matrix upon exposure to E. coli K1. These different responses of brain and non-brain endothelial cells to E. coli K1 may form the basis of E. coli K1's propensity to cause meningitis.

Omental implantation of BOECs in hemophilia dogs results in circulating FVIII antigen and a complex immune response.

PubMed

Ozelo, Margareth C; Vidal, Barbara; Brown, Christine; Notley, Colleen; Hegadorn, Carol; Webster, Sandra; Harpell, Lori; Ahlin, James; Winterborn, Andrew; Handforth, Janine; Arruda, Valder R; Hough, Christine; Lillicrap, David

2014-06-26

Ex vivo gene therapy strategies avoid systemic delivery of viruses thereby mitigating the risk of vector-associated immunogenicity. Previously, we delivered autologous factor VIII (FVIII)-expressing blood outgrowth endothelial cells (BOECs) to hemophilia A mice and showed that these cells remained sequestered within the implanted matrix and provided therapeutic levels of FVIII. Prior to translating this strategy into the canine (c) model of hemophilia A, we increased cFVIII transgene expression by at least 100-fold with the use of the elongation factor 1 alpha (EF1α) promoter and a strong endothelial enhancer element. BOECs isolated from hemophilia A dogs transduced with this lentiviral vector express levels of cFVIII ranging between 1.0 and 1.5 U/mL per 10(6) cells over 24 hours. Autologous BOECs have been implanted into the omentum of 2 normal and 3 hemophilia A dogs. These implanted cells formed new vessels in the omentum. All 3 hemophilia A dogs treated with FVIII-expressing autologous BOECs developed anti-FVIII immunoglobulin G2 antibodies, but in only 2 of the dogs were these antibodies inhibitory. FVIII antigen levels >40% in the absence of FVIII coagulant function were detected in the circulation for up to a year after a single gene therapy treatment, indicating prolonged cellular viability and synthesis of FVIII. © 2014 by The American Society of Hematology.

Environmental Factors Contribute to β Cell Endoplasmic Reticulum Stress and Neo-Antigen Formation in Type 1 Diabetes

PubMed Central

Marré, Meghan L.; Piganelli, Jon D.

2017-01-01

Type 1 diabetes (T1D) is an autoimmune disease in which immune-mediated targeting and destruction of insulin-producing pancreatic islet β cells leads to chronic hyperglycemia. There are many β cell proteins that are targeted by autoreactive T cells in their native state. However, recent studies have demonstrated that many β cell proteins are recognized as neo-antigens following posttranslational modification (PTM). Although modified neo-antigens are well-established targets of pathology in other autoimmune diseases, the effects of neo-antigens in T1D progression and the mechanisms by which they are generated are not well understood. We have demonstrated that PTM occurs during endoplasmic reticulum (ER) stress, a process to which β cells are uniquely susceptible due to the high rate of insulin production in response to dynamic glucose sensing. In the context of genetic susceptibility to autoimmunity, presentation of these modified neo-antigens may activate autoreactive T cells and cause pathology. However, inherent β cell ER stress and protein PTM do not cause T1D in every genetically susceptible individual, suggesting the contribution of additional factors. Indeed, many environmental factors, such as viral infection, chemicals, or inflammatory cytokines, are associated with T1D onset, but the mechanisms by which these factors lead to disease onset remain unknown. Since these environmental factors also cause ER stress, exposure to these factors may enhance production of neo-antigens, therefore boosting β cell recognition by autoreactive T cells and exacerbating T1D pathogenesis. Therefore, the combined effects of physiological ER stress and the stress that is induced by environmental factors may lead to breaks in peripheral tolerance, contribute to antigen spread, and hasten disease onset. This Hypothesis and Theory article summarizes what is currently known about ER stress and protein PTM in autoimmune diseases including T1D and proposes a role for

Elevated Endothelial Hypoxia-Inducible Factor-1α Contributes to Glomerular Injury and Promotes Hypertensive Chronic Kidney Disease.

PubMed

Luo, Renna; Zhang, Weiru; Zhao, Cheng; Zhang, Yujin; Wu, Hongyu; Jin, Jianping; Zhang, Wenzheng; Grenz, Almut; Eltzschig, Holger K; Tao, Lijian; Kellems, Rodney E; Xia, Yang

2015-07-01

Hypertensive chronic kidney disease is one of the most prevalent medical conditions with high morbidity and mortality in the United States and worldwide. However, early events initiating the progression to hypertensive chronic kidney disease are poorly understood. We hypothesized that elevated endothelial hypoxia-inducible factor-1α (HIF-1α) is a common early insult triggering initial glomerular injury leading to hypertensive chronic kidney disease. To test our hypothesis, we used an angiotensin II infusion model of hypertensive chronic kidney disease to determine the specific cell type and mechanisms responsible for elevation of HIF-1α and its role in the progression of hypertensive chronic kidney disease. Genetic studies coupled with reverse transcription polymerase chain reaction profiling revealed that elevated endothelial HIF-1α is essential to initiate glomerular injury and progression to renal fibrosis by the transcriptional activation of genes encoding multiple vasoactive proteins. Mechanistically, we found that endothelial HIF-1α gene expression was induced by angiotensin II in a nuclear factor-κB-dependent manner. Finally, we discovered reciprocal positive transcriptional regulation of endothelial Hif-1α and Nf-κb genes is a key driving force for their persistent activation and disease progression. Overall, our findings revealed that the stimulation of HIF-1α gene expression in endothelial cells is detrimental to induce kidney injury, hypertension, and disease progression. Our findings highlight early diagnostic opportunities and therapeutic approaches for hypertensive chronic kidney disease. © 2015 American Heart Association, Inc.

Differential response of endothelial cells to simvastatin when conditioned with steady, non-reversing pulsatile or oscillating shear stress.

PubMed

Rossi, Joanna; Jonak, Paul; Rouleau, Leonie; Danielczak, Lisa; Tardif, Jean-Claude; Leask, Richard L

2011-01-01

Few studies have investigated whether fluid mechanics can impair or enhance endothelial cell response to pharmacological agents such as statin drugs. We evaluated and compared Kruppel-like factor 2 (KLF2), endothelial nitric oxide synthase (eNOS), and thrombomodulin (TM) expression in human abdominal aortic endothelial cells (HAAEC) treated with increasing simvastatin concentrations (0.1, 1 or 10 μM) under static culture and shear stress (steady, non-reversing pulsatile, and oscillating). Simvastatin, steady flow, and non-reversing pulsatile flow each separately upregulated KLF2, eNOS, and TM mRNA. At lower simvastatin concentrations (0.1 and 1 μM), the combination of statin and unidirectional steady or pulsatile flow produced an overall additive increase in mRNA levels. At higher simvastatin concentration (10 μM), a synergistic increase in eNOS and TM mRNA expression was observed. In contrast, oscillating flow impaired KLF2 and TM, but not eNOS expression by simvastatin at 1 μM. A higher simvastatin concentration of 10 μM overcame the inhibitory effect of oscillating flow. Our findings suggest that oscillating shear stress renders the endothelial cells less responsive to simvastatin than cells exposed to unidirectional steady or pulsatile flow. Consequently, the pleiotropic effects of statins in vivo may be less effective in endothelial cells exposed to atheroprone hemodynamics.

Strategies to alleviate original antigenic sin responses to influenza viruses.

PubMed

Kim, Jin Hyang; Davis, William G; Sambhara, Suryaprakash; Jacob, Joshy

2012-08-21

Original antigenic sin is a phenomenon wherein sequential exposure to closely related influenza virus variants reduces antibody (Ab) response to novel antigenic determinants in the second strain and, consequently, impairs the development of immune memory. This could pose a risk to the development of immune memory in persons previously infected with or vaccinated against influenza. Here, we explored strategies to overcome original antigenic sin responses in mice sequentially exposed to two closely related hemagglutinin 1 neuraminidase 1 (H1N1) influenza strains A/PR/8/34 and A/FM/1/47. We found that dendritic cell-activating adjuvants [Bordetella pertussis toxin (PT) or CpG ODN or a squalene-based oil-in-water nanoemulsion (NE)], upon administration during the second viral exposure, completely protected mice from a lethal challenge and enhanced neutralizing-Ab titers against the second virus. Interestingly, PT and NE adjuvants when administered during the first immunization even prevented original antigenic sin in subsequent immunization without any adjuvants. As an alternative to using adjuvants, we also found that repeated immunization with the second viral strain relieved the effects of original antigenic sin. Taken together, our studies provide at least three ways of overcoming original antigenic sin.

Endothelial cells of extremely premature infants display impaired immune response after proinflammatory stimulation.

PubMed

Wisgrill, Lukas; Muck, Martina; Wessely, Isabelle; Berger, Angelika; Spittler, Andreas; Förster-Waldl, Elisabeth; Sadeghi, Kambis

2018-01-01

BackgroundEndothelial cells (ECs) exert immunological functions such as production of proinflammatory cytokines/chemokines as well as facilitation of extravasation of immune cells into infected tissue. Limited data are available on the functionality of ECs from extremely preterm neonates during infection. Accordingly, the aim of our study was to investigate the immune response of premature ECs after proinflammatory stimulation.MethodsCell adhesion receptors' expression and function, nuclear factor 'kappa-light-chain-enhancer' of activated B-cells (NFκB) signaling, and chemokine production were analyzed in umbilical cord ECs from extremely preterm and term neonates after proinflammatory stimulation.ResultsP-selectin and E-selectin surface expression as well as NFκB signaling were lower after lipopolysaccharide (LPS) stimulation in premature ECs. Preterm ECs exhibited lower, but significant, cell-adhesive functions after LPS stimulation compared with term ECs. CCL2/CXCL8 chemokine secretion was significantly upregulated after proinflammatory stimulation in both groups. CXCL10 production was significantly increased in term but not in preterm ECs upon stimulation with tumor necrosis factor compared with unstimulated ECs.ConclusionExtremely premature ECs showed partly reduced expression levels and function of cell adhesion molecules. Both NFκB signaling and chemokine/cytokine production were reduced in premature ECs. The diminished endothelial proinflammatory immune response might result in impaired infection control of preterm newborns rendering them prone to severe infection.

Fibroblast growth factor rescues brain endothelial cells lacking presenilin 1 from apoptotic cell death following serum starvation.

PubMed

Gama Sosa, Miguel A; De Gasperi, Rita; Hof, Patrick R; Elder, Gregory A

2016-07-22

Presenilin 1 (Psen1) is important for vascular brain development and is known to influence cellular stress responses. To understand the role of Psen1 in endothelial stress responses, we investigated the effects of serum withdrawal on wild type (wt) and Psen1-/- embryonic brain endothelial cells. Serum starvation induced apoptosis in Psen1-/- cells but did not affect wt cells. PI3K/AKT signaling was reduced in serum-starved Psen1-/- cells, and this was associated with elevated levels of phospho-p38 consistent with decreased pro-survival AKT signaling in the absence of Psen1. Fibroblast growth factor (FGF1 and FGF2), but not vascular endothelial growth factor (VEGF) rescued Psen1-/- cells from serum starvation induced apoptosis. Inhibition of FGF signaling induced apoptosis in wt cells under serum withdrawal, while blocking γ-secretase activity had no effect. In the absence of serum, FGF2 immunoreactivity was distributed diffusely in cytoplasmic and nuclear vesicles of wt and Psen1-/- cells, as levels of FGF2 in nuclear and cytosolic fractions were not significantly different. Thus, sensitivity of Psen1-/- cells to serum starvation is not due to lack of FGF synthesis but likely to effects of Psen1 on FGF release onto the cell surface and impaired activation of the PI3K/AKT survival pathway.

Endothelial Ca+-activated K+ channels in normal and impaired EDHF-dilator responses--relevance to cardiovascular pathologies and drug discovery.

PubMed

Grgic, Ivica; Kaistha, Brajesh P; Hoyer, Joachim; Köhler, Ralf

2009-06-01

The arterial endothelium critically contributes to blood pressure control by releasing vasodilating autacoids such as nitric oxide, prostacyclin and a third factor or pathway termed 'endothelium-derived hyperpolarizing factor' (EDHF). The nature of EDHF and EDHF-signalling pathways is not fully understood yet. However, endothelial hyperpolarization mediated by the Ca(2+)-activated K(+) channels (K(Ca)) has been suggested to play a critical role in initializing EDHF-dilator responses in conduit and resistance-sized arteries of many species including humans. Endothelial K(Ca) currents are mediated by the two K(Ca) subtypes, intermediate-conductance K(Ca) (KCa3.1) (also known as, a.k.a. IK(Ca)) and small-conductance K(Ca) type 3 (KCa2.3) (a.k.a. SK(Ca)). In this review, we summarize current knowledge about endothelial KCa3.1 and KCa2.3 channels, their molecular and pharmacological properties and their specific roles in endothelial function and, particularly, in the EDHF-dilator response. In addition we focus on recent experimental evidences derived from KCa3.1- and/or KCa2.3-deficient mice that exhibit severe defects in EDHF signalling and elevated blood pressures, thus highlighting the importance of the KCa3.1/KCa2.3-EDHF-dilator system for blood pressure control. Moreover, we outline differential and overlapping roles of KCa3.1 and KCa2.3 for EDHF signalling as well as for nitric oxide synthesis and discuss recent evidence for a heterogeneous (sub) cellular distribution of KCa3.1 (at endothelial projections towards the smooth muscle) and KCa2.3 (at inter-endothelial borders and caveolae), which may explain their distinct roles for endothelial function. Finally, we summarize the interrelations of altered KCa3.1/KCa2.3 and EDHF system impairments with cardiovascular disease states such as hypertension, diabetes, dyslipidemia and atherosclerosis and discuss the therapeutic potential of KCa3.1/KCa2.3 openers as novel types of blood pressure-lowering drugs.

Angiocrine factors from Akt-activated endothelial cells balance self-renewal and differentiation of haematopoietic stem cells

PubMed Central

Kobayashi, Hideki; Butler, Jason M.; O'Donnell, Rebekah; Kobayashi, Mariko; Ding, Bi-Sen; Bonner, Bryant; Chiu, Vi K.; Nolan, Daniel J.; Shido, Koji; Benjamin, Laura; Rafii, Shahin

2010-01-01

Endothelial cells establish an instructive vascular niche that reconstitutes haematopoietic stem and progenitor cells (HSPCs) through release of specific paracrine growth factors, known as angiocrine factors. However, the mechanism by which endothelial cells balance the rate of proliferation and lineage-specific differentiation of HSPCs is unknown. Here, we demonstrate that Akt activation in endothelial cells, through recruitment of mTOR, but not the FoxO pathway, upregulates specific angiocrine factors that support expansion of CD34−Flt3− KLS HSPCs with long-term haematopoietic stem cell (LT-HSC) repopulation capacity. Conversely, co-activation of Akt-stimulated endothelial cells with p42/44 MAPK shifts the balance towards maintenance and differentiation of the HSPCs. Selective activation of Akt1 in the endothelial cells of adult mice increased the number of colony forming units in the spleen and CD34−Flt3− KLS HSPCs with LT-HSC activity in the bone marrow, accelerating haematopoietic recovery. Therefore, the activation state of endothelial cells modulates reconstitution of HSPCs through the upregulation of angiocrine factors, with Akt–mTOR-activated endothelial cells supporting the self-renewal of LT-HSCs and expansion of HSPCs, whereas MAPK co-activation favours maintenance and lineage-specific differentiation of HSPCs. PMID:20972423

Transcriptional Responses of Candida albicans to Epithelial and Endothelial Cells▿ †

PubMed Central

Park, Hyunsook; Liu, Yaoping; Solis, Norma; Spotkov, Joshua; Hamaker, Jessica; Blankenship, Jill R.; Yeaman, Michael R.; Mitchell, Aaron P.; Liu, Haoping; Filler, Scott G.

2009-01-01

Candida albicans interacts with oral epithelial cells during oropharyngeal candidiasis and with vascular endothelial cells when it disseminates hematogenously. We set out to identify C. albicans genes that govern interactions with these host cells in vitro. The transcriptional response of C. albicans to the FaDu oral epithelial cell line and primary endothelial cells was determined by microarray analysis. Contact with epithelial cells caused a decrease in transcript levels of genes related to protein synthesis and adhesion, whereas contact with endothelial cells did not significantly influence any specific functional category of genes. Many genes whose transcripts were increased in response to either host cell had not been previously characterized. We constructed mutants with homozygous insertions in 22 of these uncharacterized genes to investigate their function during host-pathogen interaction. By this approach, we found that YCK2, VPS51, and UEC1 are required for C. albicans to cause normal damage to epithelial cells and resist antimicrobial peptides. YCK2 is also necessary for maintenance of cell polarity. VPS51 is necessary for normal vacuole formation, resistance to multiple stressors, and induction of maximal endothelial cell damage. UEC1 encodes a unique protein that is required for resistance to cell membrane stress. Therefore, some C. albicans genes whose transcripts are increased upon contact with epithelial or endothelial cells are required for the organism to damage these cells and withstand the stresses that it likely encounters during growth in the oropharynx and bloodstream. PMID:19700637

Caffeoyl glucosides from Nandina domestica inhibit LPS-induced endothelial inflammatory responses.

PubMed

Kulkarni, Roshan R; Lee, Wonhwa; Jang, Tae Su; Lee, JungIn; Kwak, Soyoung; Park, Mi Seon; Lee, Hyun-Shik; Bae, Jong-Sup; Na, MinKyun

2015-11-15

Endothelial dysfunction is a key pathological feature of many inflammatory diseases, including sepsis. In the present study, a new caffeoyl glucoside (1) and two known caffeoylated compounds (2 and 3) were isolated from the fruits of Nandina domestica Thunb. (Berberidaceae). The compounds were investigated for their effects against lipopolysaccharide (LPS)-mediated endothelial inflammatory responses. At 20 μM, 1 and 2 inhibited LPS-induced hyperpermeability, adhesion, and migration of leukocytes across a human endothelial cell monolayer in a dose-dependent manner suggesting that 1 and 2 may serve as potential scaffolds for the development of therapeutic agents to treat vascular inflammatory disorders. Copyright © 2015 Elsevier Ltd. All rights reserved.

Activation of the endoplasmic reticulum stress response by the amyloid-beta 1-40 peptide in brain endothelial cells.

PubMed

Fonseca, Ana Catarina R G; Ferreiro, Elisabete; Oliveira, Catarina R; Cardoso, Sandra M; Pereira, Cláudia F

2013-12-01

Neurovascular dysfunction arising from endothelial cell damage is an early pathogenic event that contributes to the neurodegenerative process occurring in Alzheimer's disease (AD). Since the mechanisms underlying endothelial dysfunction are not fully elucidated, this study was aimed to explore the hypothesis that brain endothelial cell death is induced upon the sustained activation of the endoplasmic reticulum (ER) stress response by amyloid-beta (Aβ) peptide, which deposits in the cerebral vessels in many AD patients and transgenic mice. Incubation of rat brain endothelial cells (RBE4 cell line) with Aβ1-40 increased the levels of several markers of ER stress-induced unfolded protein response (UPR), in a time-dependent manner, and affected the Ca(2+) homeostasis due to the release of Ca(2+) from this intracellular store. Finally, Aβ1-40 was shown to activate both mitochondria-dependent and -independent apoptotic cell death pathways. Enhanced release of cytochrome c from mitochondria and activation of the downstream caspase-9 were observed in cells treated with Aβ1-40 concomitantly with caspase-12 activation. Furthermore, Aβ1-40 activated the apoptosis effectors' caspase-3 and promoted the translocation of apoptosis-inducing factor (AIF) to the nucleus demonstrating the involvement of caspase-dependent and -independent mechanisms during Aβ-induced endothelial cell death. In conclusion, our data demonstrate that ER stress plays a significant role in Aβ1-40-induced apoptotic cell death in brain endothelial cells suggesting that ER stress-targeted therapeutic strategies might be useful in AD to counteract vascular defects and ultimately neurodegeneration. © 2013.

Repurposing Ospemifene for Potentiating an Antigen-Specific Immune Response

PubMed Central

Kao, Chiao-Jung; Wurz, Gregory T.; Lin, Yi-Chen; Vang, Daniel P.; Phong, Brian; DeGregorio, Michael W.

2016-01-01

Objective Ospemifene, an estrogen receptor agonist/antagonist approved for treatment of dyspareunia and vaginal dryness in postmenopausal women, has potential new indications as an immune modulator. The overall objective of the present series of preclinical studies was to evaluate the immunomodulatory activity of ospemifene in combination with a peptide cancer vaccine. Methods Immune regulating effects, mechanism of action and structure activity relationships of ospemifene and related compounds were evaluated by examining expression of T cell activating cytokines in vitro, and antigen-specific immune response and cytotoxic T-lymphocyte activity in vivo. The effects of ospemifene (OSP) on the immune response to a peptide cancer vaccine (PV) were evaluated following chronic [control (n=22); OSP 50 mg/kg (n=16); PV (n=6); OSP+PV (n=11)], intermittent [control (n=10); OSP 10 and 50 mg/kg (n=11); PV (n=11); combination treatment (n=11 each dose)] and pretreatment [control; OSP 100 mg/kg; PV 100 µg; combination treatment (n=8 all groups)] ospemifene oral dosing schedules in a total of 317 mixed-sex tumor-bearing and non-tumor-bearing mice. Results The results showed that ospemifene induced expression of the key TH1 cytokines interferon gamma and interleukin-2 in vitro, which may be mediated by stimulating T cells through phosphoinositide 3-kinase and calmodulin signaling pathways. In combination with an antigen-specific peptide cancer vaccine, ospemifene increased antigen-specific immune response and increased cytotoxic T-lymphocyte activity in tumor-bearing and non-tumor-bearing mice. The pretreatment, intermittent, and chronic dosing schedules of ospemifene activate naïve T cells, modulate antigen-induced tolerance and reduce tumor-associated, pro-inflammatory cytokines, respectively. Conclusions Taken together, ospemifene’s dose response and schedule-dependent immune modulating activity offers a method of tailoring and augmenting the efficacy of previously failed

ACTINOMYCES NEUII ENDOPHTHALMITIS AFTER INTRAVITREAL ANTI-VASCULAR ENDOTHELIAL GROWTH FACTOR INJECTION.

PubMed

Sahni, Sakshi; Watson, Randee Miller; Sheth, Veeral S

2017-01-01

To describe a case of acute endophthalmitis caused by Actinomyces neuii after intravitreal anti-vascular endothelial growth factor injection. Observational case report, review of published literature. A 67-year-old white man with wet age-related macular degeneration developed endophthalmitis secondary to A. neuii on the 10th day after intravitreal anti-vascular endothelial growth factor injection. Both anterior chamber and vitreous cultures were positive for A. neuii. He was treated successfully with intravitreal injection of vancomycin and ceftazidime. This is the first published report of culture-positive endophthalmitis caused by A. neuii after intravitreal injection.

Relationships of methacholine and adenosine monophosphate responsiveness with serum vascular endothelial growth factor in children with asthma.

PubMed

Yoo, Young; Choi, Ic Sun; Byeon, Jung Hye; Lee, Seung Min; La, Kyong Suk; Choi, Byung Min; Park, Sang Hee; Choung, Ji Tae

2010-01-01

Airway hyperresponsiveness, which is a characteristic feature of asthma, is usually measured by means of bronchial challenge with direct or indirect stimuli. Vascular endothelial growth factor (VEGF) increases vascular permeability and angiogenesis, leads to mucosal edema, narrows the airway diameter, and reduces airway flow. To examine the relationships between serum VEGF level and airway responsiveness to methacholine and adenosine monophosphate (AMP) in children with asthma. Peripheral blood eosinophil counts, serum eosinophil cationic protein (ECP) concentrations, and serum VEGF concentrations were measured in 31 asthmatic children and 26 control subjects. Methacholine and AMP bronchial challenges were performed on children with asthma. Children with asthma had a significantly higher mean (SD) level of VEGF than controls (361.2 [212.0] vs 102.7 [50.0] pg/mL; P < .001). Blood eosinophil counts and serum ECP levels significantly correlated inversely with AMP provocation concentration that caused a decrease in forced expiratory volume in 1 second of 20% (PC20) (r = -0.474, P =.01; r = -0.442, P =.03, respectively), but not with methacholine PC20 (r = -0.228, P = .26; r = -0.338, P =.10, respectively). Serum VEGF levels significantly correlated with airway responsiveness to AMP (r = -0.462; P = .009) but not to methacholine (r = -0.243; P = .19). Serum VEGF levels were increased in children with asthma and were related to airway responsiveness to AMP but not to methacholine. Increased VEGF levels in asthmatic children may result in increased airway responsiveness by mechanisms related to airway inflammation or increased permeability of airway vasculature.

Methylmercury Causes Blood-Brain Barrier Damage in Rats via Upregulation of Vascular Endothelial Growth Factor Expression

PubMed Central

Takahashi, Tetsuya; Fujimura, Masatake; Koyama, Misaki; Kanazawa, Masato; Usuki, Fusako; Nishizawa, Masatoyo; Shimohata, Takayoshi

2017-01-01

Clinical manifestations of methylmercury (MeHg) intoxication include cerebellar ataxia, concentric constriction of visual fields, and sensory and auditory disturbances. The symptoms depend on the site of MeHg damage, such as the cerebellum and occipital lobes. However, the underlying mechanism of MeHg-induced tissue vulnerability remains to be elucidated. In the present study, we used a rat model of subacute MeHg intoxication to investigate possible MeHg-induced blood-brain barrier (BBB) damage. The model was established by exposing the rats to 20-ppm MeHg for up to 4 weeks; the rats exhibited severe cerebellar pathological changes, although there were no significant differences in mercury content among the different brain regions. BBB damage in the cerebellum after MeHg exposure was confirmed based on extravasation of endogenous immunoglobulin G (IgG) and decreased expression of rat endothelial cell antigen-1. Furthermore, expression of vascular endothelial growth factor (VEGF), a potent angiogenic growth factor, increased markedly in the cerebellum and mildly in the occipital lobe following MeHg exposure. VEGF expression was detected mainly in astrocytes of the BBB. Intravenous administration of anti-VEGF neutralizing antibody mildly reduced the rate of hind-limb crossing signs observed in MeHg-exposed rats. In conclusion, we demonstrated for the first time that MeHg induces BBB damage via upregulation of VEGF expression at the BBB in vivo. Further studies are required in order to determine whether treatment targeted at VEGF can ameliorate MeHg-induced toxicity. PMID:28118383

Improved vascularization of planar membrane diffusion devices following continuous infusion of vascular endothelial growth factor.

PubMed

Trivedi, N; Steil, G M; Colton, C K; Bonner-Weir, S; Weir, G C

2000-01-01

Improving blood vessel formation around an immunobarrier device should improve the survival of the encapsulated tissue. In the present study we investigated the formation of new blood vessels around a planar membrane diffusion device (the Baxter Theracyte System) undergoing a continuous infusion of vascular endothelial growth factor through the membranes and into the surrounding tissue. Each device (20 microl) had both an inner immunoisolation membrane and an outer vascularizing membrane. Human recombinant vascular endothelial growth factor-165 was infused at 100 ng/day (low dose: n = 6) and 500 ng/day (high dose: n = 7) for 10 days into devices implanted s.c. in Sprague-Dawley rats; noninfused devices transplanted for an identical period were used as controls (n = 5). Two days following the termination of VEGF infusion, devices were loaded with 20 microl of Lispro insulin (1 U/kg) and the kinetics of insulin release from the lumen of the device was assessed. Devices were then explanted and the number of blood vessels (capillary and noncapillary) was quantified using morphometry. High-dose vascular endothelial growth factor infusion resulted in two- to threefold more blood vessels around the device than that obtained with the noninfused devices and devices infused with low-dose vascular endothelial growth factor. This increase in the number of blood vessels was accompanied by a modest increase in insulin diffusion from the device in the high-dose vascular endothelial growth factor infusion group. We conclude that vascular endothelial growth factor can be used to improve blood vessel formation adjacent to planar membrane diffusion devices.

Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity.

PubMed

Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J; Miranda, Melroy X; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F; Verrey, François; Matter, Christian M

2013-12-01

Aldosterone plays a crucial role in cardiovascular disease. 'Systemic' inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the 'endothelial' MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high 'endogenous' aldosterone) and in 'exogenous' aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Obesity-induced endothelial dysfunction depends on the 'endothelial' MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population of obese patients to decrease vascular dysfunction and subsequent atherosclerotic complications.

Vascular endothelial growth factors: A comparison between invertebrates and vertebrates.

PubMed

Kipryushina, Yulia O; Yakovlev, Konstantin V; Odintsova, Nelly A

2015-12-01

This review aims to summarize recent data concerning the structure and role of the members of the vascular endothelial growth factor (VEGF) and vascular endothelial growth factor receptor (VEGFR) families in the context of early development, organogenesis and regeneration, with a particular emphasis on the role of these factors in the development of invertebrates. Homologs of VEGF and/or VEGFR have been found in all Eumetazoa, in both Radiata and Bilateria, where they are expressed in the descendants of different germ layers and play a pivotal role in the development of animals with and without a vascular system. VEGF is a well-known angiogenesis regulator, but this factor also control cell migration during neurogenesis and the development of branching organs (the trachea) in invertebrate and vertebrate species. A possible explanation for the origin of Vegf/Vegfr in the animal kingdom and a pathway of Vegf/Vegfr evolution are discussed. Copyright © 2015 Elsevier Ltd. All rights reserved.

Enhancement of proinflammatory and procoagulant responses to silica particles by monocyte-endothelial cell interactions

PubMed Central

2012-01-01

Background Inorganic particles, such as drug carriers or contrast agents, are often introduced into the vascular system. Many key components of the in vivo vascular environment include monocyte-endothelial cell interactions, which are important in the initiation of cardiovascular disease. To better understand the effect of particles on vascular function, the present study explored the direct biological effects of particles on human umbilical vein endothelial cells (HUVECs) and monocytes (THP-1 cells). In addition, the integrated effects and possible mechanism of particle-mediated monocyte-endothelial cell interactions were investigated using a coculture model of HUVECs and THP-1 cells. Fe3O4 and SiO2 particles were chosen as the test materials in the present study. Results The cell viability data from an MTS assay showed that exposure to Fe3O4 or SiO2 particles at concentrations of 200 μg/mL and above significantly decreased the cell viability of HUVECs, but no significant loss in viability was observed in the THP-1 cells. TEM images indicated that with the accumulation of SiO2 particles in the cells, the size, structure and morphology of the lysosomes significantly changed in HUVECs, whereas the lysosomes of THP-1 cells were not altered. Our results showed that reactive oxygen species (ROS) generation; the production of interleukin (IL)-6, IL-8, monocyte chemoattractant protein 1 (MCP-1), tumor necrosis factor (TNF)-α and IL-1β; and the expression of CD106, CD62E and tissue factor in HUVECs and monocytes were significantly enhanced to a greater degree in the SiO2-particle-activated cocultures compared with the individual cell types alone. In contrast, exposure to Fe3O4 particles had no impact on the activation of monocytes or endothelial cells in monoculture or coculture. Moreover, using treatment with the supernatants of SiO2-particle-stimulated monocytes or HUVECs, we found that the enhancement of proinflammatory response by SiO2 particles was not mediated by

Nerve Growth Factor-Induced Angiogenesis: 1. Endothelial Cell Tube Formation Assay.

PubMed

Lazarovici, Philip; Lahiani, Adi; Gincberg, Galit; Haham, Dikla; Fluksman, Arnon; Benny, Ofra; Marcinkiewicz, Cezary; Lelkes, Peter I

2018-01-01

Nerve growth factor (NGF) is a neurotrophin promoting survival, proliferation, differentiation, and neuroprotection in the embryonal and adult nervous system. NGF also induces angiogenic effects in the cardiovascular system, which may be beneficial in engineering new blood vessels and for developing novel anti-angiogenesis therapies for cancer. Angiogenesis is a cellular process characterized by a number of events, including endothelial cell migration, invasion, and assembly into capillaries. In vitro endothelial tube formation assays are performed using primary human umbilical vein endothelial cells, human aortic endothelial cells, and other human or rodent primary endothelial cells isolated from the vasculature of both tumors and normal tissues. Immortalized endothelial cell lines are also used for these assays. When seeded onto Matrigel, these cells reorganize to create tubelike structure, which may be used as models for studying some aspects of in vitro angiogenesis. Image acquisition by light and fluorescence microscopy and/or quantification of fluorescently labeled cells can be carried out manually or digitally, using commercial software and automated image processing. Here we detail materials, procedure, assay conditions, and cell labeling for quantification of endothelial cell tube formation. This model can be applied to study cellular and molecular mechanisms by which NGF or other neurotrophins promote angiogenesis. This model may also be useful for the development of potential angiogenic and/or anti-angiogenic drugs targeting NGF receptors.

Endomembrane H-Ras Controls Vascular Endothelial Growth Factor-induced Nitric-oxide Synthase-mediated Endothelial Cell Migration*

PubMed Central

Haeussler, Dagmar J.; Pimentel, David R.; Hou, Xiuyun; Burgoyne, Joseph R.; Cohen, Richard A.; Bachschmid, Markus M.

2013-01-01

We demonstrate for the first time that endomembrane-delimited H-Ras mediates VEGF-induced activation of endothelial nitric-oxide synthase (eNOS) and migratory response of human endothelial cells. Using thiol labeling strategies and immunofluorescent cell staining, we found that only 31% of total H-Ras is S-palmitoylated, tethering the small GTPase to the plasma membrane but leaving the function of the large majority of endomembrane-localized H-Ras unexplained. Knockdown of H-Ras blocked VEGF-induced PI3K-dependent Akt (Ser-473) and eNOS (Ser-1177) phosphorylation and nitric oxide-dependent cell migration, demonstrating the essential role of H-Ras. Activation of endogenous H-Ras led to recruitment and phosphorylation of eNOS at endomembranes. The loss of migratory response in cells lacking endogenous H-Ras was fully restored by modest overexpression of an endomembrane-delimited H-Ras palmitoylation mutant. These studies define a newly recognized role for endomembrane-localized H-Ras in mediating nitric oxide-dependent proangiogenic signaling. PMID:23548900

Tissue factor-dependent vascular endothelial growth factor production by human fibroblasts in response to activated factor VII.

PubMed

Ollivier, V; Bentolila, S; Chabbat, J; Hakim, J; de Prost, D

1998-04-15

The transmembrane protein tissue factor (TF) is the cell surface receptor for coagulation factor VII (FVII) and activated factor VII (FVIIa). Recently, TF has been identified as a regulator of angiogenesis, tumor growth, and metastasis. This study was designed to link the binding of FVII(a) to its receptor, TF, with the subsequent triggering of angiogenesis through vascular endothelial growth factor (VEGF) production by human lung fibroblasts. We report that incubation of fibroblasts, which express constitutive surface TF, with FVII(a) induces VEGF synthesis. FVII(a)-induced VEGF secretion, assessed by a specific enzyme-linked immunosorbent assay, was time- and concentration-dependent. VEGF secretion was maximal after 24 hours of incubation of the cells with 100 nmol/L FVII(a) and represented a threefold induction of the basal VEGF level. Reverse transcriptase-polymerase chain reaction analysis of VEGF detected three mRNA species of 180, 312, and 384 bp corresponding, respectively, to VEGF121, VEGF165, and VEGF189. A 2.5- to 3.5-fold increase was observed for the 180- and 312-bp transcripts at 12 and 24 hours, respectively. FVII(a)-dependent VEGF production was inhibited by a pool of antibodies against TF, pointing to the involvement of this receptor. On specific active-site inhibition with dansyl-glutamyl-glycinyl-arginyl chloromethyl ketone, FVIIa lost 70% of its capacity to elicit VEGF production. Consistent with this, the native form (zymogen) of FVII only had a 1.8-fold stimulating effect. Protein tyrosine kinase and protein kinase C are involved in signal transduction leading to VEGF production, as shown by the inhibitory effects of genistein and GF 109203X. The results of this study indicate that TF is essential for VIIa-induced VEGF production by human fibroblasts and that its role is mainly linked to the proteolytic activity of the TF-VIIa complex.

The proangiogenic phenotype of tumor-derived endothelial cells is reverted by the overexpression of platelet-activating factor acetylhydrolase.

PubMed

Doublier, Sophie; Ceretto, Monica; Lupia, Enrico; Bravo, Stefania; Bussolati, Benedetta; Camussi, Giovanni

2007-10-01

We previously reported that human tumor-derived endothelial cells (TEC) have an angiogenic phenotype related to the autocrine production of several angiogenic factors. The purpose of the present study was to evaluate whether an enhanced synthesis of platelet-activating factor (PAF) might contribute to the proangiogenic characteristics of TEC and whether its inactivation might inhibit angiogenesis. To address the potential role of PAF in the proangiogenic characteristics of TEC, we engineered TEC to stably overexpress human plasma PAF-acetylhydrolase (PAF-AH), the major PAF-inactivating enzyme, and we evaluated in vitro and in vivo angiogenesis. TECs were able to synthesize a significantly enhanced amount of PAF compared with normal human microvascular endothelial cells when stimulated with thrombin, vascular endothelial growth factor, or soluble CD154. Transfection of TEC with PAF-AH (TEC-PAF-AH) significantly inhibited apoptosis resistance and spontaneous motility of TEC. In addition, PAF and vascular endothelial growth factor stimulation enhanced the motility and adhesion of TEC but not of TEC-PAF-AH. In vitro, TEC-PAF-AH lost the characteristic ability of TEC to form vessel-like structures when plated on Matrigel. Finally, when cells were injected s.c. within Matrigel in severe combined immunodeficiency mice or coimplanted with a renal carcinoma cell line, the overexpression of PAF-AH induced a significant reduction of functional vessel formation. These results suggest that inactivation of PAF, produced by TEC, by the overexpression of plasma PAF-AH affects survival, migration, and the angiogenic response of TEC both in vitro and in vivo.

Regression of vessels in the tunica vasculosa lentis is initiated by coordinated endothelial apoptosis: a role for vascular endothelial growth factor as a survival factor for endothelium.

PubMed

Mitchell, C A; Risau, W; Drexler, H C

1998-11-01

The development of the embryonic lens is dependent on the formation and regression of the tunica vasculosa lentis (TVL), which is a transiently occurring capillary plexus that surrounds the posterior part of the lens. In this study, by using the terminal deoxy-nucleotidyl transferase mediated nick end-labelling technique (TUNEL), electron microscopy, radioactive end-labelling of DNA extracted from TVL, and the Comet assay, we show that widespread apoptosis of the endothelial cells that constitute the TVL is occurring already at embryonic day 17.5 (E17.5) of mouse development, much earlier than was reported previously (Jack [1972a] Am. J. Ophthalmol. 74:261-272; Lang [1997] Cell Death Diff. 4:12-20). In addition to apoptotic cell death, regression of this structure is associated with loss of capillary integrity, leakage of erythrocytes into the vitreal compartment, and phagocytosis of the apoptotic endothelium by tissue macrophages (hyalocytes). In situ hybridization experiments with probes for the flk-1 receptor and its high-affinity ligand, vascular endothelial growth factor (VEGF; Terman et al. [1992] Biochem. Biophys. Res. Commun. 187:1579-1586; Millauer et al. [1993] Cell 72:835-846), revealed strong endothelial cell expression for flk-1 in the eyes of E13.5-E17.5 embryos. VEGF mRNA was detected in lens epithelial cells located at the posterior pole of the developing lens in E13.5 embryos, in close proximity to the TVL capillaries. At later times (E14.5-E17.5), when the lens epithelial cells have differentiated into primary lens fiber cells, and a thick lenticular capsule is formed, the expression of VEGF mRNA becomes restricted to the anterior and equatorial portions of the lens. The physical separation of the VEGF-producing cells from the flk-1-expressing endothelium (due to the differentiation of the lens epithelial cells into lens fiber cells and the formation of the lenticular capsule) may deprive the endothelium of an essential survival factor and, thus

Kaposi’s Sarcoma-Associated Herpesvirus Interleukin-6 Modulates Endothelial Cell Movement by Upregulating Cellular Genes Involved in Migration

PubMed Central

Giffin, Louise; West, John A.

2015-01-01

ABSTRACT Kaposi’s sarcoma-associated herpesvirus (KSHV) is the causative agent of human Kaposi’s sarcoma, a tumor that arises from endothelial cells, as well as two B cell lymphoproliferative diseases, primary effusion lymphoma and multicentric Castleman’s disease. KSHV utilizes a variety of mechanisms to evade host immune responses and promote cellular transformation and growth in order to persist for the life of the host. A viral homolog of human interleukin-6 (hIL-6) named viral interleukin-6 (vIL-6) is encoded by KSHV and expressed in KSHV-associated cancers. Similar to hIL-6, vIL-6 is secreted, but the majority of vIL-6 is retained within the endoplasmic reticulum, where it can initiate functional signaling through part of the interleukin-6 receptor complex. We sought to determine how intracellular vIL-6 modulates the host endothelial cell environment by analyzing vIL-6’s impact on the endothelial cell transcriptome. vIL-6 significantly altered the expression of many cellular genes associated with cell migration. In particular, vIL-6 upregulated the host factor carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) at the protein and message levels. CEACAM1 has been implicated in tumor invasion and metastasis and promotes migration and vascular remodeling in endothelial cells. We report that vIL-6 upregulates CEACAM1 by a STAT3-dependent mechanism and that CEACAM1 promotes vIL-6-mediated migration. Furthermore, latent and de novo KSHV infections of endothelial cells also induce CEACAM1 expression. Collectively, our data suggest that vIL-6 modulates endothelial cell migration by upregulating the expression of cellular factors, including CEACAM1. PMID:26646010

Precision cancer immunotherapy: optimizing dendritic cell-based strategies to induce tumor antigen-specific T-cell responses against individual patient tumors.

PubMed

Osada, Takuya; Nagaoka, Koji; Takahara, Masashi; Yang, Xiao Yi; Liu, Cong-Xiao; Guo, Hongtao; Roy Choudhury, Kingshuk; Hobeika, Amy; Hartman, Zachary; Morse, Michael A; Lyerly, H Kim

2015-05-01

Most dendritic cell (DC)-based vaccines have loaded the DC with defined antigens, but loading with autologos tumor-derived antigens would generate DCs that activate personalized tumor-specific T-cell responses. We hypothesized that DC matured with an optimized combination of reagents and loaded with tumor-derived antigens using a clinically feasible electroporation strategy would induce potent antitumor immunity. We first studied the effects on DC maturation and antigen presentation of the addition of picibanil (OK432) to a combination of zoledronic acid, tumor necrosis factor-α, and prostaglandin E2. Using DC matured with the optimized combination, we tested 2 clinically feasible sources of autologous antigen for electroloading, total tumor mRNA or total tumor lysate, to determine which stimulated more potent antigen-specific T cells in vitro and activated more potent antitumor immunity in vivo. The combination of tumor necrosis factor-α/prostaglandin E2/zoledronic acid/OK432 generated DC with high expression of maturation markers and antigen-specific T-cell stimulatory function in vitro. Mature DC electroloaded with tumor-derived mRNA [mRNA electroporated dendritic cell (EPDC)] induced greater expansion of antigen-specific T cells in vitro than DC electroloaded with tumor lysate (lysate EPDC). In a therapeutic model of MC38-carcinoembryonic antigen colon cancer-bearing mice, vaccination with mRNA EPDC induced the most efficient anti-carcinoembryonic antigen cellular immune response, which significantly suppressed tumor growth. In conclusion, mature DC electroloaded with tumor-derived mRNA are a potent cancer vaccine, especially useful when specific tumor antigens for vaccination have not been identified, allowing autologous tumor, and if unavailable, allogeneic cell lines to be used as an unbiased source of antigen. Our data support clinical testing of this strategy.

Arsenite induces endothelial cell permeability increase through a reactive oxygen species-vascular endothelial growth factor pathway.

PubMed

Bao, Lingzhi; Shi, Honglian

2010-11-15

As a potent environmental oxidative stressor, arsenic exposure has been reported to exacerbate cardiovascular diseases and increase vascular endothelial cell monolayer permeability. However, the underlying mechanism of this effect is not well understood. In this paper, we test our hypothesis that reactive oxygen species (ROS)-induced vascular endothelial growth factor (VEGF) expression may play an important role in an arsenic-caused increase of endothelial cell monolayer permeability. The mouse brain vascular endothelial cell bEnd3 monolayer was exposed to arsenite for 1, 3, and 6 days. The monolayer permeability, VEGF protein release, and ROS generation were determined. In addition, VE-cadherin and zonula occludens-1 (ZO-1), two membrane structure proteins, were immunostained to elucidate the effects of arsenite on the cell-cell junction. The roles of ROS and VEGF in arsenite-induced permeability was determined by inhibiting ROS with antioxidants and immuno-depleting VEGF with a VEGF antibody. We observed that arsenite increased bEnd3 monolayer permeability, elevated the production of cellular ROS, and increased VEGF release. VE-cadherin and ZO-1 disruptions were also found in cells treated with arsenite. Furthermore, both antioxidant (N-acetyl cysteine and tempol) and the VEGF antibody treatments significantly lowered the arsenite-induced permeability of the bEnd3 monolayer as well as VEGF expression. VE-cadherin and ZO-1 disruptions were also diminished by N-acetyl cysteine and the VEGF antibody. Our data suggest that the increase in VEGF expression caused by ROS may play an important role in the arsenite-induced increase in endothelial cell permeability.

HLA-B35 Upregulates Endothelin-1 and Downregulates Endothelial Nitric Oxide Synthase via Endoplasmic Reticulum Stress Response in Endothelial Cells

PubMed Central

Lenna, Stefania; Townsend, Danyelle M.; Tan, Filemon K.; Kapanadze, Bagrat; Markiewicz, Malgorzata; Trojanowska, Maria; Scorza, Raffaella

2013-01-01

The presence of the HLA-B35 allele has emerged as an important risk factor for the development of isolated pulmonary hypertension in patients with scleroderma, however the mechanisms underlying this association have not been fully elucidated. The goal of our study was to determine the molecular mechanisms that mediate the biological effects of HLA-B35 in endothelial cells (ECs). Our data demonstrate that HLA-B35 expression at physiological levels via adenoviral vector resulted in significantly increased endothelin-1 (ET-1) and a significantly decreased endothelial NO synthase (eNOS), mRNA, and protein levels. Furthermore, HLA-B35 greatly upregulated expression of chaperones, including heat shock proteins (HSPs) HSP70 (HSPA1A and HSPA1B) and HSP40 (DNAJB1 and DNAJB9), suggesting that HLA-B35 induces the endoplasmic reticulum (ER) stress and unfolded protein response in ECs. Examination of selected mediators of the unfolded protein response, including H chain binding protein (BiP; GRP78), C/Ebp homologous protein (CHOP; GADD153), endoplasmic reticulum oxidase, and protein disulfide isomerase has revealed a consistent increase of BiP expression levels. Accordingly, thapsigargin, a known ER stress inducer, stimulated ET-1mRNAand protein levels in ECs. This study suggests that HLA-B35 could contribute to EC dysfunction via ER stress-mediated induction of ET-1 in patients with pulmonary hypertension. PMID:20335527

HLA-B35 upregulates endothelin-1 and downregulates endothelial nitric oxide synthase via endoplasmic reticulum stress response in endothelial cells.

PubMed

Lenna, Stefania; Townsend, Danyelle M; Tan, Filemon K; Kapanadze, Bagrat; Markiewicz, Malgorzata; Trojanowska, Maria; Scorza, Raffaella

2010-05-01

The presence of the HLA-B35 allele has emerged as an important risk factor for the development of isolated pulmonary hypertension in patients with scleroderma, however the mechanisms underlying this association have not been fully elucidated. The goal of our study was to determine the molecular mechanisms that mediate the biological effects of HLA-B35 in endothelial cells (ECs). Our data demonstrate that HLA-B35 expression at physiological levels via adenoviral vector resulted in significantly increased endothelin-1 (ET-1) and a significantly decreased endothelial NO synthase (eNOS), mRNA, and protein levels. Furthermore, HLA-B35 greatly upregulated expression of chaperones, including heat shock proteins (HSPs) HSP70 (HSPA1A and HSPA1B) and HSP40 (DNAJB1 and DNAJB9), suggesting that HLA-B35 induces the endoplasmic reticulum (ER) stress and unfolded protein response in ECs. Examination of selected mediators of the unfolded protein response, including H chain binding protein (BiP; GRP78), C/Ebp homologous protein (CHOP; GADD153), endoplasmic reticulum oxidase, and protein disulfide isomerase has revealed a consistent increase of BiP expression levels. Accordingly, thapsigargin, a known ER stress inducer, stimulated ET-1 mRNA and protein levels in ECs. This study suggests that HLA-B35 could contribute to EC dysfunction via ER stress-mediated induction of ET-1 in patients with pulmonary hypertension.

Globotriaosylceramide induces lysosomal degradation of endothelial KCa3.1 in fabry disease.

PubMed

Choi, Shinkyu; Kim, Ji Aee; Na, Hye-Young; Cho, Sung-Eun; Park, Seonghee; Jung, Sung-Chul; Suh, Suk Hyo

2014-01-01

Globotriaosylceramide (Gb3) induces KCa3.1 downregulation in Fabry disease (FD). We investigated whether Gb3 induces KCa3.1 endocytosis and degradation. KCa3.1, especially plasma membrane-localized KCa3.1, was downregulated in both Gb3-treated mouse aortic endothelial cells (MAECs) and human umbilical vein endothelial cells. Gb3-induced KCa3.1 downregulation was prevented by lysosomal inhibitors but not by a proteosomal inhibitor. Endoplasmic reticulum stress-inducing agents did not induce KCa3.1 downregulation. Gb3 upregulated the protein levels of early endosome antigen 1 and lysosomal-associated membrane protein 2 in MAECs. Compared with MAECs from age-matched wild-type mice, those from aged α-galactosidase A (Gla)-knockout mice, an animal model of FD, showed downregulated KCa3.1 expression and upregulated early endosome antigen 1 and lysosomal-associated membrane protein 2 expression. In contrast, no significant difference was found in early endosome antigen 1 and lysosomal-associated membrane protein 2 expression between young Gla-knockout and wild-type MAECs. In aged Gla-knockout MAECs, clathrin was translocated close to the cell border and clathrin knockdown recovered KCa3.1 expression. Rab5, an effector of early endosome antigen 1, was upregulated, and Rab5 knockdown restored KCa3.1 expression, the current, and endothelium-dependent relaxation. -Gb3 accelerates the endocytosis and lysosomal degradation of endothelial KCa3.1 via a clathrin-dependent process, leading to endothelial dysfunction in FD.

An Antagonistic Vascular Endothelial Growth Factor (VEGF) Variant Inhibits VEGF-Stimulated Receptor Autophosphorylation and Proliferation of Human Endothelial Cells

NASA Astrophysics Data System (ADS)

Siemeister, Gerhard; Schirner, Michael; Reusch, Petra; Barleon, Bernhard; Marme, Dieter; Martiny-Baron, Georg

1998-04-01

Vascular endothelial growth factor (VEGF) is a potent mitogen with a unique specificity for endothelial cells and a key mediator of aberrant endothelial cell proliferation and vascular permeability in a variety of human pathological situations, such as tumor angiogenesis, diabetic retinopathy, rheumatoid arthritis, or psoriasis. VEGF is a symmetric homodimeric molecule with two receptor binding interfaces lying on each pole of the molecule. Herein we report on the construction and recombinant expression of an asymmetric heterodimeric VEGF variant with an intact receptor binding interface at one pole and a mutant receptor binding interface at the second pole of the dimer. This VEGF variant binds to VEGF receptors but fails to induce receptor activation. In competition experiments, the heterodimeric VEGF variant antagonizes VEGF-stimulated receptor autophosphorylation and proliferation of endothelial cells. A 15-fold excess of the heterodimer was sufficient to inhibit VEGF-stimulated endothelial cell proliferation by 50%, and a 100-fold excess resulted in an almost complete inhibition. By using a rational approach that is based on the structure of VEGF, we have shown the feasibility to construct a VEGF variant that acts as an VEGF antagonist.

Endothelial barrier protection by local anesthetics: ropivacaine and lidocaine block tumor necrosis factor-α-induced endothelial cell Src activation.

PubMed

Piegeler, Tobias; Votta-Velis, E Gina; Bakhshi, Farnaz R; Mao, Mao; Carnegie, Graeme; Bonini, Marcelo G; Schwartz, David E; Borgeat, Alain; Beck-Schimmer, Beatrice; Minshall, Richard D

2014-06-01

Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase-Akt-nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10 M for ropivacaine; IC50 = 5.864 × 10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10 M for ropivacaine; IC50 = 6.377 × 10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Ropivacaine and lidocaine effectively blocked inflammatory TNFα signaling in endothelial

Non-coding Double-stranded RNA and Antimicrobial Peptide LL-37 Induce Growth Factor Expression from Keratinocytes and Endothelial Cells*

PubMed Central

Adase, Christopher A.; Borkowski, Andrew W.; Zhang, Ling-juan; Williams, Michael R.; Sato, Emi; Sanford, James A.

2016-01-01

A critical function for skin is that when damaged it must simultaneously identify the nature of the injury, repair barrier function, and limit the intrusion of pathogenic organisms. These needs are carried out through the detection of damage-associated molecular patterns (DAMPs) and a response that includes secretion of cytokines, chemokines, growth factors, and antimicrobial peptides (AMPs). In this study, we analyzed how non-coding double-stranded RNA (dsRNAs) act as a DAMP in the skin and how the human cathelicidin AMP LL-37 might influence growth factor production in response to this DAMP. dsRNA alone significantly increased the expression of multiple growth factors in keratinocytes, endothelial cells, and fibroblasts. Furthermore, RNA sequencing transcriptome analysis found that multiple growth factors increase when cells are exposed to both LL-37 and dsRNA, a condition that mimics normal wounding. Quantitative PCR and/or ELISA validated that growth factors expressed by keratinocytes in these conditions included, but were not limited to, basic fibroblast growth factor (FGF2), heparin-binding EGF-like growth factor (HBEGF), vascular endothelial growth factor C (VEGFC), betacellulin (BTC), EGF, epiregulin (EREG), and other members of the transforming growth factor β superfamily. These results identify a novel role for DAMPs and AMPs in the stimulation of repair and highlight the complex interactions involved in the wound environment. PMID:27048655

Defective heat shock factor 1 inhibits the growth of fibrosarcoma derived from simian virus 40/T antigen-transformed MEF cells

PubMed Central

JIANG, QIYING; ZHANG, ZHI; LI, SHULIAN; WANG, ZHAOYANG; MA, YUANFANG; HU, YANZHONG

2015-01-01

Heat shock factor 1 (Hsf1) serves an important role in regulating the proliferation of human tumor cell lines in vitro and tissue specific tumorigenesis in certain mouse models. However, its role in viral-oncogenesis remains to be fully elucidated. In the current study, the role of Hsf1 in fibroblastoma derived from simian virus 40/T antigen (SV40/TAG)-transformed mouse embryonic fibroblast (MEF) cell lines was investigated. Knockout of Hsf1 inhibited MEF cell proliferation in vitro and fibroblastoma growth and metastasis to the lungs in vivo in nude mice. Knockout of Hsf1 increased the protein expression levels of p53 and phosphorylated retinoblastoma protein (pRb), however reduced the expression of heat shock protein 25 (Hsp25) in addition to the expression of the angiogenesis markers vascular endothelial growth factor, cluster of differentiation 34 and factor VIII related antigen. Furthermore, immunoprecipitation indicated that knockout of Hsf1 inhibited the association between SV40/TAG and p53 or pRb. These data suggest that Hsf1 is involved in the regulation of SV40/TAG-derived fibroblastoma growth and metastasis by modulating the association between SV40/TAG and tumor suppressor p53 and pRb. The current study provides further evidence that Hsf1 may be a novel therapeutic target in the treatment of cancer. PMID:26352782

In vitro antigen-induced, antigen-specific antibody production in man. Specific and polyclonal components, kinetics, and cellular requirements

PubMed Central

1981-01-01

A highly specific and reproducible antigen-induced, antigen-specific culture and assay system for antibody production by human peripheral blood B lymphocytes has been developed. The system is clearly T cell and monocyte dependent and is independent of exogenous mitogens. The major factors in our ability to trigger specific antibody production with antigen alone have been the use of extremely low concentrations of antigen in vitro (doses several orders of magnitude below those inducing a peak blastogenic response), careful attention to in vitro cell density and culture vessel geometry, and appreciation of the kinetics of the circulating antigen-inducible B cell repertoire. A dichotomy and overlap between antigen-induced, antigen-specific and antigen-induced, polyclonal responses was observed in the study of doubly immunized individuals. Whereas antibody responses highly specific for the antigen in culture were observed under one set of culture conditions (flat-bottomed vessels, 1.5 x 10(6) cells), switching to another culture system (round-bottomed vessels, 5 x 10(5) cells) resulted in polyclonal responses to antigen. Despite these culture condition-related differences in the induction of antibody synthesis, the suppression of specific antibody production that occurred at high concentrations of antigen was specific only for the antigen in culture. The capability to easily and reproducibly look at truly antigen-induced, antigen specific antibody production should be a major tool in furthering the understanding of human B cell activation and immunoregulation. PMID:6169778

Serum antibody responses to polymorphic Cryptosporidium mucin antigen in Bangladeshi children with cryptosporidiosis.

PubMed

Lai, Olivia; Morris, Christopher; Ahmed, Sabeena; Karim, Mohammed Mahbubul; Khan, Wasif; Ward, Honorine; O'Connor, Roberta

2011-09-01

Cryptosporidium is a significant cause of diarrheal disease in children in developing countries. The sporozoite antigen Muc4 is important for infection of host cells, and could be a candidate vaccine antigen. However, this antigen is polymorphic between Cryptosporidium hominis and C. parvum. We investigated antibody responses to C. hominis Muc4 and C. parvum Muc4 antigen in children in Bangladesh infected with C. hominis. Antibody responses were compared between children with cryptosporidial diarrhea (cases) and uninfected children with diarrhea (controls). There was a significant IgM response to Muc4 from both species in cases compared with controls, which increased over time, and was higher in children with persistent diarrhea. Despite sequence polymorphisms, antibody responses to C. hominis Muc4 and C. parvum Muc4 were significantly correlated. These results suggest that the human antibody response to Muc4 is cross-reactive between species, but in young children does not mature to an IgG response within the period observed in this study.

Maternal dietary antigens and the immune response in the offspring of the guinea-pig.

PubMed Central

Telemo, E; Jakobsson, I; Weström, B R; Folkesson, H

1987-01-01

Guinea-pig dams and their litters were raised on either a cow's milk protein-containing diet (MCD) or a milk-free diet (MFD). At 8 weeks of age all litters were challenged i.p. with 50 micrograms milk whey-protein concentrate (V67) and 100 mg A1(OH)3 in saline. The immune response was estimated 2 weeks later as the serum IgG antibody titres against V67, beta-lactoglobulin (beta-LG) and alpha-lactalbumin (alpha-LA) using enzyme-linked immunosorbent assay (ELISA) and the tracheal Schulze-Dale response to these antigens. Feeding milk protein antigen to dams from birth and during pregnancy induces antigen-specific hyporesponsiveness (tolerance) in their offspring, despite no direct contact between the offspring and the milk proteins. Tolerance seems to be induced by the antigen itself since withdrawal of the MCD 10 days before delivery reduced tolerance in the offspring. No tolerance was produced in the offspring of dams fed the antigen from 3 months of age (adult). beta-LG appears to be a major antigen in milk whey while alpha-LA is a minor one since there was almost no antibody or tracheal response to alpha-LA in any of the animals tested. The results indicate that maternal antigen experience and antigens present during pregnancy are important for the subsequent immune response to these antigens in offspring. PMID:3653926

Antibody Responses to Prostate-Associated Antigens in Patients with Prostatitis and Prostate Cancer

PubMed Central

Maricque, Brett B.; Eickhoff, Jens C.; McNeel, Douglas G.

2010-01-01

Background An important focus of tumor immunotherapy has been the identification of appropriate antigenic targets. Serum-based screening approaches have led to the discovery of hundreds of tumor-associated antigens recognized by IgG. Our efforts to identify immunologically recognized proteins in prostate cancer have yielded a multitude of antigens, however prioritizing these antigens as targets for evaluation in immunotherapies has been challenging. In this report, we set out to determine whether the evaluation of multiple antigenic targets would allow the identification of a subset of antigens that are common immunologic targets in patients with prostate cancer. Methods Using a phage immunoblot approach, we evaluated IgG responses in patients with prostate cancer (n=126), patients with chronic prostatitis (n=45), and men without prostate disease (n=53). Results We found that patients with prostate cancer or prostatitis have IgG specific for multiple common antigens. A subset of 23 proteins was identified to which IgG were detected in 38% of patients with prostate cancer and 33% patients with prostatitis versus 6% of controls (p<0.001 and p=0.003, respectively). Responses to multiple members were not higher in patients with advanced disease, suggesting antibody immune responses occur early in the natural history of cancer progression. Conclusions These findings suggest an association between inflammatory conditions of the prostate and prostate cancer, and suggest that IgG responses to a panel of commonly recognized prostate antigens could be potentially used in the identification of patients at risk for prostate cancer or as a tool to identify immune responses elicited to prostate tissue. PMID:20632317

Ligand-dependent development of the endothelial and hemopoietic lineages from embryonic mesodermal cells expressing vascular endothelial growth factor receptor 2

PubMed Central

Eichmann, Anne; Corbel, Catherine; Nataf, Valérie; Vaigot, Pierre; Bréant, Christiane; Le Douarin, Nicole M.

1997-01-01

The existence of a common precursor for endothelial and hemopoietic cells, termed the hemangioblast, has been postulated since the beginning of the century. Recently, deletion of the endothelial-specific vascular endothelial growth factor receptor 2 (VEGFR2) by gene targeting has shown that both endothelial and hemopoietic cells are absent in homozygous null mice. This observation suggested that VEGFR2 could be expressed by the hemangioblast and essential for its further differentiation along both lineages. However, it was not possible to exclude the hypothesis that hemopoietic failure was a secondary effect resulting from the absence of an endothelial cell microenvironment. To distinguish between these two hypotheses, we have produced a mAb directed against the extracellular domain of avian VEGFR2 and isolated VEGFR2+ cells from the mesoderm of chicken embryos at the gastrulation stage. We have found that in clonal cultures, a VEGFR2+ cell gives rise to either a hemopoietic or an endothelial cell colony. The developmental decision appears to be regulated by the binding of two different VEGFR2 ligands. Thus, endothelial differentiation requires VEGF, whereas hemopoietic differentiation occurs in the absence of VEGF and is significantly reduced by soluble VEGFR2, showing that this process could be mediated by a second, yet unidentified, VEGFR2 ligand. These observations thus suggest strongly that in the absence of the VEGFR2 gene product, the precursors of both hemopoietic and vascular endothelial lineages cannot survive. These cells therefore might be the initial targets of the VEGFR2 null mutation. PMID:9144204

PLGA nanoparticle-mediated delivery of tumor antigenic peptides elicits effective immune responses.

PubMed

Ma, Wenxue; Chen, Mingshui; Kaushal, Sharmeela; McElroy, Michele; Zhang, Yu; Ozkan, Cengiz; Bouvet, Michael; Kruse, Carol; Grotjahn, Douglas; Ichim, Thomas; Minev, Boris

2012-01-01

The peptide vaccine clinical trials encountered limited success because of difficulties associated with stability and delivery, resulting in inefficient antigen presentation and low response rates in patients with cancer. The purpose of this study was to develop a novel delivery approach for tumor antigenic peptides in order to elicit enhanced immune responses using poly(DL-lactide-co-glycolide) nanoparticles (PLGA-NPs) encapsulating tumor antigenic peptides. PLGA-NPs were made using the double emulsion-solvent evaporation method. Artificial antigen-presenting cells were generated by human dendritic cells (DCs) loaded with PLGA-NPs encapsulating tumor antigenic peptide(s). The efficiency of the antigen presentation was measured by interferon-γ ELISpot assay (Vector Laboratories, Burlingame, CA). Antigen-specific cytotoxic T lymphocytes (CTLs) were generated and evaluated by CytoTox 96(®) Non-Radioactive Cytotoxicity Assay (Promega, Fitchburg, WI). The efficiency of the peptide delivery was compared between the methods of emulsification in incomplete Freund's adjuvant and encapsulation in PLGA-NPs. Our results showed that most of the PLGA-NPs were from 150 nm to 500 nm in diameter, and were negatively charged at pH 7.4 with a mean zeta potential of -15.53 ± 0.71 mV; the PLGA-NPs could be colocalized in human DCs in 30 minutes of incubation. Human DCs loaded with PLGA-NPs encapsulating peptide induced significantly stronger CTL cytotoxicity than those pulsed with free peptide, while human DCs loaded with PLGA-NPs encapsulating a three-peptide cocktail induced a significantly greater CTL response than those encapsulating a two-peptide cocktail. Most importantly, the peptide dose encapsulated in PLGA-NPs was 63 times less than that emulsified in incomplete Freund's adjuvant, but it induced a more powerful CTL response in vivo. These results demonstrate that the delivery of peptides encapsulated in PLGA-NPs is a promising approach to induce effective antitumor CTL

Nicotine promotes vascular endothelial growth factor secretion by human trophoblast cells under hypoxic conditions and improves the proliferation and tube formation capacity of human umbilical endothelial cells.

PubMed

Zhao, Hongbo; Wu, Lanxiang; Wang, Yahui; Zhou, Jiayi; Li, Ruixia; Zhou, Jiabing; Wang, Zehua; Xu, Congjian

2017-04-01

Pre-eclampsia, characterized as defective uteroplacental vascularization, remains the major cause of maternal and fetal mortality and morbidity. Previous epidemiological studies demonstrated that cigarette smoking reduced the risk of pre-eclampsia. However, the molecular mechanism remains elusive. In the present study, it is demonstrated that a low dose of nicotine decreased soluble vascular endothelial growth factor receptor 1 (sFlt1) secretion in human trophoblast cells under hypoxic conditions. Nicotine was then observed to promote vascular endothelial growth factor (VEGF) secretion by reducing sFlt1 secretion and increasing VEGF mRNA transcription. Further data showed that nicotine enhanced hypoxia-mediated hypoxia-inducible factor-1α (HIF-1α) expression and HIF-1α small interfering RNA abrogated nicotine-induced VEGF secretion, indicating that HIF-1α may be responsible for nicotine-mediated VEGF transcription under hypoxic conditions. Moreover, conditioned medium from human trophoblast cells treated with nicotine under hypoxic conditions promoted the proliferation and tube formation capacity of human umbilical endothelial cells (HUVEC) by promoting VEGF secretion. These findings indicate that nicotine may promote VEGF secretion in human trophoblast cells under hypoxic conditions by reducing sFlt1 secretion and up-regulating VEGF transcription and improve the proliferation and tube formation of HUVEC cells, which may contribute to elucidate the protective effect of cigarette smoking against pre-eclampsia. Copyright © 2017 Reproductive Healthcare Ltd. Published by Elsevier Ltd. All rights reserved.

Antigen delivery by α2-macroglobulin enhances the cytotoxic T lymphocyte response

PubMed Central

Bowers, Edith V.; Horvath, Jeffrey J.; Bond, Jennifer E.; Cianciolo, George J.; Pizzo, Salvatore V.

2009-01-01

α2M* targets antigens to APCs for rapid internalization, processing, and presentation. When used as an antigen-delivery vehicle, α2M* amplifies MHC class II presentation, as demonstrated by increased antibody titers. Recent evidence, however, suggests that α2M* encapsulation may also enhance antigen-specific CTL immunity. In this study, we demonstrate that α2M*-delivered antigen (OVA) enhances the production of specific in vitro and in vivo CTL responses. Murine splenocytes expressing a transgenic TCR specific for CTL peptide OVA257–264 (SIINFEKL) demonstrated up to 25-fold greater IFN-γ and IL-2 secretion when treated in vitro with α2M*-OVA compared with soluble OVA. The frequency of IFN-γ-producing cells was increased ∼15-fold, as measured by ELISPOT. Expansion of the OVA-specific CD8+ T cell population, as assayed by tetramer binding and [3H]thymidine incorporation, and OVA-specific cell-mediated cytotoxicity, as determined by a flow cytometric assay, were also enhanced significantly by α2M*-OVA. Furthermore, significant CTL responses were observed at antigen doses tenfold lower than those required with OVA alone. Finally, we also observed enhanced humoral and CTL responses by naïve mice following intradermal immunization with α2M*-OVA. These α2M*-OVA-immunized mice demonstrated increased protection against a s.c.-implanted, OVA-expressing tumor, as demonstrated by delayed tumor growth and prolonged animal survival. The observation that α2M*-mediated antigen delivery elicits specific CTL responses suggests the cross-presentation of antigen onto MHC class I. These results support α2M* as an effective antigen-delivery system that may be particularly useful for vaccines based on weakly immunogenic subunits or requiring dose sparing. PMID:19652028

Endothelial dysfunction: the early predictor of atherosclerosis.

PubMed

Mudau, Mashudu; Genis, Amanda; Lochner, Amanda; Strijdom, Hans

2012-05-01

Since the discovery in the 1980s that nitric oxide (NO) is in fact the elusive endothelium-derived relaxing factor, it has become evident that NO is not only a major cardiovascular signalling molecule, but that changes in its bioavailability are crucial in determining whether atherosclerosis will develop or not. Sustained high levels of harmful circulating stimuli associated with cardiovascular risk factors such as diabetes mellitus elicit responses in endothelial cells that appear sequentially, namely endothelial cell activation and endothelial dysfunction (ED). ED, characterised by reduced NO bioavailability, is now recognised by many as an early, reversible precursor of atherosclerosis. The pathogenesis of ED is multifactorial; however, oxidative stress appears to be the common underlying cellular mechanism in the ensuing loss of vaso-active, inflammatory, haemostatic and redox homeostasis in the body's vascular system. The role of ED as a pathophysiological link between early endothelial cell changes associated with cardiovascular risk factors and the development of ischaemic heart disease is of importance to basic scientists and clinicians alike.

Reduced endothelial activation after exercise is associated with improved HbA1c in patients with type 2 diabetes and coronary artery disease.

PubMed

Byrkjeland, Rune; Njerve, Ida U; Arnesen, Harald; Seljeflot, Ingebjørg; Solheim, Svein

2017-03-01

We have previously reported insignificant changes in HbA 1c after exercise in patients with both type 2 diabetes and coronary artery disease. In this study, we investigated the effect of exercise on endothelial function and possible associations between changes in endothelial function and HbA 1c . Patients with type 2 diabetes and coronary artery disease ( n = 137) were randomised to 12 months exercise or standard follow-up. Endothelial function was assessed by circulating biomarkers (E-selectin, intercellular adhesion molecule-1, vascular cell adhesion molecule-1, von Willebrand factor, tissue plasminogen activator antigen, asymmetric dimethylarginine and L-arginine/asymmetric dimethylarginine ratio). Differences between the randomised groups were analysed by analysis of covariance and correlations by Spearman's rho or Pearson's correlation. No effect of exercise on endothelial function was demonstrated. The changes in HbA 1c in the exercise group correlated with changes in E-selectin ( r = 0.56, p < 0.001), intercellular adhesion molecule-1 ( r = 0.27, p = 0.052), vascular cell adhesion molecule-1 ( r = 0.32, p = 0.022) and tissue plasminogen activator antigen ( r = 0.35, p =  0.011). HbA 1c decreased significantly more in patients with versus without a concomitant reduction in E-selectin ( p =  0.002), intercellular adhesion molecule-1 ( p =  0.011), vascular cell adhesion molecule-1 ( p =  0.028) and tissue plasminogen activator antigen ( p =  0.009). Exercise did not affect biomarkers of endothelial function in patients with both type 2 diabetes and coronary artery disease. However, changes in biomarkers of endothelial activation correlated with changes in HbA 1c , and reduced endothelial activation was associated with improved HbA 1c after exercise.

Potential proinflammatory effects of hydroxyapatite nanoparticles on endothelial cells in a monocyte–endothelial cell coculture model

PubMed Central

Liu, Xin; Sun, Jiao

2014-01-01

Currently, synthetic hydroxyapatite nanoparticles (HANPs) are used in nanomedicine fields. The delivery of nanomedicine to the bloodstream exposes the cardiovascular system to a potential threat. However, the possible adverse cardiovascular effects of HANPs remain unclear. Current observations using coculture models of endothelial cells and monocytes with HANPs to mimic the complex physiological functionality of the vascular system demonstrate that monocytes could play an important role in the mechanisms of endothelium dysfunction induced by the exposure to HANPs. Our transmission electron microscopy analysis revealed that both monocytes and endothelial cells could take up HANPs. Moreover, our findings demonstrated that at a subcytotoxic dose, HANPs alone did not cause direct endothelial cell injury, but they did induce an indirect activation of endothelial cells, resulting in increased interleukin-6 production and elevated adhesion molecule expression after coculture with monocytes. The potential proinflammatory effect of HANPs is largely mediated by the release of soluble factors from the activated monocytes, leading to an inflammatory response of the endothelium, which is possibly dependent on p38/c-Jun N-terminal kinase, and nuclear factor-kappa B signaling activation. The use of in vitro monocyte–endothelial cell coculture models for the biocompatibility assessment of HANPs could reveal their potential proinflammatory effects on endothelial cells, suggesting that exposure to HANPs possibly increases the risk of cardiovascular disease. PMID:24648726

Peripheral blood "endothelial progenitor cells" are derived from monocyte/macrophages and secrete angiogenic growth factors.

PubMed

Rehman, Jalees; Li, Jingling; Orschell, Christie M; March, Keith L

2003-03-04

Endothelial progenitor cells (EPCs) have been isolated from peripheral blood and can enhance angiogenesis after infusion into host animals. It is not known whether the proangiogenic effects are a result of such events as endothelial differentiation and subsequent proliferation of EPCs or secondary to secretion of angiogenic growth factors. Human EPCs were isolated as previously described, and their phenotypes were confirmed by uptake of acetylated LDL and binding of ulex-lectin. EPC proliferation and surface marker expression were analyzed by flow cytometry, and conditioned medium was assayed for growth factors. The majority of EPCs expressed monocyte/macrophage markers such as CD14 (95.7+/-0.3%), Mac-1 (57.6+/-13.5%), and CD11c (90.8+/-4.9%). A much lower percentage of cells expressed the specific endothelial marker VE-cadherin (5.2+/-0.7%) or stem/progenitor-cell markers AC133 (0.16+/-0.05%) and c-kit (1.3+/-0.7%). Compared with circulating monocytes, cultured EPCs showed upregulation of monocyte activation and macrophage differentiation markers. EPCs did not demonstrate any significant proliferation but did secrete the angiogenic growth factors vascular endothelial growth factor, hepatocyte growth factor, granulocyte colony-stimulating factor, and granulocyte-macrophage colony-stimulating factor. Our findings suggest that acetylated LDL(+)ulex-lectin(+) cells, commonly referred to as EPCs, do not proliferate but release potent proangiogenic growth factors. The majority of acetylated LDL(+)ulex-lectin(+) cells are derived from monocyte/macrophages. The findings of low proliferation and endothelial differentiation suggest that their angiogenic effects are most likely mediated by growth factor secretion. These findings may allow for development of novel angiogenic therapies relying on secreted growth factors or on recruitment of endogenous monocytes/macrophages to sites of ischemia.

Hypoxia-induced endothelial NO synthase gene transcriptional activation is mediated through the tax-responsive element in endothelial cells.

PubMed

Min, Jiho; Jin, Yoon-Mi; Moon, Je-Sung; Sung, Min-Sun; Jo, Sangmee Ahn; Jo, Inho

2006-06-01

Although hypoxia is known to induce upregulation of endothelial NO synthase (eNOS) gene expression, the underlying mechanism is largely unclear. In this study, we show that hypoxia increases eNOS gene expression through the binding of phosphorylated cAMP-responsive element binding (CREB) protein (pCREB) to the eNOS gene promoter. Hypoxia (1% O2) increased both eNOS expression and NO production, peaking at 24 hours, in bovine aortic endothelial cells, and these increases were accompanied by increases in pCREB. Treatment with the protein kinase A inhibitor H-89 or transfection with dominant-negative inhibitor of CREB reversed the hypoxia-induced increases in eNOS expression and NO production, with concomitant inhibition of the phosphorylation of CREB induced by hypoxia, suggesting an involvement of protein kinase A/pCREB-mediated pathway. To map the regulatory elements of the eNOS gene responsible for pCREB binding under hypoxia, we constructed an eNOS gene promoter (-1600 to +22 nucleotides) fused with a luciferase reporter gene [pGL2-eNOS(-1600)]. Hypoxia (for 24-hour incubation) increased the promoter activity by 2.36+/-0.18-fold in the bovine aortic endothelial cells transfected with pGL2-eNOS(-1600). However, progressive 5'-deletion from -1600 to -873 completely attenuated the hypoxia-induced increase in promoter activity. Electrophoretic mobility shift, anti-pCREB antibody supershift, and site-specific mutation analyses showed that pCREB is bound to the Tax-responsive element (TRE) site, a cAMP-responsive element-like site, located at -924 to -921 of the eNOS promoter. Our data demonstrate that the interaction between pCREB and the Tax-responsive element site within the eNOS promoter may represent a novel mechanism for the mediation of hypoxia-stimulated eNOS gene expression.

Endothelial cell stimulating angiogenesis factor.

PubMed

Weiss, J B; McLaughlin, B

1998-04-01

Endothelial cell stimulating angiogenesis factor (ESAF) is a small (> 1000 Da) dialysable non-peptide molecule with potent angiogenic activity. ESAF activates the major pro-matrix metalloproteinases and also uniquely reactivates the complex of these active enzymes with their tissue inhibitors resulting in both active enzyme and inhibitor. These actions may be pivotal in its role as an angiogenic factor. ESAF is primarily involved in angiogenic conditions where inflammatory cells are not evident such as foetal bone growth and electrically stimulated skeletal muscles and proliferative retinopathy. However, high levels also occur in actively growing human intracranial tumours but it is not noticeably elevated in rheumatoid arthritic synovial fluid. Its extreme potency and low molecular mass make its structural determination difficult. Possible therapeutic applications would be in the treatment of ischaemic ulcers, acceleration of fracture repair, infertility and more modestly in the correction of baldness. Analogues of ESAF could be of value in treating angiogenic diseases such as psoriasis and proliferative retinopathy.

Antigen dose and strain variation as factors in the genetic control of the immune response to sperm whale myoglobin.

PubMed Central

Young, C R; Ebringer, A; Archer, J R

1978-01-01

The primary and secondary immune response to the antigen sperm whale myoglobin was investigated in DBA/2, 129 and B10.BR mice over a dose range of immunization from 10 to 2000 microgram. Using an antigen excess technique, the quantity of antibody produced after secondary immunization followed a sigmoidal dose-response curve and the maximal plateau level was found to be different for each strain of mice. Furthermore, the genetic control of the immune response was investigated in twelve different inbred strains of mice following secondary immunization with 500 microgram of myoglobin. A continuous distribution for the mean antibody responses was obtained for the twelve different strains of mice. High responsiveness was associated with H-2 haplotypes d, f and k located on chromosome 17, the non-agouti gene 'a' located on chromosome 2 and the chinchilla gene 'c(ch)' located on chromosome 7. It is concluded that either a large number of IR-genes to myoglobin are present in many loci located on different chromosomes or the antibody differences could be explained by a cross-tolerance mechanism requiring no IR-genes at all. PMID:417022

Vascular Repair After Menstruation Involves Regulation of Vascular Endothelial Growth Factor-Receptor Phosphorylation by sFLT-1

PubMed Central

Graubert, Michael D.; Asuncion Ortega, Maria; Kessel, Bruce; Mortola, Joseph F.; Iruela-Arispe, M. Luisa

2001-01-01

Regeneration of the endometrium after menstruation requires a rapid and highly organized vascular response. Potential regulators of this process include members of the vascular endothelial growth factor (VEGF) family of proteins and their receptors. Although VEGF expression has been detected in the endometrium, the relationship between VEGF production, receptor activation, and endothelial cell proliferation during the endometrial cycle is poorly understood. To better ascertain the relevance of VEGF family members during postmenstrual repair, we have evaluated ligands, receptors, and activity by receptor phosphorylation in human endometrium throughout the menstrual cycle. We found that VEGF is significantly increased at the onset of menstruation, a result of the additive effects of hypoxia, transforming growth factor-α, and interleukin-1β. Both VEGF receptors, FLT-1 and KDR, followed a similar pattern. However, functional activity of KDR, as determined by phosphorylation studies, revealed activation in the late menstrual and early proliferative phases. The degree of KDR phosphorylation was inversely correlated with the presence of sFLT-1. Endothelial cell proliferation analysis in endometrium showed a peak during the late menstrual and early proliferative phases in concert with the presence of VEGF, VEGF receptor phosphorylation, and decrease of sFLT-1. Together, these results suggest that VEGF receptor activation and the subsequent modulation of sFLT-1 in the late menstrual phase likely contributes to the onset of angiogenesis and endothelial repair in the human endometrium. PMID:11290558

Dynamics of heat shock protein 60 in endothelial cells exposed to cigarette smoke extract

PubMed Central

Kreutmayer, Simone Barbara; Messner, Barbara; Knoflach, Michael; Henderson, Blair; Niederegger, Harald; Böck, Günther; Van der Zee, Ruurd; Wick, Georg; Bernhard, David

2011-01-01

Heat shock protein 60 (HSP60), expressed on the surface of endothelial cells (ECs) stressed by e.g. oxidized LDL or mechanical shear, was shown to function as an auto-antigen and thus as a pro-atherosclerotic molecule. The aim of this study was to determine whether cigarette smoke chemicals can lead to the activation of the “HSP60 pathway.” It was also our aim to elucidate the dynamics of HSP60 from gene expression to endothelial surface expression and secretion. Here we show for the first time that the exposure of human umbilical vein endothelial cells (HUVECs) to cigarette smoke extract (CSE) results in an up-regulation of HSP60 mRNA. Live cell imaging analysis of a HSP60-EYFP fusion protein construct transfected into ECs revealed that mitochondrial structures collapse in response to CSE exposure. As a result, HSP60 is released from the mitochondria, transported to the cell surface, and released into the cell culture supernatant. Analysis of HSP60 in the sera of healthy young individuals exposed to secondhand smoke revealed significantly elevated levels of HSP60. Cigarette smoking is one of the most relevant risk factors for atherosclerosis. Herein, we provide evidence that cigarette smoke may initiate atherosclerosis in the sense of the “auto-immune hypothesis of atherosclerosis.” PMID:21798264

Dynamics of heat shock protein 60 in endothelial cells exposed to cigarette smoke extract.

PubMed

Kreutmayer, Simone Barbara; Messner, Barbara; Knoflach, Michael; Henderson, Blair; Niederegger, Harald; Böck, Günther; Van der Zee, Ruurd; Wick, Georg; Bernhard, David

2011-11-01

Heat shock protein 60 (HSP60), expressed on the surface of endothelial cells (ECs) stressed by e.g. oxidized LDL or mechanical shear, was shown to function as an auto-antigen and thus as a pro-atherosclerotic molecule. The aim of this study was to determine whether cigarette smoke chemicals can lead to the activation of the "HSP60 pathway." It was also our aim to elucidate the dynamics of HSP60 from gene expression to endothelial surface expression and secretion. Here we show for the first time that the exposure of human umbilical vein endothelial cells (HUVECs) to cigarette smoke extract (CSE) results in an up-regulation of HSP60 mRNA. Live cell imaging analysis of a HSP60-EYFP fusion protein construct transfected into ECs revealed that mitochondrial structures collapse in response to CSE exposure. As a result, HSP60 is released from the mitochondria, transported to the cell surface, and released into the cell culture supernatant. Analysis of HSP60 in the sera of healthy young individuals exposed to secondhand smoke revealed significantly elevated levels of HSP60. Cigarette smoking is one of the most relevant risk factors for atherosclerosis. Herein, we provide evidence that cigarette smoke may initiate atherosclerosis in the sense of the "auto-immune hypothesis of atherosclerosis." Copyright © 2011 Elsevier Ltd. All rights reserved.

Monocyte recruitment to endothelial cells in response to oscillatory shear stress

PubMed Central

Hsiai, Tzung K.; Cho, Sung K.; Wong, Pak K.; Ing, Mike; Salazar, Adler; Sevanian, Alex; Navab, Mohamad; Demer, Linda L.; Ho, Chih-Ming

2014-01-01

Leukocyte recruitment to endothelial cells is a critical event in inflammatory responses. The spatial, temporal gradients of shear stress, topology, and outcome of cellular interactions that underlie these responses have so far been inferred from static imaging of tissue sections or studies of statically cultured cells. In this report, we developed micro-electromechanical systems (MEMS) sensors, comparable to a single endothelial cell (EC) in size, to link real-time shear stress with monocyte/EC binding kinetics in a complex flow environment, simulating the moving and unsteady separation point at the arterial bifurcation with high spatial and temporal resolution. In response to oscillatory shear stress (τ) at ± 2.6 dyn/cm2 at a time-averaged shear stress (τave) = 0 and 0.5 Hz, individual monocytes displayed unique to-and-fro trajectories undergoing rolling, binding, and dissociation with other monocyte, followed by solid adhesion on EC. Our study quantified individual monocyte/EC binding kinetics in terms of displacement and velocity profiles. Oscillatory flow induces up-regulation of adhesion molecules and cytokines to mediate monocyte/EC interactions over a dynamic range of shear stress ± 2.6 dyn/cm2 (P= 0.50, n= 10).—Hsiai, T. K., Cho, S. K., Wong, P. K., Ing, M., Salazar, A., Sevanian, A., Navab, M., Demer, L. L., Ho, C.-M. Monocyte recruitment to endothelial cells in response to oscillatory shear stress. FASEB J. 17, 1648–1657 (2003) PMID:12958171

Vascular endothelial growth factor increases fenestral permeability in hepatic sinusoidal endothelial cells.

PubMed

Yokomori, Hiroaki; Oda, Masaya; Yoshimura, Kazunori; Nagai, Toshihiro; Ogi, Mariko; Nomura, Masahiko; Ishii, Hiromasa

2003-12-01

Vascular endothelial growth factor (VEGF) is an important regulator of vasculogenesis and vascular permeability. Hepatic sinusoidal endothelial cells (SECs) possess sieve-like pores that form an anastomosing labyrinth structure by the deeply invaginated plasma membrane. Caveolin is the principal structural protein in caveolae. In this study, we examined the role of VEGF on the fenestration and permeability of SECs and the relation with caveolin-1. SECs isolated from rat livers by collagenase infusion method were cultured for 24 h with (10 or 100 ng/ml) or without VEGF. The cells were then examined by transmission and scanning electron microscopy (EM). The expression of caveolin was investigated by confocal immunofluorescence, immunogold EM, and Western blot. Endocytosis and intracellular traffic was studied using horseradish peroxidase (HRP) reaction as a marker of fluid phase transport in SECs. Both transmission and scanning EM showed an increased number of sinusoidal endothelial fenestrae (SEF) in SECs cultured with VEGF. By confocal immunofluorescence, SECs cultured with VEGF displayed prominent caveolin-l-positive aggregates in the cytoplasm, especially surrounding the nucleus region. Immunogold EM depicted increased caveolin-1 reactivity on vesicles and vacuoles of VEGF-treated SECs compared with VEGF-nontreated cells. However, there was no change in the level of caveolin-1 protein expression on Western blot. After HRP injection, an increase of electron-dense tracer filled the SEF in cells treated with VEGF. Our results suggested that VEGF induced fenestration in SECs, accompanied by an increased number of caveolae-like vesicles. Increased caveolin-1 might be associated with vesicle formation but not with fenestration. Increased fenestration may augment hepatic sinusoidal permeability and transendothelial transport.

Cytotoxic-T-lymphocyte antigen 4 receptor signaling for lymphocyte adhesion is mediated by C3G and Rap1.

PubMed

Kloog, Yoel; Mor, Adam

2014-03-01

T-lymphocyte adhesion plays a critical role in both inflammatory and autoimmune responses. The small GTPase Rap1 is the key coordinator mediating T-cell adhesion to endothelial cells, antigen-presenting cells, and virus-infected cells. We describe a signaling pathway, downstream of the cytotoxic T-lymphocyte antigen 4 (CTLA-4) receptor, leading to Rap1-mediated adhesion. We identified a role for the Rap1 guanine nucleotide exchange factor C3G in the regulation of T-cell adhesion and showed that this factor is required for both T-cell receptor (TCR)-mediated and CTLA-4-mediated T-cell adhesion. Our data indicated that C3G translocates to the plasma membrane downstream of TCR signaling, where it regulates activation of Rap1. We also showed that CTLA-4 receptor signaling mediates tyrosine phosphorylation in the C3G protein, and that this is required for augmented activation of Rap1 and increased adhesion mediated by leukocyte function-associated antigen type 1 (LFA-1). Zap70 is required for C3G translocation to the plasma membrane, whereas the Src family member Hck facilitates C3G phosphorylation. These findings point to C3G and Hck as promising potential therapeutic targets for the treatment of T-cell-dependent autoimmune disorders.

Cytotoxic-T-Lymphocyte Antigen 4 Receptor Signaling for Lymphocyte Adhesion Is Mediated by C3G and Rap1

PubMed Central

Kloog, Yoel

2014-01-01

T-lymphocyte adhesion plays a critical role in both inflammatory and autoimmune responses. The small GTPase Rap1 is the key coordinator mediating T-cell adhesion to endothelial cells, antigen-presenting cells, and virus-infected cells. We describe a signaling pathway, downstream of the cytotoxic T-lymphocyte antigen 4 (CTLA-4) receptor, leading to Rap1-mediated adhesion. We identified a role for the Rap1 guanine nucleotide exchange factor C3G in the regulation of T-cell adhesion and showed that this factor is required for both T-cell receptor (TCR)-mediated and CTLA-4-mediated T-cell adhesion. Our data indicated that C3G translocates to the plasma membrane downstream of TCR signaling, where it regulates activation of Rap1. We also showed that CTLA-4 receptor signaling mediates tyrosine phosphorylation in the C3G protein, and that this is required for augmented activation of Rap1 and increased adhesion mediated by leukocyte function-associated antigen type 1 (LFA-1). Zap70 is required for C3G translocation to the plasma membrane, whereas the Src family member Hck facilitates C3G phosphorylation. These findings point to C3G and Hck as promising potential therapeutic targets for the treatment of T-cell-dependent autoimmune disorders. PMID:24396067

Kinetics and magnitude of antibody responses against the conserved 47-kilodalton antigen and the variable 56-kilodalton antigen in scrub typhus patients.

PubMed

Chen, Hua-Wei; Zhang, Zhiwen; Huber, Erin; Mutumanje, Elissa; Chao, Chien-Chung; Ching, Wei-Mei

2011-06-01

Western blot analysis of Orientia tsutsugamushi whole-cell lysates with scrub typhus patient sera has identified at least five protein antigens of O. tsutsugamushi with molecular sizes of 22 kDa, 47 kDa, 56 kDa, 58 kDa, and 110 kDa. In this study, sera from serial bleedings of 108 patients were used to study the kinetics and the magnitude of specific antibody responses against the 47-kDa and 56-kDa antigens. Recombinant protein of the conserved 47-kDa antigen (r47b) or a mixture of truncated 56-kDa antigen (r56s) from three prototype strains was used as the antigen in an enzyme-linked immunosorbent assay (ELISA). Our results showed that 76% and 93% of these patients had elevated IgM and IgG against r47b, respectively, and 98% and 100% had elevated IgM and IgG against r56s, respectively. The kinetics of antibody responses against r47b and r56s can be grouped into three patterns. In the first type of response, IgM and IgG against r47b and r56s appeared about the same time. The IgM and IgG titers against r56s were much higher than those against r47b. In the second type of response, induction of IgM appeared to be similar to that in the first type. The major difference to the first type is that the IgG titers against r47b were induced at least 1 week later than those against the r56s. The third type showed strong IgG responses against both r47b and r56s, and low or no IgM responses indicated a secondary infection. This is the first systematic investigation of antibody response kinetics against the conserved 47-kDa antigen versus the variable 56-kDa antigen in scrub typhus patients.

Endothelium-derived contracting factors mediate the Ang II-induced endothelial dysfunction in the rat aorta: preventive effect of red wine polyphenols.

PubMed

Kane, Modou O; Etienne-Selloum, Nelly; Madeira, Soccoro V F; Sarr, Mamadou; Walter, Allison; Dal-Ros, Stéphanie; Schott, Christa; Chataigneau, Thierry; Schini-Kerth, Valérie B

2010-04-01

Angiotensin II (Ang II)-induced hypertension is associated with vascular oxidative stress and an endothelial dysfunction. This study examined the role of reactive oxygen species (ROS) and endothelium-derived contracting factors in Ang II-induced endothelial dysfunction and whether these effects are prevented by red wine polyphenols (RWPs), a rich source of natural antioxidants. Rats were infused with Ang II for 14 days. RWPs were administered in the drinking water 1 week before and during the Ang II infusion. Arterial pressure was measured in conscious rats. Vascular reactivity was assessed in organ chambers and cyclooxygenase-1 (COX-1) and COX-2 expression by Western blot and immunofluorescence analyses. Ang II-induced hypertension was associated with blunted endothelium-dependent relaxations and induction of endothelium-dependent contractions in the presence of nitro-L-arginine in response to acetylcholine (Ach). These effects were not affected by the combination of membrane permeant analogs of superoxide dismutase and catalase but were abolished by the thromboxane A(2) (TP) receptor antagonist GR32191B and the COX-2 inhibitor NS-398. The COX-1 inhibitor SC-560 also prevented contractile responses to Ach. Ang II increased the expression of COX-1 and COX-2 in the aortic wall. RWPs prevented Ang II-induced hypertension, endothelial dysfunction, and upregulation of COX-1 and COX-2. Thus, Ang II-induced endothelial dysfunction cannot be explained by an acute formation of ROS reducing the bioavailability of nitric oxide but rather by COX-dependent formation of contracting factors acting on TP receptors. RWPs are able to prevent the Ang II-induced endothelial dysfunction mostly due to their antioxidant properties.

Differential procoagulant activity of microparticles derived from monocytes, granulocytes, platelets and endothelial cells: impact of active tissue factor.

PubMed

Shustova, Olga N; Antonova, Olga A; Golubeva, Nina V; Khaspekova, Svetlana G; Yakushkin, Vladimir V; Aksuk, Svetlana A; Alchinova, Irina B; Karganov, Mikhail Y; Mazurov, Alexey V

2017-07-01

: Microparticles released by activated/apoptotic cells exhibit coagulation activity as they express phosphatidylserine and some of them - tissue factor. We compared procoagulant properties of microparticles from monocytes, granulocytes, platelets and endothelial cells and assessed the impact of tissue factor in observed differences. Microparticles were sedimented (20 000g, 30 min) from the supernatants of activated monocytes, monocytic THP-1 cells, granulocytes, platelets and endothelial cells. Coagulation activity of microparticles was examined using plasma recalcification assay. The size of microparticles was evaluated by dynamic light scattering. Tissue factor activity was measured by its ability to activate factor X. All microparticles significantly accelerated plasma coagulation with the shortest lag times for microparticles derived from monocytes, intermediate - for microparticles from THP-1 cells and endothelial cells, and the longest - for microparticles from granulocytes and platelets. Average diameters of microparticles ranged within 400-600 nm. The largest microparticles were produced by endothelial cells and granulocytes, smaller - by monocytes, and the smallest - by THP-1 cells and platelets. The highest tissue factor activity was detected in microparticles from monocytes, lower activity - in microparticles from endothelial cells and THP-1 cells, and no activity - in microparticles from platelets and granulocytes. Anti-tissue factor antibodies extended coagulation lag times for microparticles from monocytes, endothelial cells and THP-1 cells and equalized them with those for microparticles from platelets and granulocytes. Higher coagulation activity of microparticles from monocytes, THP-1 cells and endothelial cells in comparison with microparticles from platelets and granulocytes is determined mainly by the presence of active tissue factor.

Blockade of tumour necrosis factor-α in experimental autoimmune encephalomyelitis reveals differential effects on the antigen-specific immune response and central nervous system histopathology.

PubMed

Batoulis, H; Recks, M S; Holland, F O; Thomalla, F; Williams, R O; Kuerten, S

2014-01-01

In various autoimmune diseases, anti-tumour necrosis factor (TNF)-α treatment has been shown to reduce both clinical disease severity and T helper type 1 (Th1)1/Th17 responses. In experimental autoimmune encephalomyelitis (EAE), however, the role of TNF-α has remained unclear. Here, C57BL/6 mice were immunized with myelin oligodendrocyte glycoprotein (MOG) peptide 35-55 and treated with anti-TNF-α, control antibody or vehicle. The clinical disease course, incidence and severity were assessed. On day 20 after immunization the antigen-specific Th1/Th17 response was evaluated by enzyme-linked immunospot (ELISPOT) in spleen and central nervous system (CNS). Also, the extent of spinal cord histopathology was analysed on semi- and ultrathin sections. Our results demonstrate that anti-TNF-α treatment reduced the incidence and delayed the onset of EAE, but had no effect on disease severity once EAE had been established. Whereas anti-TNF-α treatment induced an increase in splenic Th1/Th17 responses, there was no effect on the number of antigen-specific Th1/Th17 cells in the spinal cord. Accordingly, the degree of CNS histopathology was comparable in control and anti-TNF-α-treated mice. In conclusion, while the anti-TNF-α treatment had neither immunosuppressive effects on the Th1/Th17 response in the CNS nor histoprotective properties in EAE, it enhanced the myelin-specific T cell response in the immune periphery. © 2013 British Society for Immunology.

Factor H-binding protein, a unique meningococcal vaccine antigen.

PubMed

Pizza, Mariagrazia; Donnelly, John; Rappuoli, Rino

2008-12-30

GNA1870, also named factor H-binding protein (fHbp) or rLP-2086, is a genome-derived antigen and one of the components of a rationally designed vaccine against Neisseria meningitidis serogroup B, which has entered phase III clinical trials. It has been classified into three main non-cross-protective variant groups. GNA1870 has also been termed fHbp because of its ability to bind factor H, a key regulatory component of the alternative complement pathway. fHbp is important for survival in human blood, human sera, and in presence of antimicrobial peptides, independently of its expression level. All these properties make fHbp a unique vaccine antigen.

Endothelial Cell Proteomic Response to Rickettsia conorii Infection Reveals Activation of the Janus Kinase (JAK)-Signal Transducer and Activator of Transcription (STAT)-Inferferon Stimulated Gene (ISG)15 Pathway and Reprogramming Plasma Membrane Integrin/Cadherin Signaling.

PubMed

Zhao, Yingxin; Valbuena, Gustavo; Walker, David H; Gazi, Michal; Hidalgo, Marylin; DeSousa, Rita; Oteo, Jose Antonio; Goez, Yenny; Brasier, Allan R

2016-01-01

Rickettsia conorii is the etiologic agent of Mediterranean spotted fever, a re-emerging infectious disease with significant mortality. This Gram-negative, obligately intracellular pathogen is transmitted via tick bites, resulting in disseminated vascular endothelial cell infection with vascular leakage. In the infected human, Rickettsia conorii infects endothelial cells, stimulating expression of cytokines and pro-coagulant factors. However, the integrated proteomic response of human endothelial cells to R. conorii infection is not known. In this study, we performed quantitative proteomic profiling of primary human umbilical vein endothelial cells (HUVECs) with established R conorii infection versus those stimulated with endotoxin (LPS) alone. We observed differential expression of 55 proteins in HUVEC whole cell lysates. Of these, we observed induction of signal transducer and activator of transcription (STAT)1, MX dynamin-like GTPase (MX1), and ISG15 ubiquitin-like modifier, indicating activation of the JAK-STAT signaling pathway occurs in R. conorii-infected HUVECs. The down-regulated proteins included those involved in the pyrimidine and arginine biosynthetic pathways. A highly specific biotinylated cross-linking enrichment protocol was performed to identify dysregulation of 11 integral plasma membrane proteins that included up-regulated expression of a sodium/potassium transporter and down-regulation of α-actin 1. Analysis of Golgi and soluble Golgi fractions identified up-regulated proteins involved in platelet-endothelial adhesion, phospholipase activity, and IFN activity. Thirty four rickettsial proteins were identified with high confidence in the Golgi, plasma membrane, or secreted protein fractions. The host proteins associated with rickettsial infections indicate activation of interferon-STAT signaling pathways; the disruption of cellular adhesion and alteration of antigen presentation pathways in response to rickettsial infections are distinct from

Targeting the Endoplasmic Reticulum Unfolded Protein Response to Counteract the Oxidative Stress-Induced Endothelial Dysfunction

PubMed Central

Moltedo, Ornella; Faraonio, Raffaella

2018-01-01

In endothelial cells, the tight control of the redox environment is essential for the maintenance of vascular homeostasis. The imbalance between ROS production and antioxidant response can induce endothelial dysfunction, the initial event of many cardiovascular diseases. Recent studies have revealed that the endoplasmic reticulum could be a new player in the promotion of the pro- or antioxidative pathways and that in such a modulation, the unfolded protein response (UPR) pathways play an essential role. The UPR consists of a set of conserved signalling pathways evolved to restore the proteostasis during protein misfolding within the endoplasmic reticulum. Although the first outcome of the UPR pathways is the promotion of an adaptive response, the persistent activation of UPR leads to increased oxidative stress and cell death. This molecular switch has been correlated to the onset or to the exacerbation of the endothelial dysfunction in cardiovascular diseases. In this review, we highlight the multiple chances of the UPR to induce or ameliorate oxidative disturbances and propose the UPR pathways as a new therapeutic target for the clinical management of endothelial dysfunction. PMID:29725497

Systemic Hypoxia Changes the Organ-Specific Distribution of Vascular Endothelial Growth Factor and Its Receptors

NASA Astrophysics Data System (ADS)

Marti, Hugo H.; Risau, Werner

1998-12-01

Vascular endothelial growth factor (VEGF) plays a key role in physiological blood vessel formation and pathological angiogenesis such as tumor growth and ischemic diseases. Hypoxia is a potent inducer of VEGF in vitro. Here we demonstrate that VEGF is induced in vivo by exposing mice to systemic hypoxia. VEGF induction was highest in brain, but also occurred in kidney, testis, lung, heart, and liver. In situ hybridization analysis revealed that a distinct subset of cells within a given organ, such as glial cells and neurons in brain, tubular cells in kidney, and Sertoli cells in testis, responded to the hypoxic stimulus with an increase in VEGF expression. Surprisingly, however, other cells at sites of constitutive VEGF expression in normal adult tissues, such as epithelial cells in the choroid plexus and kidney glomeruli, decreased VEGF expression in response to the hypoxic stimulus. Furthermore, in addition to VEGF itself, expression of VEGF receptor-1 (VEGFR-1), but not VEGFR-2, was induced by hypoxia in endothelial cells of lung, heart, brain, kidney, and liver. VEGF itself was never found to be up-regulated in endothelial cells under hypoxic conditions, consistent with its paracrine action during normoxia. Our results show that the response to hypoxia in vivo is differentially regulated at the level of specific cell types or layers in certain organs. In these tissues, up- or down-regulation of VEGF and VEGFR-1 during hypoxia may influence their oxygenation after angiogenesis or modulate vascular permeability.

Air pollution upregulates endothelial cell procoagulant activity via ultrafine particle-induced oxidant signaling and tissue factor expression.

PubMed

Snow, S J; Cheng, W; Wolberg, A S; Carraway, M S

2014-07-01

Air pollution exposure is associated with cardiovascular events triggered by clot formation. Endothelial activation and initiation of coagulation are pathophysiological mechanisms that could link inhaled air pollutants to vascular events. Here we investigated the underlying mechanisms of increased endothelial cell procoagulant activity following exposure to soluble components of ultrafine particles (soluble UF). Human coronary artery endothelial cells (HCAEC) were exposed to soluble UF and assessed for their ability to trigger procoagulant activity in platelet-free plasma. Exposed HCAEC triggered earlier thrombin generation and faster fibrin clot formation, which was abolished by an anti-tissue factor (TF) antibody, indicating TF-dependent effects. Soluble UF exposure increased TF mRNA expression without compensatory increases in key anticoagulant proteins. To identify early events that regulate TF expression, we measured endothelial H2O2 production following soluble UF exposure and identified the enzymatic source. Soluble UF exposure increased endothelial H2O2 production, and antioxidants attenuated UF-induced upregulation of TF, linking the procoagulant responses to reactive oxygen species (ROS) formation. Chemical inhibitors and RNA silencing showed that NOX-4, an important endothelial source of H2O2, was involved in UF-induced upregulation of TF mRNA. These data indicate that soluble UF exposure induces endothelial cell procoagulant activity, which involves de novo TF synthesis, ROS production, and the NOX-4 enzyme. These findings provide mechanistic insight into the adverse cardiovascular effects associated with air pollution exposure. Published by Oxford University Press on behalf of Toxicological Sciences 2014. This work is written by (a) US Government employee(s) and is in the public domain in the US.

pH-Responsive Nanoparticle Vaccines for Dual-Delivery of Antigens and Immunostimulatory Oligonucleotides

PubMed Central

Wilson, John T.; Keller, Salka; Manganiello, Matthew J.; Cheng, Connie; Lee, Chen-Chang; Opara, Chinonso; Convertine, Anthony; Stayton, Patrick S.

2013-01-01

Protein subunit vaccines offer important potential advantages over live vaccine vectors, but generally elicit weaker and shorter-lived cellular immune responses. Here we investigate the use of pH-responsive, endosomolytic polymer nanoparticles that were originally developed for RNA delivery as vaccine delivery vehicles for enhancing cellular and humoral immune responses. Micellar nanoparticles were assembled from amphiphilic diblock copolymers composed of an ampholytic core-forming block and a re-designed polycationic corona block doped with thiol-reactive pyridyl disulfide groups to enable dual-delivery of antigens and immunostimulatory CpG oligodeoxynucleotide (CpG ODN) adjuvants. Polymers assembled into 23 nm particles with simultaneous packaging of CpG ODN and a thiolated protein antigen, ovalbumin (ova). Conjugation of ova to nanoparticles significantly enhanced antigen cross-presentation in vitro relative to free ova or an unconjugated, physical mixture of the parent compounds. Subcutaneous vaccination of mice with ova-nanoparticle conjugates elicited a significantly higher CD8+ T cell response (0.5% IFN-ɣ+ of CD8+) compared to mice vaccinated with free ova or a physical mixture of the two components. Significantly, immunization with ova-nanoparticle conjugates electrostatically complexed with CpG ODN (dual-delivery) enhanced CD8+ T cell responses (3.4% IFN-ɣ+ of CD8+) 7-, 18-, and 8-fold relative to immunization with conjugates, ova administered with free CpG, or a formulation containing free ova and CpG complexed to micelles, respectively. Similarly, dual-delivery carriers significantly increased CD4+IFN-ɣ+ (Th1) responses, and elicited a balanced IgG1/IgG2c antibody response. Intradermal administration further augmented cellular immune responses, with dual-delivery carriers inducing ~7% antigen-specific CD8+ T cells. This work demonstrates the ability of pH-responsive, endosomolytic nanoparticles to actively promote antigen cross-presentation and

Vascular Endothelial Growth Factor in Eye Disease

PubMed Central

Penn, J.S.; Madan, A.; Caldwell, R.B.; Bartoli, M.; Caldwell, R.W.; Hartnett, M.E.

2012-01-01

Collectively, angiogenic ocular conditions represent the leading cause of irreversible vision loss in developed countries. In the U.S., for example, retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration are the principal causes of blindness in the infant, working age and elderly populations, respectively. Evidence suggests that vascular endothelial growth factor (VEGF), a 40 kDa dimeric glycoprotein, promotes angiogenesis in each of these conditions, making it a highly significant therapeutic target. However, VEGF is pleiotropic, affecting a broad spectrum of endothelial, neuronal and glial behaviors, and confounding the validity of anti-VEGF strategies, particularly under chronic disease conditions. In fact, among other functions VEGF can influence cell proliferation, cell migration, proteolysis, cell survival and vessel permeability in a wide variety of biological contexts. This article will describe the roles played by VEGF in the pathogenesis of retinopathy of prematurity, diabetic retinopathy and age-related macular degeneration. The potential disadvantages of inhibiting VEGF will be discussed, as will the rationales for targeting other VEGF-related modulators of angiogenesis. PMID:18653375

Effects of angiopoietin-1 on inflammatory injury in endothelial progenitor cells and blood vessels.

PubMed

Wang, Yi-Qing; Song, Jing-Jin; Han, Xiao; Liu, Yi-Ye; Wang, Xi-Huang; Li, Zhi-Ming; Tzeng, Chi-Meng

2014-01-01

Endothelial progenitor cells (EPCs) and angiopoietin-1 (Ang-1) play important roles in vasculogenesis and angiogenesis, respectively. Thus, targeting both aspects of cardiovascular tissue regeneration may offer promising therapeutic options for cardiovascular disorders. To this end, we constructed a lentiviral vector (pNL) with the Ang-1 gene and transfected EPCs with it (Ang-1-EPCs) to investigate vasculogenesis in both cellular and animal models. Compared to controls, intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1) increased significantly in both untreated EPCs and in the pNL vector group. After Ang-1 transcription, ICAM-1 and VCAM-1 decreased considerably in those treatment groups. Ang-1-modified EPCs alleviated inflammatory responses induced by tumor-necrosis factor-α (TNF-α) in vitro. Moreover, Ang-1-EPC implantation inhibited neointimal hyperplasia after balloon catheter injury in rats, dramatically diminishing the intimal-media (I/M) ratio and decreasing the neointimal area. Proliferating cell nuclear antigen expression in the Ang-1-EPC group was lower than the EPC non-treatment group as well, suggesting that Ang-1-EPC improved cell survival during inflammation and promoted endothelialization in damaged blood vessels.

Extending antigen release from particulate vaccines results in enhanced antitumor immune response.

PubMed

Kapadia, Chintan H; Tian, Shaomin; Perry, Jillian L; Sailer, David; Christopher Luft, J; DeSimone, Joseph M

2018-01-10

Tumor-specific CD8 + cytotoxic T lymphocytes (CTLs) play a critical role in an anti-tumor immune response. However, vaccination intended to elicit a potent CD8 + T cell responses employing tumor-associated peptide antigens, are typically ineffective due to poor immunogenicity. Previously, we engineered a polyethylene glycol (PEG) hydrogel-based subunit vaccine for the delivery of an antigenic peptide and CpG (adjuvant) to elicit potent CTLs. In this study, we further examined the effect of antigen release kinetics on their induced immune responses. A CD8 + T cell epitope peptide from OVA (CSIINFEKL) and CpG were co-conjugated to nanoparticles utilizing either a disulfide or a thioether linkage. Subsequent studies comparing peptide release rates as a function of linker, determined that the thioether linkage provided sustained release of peptide over 72h. Ability to control the release of peptide resulted in both higher and prolonged antigen presentation when compared to disulfide-linked peptide. Both NP vaccine formulations resulted in activation and maturation of bone marrow derived dendritic cells (BMDCs) and induced potent CD8 + T cell responses when compared to soluble antigen and soluble CpG. Immunization with either disulfide or thioether linked vaccine constructs effectively inhibited EG7-OVA tumor growth in mice, however only treatment with the thioether linked vaccine construct resulted in enhanced survival. Copyright © 2017. Published by Elsevier B.V.

PLGA nanoparticle-mediated delivery of tumor antigenic peptides elicits effective immune responses

PubMed Central

Ma, Wenxue; Chen, Mingshui; Kaushal, Sharmeela; McElroy, Michele; Zhang, Yu; Ozkan, Cengiz; Bouvet, Michael; Kruse, Carol; Grotjahn, Douglas; Ichim, Thomas; Minev, Boris

2012-01-01

The peptide vaccine clinical trials encountered limited success because of difficulties associated with stability and delivery, resulting in inefficient antigen presentation and low response rates in patients with cancer. The purpose of this study was to develop a novel delivery approach for tumor antigenic peptides in order to elicit enhanced immune responses using poly(DL-lactide-co-glycolide) nanoparticles (PLGA-NPs) encapsulating tumor antigenic peptides. PLGA-NPs were made using the double emulsion-solvent evaporation method. Artificial antigen-presenting cells were generated by human dendritic cells (DCs) loaded with PLGA-NPs encapsulating tumor antigenic peptide(s). The efficiency of the antigen presentation was measured by interferon-γ ELISpot assay (Vector Laboratories, Burlingame, CA). Antigen-specific cytotoxic T lymphocytes (CTLs) were generated and evaluated by CytoTox 96® Non-Radioactive Cytotoxicity Assay (Promega, Fitchburg, WI). The efficiency of the peptide delivery was compared between the methods of emulsification in incomplete Freund’s adjuvant and encapsulation in PLGA-NPs. Our results showed that most of the PLGA-NPs were from 150 nm to 500 nm in diameter, and were negatively charged at pH 7.4 with a mean zeta potential of −15.53 ± 0.71 mV; the PLGA-NPs could be colocalized in human DCs in 30 minutes of incubation. Human DCs loaded with PLGA-NPs encapsulating peptide induced significantly stronger CTL cytotoxicity than those pulsed with free peptide, while human DCs loaded with PLGA-NPs encapsulating a three-peptide cocktail induced a significantly greater CTL response than those encapsulating a two-peptide cocktail. Most importantly, the peptide dose encapsulated in PLGA-NPs was 63 times less than that emulsified in incomplete Freund’s adjuvant, but it induced a more powerful CTL response in vivo. These results demonstrate that the delivery of peptides encapsulated in PLGA-NPs is a promising approach to induce effective antitumor

Three-dimensional culture conditions differentially affect astrocyte modulation of brain endothelial barrier function in response to transforming growth factor β1.

PubMed

Hawkins, Brian T; Grego, Sonia; Sellgren, Katelyn L

2015-05-22

Blood-brain barrier (BBB) function is regulated by dynamic interactions among cell types within the neurovascular unit, including astrocytes and endothelial cells. Co-culture models of the BBB typically involve astrocytes seeded on two-dimensional (2D) surfaces, which recent studies indicate cause astrocytes to express a phenotype similar to that of reactive astrocytes in situ. We hypothesized that the culture conditions of astrocytes would differentially affect their ability to modulate BBB function in vitro. Brain endothelial cells were grown alone or in co-culture with astrocytes. Astrocytes were grown either as conventional (2D) monolayers, or in a collagen-based gel which allows them to grow in a three-dimensional (3D) construct. Astrocytes were viable in 3D conditions, and displayed a marked reduction in their expression of glial fibrillary acidic protein (GFAP), suggesting reduced activation. Stimulation of astrocytes with transforming growth factor (TGF)β1 decreased transendothelial electrical resistance (TEER) and reduced expression of claudin-5 in co-cultures, whereas treatment of endothelial cells in the absence of astrocytes was without effect. The effect of TGFβ1 on TEER was significantly more pronounced in endothelial cells cultured with 3D astrocytes compared to 2D astrocytes. These results demonstrate that astrocyte culture conditions differentially affect their ability to modulate brain endothelial barrier function, and suggest a direct relationship between reactive gliosis and BBB permeability. Moreover, these studies demonstrate the potential importance of physiologically relevant culture conditions to in vitro modeling of disease processes that affect the neurovascular unit. Copyright © 2015 Elsevier B.V. All rights reserved.

Constructing a blood vessel on the porous scaffold modified with vascular endothelial growth factor and basic fibroblast growth factor

NASA Astrophysics Data System (ADS)

Sevostyanova, V. V.; Matveeva, V. G.; Antonova, L. V.; Velikanova, E. A.; Shabaev, A. R.; Senokosova, E. A.; Krivkina, E. O.; Vasyukov, G. Yu.; Glushkova, T. V.; Kudryavtseva, Yu. A.; Barbarash, O. L.; Barbarash, L. S.

2016-11-01

Incorporation of the growth factors into biodegradable polymers is a promising approach for the fabrication of tissue-engineered vascular grafts. Here we blended poly(ɛ-caprolactone) (PCL) with poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV) following incorporation of either vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) and then fabricated electrospun 2 mm diameter vascular grafts. Grafts without the growth factors were used as a control group. Structure of the grafts was assessed utilizing scanning electron microscopy. We further implanted our grafts into rat abdominal aorta for 1 and 3 months with the aim to test endothelialization, cell infiltration, and patency in vivo. Histological and immunofluorescence examination demonstrated enhanced endothelialization and cell infiltration of the grafts with either VEGF or bFGF compared to those without the growth factors. Grafts with VEGF showed higher patency compared to those with bFGF; however, bFGF promoted migration of smooth muscle cells and fibroblasts into the graft. Therefore, we conclude that incorporation of VEGF and bFGF into the inner and medial/outer layer, respectively, can be a promising option for the fabrication of tissue-engineered vascular grafts.

Vascular Endothelial Growth Factor (VEGF) Promotes Assembly of the p130Cas Interactome to Drive Endothelial Chemotactic Signaling and Angiogenesis.

PubMed

Evans, Ian M; Kennedy, Susan A; Paliashvili, Ketevan; Santra, Tapesh; Yamaji, Maiko; Lovering, Ruth C; Britton, Gary; Frankel, Paul; Kolch, Walter; Zachary, Ian C

2017-02-01

p130Cas is a polyvalent adapter protein essential for cardiovascular development, and with a key role in cell movement. In order to identify the pathways by which p130Cas exerts its biological functions in endothelial cells we mapped the p130Cas interactome and its dynamic changes in response to VEGF using high-resolution mass spectrometry and reconstruction of protein interaction (PPI) networks with the aid of multiple PPI databases. VEGF enriched the p130Cas interactome in proteins involved in actin cytoskeletal dynamics and cell movement, including actin-binding proteins, small GTPases and regulators or binders of GTPases. Detailed studies showed that p130Cas association of the GTPase-binding scaffold protein, IQGAP1, plays a key role in VEGF chemotactic signaling, endothelial polarization, VEGF-induced cell migration, and endothelial tube formation. These findings indicate a cardinal role for assembly of the p130Cas interactome in mediating the cell migratory response to VEGF in angiogenesis, and provide a basis for further studies of p130Cas in cell movement. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

The urea decomposition product cyanate promotes endothelial dysfunction

PubMed Central

El-Gamal, Dalia; Rao, Shailaja Prabhakar; Holzer, Michael; Hallström, Seth; Haybaeck, Johannes; Gauster, Martin; Wadsack, Christian; Kozina, Andrijana; Frank, Saša; Schicho, Rudolf; Schuligoi, Rufina; Heinemann, Akos; Marsche, Gunther

2014-01-01

The dramatic cardiovascular mortality of chronic kidney disease patients is attributable in a significant proportion to endothelial dysfunction. Cyanate, a reactive species in equilibrium with urea, is formed in excess in chronic kidney disease. Cyanate is thought to have a causal role in promoting cardiovascular disease, but the underlying mechanisms remain unclear. Immunohistochemical analysis performed in the present study revealed that carbamylated epitopes associate mainly with endothelial cells in human atherosclerotic lesions. Cyanate treatment of human coronary artery endothelial cells reduced expression of endothelial nitric oxide synthase and increased tissue factor and plasminogen activator inhibitor-1 expression. In mice, administration of cyanate - promoting protein carbamylation at levels observed in uremic patients - attenuated arterial vasorelaxation of aortic rings in response to acetylcholine, without affecting sodium nitroprusside-induced relaxation. Total endothelial nitric oxide synthase and nitric oxide production were significantly reduced in aortic tissue of cyanate-treated mice. This coincided with a marked increase of tissue factor and plasminogen activator inhibitor-1 protein levels in aortas of cyanate-treated mice. These data provide evidence that cyanate compromises endothelial functionality in vitro and in vivo and may contribute to the dramatic cardiovascular risk of patients suffering from chronic kidney disease. PMID:24940796

The power of VEGF (vascular endothelial growth factor) family molecules.

PubMed

Thomas, Jean-Leon; Eichmann, Anne

2013-05-01

Vascular endothelial growth factors (VEGFs) and their high-affinity tyrosine kinase VEGF receptors (VEGFRs) are key regulators of both angiogenesis and neurogenesis. The current issue of CMLS discusses recent literature and work implementing these signals in nervous system development, maintenance and disease pathology.

Hot, humid air increases cellular influx during the late-phase response to nasal challenge with antigen.

PubMed

Assanasen, P; Baroody, F M; Naureckas, E; Naclerio, R M

2001-12-01

Inhalation of hot, humid air (HHA: 37 degrees C, > 95% relative humidity (RH)) partially inhibits the early response to nasal challenge with antigen. To investigate whether HHA inhibited the late-phase response to nasal challenge with antigen and increased hyper-responsiveness of the nasal mucosa to histamine. Twenty subjects with seasonal allergic rhinitis, outside of their allergy season, participated in a randomized, 2-way cross-over study. The subjects continuously breathed room air (25 degrees C, 30% RH) or HHA delivered via a face mask during the entire experiment. Subjects were challenged intranasally with antigen 1 h after beginning conditioning. The response was monitored by symptoms and nasal lavage at 2-h intervals after the last antigen challenge. Eight hours after antigen challenge, nasal challenge with histamine was performed. Exposure to HHA significantly increased nasal mucosal temperature from baseline without affecting nasal secretion osmolality. HHA significantly inhibited antigen-induced sneezes, congestion, pruritus, and human serum albumin levels during the early response to antigen challenge. HHA exposure, however, was associated with an 8-fold increase in the eosinophil influx and a 15-fold increase in the levels of eosinophil cationic protein during the late-phase response compared to room air. There were no significant differences in nasal hyper-responsiveness to histamine during either exposure. HHA partially decreases the early response to nasal challenge with antigen, but dramatically increases eosinophil influx. Increasing eosinophil number had no effects on the hyper-responsiveness to histamine. We speculate that the physical conditions of air differentially impact the stages of allergic inflammation.

Impaired redox signaling and antioxidant gene expression in endothelial cells in diabetes: a role for mitochondria and the nuclear factor-E2-related factor 2-Kelch-like ECH-associated protein 1 defense pathway.

PubMed

Cheng, Xinghua; Siow, Richard C M; Mann, Giovanni E

2011-02-01

Type 2 diabetes is an age-related disease associated with vascular pathologies, including severe blindness, renal failure, atherosclerosis, and stroke. Reactive oxygen species (ROS), especially mitochondrial ROS, play a key role in regulating the cellular redox status, and an overproduction of ROS may in part underlie the pathogenesis of diabetes and other age-related diseases. Cells have evolved endogenous defense mechanisms against sustained oxidative stress such as the redox-sensitive transcription factor nuclear factor E2-related factor 2 (Nrf2), which regulates antioxidant response element (ARE/electrophile response element)-mediated expression of detoxifying and antioxidant enzymes and the cystine/glutamate transporter involved in glutathione biosynthesis. We hypothesize that diminished Nrf2/ARE activity contributes to increased oxidative stress and mitochondrial dysfunction in the vasculature leading to endothelial dysfunction, insulin resistance, and abnormal angiogenesis observed in diabetes. Sustained hyperglycemia further exacerbates redox dysregulation, thereby providing a positive feedback loop for severe diabetic complications. This review focuses on the role that Nrf2/ARE-linked gene expression plays in regulating endothelial redox homeostasis in health and type 2 diabetes, highlighting recent evidence that Nrf2 may provide a therapeutic target for countering oxidative stress associated with vascular disease and aging.

Dermal Stem Cells Can Differentiate Down an Endothelial Lineage

PubMed Central

Bell, Emma; Richardson, Gavin D.; Jahoda, Colin A.; Gledhill, Karl; Phillips, Helen M.; Henderson, Deborah; Owens, W. Andrew

2012-01-01

In this study, we have demonstrated that cells of neural crest origin located in the dermal papilla (DP) exhibit endothelial marker expression and a functional activity. When grown in endothelial growth media, DP primary cultures upregulate expression of vascular endothelial growth factor receptor 1 (FLT1) mRNA and downregulate expression of the dermal stem cell marker α-smooth muscle actin. DP cells have demonstrated functional characteristics of endothelial cells, including the ability to form capillary-like structures on Matrigel, increase uptake of low-density lipoprotein and upregulate ICAM1 (CD54) in response to tumour necrosis factor alpha (TNF-α) stimulation. We confirmed that these observations were not due to contaminating endothelial cells, by using DP clones. We have also used the WNT1cre/ROSA26R and WNT1cre/YFP lineage-tracing mouse models to identify a population of neural crest-derived cells in DP cultures that express the endothelial marker PECAM (CD31); these cells also form capillary-like structures on Matrigel. Importantly, cells of neural crest origin that express markers of endothelial and mesenchymal lineages exist within the dermal sheath of the vibrissae follicle. PMID:22571645

Immune response and histology of humoral rejection in kidney transplantation.

PubMed

González-Molina, Miguel; Ruiz-Esteban, Pedro; Caballero, Abelardo; Burgos, Dolores; Cabello, Mercedes; Leon, Miriam; Fuentes, Laura; Hernandez, Domingo

2016-01-01

The adaptive immune response forms the basis of allograft rejection. Its weapons are direct cellular cytotoxicity, identified from the beginning of organ transplantation, and/or antibodies, limited to hyperacute rejection by preformed antibodies and not as an allogenic response. This resulted in allogenic response being thought for decades to have just a cellular origin. But the experimental studies by Gorer demonstrating tissue damage in allografts due to antibodies secreted by B lymphocytes activated against polymorphic molecules were disregarded. The special coexistence of binding and unbinding between antibodies and antigens of the endothelial cell membranes has been the cause of the delay in demonstrating the humoral allogenic response. The endothelium, the target tissue of antibodies, has a high turnover, and antigen-antibody binding is non-covalent. If endothelial cells are attacked by the humoral response, immunoglobulins are rapidly removed from their surface by shedding and/or internalization, as well as degrading the components of the complement system by the action of MCP, DAF and CD59. Thus, the presence of complement proteins in the membrane of endothelial cells is transient. In fact, the acute form of antibody-mediated rejection was not demonstrated until C4d complement fragment deposition was identified, which is the only component that binds covalently to endothelial cells. This review examines the relationship between humoral immune response and the types of acute and chronic histological lesion shown on biopsy of the transplanted organ. Copyright © 2016 Sociedad Española de Nefrología. Published by Elsevier España, S.L.U. All rights reserved.

Ubiquitination of basal VEGFR2 regulates signal transduction and endothelial function

PubMed Central

Smith, Gina A.; Fearnley, Gareth W.; Abdul-Zani, Izma; Wheatcroft, Stephen B.; Tomlinson, Darren C.; Harrison, Michael A.

2017-01-01

ABSTRACT Cell surface receptors can undergo recycling or proteolysis but the cellular decision-making events that sort between these pathways remain poorly defined. Vascular endothelial growth factor A (VEGF-A) and vascular endothelial growth factor receptor 2 (VEGFR2) regulate signal transduction and angiogenesis, but how signaling and proteolysis is regulated is not well understood. Here, we provide evidence that a pathway requiring the E1 ubiquitin-activating enzyme UBA1 controls basal VEGFR2 levels, hence metering plasma membrane receptor availability for the VEGF-A-regulated endothelial cell response. VEGFR2 undergoes VEGF-A-independent constitutive degradation via a UBA1-dependent ubiquitin-linked pathway. Depletion of UBA1 increased VEGFR2 recycling from endosome-to-plasma membrane and decreased proteolysis. Increased membrane receptor availability after UBA1 depletion elevated VEGF-A-stimulated activation of key signaling enzymes such as PLCγ1 and ERK1/2. Although UBA1 depletion caused an overall decrease in endothelial cell proliferation, surviving cells showed greater VEGF-A-stimulated responses such as cell migration and tubulogenesis. Our study now suggests that a ubiquitin-linked pathway regulates the balance between receptor recycling and degradation which in turn impacts on the intensity and duration of VEGF-A-stimulated signal transduction and the endothelial response. PMID:28798148

Endothelial mineralocorticoid receptor activation mediates endothelial dysfunction in diet-induced obesity

PubMed Central

Schäfer, Nicola; Lohmann, Christine; Winnik, Stephan; van Tits, Lambertus J.; Miranda, Melroy X.; Vergopoulos, Athanasios; Ruschitzka, Frank; Nussberger, Jürg; Berger, Stefan; Lüscher, Thomas F.; Verrey, François; Matter, Christian M.

2013-01-01

Received 22 July 2012; revised 29 January 2013; accepted 4 March 2013 Aims Aldosterone plays a crucial role in cardiovascular disease. ‘Systemic’ inhibition of its mineralocorticoid receptor (MR) decreases atherosclerosis by reducing inflammation and oxidative stress. Obesity, an important cardiovascular risk factor, is an inflammatory disease associated with increased plasma aldosterone levels. We have investigated the role of the ‘endothelial’ MR in obesity-induced endothelial dysfunction, the earliest stage in atherogenesis. Methods and results C57BL/6 mice were exposed to a normal chow diet (ND) or a high-fat diet (HFD) alone or in combination with the MR antagonist eplerenone (200 mg/kg/day) for 14 weeks. Diet-induced obesity impaired endothelium-dependent relaxation in response to acetylcholine, whereas eplerenone treatment of obese mice prevented this. Expression analyses in aortic endothelial cells isolated from these mice revealed that eplerenone attenuated expression of pro-oxidative NADPH oxidase (subunits p22phox, p40phox) and increased expression of antioxidative genes (glutathione peroxidase-1, superoxide dismutase-1 and -3) in obesity. Eplerenone did not affect obesity-induced upregulation of cyclooxygenase (COX)-1 or prostacyclin synthase. Endothelial-specific MR deletion prevented endothelial dysfunction in obese (exhibiting high ‘endogenous’ aldosterone) and in ‘exogenous’ aldosterone-infused lean mice. Pre-incubation of aortic rings from aldosterone-treated animals with the COX-inhibitor indomethacin restored endothelial function. Exogenous aldosterone administration induced endothelial expression of p22phox in the presence, but not in the absence of the endothelial MR. Conclusion Obesity-induced endothelial dysfunction depends on the ‘endothelial’ MR and is mediated by an imbalance of oxidative stress-modulating mechanisms. Therefore, MR antagonists may represent an attractive therapeutic strategy in the increasing population

Thalidomide inhibits tumor necrosis factor-alpha production and antigen presentation by Langerhans cells.

PubMed

Deng, Liang; Ding, Wanhong; Granstein, Richard D

2003-11-01

Thalidomide is an effective treatment for several inflammatory and autoimmune disorders including erythema nodosum leprosum, Behcet's syndrome, discoid lupus erythematosus, and Crohn's disease. Thalidomide is believed to exert its anti-inflammatory effects, at least in part, by inhibiting tumor necrosis factor-alpha (TNF-alpha) production by monocytes. We studied the effects of thalidomide on epidermal Langerhans cells (LC). LCs are epidermal antigen-presenting dendritic cells that play important roles in skin immune responses. Using the murine epidermis-derived dendritic cell lines, XS106A from A/J mice and XS52 from BALB/c mice as surrogates for LC, we found that thalidomide inhibited TNF-alpha production in a concentration-dependent manner. Northern blot analysis revealed that thalidomide significantly decreased the peak-induced mRNA level of TNF-alpha in XS106A cells and XS52 cells. We then examined the effect of thalidomide on fresh LC enriched to approximately 98% using positive selection of Ia+ cells with antibodies conjugated to magnetic microspheres. TNF-alpha production was reduced by 67.7% at a thalidomide concentration of 200 microg per mL. Thalidomide also had a profound inhibitory effect on the ability of LC to present antigen to a responsive TH1 clone. Thalidomide inhibits TNF-alpha production and the antigen-presenting ability of epidermal LCs. These mechanisms may contribute to the therapeutic effects observed with this agent.

Characterization of a human antigen specific helper factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richardson, B.

1986-03-01

While antigen (Ag) specific helper factors have been characterized in mice, similar molecules have not been identified in humans. To characterize human antigen specific helper molecules, an IL-2 dependent tetanus toxoid (T.T.) reactive T cell line was fused with a 6-thioguanine resistant CEM line, and hybrids selected in medium containing hypoxanthine and azaserine. Hybrids were screened by culturing the cells with /sup 35/S-Met then reacting the supernatants with T.T. or hepatitis vaccine immobilized on nitrocellulose. One hybrid, TT6BA-O, was identified which secreted a Met-containing molecule which bound T.T. but not hepatitis vaccine. Supernatants from TT6BA-O, but not the parent CEMmore » line, when added to autologous peripheral blood mononuclear cells (PBMC's) stimulated secretion of T.T. specific antibodies (Abs). Specificity controls demonstrated that TT6BA-O supernatant did not induce antibodies to diphtheria toxoid, hepatitis vaccine or pneumococcal polysaccharide, and total immunoglobulin (lg) synthesis was minimally increased. In contrast, pokeweed mitogen stimulated significant lg synthesis as well as Ab's to pneumococcal polysaccharide and T.T. TT6BA-O supernatant induced anti-T.T.Ab's in autologous PBMC's but not PBMC's from 3 unrelated donors, suggesting that the activity of the helper factor is restricted, possibly by the MHC. The molecular weight of the helper factor was estimated at 100,000-150,000 by Sephacryl S-300 chromatography. Finally, the helper factor could be demonstrated to bind and elute from sephorose-immobilized T.T. and anti-DR antisera, but not anti-lg antisera or the T40/25 monoclonal antibody, which binds a nonpolymorphic determinant on the human T cell receptor. These results demonstrate that human Ag specific helper factors exist, bind antigen and bear class II MHC determinants.« less

Endothelial Barrier Protection by Local Anesthetics: Ropivacaine and Lidocaine Block Tumor Necrosis Factor-α–induced Endothelial Cell Src Activation

PubMed Central

Piegeler, Tobias; Votta-Velis, E. Gina; Bakhshi, Farnaz R.; Mao, Mao; Carnegie, Graeme; Bonini, Marcelo G.; Schwartz, David E.; Borgeat, Alain; Beck-Schimmer, Beatrice; Minshall, Richard D.

2014-01-01

Background Pulmonary endothelial barrier dysfunction mediated in part by Src-kinase activation plays a crucial role in acute inflammatory disease. Proinflammatory cytokines, such as tumor necrosis factor-α (TNFα), activate Src via phosphatidylinositide 3-kinase/Akt-dependent nitric oxide generation, a process initiated by recruitment of phosphatidylinositide 3-kinase regulatory subunit p85 to TNF-receptor-1. Because amide-linked local anesthetics have well-established anti-inflammatory effects, the authors hypothesized that ropivacaine and lidocaine attenuate inflammatory Src signaling by disrupting the phosphatidylinositide 3-kinase–Akt–nitric oxide pathway, thus blocking Src-dependent neutrophil adhesion and endothelial hyperpermeability. Methods Human lung microvascular endothelial cells, incubated with TNFα in the absence or presence of clinically relevant concentrations of ropivacaine and lidocaine, were analyzed by Western blot, probing for phosphorylated/activated Src, endothelial nitric oxide synthase, Akt, intercellular adhesion molecule-1, and caveolin-1. The effect of ropivacaine on TNFα-induced nitric oxide generation, co-immunoprecipitation of TNF-receptor-1 with p85, neutrophil adhesion, and endothelial barrier disruption were assessed. Results Ropivacaine and lidocaine attenuated TNFα-induced Src activation (half-maximal inhibitory concentration [IC50] = 8.611 × 10−10 M for ropivacaine; IC50 = 5.864 × 10−10 M for lidocaine) and endothelial nitric oxide synthase phosphorylation (IC50 = 7.572 × 10−10 M for ropivacaine; IC50 = 6.377 × 10−10 M for lidocaine). Akt activation (n = 7; P = 0.006) and stimulus-dependent binding of TNF-receptor-1 and p85 (n = 6; P = 0.043) were blocked by 1 nM of ropivacaine. TNFα-induced neutrophil adhesion and disruption of endothelial monolayers via Src-dependent intercellular adhesion molecule-1- and caveolin-1-phosphorylation, respectively, were also attenuated. Conclusions Ropivacaine and lidocaine

Vascular Endothelial Growth Factor and Angiopoietin are Required for Prostate Regeneration.

PubMed Central

Wang, Gui-min; Kovalenko, Bruce; Huang, Yili; Moscatelli, David

2007-01-01

BACKGROUND The regulation of the prostate size by androgens may be partly the result of androgen effects on the prostatic vasculature. We examined the effect of changes in androgen levels on the expression of a variety of angiogenic factors in the mouse prostate and determined if vascular endothelial growth factor (VEGF)-A and the angiopoietins are involved in the vascular response to androgens. METHODS Expression of angiogenic factors in prostate was quantitated using real-time PCR at different times after castration and after administration of testosterone to castrated mice. Angiopoietins were localized in prostate by immunohistochemistry and in situ hybridization. The roles of VEGF and the angiopoietins in regeneration of the prostate were examined in mice inoculated with cells expressing soluble VEGF receptor-2 or soluble Tie-2. RESULTS Castration resulted in a decrease in VEGF-A, VEGF-B, VEGF-C, placenta growth factor, FGF-2, and FGF-8 expression after one day. In contrast, VEGF-D mRNA levels increased. No changes in angiopoietin-1 (Ang-1), angiopoietin-2 (Ang-2), hepatocyte growth factor, VEGF receptor-1, VEGF receptor-2 or tie-2 mRNA levels were observed. Administration of testosterone to castrated mice had the opposite effect on expression of these angiogenic factors. Ang-2 was expressed predominately in prostate epithelial cells whereas Ang-1 was expressed in epithelium and smooth muscle. Inoculation of mice with cells expressing soluble VEGF receptor-2 or Tie-2 blocked the increase in vascular density normally observed after administration of testosterone to castrated mice. The soluble receptors also blocked the increase in prostate weight and proliferation of prostatic epithelial cells. CONCLUSION VEGF-A and angiopoietins are required for the vascular response to androgens and for the ability of the prostate to regenerate in response to androgens. PMID:17221843

Effects of High Intensity Training and High Volume Training on Endothelial Microparticles and Angiogenic Growth Factors

PubMed Central

Achtzehn, Silvia; Schmitz, Theresa; Bloch, Wilhelm; Mester, Joachim; Werner, Nikos

2014-01-01

Aims Endothelial microparticles (EMP) are complex vesicular structures shed from activated or apoptotic endothelial cells. As endurance exercise affects the endothelium, the objective of the study was to examine levels of EMP and angiogenic growth factors following different endurance exercise protocols. Methods 12 subjects performed 3 different endurance exercise protocols: 1. High volume training (HVT; 130 min at 55% peak power output (PPO); 2. 4×4 min at 95% PPO; 3. 4×30 sec all-out. EMPs were quantified using flow cytometry after staining platelet-poor-plasma. Events positive for Annexin-V and CD31, and negative for CD42b, were classified as EMPs. Vascular endothelial growth factor (VEGF), migratory inhibiting factor (MIF) and hepatocyte growth factor (HGF) were determined by ELISA technique. For all these measurements venous blood samples were taken pre, 0′, 30′, 60′ and 180′ after each intervention. Furthermore, in vitro experiments were performed to explore the effect of collected sera on target endothelial functions and MP uptake capacities. Results VEGF and HGF significantly increased after HIT interventions. All three interventions caused a significant decrease in EMP levels post exercise compared to pre values. The sera taken after exercise increased the uptake of EMP in target endothelial cells compared to sera taken under resting conditions, which was shown to be phosphatidylserin-dependent. Increased EMP uptake was associated with an improved protection of target cells against apoptosis. Sera taken prior and after exercise promoted target endothelial cell migration, which was abrogated after inhibition of VEGF. Conclusion Physical exercise leads to decreased EMP levels and promotes a phosphatidylserin-dependent uptake of EMP into target endothelial cells, which is associated with a protection of target cells against apoptosis. PMID:24770423

Scleroderma dermal microvascular endothelial cells exhibit defective response to pro-angiogenic chemokines

PubMed Central

Rabquer, Bradley J.; Ohara, Ray A.; Stinson, William A.; Campbell, Phillip L.; Amin, M. Asif; Balogh, Beatrix; Zakhem, George; Renauer, Paul A.; Lozier, Ann; Arasu, Eshwar; Haines, G. Kenneth; Kahaleh, Bashar; Schiopu, Elena; Khanna, Dinesh; Koch, Alisa E.

2016-01-01

Objectives. Angiogenesis plays a critical role in SSc (scleroderma). The aim of this study was to examine the expression of growth-regulated protein-γ (Gro-γ/CXCL3), granulocyte chemotactic protein 2 (GCP-2/CXCL6) and their receptor CXCR2 in endothelial cells (ECs) isolated from SSc skin and determine whether these cells mount an angiogenic response towards pro-angiogenic chemokines. The downstream signalling pathways as well as the pro-angiogenic transcription factor inhibitor of DNA-binding protein 1 (Id-1) were also examined. Methods. Skin biopsies were obtained from patients with dcSSc. ECs were isolated via magnetic positive selection. Angiogenesis was measured by EC chemotaxis assay. Results. Gro-γ/CXCL3 and GCP-2/CXCL6 were minimally expressed in both skin types but elevated in SSc serum. Pro-angiogenic chemokine mRNA was greater in SSc ECs than in normal ECs. SSc ECs did not migrate to vascular endothelial growth factor (VEGF), Gro-γ/CXCL3, GCP-2/CXCL6 or CXCL16. The signalling pathways stimulated by these chemokines were also dysregulated. Id-1 mRNA in SSc ECs was lower compared with normal ECs, and overexpression of Id-1 in SSc ECs increased their ability to migrate towards VEGF and CXCL16. Conclusion. Our results show that SSc ECs are unable to respond to pro-angiogenic chemokines despite their increased expression in serum and ECs. This might be due to the differences in the signalling pathways activated by these chemokines in normal vs SSc ECs. In addition, the lower expression of Id-1 also decreases the angiogenic response. The inability of pro-angiogenic chemokines to promote EC migration provides an additional mechanism for the impaired angiogenesis that characterizes SSc. PMID:26705326

Macrophage Migration Inhibitory Factor-Induced Autophagy Contributes to Thrombin-Triggered Endothelial Hyperpermeability in Sepsis.

PubMed

Chao, Chiao-Hsuan; Chen, Hong-Ru; Chuang, Yung-Chun; Yeh, Trai-Ming

2018-07-01

Vascular leakage contributes to the high morbidity and mortality associated with sepsis. Exposure of the endothelium to inflammatory mediators, such as thrombin and cytokines, during sepsis leads to hyperpermeability. We recently observed that autophagy, a cellular process for protein turnover, is involved in macrophage migration inhibitory factor (MIF)-induced endothelial hyperpermeability. Even though it is known that thrombin induces endothelial cells to secrete MIF and to increase vascular permeability, the possible role of autophagy in this process is unknown. In this study, we proposed and tested the hypothesis that MIF-induced autophagy plays an important role in thrombin-induced endothelial hyperpermeability. We evaluated the effects of thrombin on endothelial permeability, autophagy induction, and MIF secretion in vitro using the human microvascular endothelial cell line-1 and human umbilical vein endothelial cells. Several mechanisms/read outs of endothelial permeability and autophagy formation were examined. We observed that blocking autophagy attenuated thrombin-induced endothelial hyperpermeability. Furthermore, thrombin-induced MIF secretion was involved in this process because MIF inhibition reduced thrombin-induced autophagy and hyperpermeability. Finally, we showed that blocking MIF or autophagy effectively alleviated vascular leakage and mortality in endotoxemic mice. Thus, MIF-induced autophagy may represent a common mechanism causing vascular leakage in sepsis.

Kinetics of humoral responsiveness and antigenic distribution in operated rats.

PubMed Central

Kinnaert, P; Mahieu, A; van Geertruyden, N

1979-01-01

Wistar R/A rats were injected intravenously with 10(9) sheep red blood cells (SRBC) prior to, during or after a standard laparotomy. Stimulation of anti-SRBC antibody synthesis was already observed when the antigen was given 4 h prior to surgery and was maximal if SRBC were administered at the time of operation. The enhancing effect on the immune response lasted for 2 days after surgery. From the third post-operative day on, the injection of SRBC induced a normal humoral response. No subsequent depression was detected. Inter-organ distribution studies of 51Cr-labelled SRBC injected at various times prior, during or after the surgical procedure, showed a maximum decrease of liver uptake during operation; the depression was still present 2 h later but on the first post-operative day, no significant difference from the controls could be demonstrated. When the labelled antigen was given before surgery, organ distribution was normal. Consequently, there is no time relationship between the stimulation of antibody production and the alteration of total phagocytosis induced by surgery. Therefore, the enhanced humoral response cannot be explained only by spillover of the antigen from the liver into lymphoid organs. PMID:511217

Hepatocellular hypoxia-induced vascular endothelial growth factor expression and angiogenesis in experimental biliary cirrhosis.

PubMed

Rosmorduc, O; Wendum, D; Corpechot, C; Galy, B; Sebbagh, N; Raleigh, J; Housset, C; Poupon, R

1999-10-01

We tested the potential role of vascular endothelial growth factor (VEGF) and of fibroblast growth factor-2 (FGF-2) in the angiogenesis associated with experimental liver fibrogenesis induced by common bile duct ligation in Sprague-Dawley rats. In normal rats, VEGF and FGF-2 immunoreactivities were restricted to less than 3% of hepatocytes. One week after bile duct ligation, hypoxia was demonstrated by the immunodetection of pimonidazole adducts unevenly distributed throughout the lobule. After 2 weeks, hypoxia and VEGF expression were detected in >95% of hepatocytes and coexisted with an increase in periportal vascular endothelial cell proliferation, as ascertained by Ki67 immunolabeling. Subsequently, at 3 weeks the density of von Willebrand-labeled vascular section in fibrotic areas significantly increased. Semiquantitative reverse transcription polymerase chain reaction showed that VEGF(120) and VEGF(164) transcripts, that correspond to secreted isoforms, increased within 2 weeks, while VEGF(188) transcripts remained unchanged. FGF-2 mainly consisting of a 22-kd isoform, according to Western blot, was identified by immunohistochemistry in 49% and 100% of hepatocytes at 3 and 7 weeks, respectively. Our data provide evidence that in biliary-type liver fibrogenesis, angiogenesis is stimulated primarily by VEGF in response to hepatocellular hypoxia while FGF-2 likely contributes to the maintenance of angiogenesis at later stages.

Intestinal Epithelial Cells Modulate Antigen-Presenting Cell Responses to Bacterial DNA

PubMed Central

Campeau, J. L.; Salim, S. Y.; Albert, E. J.; Hotte, N.

2012-01-01

Intestinal epithelial cells and antigen-presenting cells orchestrate mucosal innate immunity. This study investigated the role of bacterial DNA in modulating epithelial and bone marrow-derived antigen-presenting cells (BM-APCs) and subsequent T-lymphocyte responses. Murine MODE-K epithelial cells and BM-APCs were treated with DNA from either Bifidobacterium breve or Salmonella enterica serovar Dublin directly and under coculture conditions with CD4+ T cells. Apical stimulation of MODE-K cells with S. Dublin DNA enhanced secretion of cytokines from underlying BM-APCs and induced interleukin-17 (IL-17) and gamma interferon (IFN-γ) secretion from CD4+ T cells. Bacterial DNA isolated from either strain induced maturation and increased cytokine secretion from BM-APCs. Conditioned medium from S. Dublin-treated MODE-K cells elicited an increase in cytokine secretion similar to that seen for S. Dublin DNA. Treatment of conditioned medium from MODE-K cells with RNase and protease prevented the S. Dublin-induced increased cytokine secretion. Oral feeding of mice with B. breve DNA resulted in enhanced levels of colonic IL-10 and transforming growth factor β (TGFβ) compared with what was seen for mice treated with S. Dublin DNA. In contrast, feeding mice with S. Dublin DNA increased levels of colonic IL-17 and IL-12p70. T cells from S. Dublin DNA-treated mice secreted high levels of IL-12 and IFN-γ compared to controls and B. breve DNA-treated mice. These results demonstrate that intestinal epithelial cells are able to modulate subsequent antigen-presenting and T-cell responses to bacterial DNA with pathogenic but not commensal bacterial DNA inducing effector CD4+ T lymphocytes. PMID:22615241

Endothelial effects of emission source particles: acute toxic response gene expression profiles.

PubMed

Nadadur, Srikanth S; Haykal-Coates, Najwa; Mudipalli, Anuradha; Costa, Daniel L

2009-02-01

Air pollution epidemiology has established a strong association between exposure to ambient particulate matter (PM) and cardiovascular outcomes. Experimental studies in both humans and laboratory animals support varied biological mechanisms including endothelial dysfunction as potentially a central step to the elicitation of cardiovascular events. We therefore hypothesized that relevant early molecular alterations on endothelial cells should be assessable in vitro upon acute exposure to PM components previously shown to be involved in health outcomes. Using a model emission PM, residual oil fly ash and one of its predominant constituents (vanadium-V), we focused on the development of gene expression profiles to fingerprint that particle and its constituents to explore potential biomarkers for PM-induced endothelial dysfunction. Here we present differential gene expression and transcription factor activation profiles in human vascular endothelial cells exposed to a non-cytotoxic dose of fly ash or V following semi-global gene expression profiling of approximately 8000 genes. Both fly ash and it's prime constituent, V, induced alterations in genes involved in passive and active transport of solutes across the membrane; voltage-dependent ion pumps; induction of extracellular matrix proteins and adhesion molecules; and activation of numerous kinases involved in signal transduction pathways. These preliminary data suggest that cardiovascular effects associated with exposure to PM may be mediated by perturbations in endothelial cell permeability, membrane integrity; and ultimately endothelial dysfunction.

Human leukocyte antigens and cellular immune responses to anthrax vaccine adsorbed.

PubMed

Ovsyannikova, Inna G; Pankratz, V Shane; Vierkant, Robert A; Pajewski, Nicholas M; Quinn, Conrad P; Kaslow, Richard A; Jacobson, Robert M; Poland, Gregory A

2013-07-01

Interindividual variations in vaccine-induced immune responses are in part due to host genetic polymorphisms in the human leukocyte antigen (HLA) and other gene families. This study examined associations between HLA genotypes, haplotypes, and homozygosity and protective antigen (PA)-specific cellular immune responses in healthy subjects following immunization with Anthrax Vaccine Adsorbed (AVA). While limited associations were observed between individual HLA alleles or haplotypes and variable lymphocyte proliferative (LP) responses to AVA, analyses of homozygosity supported the hypothesis of a "heterozygote advantage." Individuals who were homozygous for any HLA locus demonstrated significantly lower PA-specific LP than subjects who were heterozygous at all eight loci (median stimulation indices [SI], 1.84 versus 2.95, P = 0.009). Similarly, we found that class I (HLA-A) and class II (HLA-DQA1 and HLA-DQB1) homozygosity was significantly associated with an overall decrease in LP compared with heterozygosity at those three loci. Specifically, individuals who were homozygous at these loci had significantly lower PA-specific LP than subjects heterozygous for HLA-A (median SI, 1.48 versus 2.13, P = 0.005), HLA-DQA1 (median SI, 1.75 versus 2.11, P = 0.007), and HLA-DQB1 (median SI, 1.48 versus 2.13, P = 0.002) loci, respectively. Finally, homozygosity at an increasing number (≥ 4) of HLA loci was significantly correlated with a reduction in LP response (P < 0.001) in a dose-dependent manner. Additional studies are needed to reproduce these findings and determine whether HLA-heterozygous individuals generate stronger cellular immune response to other virulence factors (Bacillus anthracis LF and EF) than HLA-homozygous subjects.

Endothelial monocyte activating polypeptide-II modulates endothelial cell responses by degrading hypoxia-inducible factor-1alpha through interaction with PSMA7, a component of the proteasome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tandle, Anita T.; Calvani, Maura; Uranchimeg, Badarch

The majority of human tumors are angiogenesis dependent. Understanding the specific mechanisms that contribute to angiogenesis may offer the best approach to develop therapies to inhibit angiogenesis in cancer. Endothelial monocyte activating polypeptide-II (EMAP-II) is an anti-angiogenic cytokine with potent effects on endothelial cells (ECs). It inhibits EC proliferation and cord formation, and it suppresses primary and metastatic tumor growth in-vivo. However, very little is known about the molecular mechanisms behind the anti-angiogenic activity of EMAP-II. In the present study, we explored the molecular mechanism behind the anti-angiogenic activity exerted by this protein on ECs. Our results demonstrate that EMAP-IImore » binds to the cell surface {alpha}5{beta}1 integrin receptor. The cell surface binding of EMAP-II results in its internalization into the cytoplasmic compartment where it interacts with its cytoplasmic partner PSMA7, a component of the proteasome degradation pathway. This interaction increases hypoxia-inducible factor 1-alpha (HIF-1{alpha}) degradation under hypoxic conditions. The degradation results in the inhibition of HIF-1{alpha} mediated transcriptional activity as well as HIF-1{alpha} mediated angiogenic sprouting of ECs. HIF-1{alpha} plays a critical role in angiogenesis by activating a variety of angiogenic growth factors. Our results suggest that one of the major anti-angiogenic functions of EMAP-II is exerted through its inhibition of the HIF-1{alpha} activities.« less

FOXF1 transcription factor is required for formation of embryonic vasculature by regulating VEGF signaling in endothelial cells.

PubMed

Ren, Xiaomeng; Ustiyan, Vladimir; Pradhan, Arun; Cai, Yuqi; Havrilak, Jamie A; Bolte, Craig S; Shannon, John M; Kalin, Tanya V; Kalinichenko, Vladimir V

2014-09-26

Inactivating mutations in the Forkhead Box transcription factor F1 (FOXF1) gene locus are frequently found in patients with alveolar capillary dysplasia with misalignment of pulmonary veins, a lethal congenital disorder, which is characterized by severe abnormalities in the respiratory, cardiovascular, and gastrointestinal systems. In mice, haploinsufficiency of the Foxf1 gene causes alveolar capillary dysplasia and developmental defects in lung, intestinal, and gall bladder morphogenesis. Although FOXF1 is expressed in multiple mesenchyme-derived cell types, cellular origins and molecular mechanisms of developmental abnormalities in FOXF1-deficient mice and patients with alveolar capillary dysplasia with misalignment of pulmonary veins remain uncharacterized because of lack of mouse models with cell-restricted inactivation of the Foxf1 gene. In the present study, the role of FOXF1 in endothelial cells was examined using a conditional knockout approach. A novel mouse line harboring Foxf1-floxed alleles was generated by homologous recombination. Tie2-Cre and Pdgfb-CreER transgenes were used to delete Foxf1 from endothelial cells. FOXF1-deficient embryos exhibited embryonic lethality, growth retardation, polyhydramnios, cardiac ventricular hypoplasia, and vascular abnormalities in the lung, placenta, yolk sac, and retina. Deletion of FOXF1 from endothelial cells reduced endothelial proliferation, increased apoptosis, inhibited vascular endothelial growth factor signaling, and decreased expression of endothelial genes critical for vascular development, including vascular endothelial growth factor receptors Flt1 and Flk1, Pdgfb, Pecam1, CD34, integrin β3, ephrin B2, Tie2, and the noncoding RNA Fendrr. Chromatin immunoprecipitation assay demonstrated that Flt1, Flk1, Pdgfb, Pecam1, and Tie2 genes are direct transcriptional targets of FOXF1. FOXF1 is required for the formation of embryonic vasculature by regulating endothelial genes critical for vascular development and

Production and Characterization of Novel Camel Single Domain Antibody Targeting Mouse Vascular Endothelial Growth Factor.

PubMed

Kazemi-Lomedasht, Fatemeh; Behdani, Mahdi; Habibi-Anbouhi, Mahdi; Shahbazzadeh, Delavar

2016-06-01

Camel single domain antibody known as Nanobody™ refers to a novel class of monoclonal antibodies with appropriate pharmacological properties. Nanobody is an antigen-binding site of camel heavy chain antibody also known as VHH. Expression in a microbial system, stability in difficult conditions and extremes of PH, and nanomolar affinity to target an appropriate drug format makes Nanobody a potential for drug discovery. Needs for Nanobody function evaluation in animal models turned our interest to develop anti-mouse vascular endothelial growth factor (mVEGF) Nanobodies using phage display as a potent technique in the isolation of antibodies. Isolation of anti-mVEGF Nanobodies was performed on Camelus dromedarius immune library through four consecutive rounds of biopanning on immobilized mVEGF. Enrichment of the Nanobody library was monitored by polyclonal phage-ELISA, and specific Nanobodies were selected using periplasmic extract-ELISA. Selected Nanobodies were expressed in WK6 Escherichia coli cells and purified using immobilized metal affinity chromatography. Specificity and affinity of selected Nanobodies were evaluated on immobilized mVEGF. Results demonstrated the successful enrichment of the Nanobody library. Two clones named Nb5 and Nb10 were selected through screening procedures according to their signal value in periplasmic extract-ELISA. Selected Nanobodies specifically reacted to mVEGF, but cross-reactivity with other antigens was not observed. Evaluated affinity for the Nanobodies was in nanomolar range. Taken together, according to the results, the selected Nanobodies promise to be a novel tool in research and for further development of diagnostic or therapeutic purposes in pharmaceutical science.

Biological factors in plasma from diabetes mellitus patients enhance hyperglycaemia and pulsatile shear stress-induced endothelial cell apoptosis.

PubMed

Liu, X F; Yu, J Q; Dalan, R; Liu, A Q; Luo, K Q

2014-05-01

People suffering from Diabetes Mellitus (DM) are prone to an array of vascular complications leading to end organ damage. The hallmark of these vascular complications is endothelium dysfunction, which is caused by endothelial cell (EC) apoptosis. Although the endothelial cell (EC) dysfunction induced by hyperglycaemia and fluid shear stress has been studied, the effects of biological factors in the blood of DM patients on EC integrity have not been reported in the in vitro models that mimic the physiological pulsatile nature of the vascular system. This study reports the development of a hemodynamic lab-on-a-chip system to investigate this issue. The pulsatile flow was applied to a monolayer of endothelial cells expressing a fluorescence resonance energy transfer (FRET)-based biosensor that changes colour from green to blue in response to caspase-3 activation during apoptosis. Plasma samples from healthy volunteers and DM patients were compared to identify biological factors that are critical to endothelial disruption. Three types of microchannels were designed to simulate the blood vessels under healthy and partially blocked pathological conditions. The results showed that EC apoptosis rates increased with increasing glucose concentration and levels of shear stress. The rates of apoptosis further increased by a factor of 1.4-2.3 for hyperglycaemic plasma under all dynamic conditions. Under static conditions, little difference was detected in the rate of EC apoptosis between experiments using plasma from DM patients and glucose medium, suggesting that the effects of hyperglycaemia and biological factors on the induction of EC apoptosis are all shear flow-dependent. A proteomics study was then conducted to identify biological factors, demonstrating that the levels of eight proteins, including haptoglobin and clusterin, were significantly down-regulated, while six proteins, including apolipoprotein C-III, were significantly up-regulated in the plasma of DM patients

Evidence that human immunoglobulin M rheumatoid factors can Be derived from the natural autoantibody pool and undergo an antigen driven immune response in which somatically mutated rheumatoid factors have lower affinities for immunoglobulin G Fc than their germline counterparts.

PubMed

Carayannopoulos, M O; Potter, K N; Li, Y; Natvig, J B; Capra, J D

2000-04-01

The question of whether immunoglobulin (Ig)M rheumatoid factors (RF) arise as the result of an abnormal expansion of already existing clones producing natural autoantibodies or emerge as new clones that are somatically mutated owing to an antigen driven immune response has never been conclusively answered. In this study, an inhibition ELISA was utilized to measure the affinities of recombinant antibodies using VH segments reverted back to their closest germline counterparts (germline revertants). In all cases, the somatically mutated parental RFs had a decreased affinity for immunoglobulin (Ig)G Fc compared to the germline revertant, indicating that the antibodies in the germline configuration had the higher affinities. This demonstrates that somatic mutation is not a prerequisite to generate disease associated antibodies. The presence of mutations in the parental IgM RFS suggests that these cells had been involved in a germinal centre reaction. As the germinal centre is the conventional site of the acquisition of mutations during an antigen driven response, these data suggest a role for germinal centres in the generation of the antibody diversity in addition to the selection of higher affinity antibodies. Assuming that only antigen selected cells survive deletion, these data support the hypothesis that IgM RFS can be derived from the natural autoantibody repertoire and result from an antigen driven response. Mechanisms controlling the survival of B cells based on the affinity/avidity of the immunoglobulin receptor are shown to be functional in patients with rheumatoid arthritis.

Endothelial fibroblast growth factor receptor signaling is required for vascular remodeling following cardiac ischemia-reperfusion injury

PubMed Central

Castro, Angela M.; Lupu, Traian S.; Weinheimer, Carla; Smith, Craig; Kovacs, Attila

2016-01-01

Fibroblast growth factor (FGF) signaling is cardioprotective in various models of myocardial infarction. FGF receptors (FGFRs) are expressed in multiple cell types in the adult heart, but the cell type-specific FGFR signaling that mediates different cardioprotective endpoints is not known. To determine the requirement for FGFR signaling in endothelium in cardiac ischemia-reperfusion injury, we conditionally inactivated the Fgfr1 and Fgfr2 genes in endothelial cells with Tie2-Cre (Tie2-Cre, Fgfr1f/f, Fgfr2f/f DCKO mice). Tie2-Cre, Fgfr1f/f, Fgfr2f/f DCKO mice had normal baseline cardiac morphometry, function, and vessel density. When subjected to closed-chest, regional cardiac ischemia-reperfusion injury, Tie2-Cre, Fgfr1f/f, Fgfr2f/f DCKO mice showed a significantly increased hypokinetic area at 7 days, but not 1 day, after reperfusion. Tie2-Cre, Fgfr1f/f, Fgfr2f/f DCKO mice also showed significantly worsened cardiac function compared with controls at 7 days but not 1 day after reperfusion. Pathophysiological analysis showed significantly decreased vessel density, increased endothelial cell apoptosis, and worsened tissue hypoxia in the peri-infarct area at 7 days following reperfusion. Notably, Tie2-Cre, Fgfr1f/f, Fgfr2f/f DCKO mice showed no impairment in the cardiac hypertrophic response. These data demonstrate an essential role for FGFR1 and FGFR2 in endothelial cells for cardiac functional recovery and vascular remodeling following in vivo cardiac ischemia-reperfusion injury, without affecting the cardiac hypertrophic response. This study suggests the potential for therapeutic benefit from activation of endothelial FGFR pathways following ischemic injury to the heart. PMID:26747503

Endothelial fibroblast growth factor receptor signaling is required for vascular remodeling following cardiac ischemia-reperfusion injury.

PubMed

House, Stacey L; Castro, Angela M; Lupu, Traian S; Weinheimer, Carla; Smith, Craig; Kovacs, Attila; Ornitz, David M

2016-03-01

Fibroblast growth factor (FGF) signaling is cardioprotective in various models of myocardial infarction. FGF receptors (FGFRs) are expressed in multiple cell types in the adult heart, but the cell type-specific FGFR signaling that mediates different cardioprotective endpoints is not known. To determine the requirement for FGFR signaling in endothelium in cardiac ischemia-reperfusion injury, we conditionally inactivated the Fgfr1 and Fgfr2 genes in endothelial cells with Tie2-Cre (Tie2-Cre, Fgfr1(f/f), Fgfr2(f/f) DCKO mice). Tie2-Cre, Fgfr1(f/f), Fgfr2(f/f) DCKO mice had normal baseline cardiac morphometry, function, and vessel density. When subjected to closed-chest, regional cardiac ischemia-reperfusion injury, Tie2-Cre, Fgfr1(f/f), Fgfr2(f/f) DCKO mice showed a significantly increased hypokinetic area at 7 days, but not 1 day, after reperfusion. Tie2-Cre, Fgfr1(f/f), Fgfr2(f/f) DCKO mice also showed significantly worsened cardiac function compared with controls at 7 days but not 1 day after reperfusion. Pathophysiological analysis showed significantly decreased vessel density, increased endothelial cell apoptosis, and worsened tissue hypoxia in the peri-infarct area at 7 days following reperfusion. Notably, Tie2-Cre, Fgfr1(f/f), Fgfr2(f/f) DCKO mice showed no impairment in the cardiac hypertrophic response. These data demonstrate an essential role for FGFR1 and FGFR2 in endothelial cells for cardiac functional recovery and vascular remodeling following in vivo cardiac ischemia-reperfusion injury, without affecting the cardiac hypertrophic response. This study suggests the potential for therapeutic benefit from activation of endothelial FGFR pathways following ischemic injury to the heart. Copyright © 2016 the American Physiological Society.

Non-specific factor enhancement of human in vitro antigen-dependent antibody synthesis: role of B cell activation and T cell help.

PubMed Central

Brenner, M K; North, M E; Chadda, H R; Farrant, J

1984-01-01

Lectin-free supernatants obtained from PWM-stimulated lymphocytes, enable B cells to proliferate and secrete immunoglobulin. Both functions are augmented by the addition of irradiated T cells. In the presence of antigen, these supernatants also enhance specific anti-tetanus toxoid antibody production. The components of the supernatant responsible for these activities have a molecular weight between 30,000 and 60,000, and have the characteristics of non-specific factors: they are genetically unrestricted, and do not bind to either antigen or anti-DR affinity columns. There is no evidence that the partial T dependency of these factors is an indication that their target is a T cell. Instead, T cells appear necessary to move the B cell into a state of activation in which it becomes responsive to the factor. Alternative activation signals such as Staph. A. Cowan can substitute for T cell help in the proliferative response, but not for immunoglobulin or antibody synthesis. The implications of these results for the approaches used to detect and classify B cell growth factors are discussed. PMID:6608488

Ocular Angiogenesis: Vascular Endothelial Growth Factor and Other Factors.

PubMed

Rubio, Roman G; Adamis, Anthony P

2016-01-01

Systematic study of the mechanisms underlying pathological ocular neovascularization has yielded a wealth of knowledge about pro- and anti-angiogenic factors that modulate diseases such as neovascular age-related macular degeneration. The evidence implicating vascular endothelial growth factor (VEGF) in particular has led to the development of a number of approved anti-VEGF therapies. Additional proangiogenic targets that have emerged as potential mediators of ocular neovascularization include hypoxia-inducible factor-1, angiopoietin-2, platelet-derived growth factor-B and components of the alternative complement pathway. As for VEGF, knowledge of these factors has led to a product pipeline of many more novel agents that are in various stages of clinical development in the setting of ocular neovascularization. These agents are represented by a range of drug classes and, in addition to novel small- and large-molecule VEGF inhibitors, include gene therapies, small interfering RNA agents and tyrosine kinase inhibitors. In addition, combination therapy is beginning to emerge as a strategy to improve the efficacy of individual therapies. Thus, a variety of agents, whether administered alone or as adjunctive therapy with agents targeting VEGF, offer the promise of expanding the range of treatments for ocular neovascular diseases. © 2016 S. Karger AG, Basel.

Expression of epidermal growth factor receptor and vascular endothelial growth factor in malignant canine epithelial nasal tumours.

PubMed

Shiomitsu, K; Johnson, C L; Malarkey, D E; Pruitt, A F; Thrall, D E

2009-06-01

Epidermal growth factor (EGF) and vascular endothelial growth factor (VEGF) signalling pathways play a role in carcinogenesis. Inhibition of EGF receptor (EGFR) and of VEGF is effective in increasing the radiation responsiveness of neoplastic cells both in vitro and in human trials. In this study, immunohistochemical evaluation was employed to determine and characterize the potential protein expression levels and patterns of EGFR and VEGF in a variety of canine malignant epithelial nasal tumours. Of 24 malignant canine nasal tumours, 13 (54.2%) were positive for EGFR staining and 22 (91.7%) were positive for VEGF staining. The intensity and percentage of immunohistochemically positive neoplastic cells for EGFR varied. These findings indicate that EGFR and VEGF proteins were present in some malignant epithelial nasal tumours in the dogs, and therefore, it may be beneficial to treat canine patients with tumours that overexpress EGFR and VEGF with specific inhibitors in conjunction with radiation.

Neutral Polymer Micelle Carriers with pH-Responsive, Endosome-Releasing Activity Modulate Antigen Trafficking to Enhance CD8 T-Cell Responses

PubMed Central

Keller, Salka; Wilson, John T; Patilea, Gabriela I; Kern, Hanna B; Convertine, Anthony J; Stayton, Patrick S

2014-01-01

Synthetic subunit vaccines need to induce CD8+ cytotoxic T-cell (CTL) responses for effective vaccination against intracellular pathogens. Most subunit vaccines primarily generate humoral immune responses, with a weaker than desired CD8+ cytotoxic T-cell response. Here, a neutral, pH-responsive polymer micelle carrier that alters intracellular antigen trafficking was shown to enhance CD8+ T-cell responses with a correlated increase in cytosolic delivery and a decrease in exocytosis. Polymer diblock carriers consisted of a N-(2-hydroxypropyl) methacrylamide corona block with pendant pyridyl disulfide groups for reversible conjugation of thiolated ovalbumin, and a tercopolymer ampholytic core-forming block composed of propylacrylic acid (PAA), dimethylaminoethyl methacrylate (DMAEMA), and butyl methacrylate (BMA). The diblock copolymers self-assembled into 25–30 nm diameter micellar nanoparticles. Conjugation of ovalbumin to the micelles significantly enhanced antigen cross-presentation in vitro relative to free ovalbumin, an unconjugated physical mixture of ovalbumin and polymer, and a non pH-responsive micelle-ovalbumin control. Mechanistic studies in a murine dendritic cell line (DC2.4) demonstrated micelle-mediated enhancements in intracellular antigen retention and cytosolic antigen accumulation. Approximately 90% of initially internalized ovalbumin-conjugated micelles were retained in cells after 1.5 h, compared to only ~40% for controls. Furthermore, cells dosed with conjugates displayed 67-fold higher cytosolic antigen levels relative to soluble ovalbumin 4 h post uptake. Subcutaneous immunization of mice with ovalbumin-polymer conjugates significantly enhanced antigen-specific CD8+ T cell responses (0.4 % IFN-γ+ of CD8+) compared to immunization with soluble protein, ovalbumin and polymer mixture, and the control micelle without endosome-releasing activity. Additionally, pH-responsive carrier facilitated antigen delivery to antigen presenting cells in the

Neutral polymer micelle carriers with pH-responsive, endosome-releasing activity modulate antigen trafficking to enhance CD8(+) T cell responses.

PubMed

Keller, Salka; Wilson, John T; Patilea, Gabriela I; Kern, Hanna B; Convertine, Anthony J; Stayton, Patrick S

2014-10-10

Synthetic subunit vaccines need to induce CD8(+) cytotoxic T cell (CTL) responses for effective vaccination against intracellular pathogens. Most subunit vaccines primarily generate humoral immune responses, with a weaker than desired CD8(+) cytotoxic T cell response. Here, a neutral, pH-responsive polymer micelle carrier that alters intracellular antigen trafficking was shown to enhance CD8(+) T cell responses with a correlated increase in cytosolic delivery and a decrease in exocytosis. Polymer diblock carriers consisted of a N-(2-hydroxypropyl) methacrylamide corona block with pendent pyridyl disulfide groups for reversible conjugation of thiolated ovalbumin, and a tercopolymer ampholytic core-forming block composed of propylacrylic acid (PAA), dimethylaminoethyl methacrylate (DMAEMA), and butyl methacrylate (BMA). The diblock copolymers self-assembled into 25-30nm diameter micellar nanoparticles. Conjugation of ovalbumin to the micelles significantly enhanced antigen cross-presentation in vitro relative to free ovalbumin, an unconjugated physical mixture of ovalbumin and polymer, and a non-pH-responsive micelle-ovalbumin control. Mechanistic studies in a murine dendritic cell line (DC 2.4) demonstrated micelle-mediated enhancements in intracellular antigen retention and cytosolic antigen accumulation. Approximately 90% of initially internalized ovalbumin-conjugated micelles were retained in cells after 1.5h, compared to only ~40% for controls. Furthermore, cells dosed with conjugates displayed 67-fold higher cytosolic antigen levels relative to soluble ovalbumin 4h post uptake. Subcutaneous immunization of mice with ovalbumin-polymer conjugates significantly enhanced antigen-specific CD8(+) T cell responses (0.4% IFN-γ(+) of CD8(+)) compared to immunization with soluble protein, ovalbumin and polymer mixture, and the control micelle without endosome-releasing activity. Additionally, pH-responsive carrier facilitated antigen delivery to antigen presenting cells

Vaccine antigens modulate the innate response of monocytes to Al(OH)3

PubMed Central

Brummelman, Jolanda; van Els, Cécile A. C. M.; Marino, Fabio; Heck, Albert J. R.; van Riet, Elly; Metz, Bernard; Kersten, Gideon F. A.; Pennings, Jeroen L. A.; Meiring, Hugo D.

2018-01-01

Aluminum-based adjuvants have widely been used in human vaccines since 1926. In the absence of antigens, aluminum-based adjuvants can initiate the inflammatory preparedness of innate cells, yet the impact of antigens on this response has not been investigated so far. In this study, we address the modulating effect of vaccine antigens on the monocyte-derived innate response by comparing processes initiated by Al(OH)3 and by Infanrix, an Al(OH)3-adjuvanted trivalent combination vaccine (DTaP), containing diphtheria toxoid (D), tetanus toxoid (T) and acellular pertussis (aP) vaccine antigens. A systems-wide analysis of stimulated monocytes was performed in which full proteome analysis was combined with targeted transcriptome analysis and cytokine analysis. This comprehensive study revealed four major differences in the monocyte response, between plain Al(OH)3 and DTaP stimulation conditions: (I) DTaP increased the anti-inflammatory cytokine IL-10, whereas Al(OH)3 did not; (II) Al(OH)3 increased the gene expression of IFNγ, IL-2 and IL-17a in contrast to the limited induction or even downregulation by DTaP; (III) increased expression of type I interferons-induced proteins was not observed upon DTaP stimulation, but was observed upon Al(OH)3 stimulation; (IV) opposing regulation of protein localization pathways was observed for Al(OH)3 and DTaP stimulation, related to the induction of exocytosis by Al(OH)3 alone. This study highlights that vaccine antigens can antagonize Al(OH)3-induced programming of the innate immune responses at the monocyte level. PMID:29813132

Soluble tissue factor has unique angiogenic activities that selectively promote migration and differentiation but not proliferation of endothelial cells

DOE Office of Scientific and Technical Information (OSTI.GOV)

He Yingbo; Chang Guodong; Zhan Shunli

2008-06-06

The level of circulating tissue factor (TF) is up-regulated in human angiogenesis-related malignancies. However, whether circulating TF has angiogenic activities has not been determined. Soluble TF (sTF) is the main domain of circulating TF. Here, using cell migration, wound healing, and tubule formation assays, human recombinant sTF was found to significantly promote the migration and differentiation of endothelial cells. The stress fiber formation and rearrangement induced by sTF observed through immunofluorescence microscope may be responsible for the stimulatory migration effect of sTF. Nevertheless, sTF had no effects on endothelial cell proliferation. Interestingly, sTF can be internalized by endothelial cells, whichmore » implies a novel mechanism for sTF in angiogenesis. These results suggest that sTF has unique angiogenic activities and may serve as a potential therapeutic target to treat diseases associated with angiogenesis such as cancer and rheumatoid arthritis.« less

Organizational behavior of human umbilical vein endothelial cells

PubMed Central

1982-01-01

Culture conditions that favor rapid multiplication of human umbilical vein endothelial cells (HUV-EC) also support long-term serial propagation of the cells. This is routinely achieved when HUV-EC are grown in Medium 199 (M-199) supplemented with fetal bovine serum (FBS) and endothelial cell growth factor (ECGF), on a human fibronectin (HFN) matrix. The HUV-EC can shift from a proliferative to an organized state when the in vitro conditions are changed from those favoring low density proliferation to those supporting high density survival. When ECGF and HFN are omitted, cultures fail to achieve confluence beyond the first or second passage: the preconfluent cultures organize into tubular structures after 4-6 wk. Some tubes become grossly visible and float in the culture medium, remaining tethered to the plastic dish at either end of the tube. On an ultrastructural level, the tubes consist of cells, held together by junctional complexes, arranged so as to form a lumen. The smallest lumens are formed by one cell folding over to form a junction with itself. The cells contain Weibel-Palade bodies and factor VIII-related antigen. The lumens contain granular, fibrillar and amorphous debris. Predigesting the HFN matrix with trypsin (10 min, 37 degrees C) or plasmin significantly accelerates tube formation. Thrombin and plasminogen activator had no apparent effect. Disruption of the largest tubes with trypsin/EDTA permits the cells to revert to a proliferative state if plated on HFN, in M-199, FBS, and ECGF. These observations indicate that culture conditions that do not favor proliferation permit attainment of a state of nonterminal differentiation (organization) by the endothelial cell. Furthermore, proteolytic modification of the HFN matrix may play an important role in endothelial organization. PMID:6813338

Characterization of an Adhesion Molecule that Mediates Leukocyte Rolling on 24 h Cytokine- or Lipopolysaccharide-stimulated Bovine Endothelial Cells under Flow Conditions

PubMed Central

Jutila, Mark A.; Wilson, Eric; Kurk, Sandy

1997-01-01

Bovine γ/δ T cells and neutrophils roll on 24 h cytokine- or lipopolysaccharide-stimulated bovine fetal umbilical cord endothelial cells in assays done under physiological flow. An antibody directed against E- and L-selectin has minimal blocking effect on this rolling interaction. mAbs were raised against the stimulated bovine endothelial cells and screened for inhibition of γ/δ T cell rolling. One mAb (GR113) was identified that recognizes an antigen (GR antigen) selectively expressed by stimulated bovine endothelial cells isolated from fetal umbilical cord, mesenteric lymph nodes, and aorta. GR113 blocked bovine γ/δ T cell as well as neutrophil rolling on the 24 h-activated endothelial cells. The GR antigen was constitutively expressed at low levels on the cell surface of platelets and its expression was not upregulated after stimulation of these cells with thrombin or phorbol myristate acetate. However, stimulated platelets released a soluble, functionally active form of the molecule that selectively bound in solution to γ/δ T cells in a mixed lymphocyte preparation. GR113 mAb blocked the binding of the soluble platelet molecule to the γ/δ T cells. Soluble GR antigen also bound a subset of human lymphocytes. Cutaneous lymphocyte-associated antigen (CLA) bright human lymphocytes exhibited the greatest capacity to bind the GR antigen, though CLA was not required for binding. Subsets of both human CD4 and CD8 T cells bound the GR antigen. Immunoprecipitation experiments showed the GR antigen to be 110-120 kD M r. The binding of soluble GR antigen was inhibited by EDTA and O-sialoglycoprotease, but not neuraminidase treatment of the target cells. PMID:9362530

Role of xanthine oxidoreductase and NAD(P)H oxidase in endothelial superoxide production in response to oscillatory shear stress

NASA Technical Reports Server (NTRS)

McNally, J. Scott; Davis, Michael E.; Giddens, Don P.; Saha, Aniket; Hwang, Jinah; Dikalov, Sergey; Jo, Hanjoong; Harrison, David G.

2003-01-01

Oscillatory shear stress occurs at sites of the circulation that are vulnerable to atherosclerosis. Because oxidative stress contributes to atherosclerosis, we sought to determine whether oscillatory shear stress increases endothelial production of reactive oxygen species and to define the enzymes responsible for this phenomenon. Bovine aortic endothelial cells were exposed to static, laminar (15 dyn/cm2), and oscillatory shear stress (+/-15 dyn/cm2). Oscillatory shear increased superoxide (O2.-) production by more than threefold over static and laminar conditions as detected using electron spin resonance (ESR). This increase in O2*- was inhibited by oxypurinol and culture of endothelial cells with tungsten but not by inhibitors of other enzymatic sources. Oxypurinol also prevented H2O2 production in response to oscillatory shear stress as measured by dichlorofluorescin diacetate and Amplex Red fluorescence. Xanthine-dependent O2*- production was increased in homogenates of endothelial cells exposed to oscillatory shear stress. This was associated with decreased xanthine dehydrogenase (XDH) protein levels and enzymatic activity resulting in an elevated ratio of xanthine oxidase (XO) to XDH. We also studied endothelial cells lacking the p47phox subunit of the NAD(P)H oxidase. These cells exhibited dramatically depressed O2*- production and had minimal XO protein and activity. Transfection of these cells with p47phox restored XO protein levels. Finally, in bovine aortic endothelial cells, prolonged inhibition of the NAD(P)H oxidase with apocynin decreased XO protein levels and prevented endothelial cell stimulation of O2*- production in response to oscillatory shear stress. These data suggest that the NAD(P)H oxidase maintains endothelial cell XO levels and that XO is responsible for increased reactive oxygen species production in response to oscillatory shear stress.

An Investigation of the Memory Response of the Local Immune System to Shigella Antigens.

DTIC Science & Technology

1985-12-31

kAD-A±75 215 AN INVESTIOATION OF THE MEMORY RESPONSE OF THE LOCAL L/1 I IMMUNE SYSTEM TO SHIGELLA ANTIGENS(U) MICHIGAN UNIV ANN I RBOR D F KEREN 31...IMMUNE SYSTEM TO SHIGELLA ANTIGENS ANNUAL REPORT DAVID F. KEREN, M.D. DECEMBER 31, 1985 FOR THE PERIOD DECEMBER 1, 1984 - NOVEMBER 30, 1985 SUPPORTED...Security Classification) An Investigation of the Memory Response of the Local Immune System to Shigella Antigens 12 PERSONAL AUTHOR(S) Keren, David F

Crosstalk between reticular adherens junctions and platelet endothelial cell adhesion molecule-1 regulates endothelial barrier function.

PubMed

Fernández-Martín, Laura; Marcos-Ramiro, Beatriz; Bigarella, Carolina L; Graupera, Mariona; Cain, Robert J; Reglero-Real, Natalia; Jiménez, Anaïs; Cernuda-Morollón, Eva; Correas, Isabel; Cox, Susan; Ridley, Anne J; Millán, Jaime

2012-08-01

Endothelial cells provide a barrier between the blood and tissues, which is reduced during inflammation to allow selective passage of molecules and cells. Adherens junctions (AJ) play a central role in regulating this barrier. We aim to investigate the role of a distinctive 3-dimensional reticular network of AJ found in the endothelium. In endothelial AJ, vascular endothelial-cadherin recruits the cytoplasmic proteins β-catenin and p120-catenin. β-catenin binds to α-catenin, which links AJ to actin filaments. AJ are usually described as linear structures along the actin-rich intercellular contacts. Here, we show that these AJ components can also be organized in reticular domains that contain low levels of actin. Reticular AJ are localized in areas where neighboring cells overlap and encompass the cell adhesion receptor platelet endothelial cell adhesion molecule-1 (PECAM-1). Superresolution microscopy revealed that PECAM-1 forms discrete structures distinct from and distributed along AJ, within the voids of reticular domains. Inflammatory tumor necrosis factor-α increases permeability by mechanisms that are independent of actomyosin-mediated tension and remain incompletely understood. Reticular AJ, but not actin-rich linear AJ, were disorganized by tumor necrosis factor-α. This correlated with PECAM-1 dispersal from cell borders. PECAM-1 inhibition with blocking antibodies or small interfering RNA specifically disrupted reticular AJ, leaving linear AJ intact. This disruption recapitulated typical tumor necrosis factor-α-induced alterations of barrier function, including increased β-catenin phosphorylation, without altering the actomyosin cytoskeleton. We propose that reticular AJ act coordinately with PECAM-1 to maintain endothelial barrier function in regions of low actomyosin-mediated tension. Selective disruption of reticular AJ contributes to permeability increase in response to tumor necrosis factor-α.

Correlates of endothelial function and the peak systolic blood pressure response to a graded maximal exercise test.

PubMed

Olson, Kayla M; Augeri, Amanda L; Seip, Richard L; Tsongalis, Gregory J; Thompson, Paul D; Pescatello, Linda S

2012-05-01

An elevated systolic blood pressure (SBP) response to a graded maximal exercise stress test (GEST) may be a predictor of endothelial dysfunction and hypertension. We examined relationships among the GEST peak SBP response and indicators of endothelial function. Men (n=48, 43.7±1.4 yr) with high BP (145.1±1.5/85.5±1.1 mmHg) completed a GEST. Peak SBP was the highest SBP achieved during the GEST. Blood samples were taken for fasting glucose and insulin, nitric oxide (NO), and DNA. Endothelial nitric oxide synthase (NOS3, rs2070744) -786 T>C genotyping was determined by PCR. NOS3 genotypes were combined using a dominant model [TT (n=24); TC/CC (n=24)]. Brachial artery reactivity (BAR) was determined via ultrasound before, 1 min, and 3 min post occlusion and calculated as % change. Analysis of variance (ANOVA) tested changes in the peak SBP GEST response by NOS3 genotype. Multiple variable regression analyses examined relationships among the GEST peak SBP response and measures of endothelial function. %BAR change at 1 min (r(2)=0.093, p=0.020), glucose (r(2)=0.062, p=0.014), NOS3 -786 T>C (r(2)=0.040, p=0.024), NO (r(2)=0.037, p=0.064), and age (r(2)=0.009, p=0.014) explained 24.1% of the GEST peak SBP response (p=0.043). The GEST peak SBP change from baseline was 11.1±5.0 mmHg higher among those with the NOS3 C allele (92.4 mmHg+3.8) than the NOS3 TT genotype (81.3 mmHg+3.2) (p=0.03). Indicators of endothelial function appear to explain a clinically significant portion of the GEST peak SBP response. Further investigation is needed to unravel the mechanisms by which endothelial function influences the GEST peak SBP response. Published by Elsevier Ireland Ltd.

Central Role of eNOS in the Maintenance of Endothelial Homeostasis

PubMed Central

Rodriguez-Mateos, Ana; Kelm, Malte

2015-01-01

Abstract Significance: Disruption of endothelial function is considered a key event in the development and progression of atherosclerosis. Endothelial nitric oxide synthase (eNOS) is a central regulator of cellular function that is important to maintain endothelial homeostasis. Recent Advances: Endothelial homeostasis encompasses acute responses such as adaption of flow to tissue's demand and more sustained responses to injury such as re-endothelialization and sprouting of endothelial cells (ECs) and attraction of circulating angiogenic cells (CAC), both of which support repair of damaged endothelium. The balance and the intensity of endothelial damage and repair might be reflected by changes in circulating endothelial microparticles (EMP) and CAC. Flow-mediated vasodilation (FMD) is a generally accepted clinical read-out of NO-dependent vasodilation, whereas EMP are upcoming prognostically validated markers of endothelial injury and CAC are reflective of the regenerative capacity with both expressing a functional eNOS. These markers can be integrated in a clinical endothelial phenotype, reflecting the net result between damage from risk factors and endogenous repair capacity with NO representing a central signaling molecule. Critical Issues: Improvements of reproducibility and observer independence of FMD measurements and definitions of relevant EMP and CAC subpopulations warrant further research. Future Directions: Endothelial homeostasis may be a clinical therapeutic target for cardiovascular health maintenance. Antioxid. Redox Signal. 22, 1230–1242. PMID:25330054

Isolated tumor endothelial cells maintain specific character during long-term culture

DOE Office of Scientific and Technical Information (OSTI.GOV)

Matsuda, Kohei; Oral Pathology and Biology, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586; Oral and Maxillofacial Surgery, Hokkaido University Graduate School of Dental Medicine, N13 W7, Kita-ku, Sapporo 060-8586

Tumor angiogenesis is necessary for solid tumor progression and metastasis. Increasing evidence indicates that tumor endothelial cells (TECs) are more relevant to the study of tumor angiogenesis than normal endothelial cells (NECs) because their morphologies and gene expression are different from NECs. However, it is challenging to isolate and culture large numbers of pure ECs from tumor tissue since the percentage of ECs is only about 1-2% and tumor cells and fibroblasts easily overgrow them. In addition, there has been concern that isolated TECs may lose their special phenotype once they are dissociated from tumor cells. In this study, wemore » have successfully purified murine TECs from four different human tumor xenografts and NECs from murine dermal tissue. Isolated ECs expressed endothelial markers, such as CD31, VE-cadherin (CD144), and endoglin (CD105), for more than 3 months after isolation. TECs maintained tumor endothelial-specific markers, such as tumor endothelial marker 8 (TEM8) and aminopeptidase N (APN), as in tumor blood vessels in vivo. In addition, TECs were more proliferative and motile than NECs. TECs showed a higher response to VEGF and higher expression of VEGF receptors-1 and -2 than NECs did. Stem cell antigen-1 was up-regulated in all four TECs, suggesting that they have a kind of stemness. Cultured TECs maintain distinct biological differences from NECs as in vivo. In conclusion, it was suggested that TECs are relevant material for tumor angiogenesis research.« less

(-)-7(S)-hydroxymatairesinol protects against tumor necrosis factor-α-mediated inflammation response in endothelial cells by blocking the MAPK/NF-κB and activating Nrf2/HO-1.

PubMed

Yang, Di; Xiao, Chen-Xi; Su, Zheng-Hua; Huang, Meng-Wei; Qin, Ming; Wu, Wei-Jun; Jia, Wan-Wan; Zhu, Yi-Zhun; Hu, Jin-Feng; Liu, Xin-Hua

2017-08-15

Endothelial inflammation is an increasingly prevalent condition in the pathogenesis of many cardiovascular diseases. (-)-7(S)-hydroxymatairesinol (7-HMR), a naturally occurring plant lignan, possesses both antioxidant and anti-cancer properties and therefore would be a good strategy to suppress tumor necrosis factor-α (TNF-α)-mediated inflammation in vascular endothelial cells (VECs). The objective of this study is to evaluate for its anti-inflammatory effect on TNF-α-stimulated VECs and underling mechanisms. The effect of the 7-HMR on suppression of TNF-α-induced inflammation mediators in VECs were determined by qRT-PCR and Western blot. MAPKs and phosphorylation of Akt, HO-1 and NF-κB p65 were examined using Western blot. Nuclear localisation of NF-κB was also examined using Western blot and immunofluorescence. Here we found that 7-HMR could suppress TNF-α-induced inflammatory mediators, such as vascularcelladhesion molecule-1, interleukin-6 and inducible nitric oxide synthase expression both in mRNA and protein levels, and concentration-dependently attenuated reactive oxidase species generation. We further identified that 7-HMR remarkably induced superoxide dismutase and heme oxygenase-1 expression associated with degradation of Kelch-like ECH-associated protein 1 (keap1) and up-regulated nuclear factor erythroid 2-related factor 2 (Nrf2). In addition, 7-HMR time- and concentration-dependently attenuated TNF-α-induced phosphorylation of extracellular signal-regulated kinase 1/2 (ERK) and Akt, but not p38, or c-Jun N-terminal kinase 1/2. Moreover, 7-HMR significantly suppressed TNF-α-mediated nuclear factor-κB (NF-κB) activation by inhibiting phosphorylation and nuclear translocation of NF-κB p65. Our results demonstrated that 7-HMR inhibited TNF-α-stimulated endothelial inflammation, at least in part, through inhibition of NF-κB activation and upregulation of Nrf2-antioxidant response element signaling pathway, suggesting 7-HMR might be used as a

Tissue Factor Inflammatory Response Regulated by Promoter Genotype and p38 MAPK in Neonatal vs. Adult Microvascular Endothelial Cells

PubMed Central

Buzby, Jeffrey S.; Williams, Shirley A.; Imfeld, Karen L.; Kunicki, Thomas J.; Nugent, Diane J.

2014-01-01

Objective and design Variable tissue factor (TF) expression by human microvascular endothelial cells (HMVEC) may be regulated by two promoter haplotypes, distinguished by an 18 base pair deletion (D) or insertion (I) at -1208. We sought to determine the relationship between these haplotypes and interleukin-1 (IL-1α)-induced TF expression in neonatal versus adult HMVEC. Results IL-1-stimulated TF mRNA, protein, and activity were significantly higher in neonatal compared to adult D/D donors. IL-1-stimulated HMVEC from neonatal D/D donors expressed 3-fold higher levels of TF mRNA, 2-fold higher TF protein, and 4-fold increased TF activity compared to HMVEC from adult D/D donors. These results indicate that homozygosity for the D haplotype is characterized by increased response to IL-1 in neonates but not adults. IL-1 induced increased phosphorylation of p38 mitogen-activated protein kinase (MAPK), which was significantly greater in neonatal compared to adult HMVEC. Moreover, inhibition of the p38 MAPK pathway reduced IL-1-stimulated TF mRNA expression in D/D neonatal but not adult HMVEC. Conclusions Up-regulation of D/D neonatal HMVEC TF expression by IL-1 is mediated through the p38 MAPK pathway. This heightened response of D/D neonatal HMVEC to inflammatory stimuli may contribute to increased microvascular coagulopathies in susceptible newborn infants. PMID:24385191

Endothelial MMP14 is required for endothelial-dependent growth support of human airway basal cells

PubMed Central

Ding, Bi-Sen; Gomi, Kazunori; Rafii, Shahin; Crystal, Ronald G.; Walters, Matthew S.

2015-01-01

ABSTRACT Human airway basal cells are the stem (or progenitor) population of the airway epithelium, and play a central role in anchoring the epithelium to the basement membrane. The anatomic position of basal cells allows for potential paracrine signaling between them and the underlying non-epithelial stromal cells. In support of this, we have previously demonstrated that endothelial cells support growth of basal cells during co-culture through vascular endothelial growth factor A (VEGFA)-mediated signaling. Building on these findings, we found, by RNA sequencing analysis, that basal cells expressed multiple fibroblast growth factor (FGF) ligands (FGF2, FGF5, FGF11 and FGF13) and that only FGF2 and FGF5 were capable of functioning in a paracrine manner to activate classical FGF receptor (FGFR) signaling. Antibody-mediated blocking of FGFR1 during basal-cell–endothelial-cell co-culture significantly reduced the endothelial-cell-dependent basal cell growth. Stimulation of endothelial cells with basal-cell-derived growth factors induced endothelial cell expression of matrix metallopeptidase 14 (MMP14), and short hairpin RNA (shRNA)-mediated knockdown of endothelial cell MMP14 significantly reduced the endothelial-cell-dependent growth of basal cells. Overall, these data characterize a new growth-factor-mediated reciprocal ‘crosstalk’ between human airway basal cells and endothelial cells that regulates proliferation of basal cells. PMID:26116571

Connective tissue growth factor linked to the E7 tumor antigen generates potent antitumor immune responses mediated by an antiapoptotic mechanism.

PubMed

Cheng, W-F; Chang, M-C; Sun, W-Z; Lee, C-N; Lin, H-W; Su, Y-N; Hsieh, C-Y; Chen, C-A

2008-07-01

A novel method for generating an antigen-specific cancer vaccine and immunotherapy has emerged using a DNA vaccine. However, antigen-presenting cells (APCs) have a limited life span, which hinders their long-term ability to prime antigen-specific T cells. Connective tissue growth factor (CTGF) has a role in cell survival. This study explored the intradermal administration of DNA encoding CTGF with a model tumor antigen, human papilloma virus type 16 E7. Mice vaccinated with CTGF/E7 DNA exhibited a dramatic increase in E7-specific CD4(+) and CD8(+) T-cell precursors. They also showed an impressive antitumor effect against E7-expressing tumors compared with mice vaccinated with the wild-type E7 DNA. The delivery of DNA encoding CTGF and E7 or CTGF alone could prolong the survival of transduced dendritic cells (DCs) in vivo. In addition, CTGF/E7-transduced DCs could enhance a higher number of E7-specific CD8(+) T cells than E7-transduced DCs. By prolonging the survival of APCs, DNA vaccine encoding CTGF linked to a tumor antigen represents an innovative approach to enhance DNA vaccine potency and holds promise for cancer prophylaxis and immunotherapy.

The Effect of Levonorgestrel on Fibrinolytic Factors in Human Endometrial Endothelial Cells.

PubMed

Pakrashi, Tarita; Taylor, Joelle E; Nelson, Ashley; Archer, David F; Jacot, Terry

2016-11-01

The levonorgestrel-releasing intrauterine system is considered a highly effective treatment of heavy menstrual bleeding (HMB). While LNG has established effects on the stromal and glandular compartments of the endometrial tissue, its effect on the endometrial endothelial cells has not been investigated. We examined whether LNG regulates fibrinolytic factors, tissue plasminogen activator (tPA), and urokinase plasminogen activator (uPA) secreted by human endometrial endothelial cells (HEECs) and determined the steroid receptor through which LNG exerts its effect on the endothelium. The HEECs were treated with LNG or progesterone and levels of tPA and plasminogen activator inhibitor 1 (PAI-1) measured. The HEECs were specifically examined for the presence of androgen receptors through Western blot. Levonorgestrel ± flutamide were added to HEECs and the levels of tPA and uPA were examined. An enzyme-linked immunosorbent assay performed on culture media confirmed a statistically significant decrease in tPA levels in cells treated with LNG (77.80% ± 8.0% of control; n = 5, P < .05 vs control) but not progesterone. The androgen receptor (110 kDa) was detected in HEEC lysates. The decrease in tPA was blocked by the addition of flutamide (101.3% ± 16% of control), a classic nonsteroidal androgen receptor blocker. There was no change in uPA or PAI-1 levels in cells treated with LNG. Levonorgestrel decreases tPA levels through the androgen receptor in HEECs. Thus, LNG inhibits tPA secretion by the endometrial endothelial cell. This response suggests reduction in HMB with LNG-IUS could reflect an LNG-mediated promotion of hemostasis. © The Author(s) 2016.

Guanylyl cyclase-dependent chemotaxis of endothelial cells in response to nitric oxide gradients.

PubMed

Isenberg, Jeff S; Ridnour, Lisa A; Thomas, Douglas D; Wink, David A; Roberts, David D; Espey, Michael Graham

2006-03-15

Nitric oxide (NO) is an important regulator of angiogenesis and neovascularization. The nature of endothelial cell motility responses to NO was examined using a Boyden chamber method. NO generated via decomposition of either DEA/NO or DETA/NO produced increases in human umbilical vein endothelial cell (HUVEC) chemotaxis, which were completely abrogated by ODQ, a soluble guanylyl cyclase inhibitor. Measurements of NO either directly by chemiluminescence or its chemistry with diaminofluorescein revealed that chemotaxis was driven by subtle NO gradients between the lower and the upper wells in this system. In addition to diffusion and volatilization from the upper chambers, the data showed that HUVEC consumption of NO contributed to these sustained gradients. Comparison of DEA/NO- and DETA/NO-mediated responses suggested that the persistence of spatial NO gradients is as significant as the absolute magnitude of NO exposure per unit time. The findings suggest that subnanomolar NO gradients are sufficient to mobilize endothelial cell migration into hypoxic tissue during neovascularization events, such as in wound healing and cancer.

Immunotherapy for Prostate Cancer: Lessons from Responses to Tumor-Associated Antigens

PubMed Central

Westdorp, Harm; Sköld, Annette E.; Snijer, Berit A.; Franik, Sebastian; Mulder, Sasja F.; Major, Pierre P.; Foley, Ronan; Gerritsen, Winald R.; de Vries, I. Jolanda M.

2014-01-01

Prostate cancer (PCa) is the most common cancer in men and the second most common cause of cancer-related death in men. In recent years, novel therapeutic options for PCa have been developed and studied extensively in clinical trials. Sipuleucel-T is the first cell-based immunotherapeutic vaccine for treatment of cancer. This vaccine consists of autologous mononuclear cells stimulated and loaded with an immunostimulatory fusion protein containing the prostate tumor antigen prostate acid posphatase. The choice of antigen might be key for the efficiency of cell-based immunotherapy. Depending on the treatment strategy, target antigens should be immunogenic, abundantly expressed by tumor cells, and preferably functionally important for the tumor to prevent loss of antigen expression. Autoimmune responses have been reported against several antigens expressed in the prostate, indicating that PCa is a suitable target for immunotherapy. In this review, we will discuss PCa antigens that exhibit immunogenic features and/or have been targeted in immunotherapeutic settings with promising results, and we highlight the hurdles and opportunities for cancer immunotherapy. PMID:24834066

The procyanidin-induced pseudo laminar shear stress response: a new concept for the reversal of endothelial dysfunction.

PubMed

Corder, Roger; Warburton, Richard C; Khan, Noorafza Q; Brown, Ruth E; Wood, Elizabeth G; Lees, Delphine M

2004-11-01

Reduced endothelium-dependent vasodilator responses with increased synthesis of ET-1 (endothelin-1) are characteristics of endothelial dysfunction in heart failure and are predictive of mortality. Identification of treatments that correct these abnormalities may have particular benefit for patients who become refractory to current regimens. Hawthorn preparations have a long history in the treatment of heart failure. Therefore we tested their inhibitory effects on ET-1 synthesis by cultured endothelial cells. These actions were compared with that of GSE (grape seed extract), as the vasoactive components of both these herbal remedies are mainly oligomeric flavan-3-ols called procyanidins. This showed extracts of hawthorn and grape seed were equipotent as inhibitors of ET-1 synthesis. GSE also produced a potent endothelium-dependent vasodilator response on preparations of isolated aorta. Suppression of ET-1 synthesis at the same time as induction of endothelium-dependent vasodilation is a similar response to that triggered by laminar shear stress. Based on these results and previous findings, we hypothesize that through their pharmacological properties procyanidins stimulate a pseudo laminar shear stress response in endothelial cells, which helps restore endothelial function and underlies the benefit from treatment with hawthorn extract in heart failure.

Vascular endothelial growth factor and platelet-derived growth factor are potential angiogenic and metastatic factors in human breast cancer.

PubMed

Anan, K; Morisaki, T; Katano, M; Ikubo, A; Kitsuki, H; Uchiyama, A; Kuroki, S; Tanaka, M; Torisu, M

1996-03-01

Angiogenesis is a prerequisite for tumor growth and metastasis. Tumor angiogenesis may be mediated by several angiogenic factors such as vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), transforming growth factor-alpha, and basic fibroblast growth factor. Differential mRNA expressions of VEGF, PDGF (A chain), transforming growth factor-alpha and basic fibroblast growth factor in 32 primary invasive breast tumors were examined by reverse transcriptase-polymerase chain reaction. We analyzed relationships between mRNA expressions of these angiogenic factors and the degree of angiogenesis, tumor size, and metastasis. Quantification of angiogenesis was achieved by the immunohistochemical staining of endothelial cells with antibody to CD31. VEGF and PDGF-A mRNAs were expressed more frequently in breast tumors than in nontumor breast tissues, whereas no difference was found in expression frequency of either transforming growth factor-alpha or basic fibroblast growth factor mRNA. Vascular counts in tumors correlated with each expression frequency of VEGF and PDGF-A mRNA. PDGF-A mRNA was expressed more frequently in tumors with lymph node metastasis than in those without metastasis. Expression of VEGF and PDGF mRNAs detected by reverse transcriptase-polymerase chain reaction in breast tumors correlates with tumor-related characteristics of angiogenesis and metastatic potential. Analysis of these mRNAs by reverse transcriptase-polymerase chain reaction may be useful for assessing the biologic behavior of a breast tumor before surgical treatment.

Endothelial Cell Implantation and Survival within Experimental Gliomas

NASA Astrophysics Data System (ADS)

Lal, Bachchu; Indurti, Ravi R.; Couraud, Pierre-Olivier; Goldstein, Gary W.; Laterra, John

1994-10-01

The delivery of therapeutic genes to primary brain neoplasms opens new opportunities for treating these frequently fatal tumors. Efficient gene delivery to tissues remains an important obstacle to therapy, and this problem has unique characteristics in brain tumors due to the blood-brain and blood-tumor barriers. The presence of endothelial mitogens and vessel proliferation within solid tumors suggests that genetically modified endothelial cells might efficiently transplant to brain tumors. Rat brain endothelial cells immortalized with the adenovirus E1A gene and further modified to express the β-galactosidase reporter were examined for their ability to survive implantation to experimental rat gliomas. Rats received 9L, F98, or C6 glioma cells in combination with endothelial cells intracranially to caudate/putamen or subcutaneously to flank. Implanted endothelial cells were identified by β-galactosidase histochemistry or by polymerase chain reaction in all tumors up to 35 days postimplantation, the latest time examined. Implanted endothelial cells appeared to cooperate in tumor vessel formation and expressed the brain-specific endothelial glucose transporter type 1 as identified by immunohistochemistry. The proliferation of implanted endothelial cells was supported by their increased number within tumors between postimplantation days 14 and 21 (P = 0.015) and by their expression of the proliferation antigen Ki67. These findings establish that genetically modified endothelial cells can be stably engrafted to growing gliomas and suggest that endothelial cell implantation may provide a means of delivering therapeutic genes to brain neoplasms and other solid tumors. In addition, endothelial implantation to brain may be useful for defining mechanisms of brain-specific endothelial differentiation.

Antigen-Specific Interferon-Gamma Responses and Innate Cytokine Balance in TB-IRIS

PubMed Central

Goovaerts, Odin; Jennes, Wim; Massinga-Loembé, Marguerite; Ceulemans, Ann; Worodria, William; Mayanja-Kizza, Harriet; Colebunders, Robert; Kestens, Luc

2014-01-01

Background Tuberculosis-associated immune reconstitution inflammatory syndrome (TB-IRIS) remains a poorly understood complication in HIV-TB patients receiving antiretroviral therapy (ART). TB-IRIS could be associated with an exaggerated immune response to TB-antigens. We compared the recovery of IFNγ responses to recall and TB-antigens and explored in vitro innate cytokine production in TB-IRIS patients. Methods In a prospective cohort study of HIV-TB co-infected patients treated for TB before ART initiation, we compared 18 patients who developed TB-IRIS with 18 non-IRIS controls matched for age, sex and CD4 count. We analyzed IFNγ ELISpot responses to CMV, influenza, TB and LPS before ART and during TB-IRIS. CMV and LPS stimulated ELISpot supernatants were subsequently evaluated for production of IL-12p70, IL-6, TNFα and IL-10 by Luminex. Results Before ART, all responses were similar between TB-IRIS patients and non-IRIS controls. During TB-IRIS, IFNγ responses to TB and influenza antigens were comparable between TB-IRIS patients and non-IRIS controls, but responses to CMV and LPS remained significantly lower in TB-IRIS patients. Production of innate cytokines was similar between TB-IRIS patients and non-IRIS controls. However, upon LPS stimulation, IL-6/IL-10 and TNFα/IL-10 ratios were increased in TB-IRIS patients compared to non-IRIS controls. Conclusion TB-IRIS patients did not display excessive IFNγ responses to TB-antigens. In contrast, the reconstitution of CMV and LPS responses was delayed in the TB-IRIS group. For LPS, this was linked with a pro-inflammatory shift in the innate cytokine balance. These data are in support of a prominent role of the innate immune system in TB-IRIS. PMID:25415590

Humoral Responses to Diverse Autoimmune Disease-Associated Antigens in Multiple Sclerosis.

PubMed

Malyavantham, Kishore; Weinstock-Guttman, Bianca; Suresh, Lakshmanan; Zivadinov, Robert; Shanahan, Thomas; Badgett, Darlene; Ramanathan, Murali

2015-01-01

To compare frequencies of autoreactive antibody responses to endogenous disease-associated antigens in healthy controls (HC), relapsing and progressive MS and to assess their associations with clinical and MRI measures of MS disease progression. The study analyzed 969 serum samples from 315 HC, 411 relapsing remitting MS (RR-MS), 128 secondary progressive MS (SP-MS), 33 primary progressive MS (PP-MS) and 82 patients with other neurological diseases for autoantibodies against two putative MS antigens CSF114(Glc) and KIR4.1a and KIR4.1b and against 24 key endogenous antigens linked to diseases such as vasculitis, systemic sclerosis, rheumatoid arthritis, Sjogren's syndrome, systemic lupus erythematosus, polymyositis, scleroderma, polymyositis, dermatomyositis, mixed connective tissue disease and primary biliary cirrhosis. Associations with disability and MRI measures of lesional injury and neurodegeneration were assessed. The frequencies of anti-KIR4.1a and anti-KIR4.1b peptide IgG positivity were 9.8% and 11.4% in HC compared to 4.9% and 7.5% in RR-MS, 8.6% for both peptides in SP-MS and 6.1% for both peptides in PP-MS (p = 0.13 for KIR4.1a and p = 0.34 for KIR4.1b), respectively. Antibodies against CSF114(Glc), KIR4.1a and KIR4.1b peptides were not associated with MS compared to HC, or with MS disease progression. HLA DRB1*15:01 positivity and anti-Epstein Barr virus antibodies, which are MS risk factors, were not associated with these putative MS antibodies. Antibody responses to KIR4.1a and KIR4.1b peptides are not increased in MS compared to HC nor associated with MS disease progression. The frequencies of the diverse autoreactive antibodies investigated are similar in MS and HC.

Characterization of the Apa antigen from M. avium subsp. paratuberculosis: a conserved Mycobacterium antigen that elicits a strong humoral response in cattle.

PubMed

Gioffré, A; Echeverría-Valencia, G; Arese, A; Morsella, C; Garbaccio, S; Delgado, F; Zumárraga, M; Paolicchi, F; Cataldi, A; Romano, M I

2009-12-15

Johne's disease or paratuberculosis is widespread in almost all countries and remains difficult to eradicate. Nowadays, diagnosis of Mycobacterium avium subsp. paratuberculosis (MPTB) infection is one of the main concerns. In this work, we evaluated the expression, biochemical properties and antigenicity of the Apa antigen, encoded by the gene annotated as MAP1569, in the MPTB genome. We confirmed its expression in MPTB and its glycosylation by the ConA binding assay. Although the MPTB-Apa is not an immunodominant antigen, MPTB-infected cattle showed a strong humoral response to recombinant Apa by Western blot and ELISA. Milk was also a suitable sample to be tested by ELISA. We comparatively analysed the humoral cross-reactivity to the Apa from MPTB (MPTB-Apa) and the orthologue from Mycobacterium tuberculosis (MT-Apa, identical to that from Mycobacterium bovis) in both infected and control cows. Response of M. bovis- and MPTB-infected animals against MT-Apa was similar (P=0.6985) but the response of the M. bovis-infected ones to MPTB-Apa was differential, being significantly diminished (P<0.0001). Although 6 out 45 animals from MPTB-infected herds responded to MPTB-Apa stimulation in the IFNgamma release assay, we found no significant differences when compared infected herds with non-infected ones (P=0.34). This antigen, in contrast to bovine Purified Protein Derivative (PPDb), was strongly represented in avian PPD (PPDa), as shown by the recognition of BALB/c mice hyperimmune sera against MPTB-Apa by Dot-blot immunoassay. We therefore demonstrated the antigenicity of Apa in MPTB-infected animals and a differential response to the recombinant antigen when compared to M. bovis-infected animals. These traits herein described, added to the usefulness of milk samples to detect IgG anti-Apa, could be important for routine screening in dairy cattle, considering a multiantigenic approach to overcome the lack of immunodominance.

Vascular endothelial growth factor modified macrophages transdifferentiate into endothelial-like cells and decrease foam cell formation.

PubMed

Yan, Dan; He, Yujuan; Dai, Jun; Yang, Lili; Wang, Xiaoyan; Ruan, Qiurong

2017-06-30

Macrophages are largely involved in the whole process of atherosclerosis from an initiation lesion to an advanced lesion. Endothelial disruption is the initial step and macrophage-derived foam cells are the hallmark of atherosclerosis. Promotion of vascular integrity and inhibition of foam cell formation are two important strategies for preventing atherosclerosis. How can we inhibit even the reverse negative role of macrophages in atherosclerosis? The present study was performed to investigate if overexpressing endogenous human vascular endothelial growth factor (VEGF) could facilitate transdifferentiation of macrophages into endothelial-like cells (ELCs) and inhibit foam cell formation. We demonstrated that VEGF-modified macrophages which stably overexpressed human VEGF (hVEGF 165 ) displayed a high capability to alter their phenotype and function into ELCs in vitro Exogenous VEGF could not replace endogenous VEGF to induce the transdifferentiation of macrophages into ELCs in vitro We further showed that VEGF-modified macrophages significantly decreased cytoplasmic lipid accumulation after treatment with oxidized LDL (ox-LDL). Moreover, down-regulation of CD36 expression in these cells was probably one of the mechanisms of reduction in foam cell formation. Our results provided the in vitro proof of VEGF-modified macrophages as atheroprotective therapeutic cells by both promotion of vascular repair and inhibition of foam cell formation. © 2017 The Author(s).

Proteomic Profiling of Serological Responses to Aspergillus fumigatus Antigens in Patients with Invasive Aspergillosis.

PubMed

Teutschbein, Janka; Simon, Svenja; Lother, Jasmin; Springer, Jan; Hortschansky, Peter; Morton, C Oliver; Löffler, Jürgen; Einsele, Hermann; Conneally, Eibhlin; Rogers, Thomas R; Guthke, Reinhard; Brakhage, Axel A; Kniemeyer, Olaf

2016-05-06

Aspergillus fumigatus is the species that most commonly causes the opportunistic infection invasive aspergillosis (IA) in patients being treated for hematological malignancies. Little is known about the A. fumigatus proteins that trigger the production of Aspergillus-specific IgG antibodies during the course of IA. To characterize the serological response to A. fumigatus protein antigens, mycelial proteins were separated by 2-D gel electrophoresis. The gels were immunoblotted with sera from patients with probable and proven IA and control patients without IA. We identified 49 different fungal proteins, which gave a positive IgG antibody signal. Most of these antigens play a role in primary metabolism and stress responses. Overall, our analysis identified 18 novel protein antigens from A. fumigatus. To determine whether these antigens can be used as diagnostic or prognostic markers or exhibit a protective activity, we employed supervised machine learning with decision trees. We identified two candidates for further analysis, the protein antigens CpcB and Shm2. Heterologously produced Shm2 induced a strongly proinflammatory response in human peripheral blood mononuclear cells after in vitro stimulation. In contrast, CpcB did not activate the immune response of PBMCs. These findings could serve as the basis for the development of an immunotherapy of IA.

Serological responses to Cryptosporidium antigens in inhabitants of Hungary using conventionally filtered surface water and riverbank filtered drinking water.

PubMed

Farkas, K; Plutzer, J; Moltchanova, E; Török, A; Varró, M J; Domokos, K; Frost, F; Hunter, P R

2015-10-01

In this study the putative protective seroprevalence (PPS) of IgG antibodies to the 27-kDa and 15/17-kDa Cryptosporidium antigens in sera of healthy participants who were and were not exposed to Cryptosporidium oocysts via surface water-derived drinking water was compared. The participants completed a questionnaire regarding risk factors that have been shown to be associated with infection. The PPS was significantly greater (49-61%) in settlements where the drinking water originated from surface water, than in the control city where riverbank filtration was used (21% and 23%). Logistic regression analysis on the risk factors showed an association between bathing/swimming in outdoor pools and antibody responses to the 15/17-kDa antigen complex. Hence the elevated responses were most likely due to the use of contaminated water. Results indicate that waterborne Cryptosporidium infections occur more frequently than reported but may derive from multiple sources.

Factor VIII-associated antigen in human lymphatic endothelium.

PubMed

Nagle, R B; Witte, M H; Martinez, A P; Witte, C L; Hendrix, M J; Way, D; Reed, K

1987-03-01

Lymphatic vascular endothelium both on tissue section and in culture exhibits positivity for Factor VIII-associated antigen although staining is generally less intense and more spotty than in comparable blood vascular endothelium. Lymphatic endothelium also exhibits Weibel-Palade bodies. Neither marker, therefore, reliably distinguishes blood vascular endothelium from lymphatic endothelium.

Functional characterization of human pluripotent stem cell-derived arterial endothelial cells.

PubMed

Zhang, Jue; Chu, Li-Fang; Hou, Zhonggang; Schwartz, Michael P; Hacker, Timothy; Vickerman, Vernella; Swanson, Scott; Leng, Ning; Nguyen, Bao Kim; Elwell, Angela; Bolin, Jennifer; Brown, Matthew E; Stewart, Ron; Burlingham, William J; Murphy, William L; Thomson, James A

2017-07-25

Here, we report the derivation of arterial endothelial cells from human pluripotent stem cells that exhibit arterial-specific functions in vitro and in vivo. We combine single-cell RNA sequencing of embryonic mouse endothelial cells with an EFNB2-tdTomato/EPHB4-EGFP dual reporter human embryonic stem cell line to identify factors that regulate arterial endothelial cell specification. The resulting xeno-free protocol produces cells with gene expression profiles, oxygen consumption rates, nitric oxide production levels, shear stress responses, and TNFα-induced leukocyte adhesion rates characteristic of arterial endothelial cells. Arterial endothelial cells were robustly generated from multiple human embryonic and induced pluripotent stem cell lines and have potential applications for both disease modeling and regenerative medicine.

Antiangiogenic activity of vitexicarpine in experimentally induced hepatocellular carcinoma: Impact on vascular endothelial growth factor pathway.

PubMed

Hassoun, Shimaa M; Abdel-Rahman, Noha; Eladl, Entsar I; El-Shishtawy, Mamdouh M

2017-06-01

Angiogenesis plays important roles in progression of hepatocellular carcinoma. The antiangiogenic mechanisms of vitexicarpine are not fully defined. Therefore, we conducted the following study to evaluate the antiangiogenic mechanism and antitumor activity of vitexicarpine in vivo model of hepatocellular carcinoma through modulation of vascular endothelial growth factor signaling pathway. Hepatocellular carcinoma was induced in Sprague Dawley rats by thioacetamide. Hepatocellular carcinoma was assessed by measuring serum alpha-fetoprotein and investigating liver sections stained with hematoxylin/eosin. Hepatocellular carcinoma rats were injected with vitexicarpine (150 mg/kg) for 2 weeks. Hepatic vascular endothelial growth factor was measured by enzyme-linked immunosorbent assay. Protein and expression of hepatic phospho-Ser473-AKT (p-AKT) and phospho-Tyr419-Src (p-Src) were determined. The apoptotic pathway was evaluated by assessment of protein expression of caspase-3. Vitexicarpine increased rats' survival time and decreased serum alpha-fetoprotein as well as it ameliorated fibrosis and massive hepatic tissue breakdown. It attenuated hepatocellular carcinoma-induced protein and gene expression of vascular endothelial growth factor, p-AKT, p-Src, and caspase-3. In conclusion, this study suggests that vitexicarpine possesses both antiangiogenic and antitumor activities through inhibition of vascular endothelial growth factor, p-AKT/AKT, and p-Src with subsequent inhibition of apoptotic pathway.

Asthma treatment outcome in children is associated with vascular endothelial growth factor A (VEGFA) polymorphisms.

PubMed

Balantic, Mateja; Rijavec, Matija; Skerbinjek Kavalar, Maja; Suskovic, Stanislav; Silar, Mira; Kosnik, Mitja; Korosec, Peter

2012-06-01

Asthma is a common chronic disease characterized by airway inflammation and structural remodeling. Vascular endothelial growth factor (VEGF), a major regulator of angiogenesis, is elevated in asthma patients. VEGF contributes to airway responsiveness and remodeling. It has been shown that treatment of asthma patients decreases VEGF levels, and inhibition of VEGF diminishes asthma symptoms in mice. Therefore, polymorphisms in the vascular endothelial growth factor A (VEGFA) gene might be associated with asthma treatment response. This study enrolled 131 children with asthma treated with different therapies - specifically, the inhaled corticosteroid (ICS) fluticasone propionate or the leukotriene receptor antagonist (LTRA) montelukast. We performed an association analysis between improvement of lung function - assessed by measurement of the percentage of the predicted forced expiratory volume in 1 second (%predicted FEV(1)), the ratio between the FEV(1) and the forced vital capacity (FEV(1)/FVC) after 6 and 12 months of treatment, and asthma control after 12 months of treatment - and two polymorphisms, rs2146323 and rs833058, in the VEGFA gene. Polymorphism rs2146323 A>C in VEGFA was associated with response to ICS therapy. Asthma patients with the AA genotype had a greater improvement in the %predicted FEV(1) than those with the AC or CC genotype (p = 0.018). Conversely, the AA genotype in rs2146323 was associated with uncontrolled asthma in patients regularly receiving LTRA therapy (p = 0.020) and a worse FEV(1)/FVC ratio in patients who episodically used LTRA therapy (p = 0.044). Furthermore, polymorphism rs833058 C>T was associated with treatment response to episodically used LTRA therapy. A subgroup of patients with the TT genotype had an improvement in the %predicted FEV(1), compared with no improvement in patients with the CT or CC genotype (p = 0.029). Our results showed that treatment response to commonly used asthma therapies (ICS or LTRA) is associated

Phloretin suppresses thrombin-mediated leukocyte-platelet-endothelial interactions.

PubMed

Kim, Min Soo; Park, Sin-Hye; Han, Seon-Young; Kim, Yun-Ho; Lee, Eun-Jung; Yoon Park, Jung Han; Kang, Young-Hee

2014-04-01

Thrombin playing a pivotal role in coagulation cascade may influence the onset and progression of atherosclerosis as a pro-inflammatory mediator. This study investigated whether phloretin found in apple tree leaves, severed a linkage between thrombosis and atherosclerosis by thrombin. Human endothelial cells were pre-treated with 1-20 μM phloretin and stimulated with 10 U/mL thrombin. Phloretin attenuated adhesion of THP-1 monocytes and platelets to thrombin-inflamed endothelial cells with concurrent inhibition of protease-activated receptor (PAR-1) induction. The thrombin induction of endothelial CD40, endothelial integrin β3 and P-selectin, and monocytic CD40L was dampened by phloretin. Additionally, phloretin inhibited monocyte secretion of MCP-1, IL-6 and IL-8 responsible for pro-inflammatory activity of thrombin inducing endothelial CD40. The monocyte COX-2 induction and PGE2 secretion due to thrombin were down-regulated by phloretin, deterring endothelial CD40 expression. Thrombin promoted production of PAI-1 and tissue factor in monocytes was attenuated by phloretin through blocking PAR-1 and CD40. Thrombin up-regulated the induction of endothelial connective tissue growth factor independent of PAR-1 activation, which was reversed by phloretin. Phloretin disturbed tethering and stable adhesion of monocytes and platelets onto endothelium during increased thrombosis by thrombin. Phloretin would be a potent agent preventing thrombosis and atherosclerosis. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Preexposure to ozone blocks the antigen-induced late asthmatic response of the canine peripheral airways

DOE Office of Scientific and Technical Information (OSTI.GOV)

Turner, C.R.; Kleeberger, S.R.; Spannhake, E.W.

1989-01-01

The influence of exposure of the airways to ozone on acute allergic responsiveness has been investigated in several species. Little is known, however, about the effect of this environmental pollutant on the late asthmatic response (LAR) in animals in which it is exhibited. The purpose of this study was to evaluate this effect in the canine peripheral airways and to assess the potential role of mast cells in modulating the effect. A series of experiments on seven mongrel dogs demonstrated that the numbers of mast cells at the base of the epithelial region of small subsegmental airways exposed to 1more » ppm ozone for 5 min were significantly (p less than .01) increased 3 h following exposure compared to air exposed or nonexposed control airways. In a second series of experiments performed on eight additional mongrel dogs with inherent sensitivity to Ascaris suum antigen, antigen aerosol was administered to the sublobar segment 3 h following ozone preexposure when mast cell numbers were presumed to be increased. These experiments were performed to determine whether ozone preexposure could enhance the late-phase response to antigen by virtue of acutely increasing the number of mast cells available to bind the antigen. Four of the eight dogs tested displayed a late-phase response to antigen following air-sham preexposure. In these four dogs, simultaneous ozone preexposure of a contralateral lobe completely blocked the late-phase response to antigen. These results indicate that the consequences of a single exposure to ozone persist beyond its effects on acute antigen-induced bronchoconstriction and extend to the complex processes involved with the late response. This attenuating effect of ozone is seen under conditions where mast-cell numbers in the airways are increased above baseline levels.« less

Immunity to tumour antigens.

PubMed

Li, Geng; Ali, Selman A; McArdle, Stephanie E B; Mian, Shahid; Ahmad, Murrium; Miles, Amanda; Rees, Robert C

2005-01-01

During the last decade, a large number of human tumour antigens have been identified. These antigens are classified as tumour-specific shared antigens, tissue-specific differentiation antigens, overexpressed antigens, tumour antigens resulting from mutations, viral antigens and fusion proteins. Antigens recognised by effectors of immune system are potential targets for antigen-specific cancer immunotherapy. However, most tumour antigens are self-proteins and are generally of low immunogenicity and the immune response elicited towards these tumour antigens is not always effective. Strategies to induce and enhance the tumour antigen-specific response are needed. This review will summarise the approaches to discovery of tumour antigens, the current status of tumour antigens, and their potential application to cancer treatment.

Characterisation of antibody responses in pigs induced by recombinant oncosphere antigens from Taenia solium.

PubMed

Jayashi, César M; Gonzalez, Armando E; Castillo Neyra, Ricardo; Kyngdon, Craig T; Gauci, Charles G; Lightowlers, Marshall W

2012-12-14

Recombinant antigens cloned from the oncosphere life cycle stage of the cestode parasite Taenia solium (T. solium) have been proven to be effective as vaccines for protecting pigs against infections with T. solium. Previous studies have defined three different host protective oncosphere antigens, TSOL18, TSOL16 and TSOL45. In this study, we evaluated the potential for combining the antigens TSOL16 and TSOL18 as a practical vaccine. Firstly, in a laboratory trial, we compared the immunogenicity of the combined antigens (TSOL16/18) versus the immunogenicity of the antigens separately. Secondly, in a field trial, we tested the ability of the TSOL16/18 vaccine to induce detectable antibody responses in animals living under environmental stress and traditionally reared in areas where T. solium cysticercosis is endemic; and finally, we characterised the immune response of the study population. Pigs of 8-16 weeks of age were vaccinated with 200 μg each of TSOL16 and TSOL18, plus 5mg of Quil-A. Specific total IgG, IgG(1) and IgG(2) antibody responses induced by TSOL16 and TSOL18 were determined with ELISA. The immunogenicity of both antigens was retained in the combined TSOL16/18 vaccine. The combined vaccine TSOL16/18 induced detectable specific anti-TSOL18 antibody responses in 100% (113/113) and specific anti-TSOL16 in 99% (112/113) of the vaccinated animals measured at 2 weeks following the booster vaccination. From the two IgG antibody subtypes analysed we found there was stronger response to IgG(2). Copyright © 2012 Elsevier Ltd. All rights reserved.

Hypoxia and alkalinization inhibit endothelium-derived nitric oxide but not endothelium-derived hyperpolarizing factor responses in porcine coronary artery.

PubMed

Shimizu, S; Paul, R J

1999-10-01

We investigated the mechanisms by which hypoxia and alkalinization inhibit the endothelium-dependent relaxation to Substance P (SP) in porcine coronary artery. In a KCl contracture, the major component of the SP response is endothelium-derived nitric oxide (EDNO), whereas with receptor-mediated 9,11-dideoxy-llalpha, 9alpha-epoxymethanoprostaglandin F(2alpha) (U46619) stimulation, the SP response is dependent on both EDNO and endothelium-derived hyperpolarization factor. Intracellular alkalinization by NH(4)Cl reduced the peak of SP responses when arteries were contracted with KCl, whereas with U46619 stimulation, the peak was little effected but the duration was shortened. In endothelial cell-denuded arteries, alkalinization with NH(4)Cl shifted the sodium nitroprusside concentration-relaxation relations rightward. The effects of NH(4)Cl in SP- and sodium nitroprusside-induced relaxations were attenuated by decreasing extracellular pH (pH(o)) from 7.4 to 7.2, which normalized intracellular pH (pH(i)) to control levels. In contrast, in U46619 contractures, the SP response in the presence of a NO synthase inhibitor was unaffected by NH(4)Cl. Moreover, hypoxia blunted but did not abolish the responses to SP for U46619 contractures; addition of KCl, however, abolished the SP response under hypoxia. Endothelial [Ca(2+)](i) was measured with fura-2 differentially loaded only into endothelial cells on intact arteries. Despite the attenuation of the SP response in KCl contractures by NH(4)Cl or hypoxia, endothelial [Ca(2+)](i) responses were unchanged. Our results suggest that hypoxia and alkalinization inhibit EDNO but not endothelium-derived hyperpolarization factor relaxations through a mechanism(s) not involving endothelial cell [Ca(2+)](i). Inhibition of EDNO relaxation by alkalinization with NH(4)Cl is likely to occur at the level of activation of guanylate cyclase and/or at a step downstream in smooth muscle.

JunB is required for endothelial cell morphogenesis by regulating core-binding factor β

PubMed Central

Licht, Alexander H.; Pein, Oliver T.; Florin, Lore; Hartenstein, Bettina; Reuter, Hendrik; Arnold, Bernd; Lichter, Peter; Angel, Peter; Schorpp-Kistner, Marina

2006-01-01

The molecular mechanism triggering the organization of endothelial cells (ECs) in multicellular tubules is mechanistically still poorly understood. We demonstrate that cell-autonomous endothelial functions of the AP-1 subunit JunB are required for proper endothelial morphogenesis both in vivo in mouse embryos with endothelial-specific ablation of JunB and in in vitro angiogenesis models. By cDNA microarray analysis, we identified core-binding factor β (CBFβ), which together with the Runx proteins forms the heterodimeric core-binding transcription complex CBF, as a novel JunB target gene. In line with our findings, expression of the CBF target MMP-13 was impaired in JunB-deficient ECs. Reintroduction of CBFβ into JunB-deficient ECs rescued the tube formation defect and MMP-13 expression, indicating an important role for CBFβ in EC morphogenesis. PMID:17158955

γδ T cells recognize a microbial encoded B cell antigen to initiate a rapid antigen specific Interleukin 17 response

PubMed Central

Zeng, Xun; Wei, Yu-ling; Huang, Jun; Newell, Evan W.; Yu, Hongxiang; Kidd, Brian A.; Kuhns, Michael S.; Waters, Ray W.; Davis, Mark M.; Weaver, Casey T.; Chien, Yueh-hsiu

2012-01-01

Summary γδ T cells contribute uniquely to host immune defense. However, how they function remains an enigma. Although it is unclear what most γδ T cells recognize, common dogma asserts that they recognize self-antigens. While they are the major initial Interleukin-17 (IL-17) producers in infections, it is unclear what is required to trigger these cells to act. Here, we report that a noted B cell antigen, the algae protein-phycoerythrin (PE) is an antigen for murine and human γδ T cells. PE also stained specific bovine γδ T cells. Employing this specificity, we demonstrated that antigen recognition, but not extensive clonal expansion, was required to activate naïve γδ T cells to make IL-17. In this activated state, γδ T cells gained the ability to respond to cytokine signals that perpetuated the IL-17 production. These results underscore the adaptability of lymphocyte antigen receptors and suggest a previously unrecognized antigen-driven rapid response in protective immunity prior to the maturation of classical adaptive immunity. PMID:22960222

The endogenous zinc finger transcription factor, ZNF24, modulates the angiogenic potential of human microvascular endothelial cells

PubMed Central

Jia, Di; Huang, Lan; Bischoff, Joyce; Moses, Marsha A.

2015-01-01

We have previously identified a zinc finger transcription factor, ZNF24 (zinc finger protein 24), as a novel inhibitor of tumor angiogenesis and have demonstrated that ZNF24 exerts this effect by repressing the transcription of VEGF in breast cancer cells. Here we focused on the role of ZNF24 in modulating the angiogenic potential of the endothelial compartment. Knockdown of ZNF24 by siRNA in human primary microvascular endothelial cells (ECs) led to significantly decreased cell migration and invasion compared with control siRNA. ZNF24 knockdown consistently led to significantly impaired VEGF receptor 2 (VEGFR2) signaling and decreased levels of matrix metalloproteinase-2 (MMP-2), with no effect on levels of major regulators of MMP-2 activity such as the tissue inhibitors of metalloproteinases and MMP-14. Moreover, silencing ZNF24 in these cells led to significantly decreased EC proliferation. Quantitative PCR array analyses identified multiple cell cycle regulators as potential ZNF24 downstream targets which may be responsible for the decreased proliferation in ECs. In vivo, knockdown of ZNF24 specifically in microvascular ECs led to significantly decreased formation of functional vascular networks. Taken together, these results demonstrate that ZNF24 plays an essential role in modulating the angiogenic potential of microvascular ECs by regulating the proliferation, migration, and invasion of these cells.— Jia, D., Huang, L., Bischoff, J., Moses, M. A. The endogenous zinc finger transcription factor, ZNF24, modulates the angiogenic potential of human microvascular endothelial cells. PMID:25550468

Sulphonated Formononetin Induces Angiogenesis through Vascular Endothelial Growth Factor/cAMP Response Element-Binding Protein/Early Growth Response 3/Vascular Cell Adhesion Molecule 1 and Wnt/β-Catenin Signaling Pathway.

PubMed

Dong, Zhaoju; Shi, Yanan; Zhao, Huijuan; Li, Ning; Ye, Liang; Zhang, Shuping; Zhu, Haibo

2018-01-01

Sodium formononetin-3'-sulphonate (Sul-F) is a derivative of the isoflavone formononetin. In this study, we investigated whether Sul-F can regulate angiogenesis and the potential mechanism in vitro. We examined the effects of Sul-F on cell proliferation, cell invasion, and tube formation in the human umbilical vein endothelial cell line (HUVEC). To better understand the mechanism involved, we investigated effects of the following compounds: cAMP response element-binding protein (CREB) inhibitor 2-naphthol-AS-E-phosphate (KG-501), early growth response 3 (Egr-3) siRNA, vascular endothelial growth factor (VEGF) antagonist soluble VEGF receptor 1 (sFlt-1), VEGF receptor 2 blocker SU-1498, Wnt5a antagonist WIF-1 recombinant protein (WIF-1), and inhibitor of Wnt/β-catenin recombinant Dickkopf-1 protein (DKK-1). HUVEC proliferation was tested by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT). A scratch adhesion test was used to assess cell invasion ability. Matrigel tube formation assay was performed to test capillary tube formation ability. Activation of the VEGF/CREB/Egr-3/Vascular cell adhesion molecule 1 (VCAM-1) pathway in HUVEC was tested by Western blot analysis. Our results suggest that Sul-F induced angiogenesis in vitro by enhancing cell proliferation, invasion, and tube formation. The increase in proliferation and tube formation by Sul-F was counteracted by DKK-1, WIF-1, SU1498, KG-501, sFlt-1, and Egr-3 siRNA. These results may suggest that Sul-F induces angiogenesis in vitro via a programed Wnt/β-catenin pathway and VEGF/CREB/Egr-3/VCAM-1 signaling axis. © 2017 S. Karger AG, Basel.

Association between anthropometry, cardiometabolic risk factors, & early life factors & adult measures of endothelial function: Results from the New Delhi Birth Cohort.

PubMed

Huffman, Mark D; Khalil, Anita; Osmond, Clive; Fall, Caroline H D; Tandon, Nikhil; Lakshmy, Ramakrishnan; Ramji, Siddharth; Gera, Tarun; Prabhakaran, Poornima; Dey Biswas, S K; Reddy, K Srinath; Bhargava, Santosh K; Sachdev, Harshpal S; Prabhakaran, Dorairaj

2015-12-01

Abnormal endothelial function represents a preclinical marker of atherosclerosis. This study was conducted to evaluate associations between anthropometry, cardiometabolic risk factors, and early life factors and adult measures of endothelial function in a young urban Indian cohort free of clinical cardiovascular disease. Absolute changes in brachial artery diameter following cuff inflation and sublingual nitroglycerin (400 µg) were recorded to evaluate endothelium-dependent and -independent measures of endothelial function in 600 participants (362 men; 238 women) from the New Delhi Birth Cohort (2006-2009). Data on anthropometry, cardiometabolic risk factors, medical history, socio-economic position, and lifestyle habits were collected. Height and weight were recorded at birth, two and 11 yr of age. Age- and sex-adjusted linear regression models were developed to evaluate these associations. The mean age of participants was 36±1 yr. Twenty two per cent men and 29 per cent women were obese (BMI th > 30 kg/m [2] ). Mean systolic blood pressure (SBP) was 131±14 and 119±13 mmHg, and diabetes prevalence was 12 and 8 per cent for men and women, respectively. Brachial artery diameter was higher for men compared with women both before (3.48±0.37 and 2.95±0.35 cm) and after hyperaemia (3.87±0.37 vs. 3.37±0.35 cm). A similar difference was seen before and after nitroglycerin. Markers of increased adiposity, smoking, SBP, and metabolic syndrome, but not early life anthropometry, were inversely associated with endothelial function after adjustment for age and sex. The analysis of the current prospective data from a young urban Indian cohort showed that cardiometabolic risk factors, but not early life anthropometry, were associated with worse endothelial function.

Association between anthropometry, cardiometabolic risk factors, & early life factors & adult measures of endothelial function: Results from the New Delhi Birth Cohort

PubMed Central

Huffman, Mark D.; Khalil, Anita; Osmond, Clive; Fall, Caroline H. D.; Tandon, Nikhil; Lakshmy, Ramakrishnan; Ramji, Siddharth; Gera, Tarun; Prabhakaran, Poornima; Dey Biswas, S. K.; Reddy, K. Srinath; Bhargava, Santosh K.; Sachdev, Harshpal S.; Prabhakaran, Dorairaj

2015-01-01

Background & objectives: Abnormal endothelial function represents a preclinical marker of atherosclerosis. This study was conducted to evaluate associations between anthropometry, cardiometabolic risk factors, and early life factors and adult measures of endothelial function in a young urban Indian cohort free of clinical cardiovascular disease. Methods: Absolute changes in brachial artery diameter following cuff inflation and sublingual nitroglycerin (400 µg) were recorded to evaluate endothelium-dependent and -independent measures of endothelial function in 600 participants (362 men; 238 women) from the New Delhi Birth Cohort (2006-2009). Data on anthropometry, cardiometabolic risk factors, medical history, socio-economic position, and lifestyle habits were collected. Height and weight were recorded at birth, two and 11 yr of age. Age- and sex-adjusted linear regression models were developed to evaluate these associations. Results: The mean age of participants was 36±1 yr. Twenty two per cent men and 29 per cent women were obese (BMI > 30 kg/m2). Mean systolic blood pressure (SBP) was 131±14 and 119±13 mmHg, and diabetes prevalence was 12 and 8 per cent for men and women, respectively. Brachial artery diameter was higher for men compared with women both before (3.48±0.37 and 2.95±0.35 cm) and after hyperaemia (3.87±0.37 vs. 3.37±0.35 cm). A similar difference was seen before and after nitroglycerin. Markers of increased adiposity, smoking, SBP, and metabolic syndrome, but not early life anthropometry, were inversely associated with endothelial function after adjustment for age and sex. Interpretation & conclusions: The analysis of the current prospective data from a young urban Indian cohort showed that cardiometabolic risk factors, but not early life anthropometry, were associated with worse endothelial function. PMID:26831418

The biological and practical significance of antigenic variability in protective T cell responses against Theileria parva.

PubMed

Morrison, W I

2007-08-19

The evolution of antigenically distinct pathogen strains that fail to cross-protect is well documented for pathogens controlled primarily by humoral immune responses. Unlike antibodies, which recognise native proteins, protective T cells can potentially recognise epitopes in a variety of proteins that are not necessarily displayed on the pathogen surface. Moreover, individual hosts of different MHC genotypes generally respond to different sets of epitopes. It is therefore less easy to envisage how strain restricted immunity can arise for pathogens controlled by T cell responses, particularly in antigenically complex parasites. Nevertheless, strain restricted immunity is clearly a feature of a number of parasitic infections, where immunity is known to be mediated by T cell responses. One such parasite is Theileria parva which induces potent CD8 T cell responses that play an important role in immunity. CD8 T cells specific for parasitized lymphoblasts exhibit strain specificity, which appears to correlate with the ability of parasite strains to cross-protect. Studies using recently identified T. parva antigens recognised by CD8 T cells have shown that the strain restricted nature of immunity is a consequence of the CD8 T cell response in individual animals being focused on a limited number of dominant polymorphic antigenic determinants. Responses in animals of different MHC genotypes are often directed to different parasite antigens, indicating that, at the host population level, a larger number of parasite proteins can serve as targets for the protective T cell response. Nevertheless, the finding that parasite strains show overlapping antigenic profiles, probably as a consequence of sexual recombination, suggests that induction of responses to an extended but limited set of antigens in individual animals may overcome the strain restricted nature of immunity.

Strong Antibody Responses Induced by Protein Antigens Conjugated onto the Surface of Lecithin-Based Nanoparticles

PubMed Central

Sloat, Brian R.; Sandoval, Michael A.; Hau, Andrew M.; He, Yongqun; Cui, Zhengrong

2009-01-01

An accumulation of research over the years has demonstrated the utility of nanoparticles as antigen carriers with adjuvant activity. Herein we defined the adjuvanticity of a novel lecithin-based nanoparticle engineered from emulsions. The nanoparticles were spheres of around 200 nm. Model protein antigens, bovine serum albumin (BSA) or Bacillus anthracis protective antigen (PA) protein, were covalently conjugated onto the nanoparticles. Mice immunized with the BSA-conjugated nanoparticles developed strong anti-BSA antibody responses comparable to that induced by BSA adjuvanted with incomplete Freund's adjuvant and 6.5-fold stronger than that induced by BSA adsorbed onto aluminum hydroxide. Immunization of mice with the PA-conjugated nanoparticles elicited a quick, strong, and durable anti-PA antibody response that afforded protection of the mice against a lethal dose of anthrax lethal toxin challenge. The potent adjuvanticity of the nanoparticles was likely due to their ability to move the antigens into local draining lymph nodes, to enhance the uptake of the antigens by antigen-presenting cells (APCs), and to activate APCs. This novel nanoparticle system has the potential to serve as a universal protein-based vaccine carrier capable of inducing strong immune responses. PMID:19729045

Enhancement of MHC-I antigen presentation via architectural control of pH-responsive, endosomolytic polymer nanoparticles.

PubMed

Wilson, John T; Postma, Almar; Keller, Salka; Convertine, Anthony J; Moad, Graeme; Rizzardo, Ezio; Meagher, Laurence; Chiefari, John; Stayton, Patrick S

2015-03-01

Protein-based vaccines offer a number of important advantages over organism-based vaccines but generally elicit poor CD8(+) T cell responses. We have previously demonstrated that pH-responsive, endosomolytic polymers can enhance protein antigen delivery to major histocompatibility complex class I (MHC-I) antigen presentation pathways thereby augmenting CD8(+) T cell responses following immunization. Here, we describe a new family of nanocarriers for protein antigen delivery assembled using architecturally distinct pH-responsive polymers. Reversible addition-fragmentation chain transfer (RAFT) polymerization was used to synthesize linear, hyperbranched, and core-crosslinked copolymers of 2-(N,N-diethylamino)ethyl methacrylate (DEAEMA) and butyl methacrylate (BMA) that were subsequently chain extended with a hydrophilic N,N-dimethylacrylamide (DMA) segment copolymerized with thiol-reactive pyridyl disulfide (PDS) groups. In aqueous solution, polymer chains assembled into 25 nm micellar nanoparticles and enabled efficient and reducible conjugation of a thiolated protein antigen, ovalbumin. Polymers demonstrated pH-dependent membrane-destabilizing activity in an erythrocyte lysis assay, with the hyperbranched and cross-linked polymer architectures exhibiting significantly higher hemolysis at pH ≤ 7.0 than the linear diblock. Antigen delivery with the hyperbranched and cross-linked polymer architecture enhanced in vitro MHC-I antigen presentation relative to free antigen, whereas the linear construct did not have a discernible effect. The hyperbranched system elicited a four- to fivefold increase in MHC-I presentation relative to the cross-linked architecture, demonstrating the superior capacity of the hyperbranched architecture in enhancing MHC-I presentation. This work demonstrates that the architecture of pH-responsive, endosomolytic polymers can have dramatic effects on intracellular antigen delivery, and offers a promising strategy for enhancing CD8(+) T cell

Priming Dental Pulp Stem Cells With Fibroblast Growth Factor-2 Increases Angiogenesis of Implanted Tissue-Engineered Constructs Through Hepatocyte Growth Factor and Vascular Endothelial Growth Factor Secretion

PubMed Central

Gorin, Caroline; Rochefort, Gael Y.; Bascetin, Rumeyza; Ying, Hanru; Lesieur, Julie; Sadoine, Jérémy; Beckouche, Nathan; Berndt, Sarah; Novais, Anita; Lesage, Matthieu; Hosten, Benoit; Vercellino, Laetitia; Merlet, Pascal; Le-Denmat, Dominique; Marchiol, Carmen; Letourneur, Didier; Nicoletti, Antonino; Vital, Sibylle Opsahl; Poliard, Anne; Salmon, Benjamin; Germain, Stéphane

2016-01-01

Tissue engineering strategies based on implanting cellularized biomaterials are promising therapeutic approaches for the reconstruction of large tissue defects. A major hurdle for the reliable establishment of such therapeutic approaches is the lack of rapid blood perfusion of the tissue construct to provide oxygen and nutrients. Numerous sources of mesenchymal stem cells (MSCs) displaying angiogenic potential have been characterized in the past years, including the adult dental pulp. Establishment of efficient strategies for improving angiogenesis in tissue constructs is nevertheless still an important challenge. Hypoxia was proposed as a priming treatment owing to its capacity to enhance the angiogenic potential of stem cells through vascular endothelial growth factor (VEGF) release. The present study aimed to characterize additional key factors regulating the angiogenic capacity of such MSCs, namely, dental pulp stem cells derived from deciduous teeth (SHED). We identified fibroblast growth factor-2 (FGF-2) as a potent inducer of the release of VEGF and hepatocyte growth factor (HGF) by SHED. We found that FGF-2 limited hypoxia-induced downregulation of HGF release. Using three-dimensional culture models of angiogenesis, we demonstrated that VEGF and HGF were both responsible for the high angiogenic potential of SHED through direct targeting of endothelial cells. In addition, FGF-2 treatment increased the fraction of Stro-1+/CD146+ progenitor cells. We then applied in vitro FGF-2 priming to SHED before encapsulation in hydrogels and in vivo subcutaneous implantation. Our results showed that FGF-2 priming is more efficient than hypoxia at increasing SHED-induced vascularization compared with nonprimed controls. Altogether, these data demonstrate that FGF-2 priming enhances the angiogenic potential of SHED through the secretion of both HGF and VEGF. Significance The results from the present study show that fibroblast growth factor-2 (FGF-2) priming is more

Early Growth Response-1 Induces and Enhances Vascular Endothelial Growth Factor-A Expression in Lung Cancer Cells

PubMed Central

Shimoyamada, Hiroaki; Yazawa, Takuya; Sato, Hanako; Okudela, Koji; Ishii, Jun; Sakaeda, Masashi; Kashiwagi, Korehito; Suzuki, Takehisa; Mitsui, Hideaki; Woo, Tetsukan; Tajiri, Michihiko; Ohmori, Takahiro; Ogura, Takashi; Masuda, Munetaka; Oshiro, Hisashi; Kitamura, Hitoshi

2010-01-01

Vascular endothelial growth factor-A (VEGF-A) is crucial for angiogenesis, vascular permeability, and metastasis during tumor development. We demonstrate here that early growth response-1 (EGR-1), which is induced by the extracellular signal–regulated kinase (ERK) pathway activation, activates VEGF-A in lung cancer cells. Increased EGR-1 expression was found in adenocarcinoma cells carrying mutant K-RAS or EGFR genes. Hypoxic culture, siRNA experiment, luciferase assays, chromatin immunoprecipitation, electrophoretic mobility shift assays, and quantitative RT-PCR using EGR-1–inducible lung cancer cells demonstrated that EGR-1 binds to the proximal region of the VEGF-A promoter, activates VEGF-A expression, and enhances hypoxia inducible factor 1α (HIF-1α)-mediated VEGF-A expression. The EGR-1 modulator, NAB-2, was rapidly induced by increased levels of EGR-1. Pathology samples of human lung adenocarcinomas revealed correlations between EGR-1/HIF-1α and VEGF-A expressions and relative elevation of EGR-1 and VEGF-A expression in mutant K-RAS- or EGFR-carrying adenocarcinomas. Both EGR-1 and VEGF-A expression increased as tumors dedifferentiated, whereas HIF-1α expression did not. Although weak correlation was found between EGR-1 and NAB-2 expressions on the whole, NAB-2 expression decreased as tumors dedifferentiated, and inhibition of DNA methyltransferase/histone deacetylase increased NAB-2 expression in lung cancer cells despite no epigenetic alteration in the NAB-2 promoter. These findings suggest that EGR-1 plays important roles on VEGF-A expression in lung cancer cells, and epigenetic silencing of transactivator(s) associated with NAB-2 expression might also contribute to upregulate VEGF-A expression. PMID:20489156

Regulation by basic fibroblast growth factor of glycosaminoglycan biosynthesis in cultured vascular endothelial cells.

PubMed

Kaji, T; Hiraga, S; Ohkawara, S; Inada, M; Yamamoto, C; Kozuka, H; Koizumi, F

1995-05-01

The alteration of glycosaminoglycans (GAGs) in cultured bovine aortic endothelial cells after exposure to basic fibroblast growth factor (bFGF) was investigated. It was found that the incorporation of [3H]glucosamine into GAGs was markedly increased by bFGF in both the cell layer and the conditioned medium; however, that of [35S]sulfate was not changed by the growth factor. These results indicated that bFGF enhanced the sugar-chain formation but did not affect their sulfation in endothelial GAG production. Similar changes were observed in either bovine aortic smooth-muscle cells and human fibroblastic IMR-90 cells to greater and lesser degrees, respectively. Characterization of GAGs in the endothelial cell layer and the conditioned medium revealed that bFGF enhanced both heparan sulfate and the other GAGs to a similar degree. The present data suggest that bFGF may be involved in the regulation of the blood coagulation system via altering GAGs of the vascular tissue when the endothelium was damaged.

Triglycerides as an early pathophysiological marker of endothelial dysfunction in nondiabetic women with a previous history of gestational diabetes.

PubMed

Sokup, Alina; Góralczyk, Barbara; Góralczyk, Krzysztof; Rość, Danuta

2012-02-01

To investigate whether baseline triglyceride levels are associated with early glucose dysregulation and/or cardiovascular risk in women with a previous history of gestational diabetes. Prospective postpregnancy cohort study. Polish university hospitals. Participants included 125 women with previous gestational diabetes and 40 women with normal glucose regulation during pregnancy. All women were studied 2-24 months (mean 12 ± 10 months) after the index pregnancy. Women with previous gestational diabetes were divided into tertiles in accordance with baseline triglyceride levels. We assessed glucose regulation (oral glucose tolerance test), insulin resistance (homeostasis model assessment), markers of endothelial dysfunction (soluble: intercellular adhesion molecule-1, vascular cell adhesion molecule-1, E-selectin, tissue plasminogen activator antigen, von Willebrand factor antigen), fibrinolysis (plasminogen activator inhibitor antigen), inflammation (high-sensitivity C-reactive protein) and lipid levels. Women with previous gestational diabetes (78% normal glucose regulation, 22% impaired glucose tolerance) had a high cardiometabolic risk profile compared with control women (100% normal glucose regulation). Baseline triglycerides >0.83 mmol/l were associated with a higher prevalence of impaired glucose tolerance, higher high-sensitivity C-reactive protein and triglyceride/high-density lipoprotein-cholesterol ratio. Triglycerides >1.22 mmol/l were associated with higher body fat indexes, higher insulin resistance, higher levels of endothelial dysfunction biomarkers, higher plasminogen activator inhibitor antigen and dyslipidemia. Only E-selectin was independently associated with triglyceride levels. Baseline triglyceride levels are a cardiovascular risk marker as well as a pathophysiological parameter independently associated with endothelial dysfunction in nondiabetic women with previous gestational diabetes at 2-24 months after an index pregnancy. Normalization of

Phthalimide neovascular factor 1 (PNF1) modulates MT1-MMP activity in human microvascular endothelial cells

PubMed Central

Wieghaus, Kristen A.; Gianchandani, Erwin P.; Neal, Rebekah A.; Paige, Mikell A.; Brown, Milton L.; Papin, Jason A.; Botchwey, Edward A.

2009-01-01

We are creating synthetic pharmaceuticals with angiogenic activity and potential to promote vascular invasion. We previously demonstrated that one of these molecules, phthalimide neovascular factor 1 (PNF1), significantly expands microvascular networks in vivo following sustained release from poly(lactic-co-glycolic acid) (PLAGA) films. In addition, to probe PNF1 mode-of-action, we recently applied a novel pathway-based compendium analysis to a multi-timepoint, controlled microarray dataset of PNF1-treated (versus control) human microvascular endothelial cells (HMVECs), and we identified induction of tumor necrosis factor-alpha (TNF-α) and, subsequently, transforming growth factor-beta (TGF-β) signaling networks by PNF1. Here we validate this microarray data-set with quantitative real-time polymerase chain reaction (RT-PCR) analysis. Subsequently, we probe this dataset and identify three specific TGF-β-induced genes with regulation by PNF1 conserved over multiple timepoints—amyloid beta (A4) precursor protein (APP), early growth response 1 (EGR-1), and matrix metalloproteinase 14 (MMP14 or MT1-MMP)—that are also implicated in angiogenesis. We further focus on MMP14 given its unique role in angiogenesis, and we validate MT1-MMP modulation by PNF1 with an in vitro fluorescence assay that demonstrates the direct effects that PNF1 exerts on functional metalloproteinase activity. We also utilize endothelial cord formation in collagen gels to show that PNF1-induced stimulation of endothelial cord network formation in vitro is in some way MT1-MMP-dependent. Ultimately, this new network analysis of our transcriptional footprint characterizing PNF1 activity 1–48 h post-supplementation in HMVECs coupled with corresponding validating experiments suggests a key set of a few specific targets that are involved in PNF1 mode-of-action and important for successful promotion of the neovascularization that we have observed by the drug in vivo. PMID:19326468

Phthalimide neovascular factor 1 (PNF1) modulates MT1-MMP activity in human microvascular endothelial cells.

PubMed

Wieghaus, Kristen A; Gianchandani, Erwin P; Neal, Rebekah A; Paige, Mikell A; Brown, Milton L; Papin, Jason A; Botchwey, Edward A

2009-07-01

We are creating synthetic pharmaceuticals with angiogenic activity and potential to promote vascular invasion. We previously demonstrated that one of these molecules, phthalimide neovascular factor 1 (PNF1), significantly expands microvascular networks in vivo following sustained release from poly(lactic-co-glycolic acid) (PLAGA) films. In addition, to probe PNF1 mode of action, we recently applied a novel pathway-based compendium analysis to a multi-timepoint, controlled microarray data set of PNF1-treated (vs. control) human microvascular endothelial cells (HMVECs), and we identified induction of tumor necrosis factor-alpha (TNF-alpha) and, subsequently, transforming growth factor-beta (TGF-beta) signaling networks by PNF1. Here we validate this microarray data set with quantitative real-time polymerase chain reaction (RT-PCR) analysis. Subsequently, we probe this data set and identify three specific TGF-beta-induced genes with regulation by PNF1 conserved over multiple timepoints-amyloid beta (A4) precursor protein (APP), early growth response 1 (EGR-1), and matrix metalloproteinase 14 (MMP14 or MT1-MMP)-that are also implicated in angiogenesis. We further focus on MMP14 given its unique role in angiogenesis, and we validate MT1-MMP modulation by PNF1 with an in vitro fluorescence assay that demonstrates the direct effects that PNF1 exerts on functional metalloproteinase activity. We also utilize endothelial cord formation in collagen gels to show that PNF1-induced stimulation of endothelial cord network formation in vitro is in some way MT1-MMP-dependent. Ultimately, this new network analysis of our transcriptional footprint characterizing PNF1 activity 1-48 h post-supplementation in HMVECs coupled with corresponding validating experiments suggests a key set of a few specific targets that are involved in PNF1 mode of action and important for successful promotion of the neovascularization that we have observed by the drug in vivo.

Peripheral blood CD34+KDR+ endothelial progenitor cells are determinants of subclinical atherosclerosis in a middle-aged general population.

PubMed

Fadini, Gian Paolo; Coracina, Anna; Baesso, Ilenia; Agostini, Carlo; Tiengo, Antonio; Avogaro, Angelo; de Kreutzenberg, Saula Vigili

2006-09-01

Disruption of the endothelial layer is the first step in the atherogenic process. Experimental studies have shown that endothelial progenitor cells (EPCs) are involved in endothelial homeostasis and repair. Conversely, EPC depletion has been demonstrated in the setting of established atherosclerotic diseases. With this background, we evaluated whether variations in the number of EPCs are associated with subclinical atherosclerosis in healthy subjects. Carotid intima-media thickness (IMT), high-sensitive C-reactive protein (hsCRP), levels of circulating EPCs, and cardiovascular risk were compared in 137 healthy subjects. Six subpopulations of progenitor cells were determined by flow cytometry on the basis of the surface expression of CD34, CD133, and KDR antigens: CD34(+), CD133(+), CD34(+)CD133(+), CD34(+)KDR(+), CD133(+)KDR(+), and CD34(+)CD133(+)KDR(+). Among different antigenic profiles of EPCs, only CD34(+)KDR(+) cells were significantly reduced in subjects with increased IMT. Specifically, CD34(+)KDR(+) cells were inversely correlated with IMT, even after adjustment for hsCRP and 10-year Framingham risk and independently of other cardiovascular parameters. Depletion of CD34(+)KDR(+) EPCs is an independent predictor of early subclinical atherosclerosis in healthy subjects and may provide additional information beyond classic risk factors and inflammatory markers.

Randomized study of teriflunomide effects on immune responses to neoantigen and recall antigens

PubMed Central

Wiendl, Heinz; Miller, Barry; Benamor, Myriam; Truffinet, Philippe; Church, Meg; Menguy-Vacheron, Francoise

2015-01-01

Objective: To evaluate immune responses to neoantigen and recall antigens in healthy subjects treated with teriflunomide. Methods: This was a randomized, double-blind, placebo-controlled study. Subjects received oral teriflunomide (70 mg once daily for 5 days followed by 14 mg once daily for 25 days) or placebo for 30 days. Antibody responses were evaluated following rabies vaccination (neoantigen) applied at days 5, 12, and 31 of the treatment period. Occurrence of delayed-type hypersensitivity (DTH) to Candida albicans, Trichophyton, and tuberculin (recall antigens) was assessed before and at the end of treatment to investigate cellular memory response. Safety and pharmacokinetics were evaluated. Results: Forty-six randomized subjects were treated (teriflunomide, n = 23; placebo, n = 23) and completed the rabies vaccination. Geometric mean titers for rabies antibodies were lower with teriflunomide at days 31 and 38 than with placebo. However, all subjects achieved sufficient seroprotection following rabies vaccination (titers well above the 0.5 IU/mL threshold). Overall, the DTH response to recall antigens in the teriflunomide group did not notably differ from responses in the placebo group. Conclusions: Following vaccination, geometric mean titers for rabies antibodies were lower with teriflunomide than with placebo. However, teriflunomide did not limit the ability to achieve seroprotective titers against this neoantigen. Evaluation of DTH showed that teriflunomide had no adverse impact on the cellular memory response to recall antigens. Classification of evidence: This study provides Class II evidence that in normal subjects treated with teriflunomide, antibody titer responses to rabies vaccination are lower than with placebo but sufficient for seroprotection. PMID:25738167

Expression of Vascular Endothelial Growth Factor Receptors in Benign Vascular Lesions of the Orbit: A Case Series.

PubMed

Atchison, Elizabeth A; Garrity, James A; Castillo, Francisco; Engman, Steven J; Couch, Steven M; Salomão, Diva R

2016-01-01

Vascular lesions of the orbit, although not malignant, can cause morbidity because of their location near critical structures in the orbit. For the same reason, they can be challenging to remove surgically. Anti-vascular endothelial growth factor (VEGF) drugs are increasingly being used to treat diseases with prominent angiogenesis. Our study aimed to determine to what extent VEGF receptors and their subtypes are expressed on selected vascular lesions of the orbit. Retrospective case series of all orbital vascular lesions removed by one of the authors (JAG) at the Mayo Clinic. A total of 52 patients who underwent removal of vascular orbital lesions. The pathology specimens from the patients were retrieved, their pathologic diagnosis was confirmed, demographic and clinical information were gathered, and sections from vascular tumors were stained with vascular endothelial growth factor receptor (VEGFR), vascular endothelial growth factor receptor type 1 (VEGFR1), vascular endothelial growth factor receptor type 2 (VEGFR2), and vascular endothelial growth factor receptor type 3 (VEGFR3). The existence and pattern of staining with VEGF and its subtypes on these lesions. There were 28 specimens of venous malformations, 4 capillary hemangiomas, 7 lymphatic malformations, and 6 lymphaticovenous malformations. All samples stained with VEGF, 55% stained with VEGFR1, 98% stained with VEGFR2, and 96% stained with VEGFR3. Most (94%) of the VEGFR2 staining was diffuse. Most orbital vascular lesions express VEGF receptors, which may suggest a future target for nonsurgical treatment. Copyright © 2016 American Academy of Ophthalmology. Published by Elsevier Inc. All rights reserved.

Matrix metalloproteinase 9-mediated shedding of syndecan 4 in response to tumor necrosis factor α: a contributor to endothelial cell glycocalyx dysfunction.

PubMed

Ramnath, Raina; Foster, Rebecca R; Qiu, Yan; Cope, George; Butler, Matthew J; Salmon, Andrew H; Mathieson, Peter W; Coward, Richard J; Welsh, Gavin I; Satchell, Simon C

2014-11-01

The endothelial surface glycocalyx is a hydrated mesh in which proteoglycans are prominent. It is damaged in diseases associated with elevated levels of tumor necrosis factor α (TNF-α). We investigated the mechanism of TNF-α-induced disruption of the glomerular endothelial glycocalyx. We used conditionally immortalized human glomerular endothelial cells (GEnCs), quantitative PCR arrays, Western blotting, immunoprecipitation, immunofluorescence, and dot blots to examine the effects of TNF-α. TNF-α induced syndecan 4 (SDC4) mRNA up-regulation by 2.5-fold, whereas cell surface SDC4 and heparan sulfate (HS) were reduced by 36 and 30%, respectively, and SDC4 and sulfated glycosaminoglycan in the culture medium were increased by 52 and 65%, respectively, indicating TNF-α-induced shedding. Small interfering (siRNA) knockdown of SDC4 (by 52%) caused a corresponding loss of cell surface HS of similar magnitude (38%), and immunoprecipitation demonstrated that SDC4 and HS are shed as intact proteoglycan ectodomains. All of the effects of TNF-α on SDC4 and HS were abrogated by the metalloproteinase (MMP) inhibitor batimastat. Also abrogated was the associated 37% increase in albumin passage across GEnC monolayers. Specific MMP9 knockdown by siRNA similarly blocked TNF-α effects. SDC4 is the predominant HS proteoglycan in the GEnC glycocalyx. TNF-α-induced MMP9-mediated shedding of SDC4 is likely to contribute to the endothelial glycocalyx disruption observed in diabetes and inflammatory states. © FASEB.

Fluidization, resolidification, and reorientation of the endothelial cell in response to slow tidal stretches

PubMed Central

Krishnan, Ramaswamy; Canović, Elizabeth Peruski; Iordan, Andreea L.; Rajendran, Kavitha; Manomohan, Greeshma; Pirentis, Athanassios P.; Smith, Michael L.; Butler, James P.; Fredberg, Jeffrey J.

2012-01-01

Mechanical stretch plays an important role in regulating shape and orientation of the vascular endothelial cell. This morphological response to stretch is basic to angiogenesis, neovascularization, and vascular homeostasis, but mechanism remains unclear. To elucidate mechanisms, we used cell mapping rheometry to measure traction forces in primary human umbilical vein endothelial cells subjected to periodic uniaxial stretches. Onset of periodic stretch of 10% strain amplitude caused a fluidization response typified by attenuation of traction forces almost to zero. As periodic stretch continued, the prompt fluidization response was followed by a slow resolidification response typified by recovery of the traction forces, but now aligned along the axis perpendicular to the imposed stretch. Reorientation of the cell body lagged reorientation of the traction forces, however. Together, these observations demonstrate that cellular reorientation in response to periodic stretch is preceded by traction attenuation by means of cytoskeletal fluidization and subsequent traction recovery transverse to the stretch direction by means of cytoskeletal resolidification. PMID:22700796

Cyclic adenosine monophosphate levels and the function of skin microvascular endothelial cells.

PubMed

Tuder, R M; Karasek, M A; Bensch, K G

1990-02-01

The maintenance of the normal epithelioid morphology of human dermal microvascular endothelial cells (MEC) grown in vitro depends strongly on the presence of factors that increase intracellular levels of cyclic AMP. Complete removal of dibutyryl cAMP and isobutylmethylxanthine (IMX) from the growth medium results in a progressive transition from an epithelioid to a spindle-shaped cell line. This transition cannot be reversed by the readdition of dibutyryl cAMP and IMX to the growth medium or by addition of agonists that increase cAMP levels. Spindle-shaped MEC lose the ability to express Factor VIII rAG and DR antigens and to bind peripheral blood mononuclear leukocyte (PBML). Ultrastructural analyses of transitional cells and spindle-shaped cells show decreased numbers of Weibel-Palade bodies in transitional cells and their complete absence in spindle-shaped cells. Interferon-gamma alters several functional properties of both epithelioid and spindle-shaped cells. In the absence of dibutyryl cAMP it accelerates the transition from epithelial to spindle-shaped cells, whereas in the presence of cyclic AMP interferon-gamma increases the binding of PBMLs to both epithelioid and spindle-shaped MEC and the endocytic activity of the endothelial cells. These results suggest that cyclic AMP is an important second messenger in the maintenance of several key functions of microvascular endothelial cells. Factors that influence the levels of this messenger in vivo can be expected to influence the angiogenic and immunologic functions of the microvasculature.

Expression of vascular endothelial growth factor mRNA in non-small-cell lung carcinomas

PubMed Central

Fontanini, G; Boldrini, L; Chinè, S; Pisaturo, F; Basolo, F; Calcinai, A; Lucchi, M; Mussi, A; Angeletti, C A; Bevilacqua, G

1999-01-01

The vascular endothelial growth factor (VEGF) has been shown to be strictly related to vascular permeability and endothelial cell growth under physiological and pathological conditions. In tumour development and progression, VEGF plays a pivotal role in the development of the tumoral vascular network, and useful information in the progression of human cancer can be obtained by analysing the vascular endothelial growth factor expression of the tumours. In this study, we investigated the vascular endothelial growth factor transcript expression in non-small-cell lung carcinomas to evaluate the significance of this factor in a group of cancers in which the vascular pattern has been shown to significantly affect progression. Surgical samples of 42 patients with NSCLC were studied using reverse transcription polymerase chain reaction (PCR) analysis and in situ hybridization. Thirty-three out of 42 cases (78.6%) showed VEGF transcript expression predominantly as transcripts for the secretory forms of VEGF (isoforms 121 and 165). In situ hybridization, performed on 24 out of 42 samples, showed that the VEGF transcript expression was in several cases present in the cytoplasm both of neoplastic and normal cells, even if the VEGF mRNA was less expressed in the corresponding non-tumoral part. The VEGF 121 expression was associated with hilar and/or mediastinal nodal involvement (P = 0.02), and, taken together, the VEGF isoforms were shown to significantly influence overall (P = 0.02) and disease-free survival (P = 0.03). As a regulator of tumour angiogenesis, VEGF may represent a useful indicator of progression and poor prognosis in non-small-cell lung carcinomas. © 1999 Cancer Research Campaign PMID:9888482

Antigen-specific T cell therapies for cancer

PubMed Central

Manzo, Teresa; Heslop, Helen E.; Rooney, Cliona M.

2015-01-01

Adoptively transferred antigen-specific T cells that recognize tumor antigens through their native receptors have many potential benefits as treatment for virus-associated diseases and malignancies, due to their ability to selectively recognize tumor antigens, expand and persist to provide long-term protection. Infusions of T cells targeting Epstein–Barr virus (EBV) antigens have shown encouraging response rates in patients with post-transplant lymphoproliferative disease as well as EBV-positive lymphomas and nasopharyngeal cancer, although a recent study also showed that human papilloma virus-reactive T cells can induce complete regression of metastatic cervical cancer. This strategy is also being evaluated to target non-viral tumor-associated antigens. Targeting these less immunogenic antigens is more challenging, as tumor antigens are generally weak, and high avidity T cells specific for self-antigens are deleted in the thymus, but tumor responses have been reported. Current research focusses on defining factors that promote in vivo persistence of transferred cells and ameliorate the immunosuppressive microenvironment. To this end, investigators are evaluating the effects of combining adoptive transfer of antigen-specific T cells with other immunotherapy moieties such as checkpoint inhibitors. Genetic modification of infused T cells may also be used to overcome tumor evasion mechanisms, and vaccines may be used to promote in vivo proliferation. PMID:26160910

The secretome of endothelial progenitor cells promotes brain endothelial cell activity through PI3-kinase and MAP-kinase.

PubMed

Di Santo, Stefano; Seiler, Stefanie; Fuchs, Anna-Lena; Staudigl, Jennifer; Widmer, Hans Rudolf

2014-01-01

Angiogenesis and vascular remodelling are crucial events in tissue repair mechanisms promoted by cell transplantation. Current evidence underscores the importance of the soluble factors secreted by stem cells in tissue regeneration. In the present study we investigated the effects of paracrine factors derived from cultured endothelial progenitor cells (EPC) on rat brain endothelial cell properties and addressed the signaling pathways involved. Endothelial cells derived from rat brain (rBCEC4) were incubated with EPC-derived conditioned medium (EPC-CM). The angiogenic response of rBCEC4 to EPC-CM was assessed as effect on cell number, migration and tubular network formation. In addition, we have compared the outcome of the in vitro experiments with the effects on capillary sprouting from rat aortic rings. The specific PI3K/AKT inhibitor LY294002 and the MEK/ERK inhibitor PD98059 were used to study the involvement of these two signaling pathways in the transduction of the angiogenic effects of EPC-CM. Viable cell number, migration and tubule network formation were significantly augmented upon incubation with EPC-CM. Similar findings were observed for aortic ring outgrowth with significantly longer sprouts. The EPC-CM-induced activities were significantly reduced by the blockage of the PI3K/AKT and MEK/ERK signaling pathways. Similarly to the outcome of the rBCEC4 experiments, inhibition of the PI3K/AKT and MEK/ERK pathways significantly interfered with capillary sprouting induced by EPC-CM. The present study demonstrates that EPC-derived paracrine factors substantially promote the angiogenic response of brain microvascular endothelial cells. In addition, our findings identified the PI3K/AKT and MEK/ERK pathways to play a central role in mediating these effects.

Inhibition of endothelial receptor expression and of T-cell ligand activity by mycophenolate mofetil.

PubMed

Blaheta, R A; Leckel, K; Wittig, B; Zenker, D; Oppermann, E; Harder, S; Scholz, M; Weber, S; Schuldes, H; Encke, A; Markus, B H

1998-12-01

The novel immunosuppressive drug mycophenolate mofetil (CellCept, MMF) blocks DNA-synthesis by the inhibition of the enzyme inosine monophosphate dehydrogenase (IMDH). IMDH is also involved in the synthesis of adhesion receptors which are known to play an important role in the regulation of cell-cell contacts. Therefore, application of MMF might lead to a reduction of cellular infiltrates in the course of transplant rejection. To evaluate the therapeutic value of MMF, we investigated to what extent MMF blocks T-lymphocyte infiltration in vitro with regard to (a) adhesion to endothelial cells, (b) horizontal migration along these cells and (c) penetration through the endothelial cells. The results demonstrated a strong inhibition of both CD4+ and CD8+ T-cell adhesion and penetration by MMF. The ID50 value for CD4+ T-cell adhesion was calculated to be 0.03 microM and the ID50 value for CD4+ T-cell penetration 1.21 microM. MMF did not significantly influence the horizontal migration of T-lymphocytes along the human vascular endothelial cell (HUVEC) borders. FACS-analysis revealed a diminished E-selectin and P-selectin expression on endothelial cell membranes in the presence of MMF. Although MMF did not interfere with the synthesis of T-cell adhesion ligands, the binding activity of lymphocytic leucocyte function associated antigen 1 (LFA-1), very late antigen 4 (VLA-4) and PSGL-1 (P-selectin glycoprotein ligand 1) to immobilized intercellular adhesion molecule 1 (ICAM-1), vascular cell adhesion molecule 1 (VCAM-1) and P-selectin was impaired. Moreover, MMF prevented VLA-4 and PSGL-1 receptor accumulation on the membranes of T-cell pseudopodia. It can be concluded that MMF possesses potent infiltration blocking properties. MMF evoked down-regulation of specific endothelial membrane molecules and the loss of protein localization in the lymphocyte protrusions might be predominantly responsible for the observed blockade of cell adhesion and penetration.

Dynamic regulation of canonical TGFβ signalling by endothelial transcription factor ERG protects from liver fibrogenesis.

PubMed

Dufton, Neil P; Peghaire, Claire R; Osuna-Almagro, Lourdes; Raimondi, Claudio; Kalna, Viktoria; Chuahan, Abhishek; Webb, Gwilym; Yang, Youwen; Birdsey, Graeme M; Lalor, Patricia; Mason, Justin C; Adams, David H; Randi, Anna M

2017-10-12

The role of the endothelium in protecting from chronic liver disease and TGFβ-mediated fibrosis remains unclear. Here we describe how the endothelial transcription factor ETS-related gene (ERG) promotes liver homoeostasis by controlling canonical TGFβ-SMAD signalling, driving the SMAD1 pathway while repressing SMAD3 activity. Molecular analysis shows that ERG binds to SMAD3, restricting its access to DNA. Ablation of ERG expression results in endothelial-to-mesenchymal transition (EndMT) and spontaneous liver fibrogenesis in EC-specific constitutive hemi-deficient (Erg cEC-Het ) and inducible homozygous deficient mice (Erg iEC-KO ), in a SMAD3-dependent manner. Acute administration of the TNF-α inhibitor etanercept inhibits carbon tetrachloride (CCL 4 )-induced fibrogenesis in an ERG-dependent manner in mice. Decreased ERG expression also correlates with EndMT in tissues from patients with end-stage liver fibrosis. These studies identify a pathogenic mechanism where loss of ERG causes endothelial-dependent liver fibrogenesis via regulation of SMAD2/3. Moreover, ERG represents a promising candidate biomarker for assessing EndMT in liver disease.The transcription factor ERG is key to endothelial lineage specification and vascular homeostasis. Here the authors show that ERG balances TGFβ signalling through the SMAD1 and SMAD3 pathways, protecting the endothelium from endothelial-to-mesenchymal transition and consequent liver fibrosis in mice via a SMAD3-dependent mechanism.

Canine splenic haemangiosarcoma: influence of metastases, chemotherapy and growth pattern on post-splenectomy survival and expression of angiogenic factors.

PubMed

Göritz, M; Müller, K; Krastel, D; Staudacher, G; Schmidt, P; Kühn, M; Nickel, R; Schoon, H-A

2013-07-01

Splenic haemangiosarcomas (HSAs) from 122 dogs were characterized and classified according to their patterns of growth, survival time post splenectomy, metastases and chemotherapy. The most common pattern of growth was a mixture of cavernous, capillary and solid tumour tissue. Survival time post splenectomy was independent of the growth pattern; however, it was influenced by chemotherapy and metastases. Immunohistochemical assessment of the expression of angiogenic factors (fetal liver kinase-1, angiopoietin-2, angiopoietin receptor-2 and vascular endothelial growth factor A) and conventional endothelial markers (CD31, factor VIII-related antigen) revealed variable expression, particularly in undifferentiated HSAs. Therefore, a combination of endothelial markers should be used to confirm the endothelial origin of splenic tumours. Copyright © 2012 Elsevier Ltd. All rights reserved.

Risk factors for donor endothelial loss in eye bank-prepared posterior lamellar corneal tissue for descemet stripping automated endothelial keratoplasty.

PubMed

Liu, Yu-Chi; Alvarez Paraz, Carisa M; Cajucom-Uy, Howard Yu; Agahari, Djoni; Sethuraman, Selvam; Tan, Donald T-H; Mehta, Jodhbir S

2014-07-01

The aim of this study was to investigate donor, tissue, and precut procedure risk factors for endothelial cell density (ECD) loss in posterior lamellar corneal tissue preparation by an eye bank for Descemet stripping automated endothelial keratoplasty. A total of 259 corneoscleral rims precut by the Singapore Eye Bank from October 2011 to August 2013 were evaluated. Donor characteristics, tissue characteristics, and precut procedure parameters were analyzed. The mean donor age was 57.18 ± 11.35 years, and the mean cutting transition time was 4.16 ± 0.75 seconds. The mean ECD was 2826 ± 225 and 2787 ± 224 cells per square millimeter before and after precutting, respectively, with an average ECD change of -1.38% ± 3.28%. The precutting procedure failure rate was 1.2%. Mutivariate regression analysis showed that an older donor age, a higher ECD before cutting, and a slower cutting transition speed were significant factors. Corneas with an ECD >2800 cells per square millimeter before precutting, cutting transition time >5.5 seconds, and corneas with donor age >65 years were significantly more likely to have greater than 5% ECD loss after precutting (odds ratio, 6.42, 1.66, and 1.62; 95% confidence interval, 1.44-29.43, 1.45-2.72, and 1.66-5.82, respectively). Donor source, death-to-preservation time (range, 0.67-10.88 hours), death-to-precutting time (range, 0-7 days), and graft thickness (range, 43-232 μm) were not statistically significant factors. The ECD loss in the precut tissue prepared by the eye bank was very low. The risk factors identified provide better understanding of how to improve the quality and safety profiles when preparing graft tissue for Descemet stripping automated endothelial keratoplasty.

Mycobacterium leprae antigens involved in human immune responses. I. Identification of four antigens by monoclonal antibodies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Britton, W.J.; Hellqvist, L.; Basten, A.

1985-12-01

Four distinct antigens were identified in soluble sonicates of Mycobacterium leprae by using a panel of 11 monoclonal antibodies. Cross-reactivity studies with other mycobacterial species were conducted by using ELISA and immunoblot assays, and demonstrated that determinants on two of the antigens were present in many mycobacteria, whereas the other two were limited in distribution. Competitive inhibition experiments with radiolabeled monoclonal antibodies showed cross-inhibition between antibodies identifying two of the four antigenicbands. These two bands, of M/sub tau/ 4.5 to 6 KD and 30 to 40 KD, were resistant to protease treatment after immunoblotting. In contrast the two other bandsmore » of 16 and 70 KD were protease-sensitive. Although all four bands reacted with some human lepromatous leprosy sera in immunoblots, the 4.5 to 6 KD and 30 to 40 KD bands were most prominent. Lepromatous leprosy sera also inhibited the binding of radiolabeled monoclonal antibodies to each of the four antigens, with the mean titer causing 50% inhibition being higher for antibodies reacting with the 4.5 to 6 KD and 30 to 40 KD bands. These findings indicated that all four antigens were involved in the human B cell response to M. leprae.« less

Isolation and characterization of conditionally immortalized mouse glomerular endothelial cell lines.

PubMed

Rops, Angelique L; van der Vlag, Johan; Jacobs, Cor W; Dijkman, Henry B; Lensen, Joost F; Wijnhoven, Tessa J; van den Heuvel, Lambert P; van Kuppevelt, Toin H; Berden, Jo H

2004-12-01

The culture and establishment of glomerular cell lines has proven to be an important tool for the understanding of glomerular cell functions in glomerular physiology and pathology. Especially, the recent establishment of a conditionally immortalized visceral epithelial cell line has greatly boosted the research on podocyte biology. Glomeruli were isolated from H-2Kb-tsA58 transgenic mice that contain a gene encoding a temperature-sensitive variant of the SV40 large tumor antigen, facilitating proliferative growth at 33 degrees C and differentiation at 37 degrees C. Glomerular endothelial cells were isolated from glomerular outgrowth by magnetic beads loaded with CD31, CD105, GSL I-B4, and ULEX. Clonal cell lines were characterized by immunofluorescence staining with antibodies/lectins specific for markers of endothelial cells, podocytes, and mesangial cells. Putative glomerular endothelial cell lines were analyzed for (1) cytokine-induced expression of adhesion molecules; (2) tube formation on Matrigel coating; and (3) the presence of fenestrae. As judged by immunostaining for Wilms tumor-1, smooth muscle actin (SMA), podocalyxin, and von Willebrand factor (vWF), we obtained putative endothelial, podocyte and mesangial cell lines. The mouse glomerular endothelial cell clone #1 (mGEnC-1) was positive for vWF, podocalyxin, CD31, CD105, VE-cadherin, GSL I-B4, and ULEX, internalized acetylated-low-density lipoprotein (LDL), and showed increased expression of adhesion molecules after activation with proinflammatory cytokines. Furthermore, mGEnC-1 formed tubes and contained nondiaphragmed fenestrae. The mGEnC-1 represents a conditionally immortalized cell line with various characteristics of differentiated glomerular endothelial cells when cultured at 37 degrees C. Most important, mGEnC-1 contains nondiaphragmed fenestrae, which is a unique feature of glomerular endothelial cells.

Angiotensin II type 1 receptor blockers prevent tumor necrosis factor-alpha-mediated endothelial nitric oxide synthase reduction and superoxide production in human umbilical vein endothelial cells.

PubMed

Kataoka, Hiroki; Murakami, Ryuichiro; Numaguchi, Yasushi; Okumura, Kenji; Murohara, Toyoaki

2010-06-25

Decrease in endothelial nitric oxide synthase (eNOS) expression is one of the adverse outcomes of endothelial dysfunction. Tumor necrosis factor-alpha (TNF-alpha) is known to decrease eNOS expression and is an important mediator of endothelial dysfunction. We hypothesized that an angiotensin II type 1 (AT1) receptor blocker would improve endothelial function via not only inhibition of the angiotensin II signaling but also inhibition of the TNF-alpha-mediated signaling. Therefore we investigated whether an AT1 receptor blocker would restore the TNF-alpha-induced decrease in eNOS expression in cultured human umbilical vein endothelial cells (HUVEC). Pretreatment of HUVEC with an antioxidant (superoxide dismutase, alpha-tocopherol) or AT1 receptor blockers (olmesartan or candesartan) restored the TNF-alpha-dependent reduction of eNOS. The AT1 receptor blocker decreased the TNF-alpha-dependent increase of 8-isoprostane. The superoxide dismutase activities in HUVEC were stable during AT1 receptor blocker treatment, and the AT1 receptor blocker did not scavenge superoxide directly. The AT1 receptor blocker also decreased TNF-alpha-induced phosphorylation of I kappaB alpha and cell death. These results suggest that AT1 receptor blockers are able to ameliorate TNF-alpha-dependent eNOS reduction or cell injury by inhibiting superoxide production or nuclear factor-kappaB activation. (c) 2010 Elsevier B.V. All rights reserved.

Influence of methylenetetrahydrofolate reductase genotype, exercise and other risk factors on endothelial function in healthy individuals.

PubMed

Pullin, Catherine H; Wilson, John F; Ashfield-Watt, Pauline A L; Clark, Zoë E; Whiting, Jenny M; Lewis, Malcolm J; McDowell, Ian F W

2002-01-01

Cardiovascular disease has a multifactorial aetiology that is influenced by both genetic and environmental factors. Endothelial dysfunction is a key event in the pathogenesis of vascular disease that occurs before structural vascular changes or clinical symptoms are evident. Conventional risk factors, for example hypertension and diabetes mellitus, are associated with endothelial dysfunction, but the influence of other putative risk factors is not clear. The methylenetetrahydrofolate reductase (MTHFR) C677T genotype, a common polymorphism that induces hyperhomocysteinaemia, has been proposed as being a genetic risk factor for cardiovascular disease. A total of 126 healthy adults recruited by MTHFR C677T genotype (42 of each genotype, i.e. CC, CT and TT) underwent assessment of endothelial function. Brachial artery endothelium-dependent flow-mediated dilatation (FMD) was measured using high-resolution ultrasonic vessel "wall-tracking". Using multiple regression analysis, MTHFR genotype and 21 other subject and subject-lifestyle variables were investigated as potential predictors of endothelial function. FMD was influenced positively by frequency of aerobic exercise and by hormone replacement therapy, and negatively by increases in systolic blood pressure. MTHFR C677T genotype and the associated variation in plasma homocysteine levels did not influence FMD. Additionally, other factors, including plasma cholesterol and self-supplementation with either antioxidant vitamins or cod liver oil, showed no significant relationship with FMD, although these findings are compromised by the narrow range studied for cholesterol and the small number of subjects taking supplements. These observations have implications for risk factor management in the primary prevention of cardiovascular disease in healthy individuals.

Antigen-specific helper factors present in the supernatant of concanavalin A-induced spleen cell cultures.

PubMed

Kilburn, D G; Anaka, R

1981-08-01

The supernatants from cultures of concanavalin A-induced spleen cells contained both antigen-specific and nonspecific (Interleukin 2) helper factors (Hf). The antigen-specific factor could be isolated from the supernatant by adsorption onto and elution from antigen-Sepharose immunoadsorbents. Specific Hf was produced in cultures of either immune or nonimmune spleen cells although in the latter case the quantity of Hf was significantly less. The specific Hf did not manifest the thymocyte stimulatory property of 112.

Antihypertensive methyldopa, labetalol, hydralazine, and clonidine reversed tumour necrosis factor-α inhibited endothelial nitric oxide synthase expression in endothelial-trophoblast cellular networks.

PubMed

Xu, Bei; Bobek, Gabriele; Makris, Angela; Hennessy, Annemarie

2017-03-01

Medications used to control hypertension in pregnancy also improve trophoblast and endothelial cellular interaction in vitro. Tumour necrosis factor-α (TNF-α) inhibits trophoblast and endothelial cellular interactions and simultaneously decreases endothelial nitric oxide synthase (eNOS) expression. This study investigated whether antihypertensive medications improved these cellular interactions by modulating eNOS and inducible nitric oxide synthase (iNOS) expression. Human uterine myometrial microvascular endothelial cells (UtMVECs) were pre-incubated with (or without) low dose TNF-α (0.5 ng/mL) or TNF-α plus soluble fms-like tyrosine kinase-1 (sFlt-1) (100 ng/mL). The endothelial cells were cultured on Matrigel. After endothelial cellular networks appeared, trophoblast derived HTR-8/SVneo cells were co-cultured in the presence of clinically relevant doses of methyldopa, labetalol, hydralazine or clonidine for 24 hours. Cells were retrieved from the Matrigel to extract mRNA and eNOS and iNOS expression were examined by quantitative PCR. Methyldopa, labetalol, hydralazine and clonidine reversed the inhibitory effect of TNF-α on eNOS mRNA expression. After pre-incubating endothelial cells with TNF-α and sFlt-1, all the medications except methyldopa lost their effect on eNOS mRNA expression. In the absence of TNF-α, antihypertensive medications did not change eNOS expression. The mRNA expression of iNOS was not affected by TNF-α or any medications. This study shows that selected antihypertensive medications used in the treatment of hypertension in pregnancy increase eNOS expression in vitro when induced by the inflammatory TNF-α. The anti-angiogenic molecule sFlt-1 may antagonise the potential benefit of these medications by interfering with the NOS pathway. © 2016 John Wiley & Sons Australia, Ltd.

The effect of glycosylation of antigens on the antibody responses against Echinostoma caproni (Trematoda: Echinostomatidae).

PubMed

Sotillo, Javier; Cortés, Alba; Muñoz-Antoli, Carla; Fried, Bernard; Esteban, J Guillermo; Toledo, Rafael

2014-09-01

In the present study, we analyse the effect of glycosylation in Echinostoma caproni (Trematoda: Echinostomatidae) antigens in antibody responses against the parasite in experimentally infected mice. It has been previously demonstrated that the mouse is a host of high compatibility with E. caproni and develops elevated responses of IgG, IgG1, IgG3 and IgM as a consequence of the infection, though the role of glycans in these responses remains unknown. To this purpose, the responses generated in mice against non-treated excretory/secretory antigens of E. caproni were compared with those observed after N-deglycosylation, O-deglycosylation and double deglycosylation of the antigens by indirect ELISA and western blot. Our results suggest that E. caproni-expressed glycans play a major role in the modulation of the immune responses. The results obtained indicate that IgG subclass responses generated in mice against E. caproni are essentially due to glycoproteins and may affect the Th1/Th2 biasing. The reactivity significantly decreased after any of the deglycosylation treatments and the N-glycans appears to be of greater importance than O-glycans. Interestingly, the IgM response increased after N-deglycosylation suggesting that carbohydrates may mask peptide antigens.

Suppression of antigen-specific antibody responses in mice ...

EPA Pesticide Factsheets

T-cell-dependent antibody responses (TDAR) are suppressed in female C57BL/6N mice exposed to ≥3.75 mg/kg of perfluorooctanoic acid (PFOA) for 15 days. To determine if suppression of humoral immunity by PFOA is peroxisome proliferator activated receptor alpha (PPARa)-dependent and if suppression is associated with specific targeting of T- or B-cells, three separate experiments were conducted: (1) female PPARa constitutive knockout (PPARa KO; B6.129S4-Ppar(tm1Gonz)N12) and wild-type controls (WT; C57BL/6-Tac) exposed to 0, 7.5, or 30 mg PFOA/kg for 15 days were immunized on Day 11 with a T-cell-dependent antigen and sera then collected for measures of antigen-specific lgM titers (TDAR) 5 days later; (2) female C57BL/6N WT mice exposed to 0, 0.94, 1.88, 3.75, or 7.5mg PFOA/kg for 15 days were immunized with a T-cell-independent antigen on Day 11 and sera were then collected foranalyses of antigen-specific lgM titers (TIAR) 7 days later; and (3) splenic lymphocyte phenotypes were assessed in unimmunized female C57BL/6N WT mice exposed to 0, 3.75, or 7.5 mg PFOA/kg for 10 days to investigate effects of PFOA in the absence of specific immunization. Separate groups of mice were immunized with a T-cell-dependent antigen after 11 days of exposure and splenic lymphocyte sub-populations were assessed after 13 or 15 days of exposure to assess numbers of stimulated cells. The results indicated that exposure to ≥1.88mg PFOA/kg suppressed the TIAR; exposure to 30 mg PFOA/k

Interplay between immune responses to HLA and non-HLA self-antigens in allograft rejection.

PubMed

Angaswamy, Nataraju; Tiriveedhi, Venkataswarup; Sarma, Nayan J; Subramanian, Vijay; Klein, Christina; Wellen, Jason; Shenoy, Surendra; Chapman, William C; Mohanakumar, T

2013-11-01

Recent studies strongly suggest an increasing role for immune responses against self-antigens (Ags) which are not encoded by the major histocompatibility complex in the immunopathogenesis of allograft rejection. Although, improved surgical techniques coupled with improved methods to detect and avoid sensitization against donor human leukocyte antigen (HLA) have improved the immediate and short term function of transplanted organs. However, acute and chronic rejection still remains a vexing problem for the long term function of the transplanted organ. Immediately following organ transplantation, several factors both immune and non immune mechanisms lead to the development of local inflammatory milieu which sets the stage for allograft rejection. Traditionally, development of antibodies (Abs) against mismatched donor HLA have been implicated in the development of Ab mediated rejection. However, recent studies from our laboratory and others have demonstrated that development of humoral and cellular immune responses against non-HLA self-Ags may contribute in the pathogenesis of allograft rejection. There are reports demonstrating that immune responses to self-Ags especially Abs to the self-Ags as well as cellular immune responses especially through IL17 has significant pro-fibrotic properties leading to chronic allograft failure. This review summarizes recent studies demonstrating the role for immune responses to self-Ags in allograft immunity leading to rejection as well as present recent evidence suggesting there is interplay between allo- and autoimmunity leading to allograft dysfunction. Copyright © 2013 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.

Enhancement of antibody response by one-trial conditioning: contrasting results using different antigens.

PubMed

Espinosa, Enrique; Calderas, Tania; Flores-Muciño, Oscar; Pérez-García, Georgina; Vázquez-Camacho, Ana C; Bermúdez-Rattoni, Federico

2004-01-01

New research in conditioned enhancement of antibody response requires a general paradigm effective with different antigens. In this experiment series we applied a one-trial protocol using keyhole limpet hemocyanin immunization as an unconditioned stimulus. Several different conditions were tested. Two different times between conditioning and test trial, two relevant antigen doses and the use of an antigen booster during test trial were investigated. We did not find a conditioned effect in any of the conditions used. In contrast, we found a reliable albeit modest conditioned effect using hen egg lysozyme as unconditioned stimulus. By comparing these and other findings we conclude that the number of conditioning trials is a possible requirement for a more reliable conditioning of antibody response.

Endothelial MMP-9 drives the inflammatory response in abdominal aortic aneurysm (AAA).

PubMed

Ramella, Martina; Boccafoschi, Francesca; Bellofatto, Kevin; Md, Antonia Follenzi; Fusaro, Luca; Boldorini, Renzo; Casella, Francesco; Porta, Carla; Settembrini, Piergiorgio; Cannas, Mario

2017-01-01

Progression of abdominal aortic aneurysm (AAA) is typified by chronic inflammation and extracellular matrix (ECM) degradation of the aortic wall. Vascular inflammation involves complex interactions among inflammatory cells, endothelial cells (ECs), vascular smooth muscle cells (vSMCs), and ECM. Although vascular endothelium and medial neoangiogenesis play a key role in AAA, the molecular mechanisms underlying their involvement are only partially understood. In AAA biopsies, we found increased MMP-9, IL-6, and monocyte chemoattractant protein-1 (MCP-1), which correlated with massive medial neo-angiogenesis (C4d positive staining). In this study, we developed an in vitro model in order to characterize the role of endothelial matrix metalloproteinase-9 (e-MMP-9) as a potential trigger of medial disruption and in the inflammatory response bridging between ECs and vSMC. Lentiviral-mediated silencing of e-MMP-9 through RNA interference inhibited TNF-alpha-mediated activation of NF-κB in EA.hy926 human endothelial cells. In addition, EA.hy926 cells void of MMP-9 failed to migrate in a 3D matrix. Moreover, silenced EA.hy926 affected vSMC behavior in terms of matrix remodeling. In fact, also MMP-9 in vSMC resulted inhibited when endothelial MMP-9 was suppressed.

Analysis of Host Responses to Mycobacterium tuberculosis Antigens in a Multi-Site Study of Subjects with Different TB and HIV Infection States in Sub-Saharan Africa

PubMed Central

Sutherland, Jayne S.; Lalor, Maeve K.; Black, Gillian F.; Ambrose, Lyn R.; Loxton, Andre G.; Chegou, Novel N.; Kassa, Desta; Mihret, Adane; Howe, Rawleigh; Mayanja-Kizza, Harriet; Gomez, Marie P.; Donkor, Simon; Franken, Kees; Hanekom, Willem; Klein, Michel R.; Parida, Shreemanta K.; Boom, W. Henry; Thiel, Bonnie A.; Crampin, Amelia C.; Ota, Martin; Walzl, Gerhard; Ottenhoff, Tom H. M.; Dockrell, Hazel M.; Kaufmann, Stefan H. E.

2013-01-01

Background Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. Methods We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. Results There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST- and TST+ contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST+ contacts (LTBI) compared to TB and TST- contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. Conclusions Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may

Analysis of host responses to Mycobacterium tuberculosis antigens in a multi-site study of subjects with different TB and HIV infection states in sub-Saharan Africa.

PubMed

Sutherland, Jayne S; Lalor, Maeve K; Black, Gillian F; Ambrose, Lyn R; Loxton, Andre G; Chegou, Novel N; Kassa, Desta; Mihret, Adane; Howe, Rawleigh; Mayanja-Kizza, Harriet; Gomez, Marie P; Donkor, Simon; Franken, Kees; Hanekom, Willem; Klein, Michel R; Parida, Shreemanta K; Boom, W Henry; Thiel, Bonnie A; Crampin, Amelia C; Ota, Martin; Walzl, Gerhard; Ottenhoff, Tom H M; Dockrell, Hazel M; Kaufmann, Stefan H E

2013-01-01

Tuberculosis (TB) remains a global health threat with 9 million new cases and 1.4 million deaths per year. In order to develop a protective vaccine, we need to define the antigens expressed by Mycobacterium tuberculosis (Mtb), which are relevant to protective immunity in high-endemic areas. We analysed responses to 23 Mtb antigens in a total of 1247 subjects with different HIV and TB status across 5 geographically diverse sites in Africa (South Africa, The Gambia, Ethiopia, Malawi and Uganda). We used a 7-day whole blood assay followed by IFN-γ ELISA on the supernatants. Antigens included PPD, ESAT-6 and Ag85B (dominant antigens) together with novel resuscitation-promoting factors (rpf), reactivation proteins, latency (Mtb DosR regulon-encoded) antigens, starvation-induced antigens and secreted antigens. There was variation between sites in responses to the antigens, presumably due to underlying genetic and environmental differences. When results from all sites were combined, HIV- subjects with active TB showed significantly lower responses compared to both TST(-) and TST(+) contacts to latency antigens (Rv0569, Rv1733, Rv1735, Rv1737) and the rpf Rv0867; whilst responses to ESAT-6/CFP-10 fusion protein (EC), PPD, Rv2029, TB10.3, and TB10.4 were significantly higher in TST(+) contacts (LTBI) compared to TB and TST(-) contacts fewer differences were seen in subjects with HIV co-infection, with responses to the mitogen PHA significantly lower in subjects with active TB compared to those with LTBI and no difference with any antigen. Our multi-site study design for testing novel Mtb antigens revealed promising antigens for future vaccine development. The IFN-γ ELISA is a cheap and useful tool for screening potential antigenicity in subjects with different ethnic backgrounds and across a spectrum of TB and HIV infection states. Analysis of cytokines other than IFN-γ is currently on-going to determine correlates of protection, which may be useful for vaccine efficacy

Impact of antigens, adjuvants and strains on sexually dimorphic antibody response to vaccines in mice.

PubMed

Li, Xin; Guo, Sheng; Yang, Lei; Hua, Li; Li, Zhiqin; Hao, Xu; Yu, Yongli; Sun, Wei; Wang, Liying

2017-07-01

Sexually dimorphic antibody response to vaccines has long been noticed. In addition to sex hormones, other factors such as antigens, adjuvants and strains of mice, as shown by indirect evidence, could also impact the sexual dimorphism. To clarify this, we immunized both gender mice of distinct strains with inactivated FMDV or HBsAg with or without adjuvants, and detected the specific antibody response of the mice. We found that in absence of adjuvants, the recombinant HBsAg but not the inactivated FMDV induced enhanced IgG antibody response in the female BALB/c mice. The o/w emulsion could facilitate the HBsAg to induce the comparable level of IgG antibodies in the male BALB/c mice as that in the females. The o/w emulsion rather than ISA206, a w/o/w emulsion, could assist the inactivated FMDV to induce higher levels of IgM antibodies in the female BALB/c mice. Moreover, the sexually dimorphic antibody response varied among the ICR, BALB/c and the F1 (BALB/c × C57BL/6) mice. Thus the data suggest that antigens, adjuvants and strains all impact the sexually dimorphic antibody response to vaccines and may provide insights for developing gender-based vaccines. Copyright © 2017 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.

Temporal and spatial correlation of platelet-activating factor-induced increases in endothelial [Ca²⁺]i, nitric oxide, and gap formation in intact venules.

PubMed

Zhou, Xueping; He, Pingnian

2011-11-01

We have previously demonstrated that platelet-activating factor (PAF)-induced increases in microvessel permeability were associated with endothelial gap formation and that the magnitude of peak endothelial intracellular Ca(2+) concentration ([Ca(2+)](i)) and nitric oxide (NO) production at the single vessel level determines the degree of the permeability increase. This study aimed to examine whether the magnitudes of PAF-induced peak endothelial [Ca(2+)](i), NO production, and gap formation are correlated at the individual endothelial cell level in intact rat mesenteric venules. Endothelial gaps were quantified by the accumulation of fluorescent microspheres at endothelial clefts using confocal imaging. Endothelial [Ca(2+)](i) was measured on fura-2- or fluo-4-loaded vessels, and 4,5-diaminofluorescein (DAF-2) was used for NO measurements. The results showed that increases in endothelial [Ca(2+)](i), NO production, and gap formation occurred in all endothelial cells when vessels were exposed to PAF but manifested a spatial heterogeneity in magnitudes among cells in each vessel. PAF-induced peak endothelial [Ca(2+)](i) preceded the peak NO production by 0.6 min at the cellular level, and the magnitudes of NO production and gap formation linearly correlated with that of the peak endothelial [Ca(2+)](i) in each cell, suggesting that the initial levels of endothelial [Ca(2+)](i) determine downstream NO production and gap formation. These results provide direct evidence from intact venules that inflammatory mediator-induced increases in microvessel permeability are associated with the generalized formation of endothelial gaps around all endothelial cells. The spatial differences in the molecular signaling that were initiated by the heterogeneous endothelial Ca(2+) response contribute to the heterogeneity in permeability increases along the microvessel wall during inflammation.

Targeting Tumor Necrosis Factor-α with Adalimumab: Effects on Endothelial Activation and Monocyte Adhesion

PubMed Central

Oberoi, Raghav; Schuett, Jutta; Schuett, Harald; Koch, Ann-Kathrin; Luchtefeld, Maren

2016-01-01

Objective It is well known that atherosclerotic inflammatory vascular disease is critically driven by oxidized lipids and cytokines. In this regard, tumor necrosis factor (TNF)-α is known as a crucial mediator of early pro-atherosclerotic events. Epidemiologic data suggest that blockade of TNF-α has beneficial effects on vascular outcomes in patients with rheumatoid arthritis, however, detailed mechanistic studies are still lacking. This study aims to elucidate effects of TNF-α blockade by adalimumab–which is approved for several inflammatory disorders–on endothelial activation and monocyte adhesion under pro-atherosclerotic conditions. Methods and Results Phorbol myristate acetate (PMA) differentiated THP-1 macrophages were stimulated with oxidized low density lipoprotein and subsequent analysis of this conditioned media (oxLDL CM) revealed a strong release of TNF-α. The TNF-α rich supernatant led to activation of human umbilical vein endothelial cells (HUVEC) as shown by enhanced expression of major adhesion molecules, such as vascular cell adhesion molecule-1 (VCAM-1), intercellular adhesion molecule-1 (ICAM-1) and E-selectin which was suppressed by the TNF-α inhibitor adalimumab. Accordingly, adalimumab effectively prevented THP-1 monocyte adhesion to endothelial cells under static as well as under flow conditions. Furthermore, adalimumab suppressed endothelial leakage as shown by Evan's blue diffusion across a confluent endothelial monolayer. Of note, after intraperitoneal injection we detected abundant deposition of fluorophore-labelled adalimumab in atherosclerotic plaques of hypercholesterolemic mice. Conclusion Our results show that adalimumab prevents major inflammatory effects of TNF-α on endothelial activation, endothelial monocyte adhesion, endothelial leakage and therefore extends the therapeutic options of adalimumab to limit vascular inflammation. PMID:27467817

Antigen Specific Responses and ANA production in B6.Sle1b mice: A role for SAP

PubMed Central

Jennings, Paula; Chan, Alice; Schwartzberg, Pamela; Wakeland, Edward K.; Yuan, Dorothy

2010-01-01

B6.Sle1b mice, which contain the Sle1b gene interval derived from lupus prone NZM2410 mice on a C57BL/6 background, present with gender-biased, highly penetrant anti-nuclear antibody (ANA) production. To obtain some insight into the possible induction mechanism of autoantibodies in these mice we compared antigen specific T dependent (TD) and T independent (TI-II) responses between B6.Sle1b and B6 mice before the development of high ANA titers. Our results show that B6.Sle1b mice mount enhanced responses to a TI-II antigen. Additionally, the memory T cell response generated by a TD antigen was also increased. This enhancement correlates with the greater ability of B cells from B6.Sle1b mice to present antigen to T cells. The SLAM Associated Protein (SAP) is critical for signaling of many of the molecules encoded by the SLAM/CD2 gene cluster, candidates for mediating the Sle1b phenotype; therefore, we also investigated the effect of sap deletion in these strains on the TD and TI-II responses as well as on ANA production. The results of these studies of responses to non-self antigens provide further insight for the mechanism by which responses to self-antigens might be initiated in the context of specific genetic alterations. PMID:18845419

Antigen-dependent fluorescence response of anti-c-Myc Quenchbody studied by molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Mori, Yoshiharu; Okumura, Hisashi; Watanabe, Takayoshi; Hohsaka, Takahiro

2018-04-01

We performed metadynamics molecular dynamics simulations to reveal mechanism of antigen-dependent fluorescence response observed for site-specifically fluorescent-labeled single-chain antibody against c-Myc peptide antigen. We found that VH and VL bind with each other only when the antigen exists and that the fluorophore labeled at the N-terminus of VH interacts with Trp103 most stably. These results support the mechanism proposed from previous experiments: In the absence of antigen, Trp residues are partially exposed at the interface of VH and quench the fluorophore. In the presence of antigen, the Trp residues are buried between VH and VL , and the quenching is eliminated.

The targeting expression of the vascular endothelial growth factor gene in endothelial cells regulated by HRE.ppET-1.

PubMed

Zheng, Xiangrong; Zhang, Shangshang; Yang, Yujia; Wang, Xia; Zhong, Le; Yu, Xiaohe

2008-11-01

The success of gene therapy depends largely on the efficacy of gene delivery vector systems that can deliver genes to target organs or cells selectively and efficiently with minimal toxicity. Here, we show that by using the HRE.ppET-1 regulatory element, we were able to restrict expression of the transgene of vascular endothelial growth factor (VEGF) to endothelial cells exclusively in hypoxic conditions. Eukaryotic expression vectors such as pEGFP-HRE.ppET-1, pcDNA3.1-VEGF+Pa, pcDNA3.1-ppET-1+ EGF+Pa, and pcDNA3.1-HRE.ppET-1+VEGF+Pa were constructed by using a series of nuclear molecule handling methods like PCR, enzyme digestion. The recombinant vectors were transfected into HUVEC cells and HL7702 cells by the lipofectin method. GFP expression was observed with a fluorescence microscope to validate the specificity of expression in endothelial cells under the regulation of HRE.ppET-1 element. Cobalt chloride (final concentration 100 mumol/L) was added to the medium to mimic hypoxia in vitro. After transfection of vectors, the expression of VEGF mRNA was detected by RT-PCR, and the expression of VEGF was detected by Western blotting and ELISA methods under normoxia and hypoxia, respectively. The cell proliferation rate was detected by the MTT test. The expression of GFP revealed that the exterior gene was transcripted effectively in endothelial cells regulated by the HRE.ppET-1 element, while the expression of GFP was very weak in nonendothelial cells. The results of RT-PCR, Western blotting and ELISA showed that VEGF gene expression in the pcDNA3.1-HRE.ppET-1+VEGF+Pa group and in the pcDNA3.1-ppET-1+VEGF+Pa group was higher in hypoxia than it was in normoxia (P<0.05). The MTT test showed that the proliferation rate of HUVEC transfected with HPVA under hypoxia exceeded that of the control group. We conclude that the HRE.ppET-1 element was expressed specifically in endothelial cells, and can increase the expression of VEGF in hypoxia and stimulate proliferation of

Acidosis Activation of the Proton-Sensing GPR4 Receptor Stimulates Vascular Endothelial Cell Inflammatory Responses Revealed by Transcriptome Analysis

PubMed Central

Dong, Lixue; Li, Zhigang; Leffler, Nancy R.; Asch, Adam S.; Chi, Jen-Tsan; Yang, Li V.

2013-01-01

Acidic tissue microenvironment commonly exists in inflammatory diseases, tumors, ischemic organs, sickle cell disease, and many other pathological conditions due to hypoxia, glycolytic cell metabolism and deficient blood perfusion. However, the molecular mechanisms by which cells sense and respond to the acidic microenvironment are not well understood. GPR4 is a proton-sensing receptor expressed in endothelial cells and other cell types. The receptor is fully activated by acidic extracellular pH but exhibits lesser activity at the physiological pH 7.4 and minimal activity at more alkaline pH. To delineate the function and signaling pathways of GPR4 activation by acidosis in endothelial cells, we compared the global gene expression of the acidosis response in primary human umbilical vein endothelial cells (HUVEC) with varying level of GPR4. The results demonstrated that acidosis activation of GPR4 in HUVEC substantially increased the expression of a number of inflammatory genes such as chemokines, cytokines, adhesion molecules, NF-κB pathway genes, and prostaglandin-endoperoxidase synthase 2 (PTGS2 or COX-2) and stress response genes such as ATF3 and DDIT3 (CHOP). Similar GPR4-mediated acidosis induction of the inflammatory genes was also noted in other types of endothelial cells including human lung microvascular endothelial cells and pulmonary artery endothelial cells. Further analyses indicated that the NF-κB pathway was important for the acidosis/GPR4-induced inflammatory gene expression. Moreover, acidosis activation of GPR4 increased the adhesion of HUVEC to U937 monocytic cells under a flow condition. Importantly, treatment with a recently identified GPR4 antagonist significantly reduced the acidosis/GPR4-mediated endothelial cell inflammatory response. Taken together, these results show that activation of GPR4 by acidosis stimulates the expression of a wide range of inflammatory genes in endothelial cells. Such inflammatory response can be suppressed by

Profile of von Willebrand factor antigen and von Willebrand factor propeptide in an overall TIA and ischaemic stroke population and amongst subtypes.

PubMed

Tobin, W O; Kinsella, J A; Kavanagh, G F; O'Donnell, J S; McGrath, R T; Tierney, S; Egan, B; Feeley, T M; Coughlan, T; Collins, D R; O'Neill, D; Murphy, Sjx; Lim, S J; Murphy, R P; McCabe, Djh

2017-04-15

Von Willebrand factor propeptide (VWF:Ag II) is proposed to be a more sensitive marker of acute endothelial activation than von Willebrand factor antigen (VWF:Ag). Simultaneous data on VWF:Ag and VWF:Ag II profiles are very limited following TIA and ischaemic stroke. In this prospective, observational, case-control study, plasma VWF:Ag and VWF:Ag II levels were quantified in 164 patients≤4weeks of TIA or ischaemic stroke (baseline), and then ≥14days (14d) and ≥90days (90d) later, and compared with those from 27 healthy controls. TIA and stroke subtyping was performed according to the TOAST classification. The relationship between VWF:Ag and VWF:Ag II levels and platelet activation status was assessed. 'Unadjusted' VWF:Ag and VWF:Ag II levels were higher in patients at baseline, 14d and 90d than in controls (p≤0.03). VWF:Ag levels remained higher in patients than controls at baseline (p≤0.03), but not at 14d or 90d after controlling for differences in age or hypertension, and were higher in patients at baseline and 90d after controlling for smoking status (p≤0.04). 'Adjusted' VWF:Ag II levels were not higher in patients than controls after controlling for age, hypertension or smoking (p≥0.1). Patients with symptomatic carotid stenosis (N=46) had higher VWF:Ag and VWF:Ag II levels than controls at all time-points (p≤0.002). There was no significant correlation between platelet activation status and VWF:Ag or VWF:Ag II levels. VWF:Ag and VWF:Ag II levels are increased in an overall TIA and ischaemic stroke population, especially in patients with recently symptomatic carotid stenosis. VWF:Ag II was not superior to VWF:Ag at detecting acute endothelial activation in this cohort and might reflect timing of blood sampling in our study. Copyright © 2017 Elsevier B.V. All rights reserved.

Constitutive production and thrombin-induced release of vascular endothelial growth factor by human megakaryocytes and platelets

PubMed Central

Möhle, Robert; Green, David; Moore, Malcolm A. S.; Nachman, Ralph L.; Rafii, Shahin

1997-01-01

We have shown that coculture of bone marrow microvascular endothelial cells with hematopoietic progenitor cells results in proliferation and differentiation of megakaryocytes. In these long-term cultures, bone marrow microvascular endothelial cell monolayers maintain their cellular integrity in the absence of exogenous endothelial growth factors. Because this interaction may involve paracrine secretion of cytokines, we evaluated megakaryocytic cells for secretion of vascular endothelial growth factor (VEGF). Megakaryocytes (CD41a+) were generated by ex vivo expansion of hematopoietic progenitor cells with kit-ligand and thrombopoietin for 10 days and further purified with immunomagnetic microbeads. Using reverse transcription–PCR, we showed that megakaryocytic cell lines (Dami, HEL) and purified megakaryocytes expressed mRNA of the three VEGF isoforms (121, 165, and 189 amino acids). Large quantities of VEGF (>1 ng/106 cells/3 days) were detected in the supernatant of Dami cells, ex vivo-generated megakaryocytes, and CD41a+ cells isolated from bone marrow. The constitutive secretion of VEGF by CD41a+ cells was stimulated by growth factors of the megakaryocytic lineage (interleukin 3, thrombopoietin). Western blotting of heparin–Sepharose-enriched supernatant mainly detected the isoform VEGF165. In addition, immunohistochemistry showed intracytoplasmic VEGF in polyploid megakaryocytes. Thrombin stimulation of megakaryocytes and platelets resulted in rapid release of VEGF within 30 min. We conclude that human megakaryocytes produce and secrete VEGF in an inducible manner. Within the bone marrow microenvironment, VEGF secreted by megakaryocytes may contribute to the proliferation of endothelial cells. VEGF delivered to sites of vascular injury by activated platelets may initiate angiogenesis. PMID:9012841

Neisseria Heparin Binding Antigen is targeted by the human alternative pathway C3-convertase

PubMed Central

Di Fede, Martina; Biagini, Massimiliano; Cartocci, Elena; Parillo, Carlo; Greco, Alessandra; Martinelli, Manuele; Marchi, Sara; Pezzicoli, Alfredo; Delany, Isabel

2018-01-01

Neisserial Heparin Binding Antigen (NHBA) is a surface-exposed lipoprotein specific for Neisseria and constitutes one of the three main protein antigens of the Bexsero vaccine. Meningococcal and human proteases, cleave NHBA protein upstream or downstream of a conserved Arg-rich region, respectively. The cleavage results in the release of the C-terminal portion of the protein. The C-terminal fragment originating from the processing of meningococcal proteases, referred to as C2 fragment, exerts a toxic effect on endothelial cells altering the endothelial permeability. In this work, we reported that recombinant C2 fragment has no influence on the integrity of human airway epithelial cell monolayers, consistent with previous findings showing that Neisseria meningitidis traverses the epithelial barrier without disrupting the junctional structures. We showed that epithelial cells constantly secrete proteases responsible for a rapid processing of C2 fragment, generating a new fragment that does not contain the Arg-rich region, a putative docking domain reported to be essential for C2-mediated toxic effect. Moreover, we found that the C3-convertase of the alternative complement pathway is one of the proteases responsible for this processing. Overall, our data provide new insights on the cleavage of NHBA protein during meningococcal infection. NHBA cleavage may occur at different stages of the infection, and it likely has a different role depending on the environment the bacterium is interacting with. PMID:29579105

Differential T cell response against BK virus regulatory and structural antigens: A viral dynamics modelling approach.

PubMed

Blazquez-Navarro, Arturo; Schachtner, Thomas; Stervbo, Ulrik; Sefrin, Anett; Stein, Maik; Westhoff, Timm H; Reinke, Petra; Klipp, Edda; Babel, Nina; Neumann, Avidan U; Or-Guil, Michal

2018-05-01

BK virus (BKV) associated nephropathy affects 1-10% of kidney transplant recipients, leading to graft failure in about 50% of cases. Immune responses against different BKV antigens have been shown to have a prognostic value for disease development. Data currently suggest that the structural antigens and regulatory antigens of BKV might each trigger a different mode of action of the immune response. To study the influence of different modes of action of the cellular immune response on BKV clearance dynamics, we have analysed the kinetics of BKV plasma load and anti-BKV T cell response (Elispot) in six patients with BKV associated nephropathy using ODE modelling. The results show that only a small number of hypotheses on the mode of action are compatible with the empirical data. The hypothesis with the highest empirical support is that structural antigens trigger blocking of virus production from infected cells, whereas regulatory antigens trigger an acceleration of death of infected cells. These differential modes of action could be important for our understanding of BKV resolution, as according to the hypothesis, only regulatory antigens would trigger a fast and continuous clearance of the viral load. Other hypotheses showed a lower degree of empirical support, but could potentially explain the clearing mechanisms of individual patients. Our results highlight the heterogeneity of the dynamics, including the delay between immune response against structural versus regulatory antigens, and its relevance for BKV clearance. Our modelling approach is the first that studies the process of BKV clearance by bringing together viral and immune kinetics and can provide a framework for personalised hypotheses generation on the interrelations between cellular immunity and viral dynamics.

A NOS3 polymorphism determines endothelial response to folate in children with type 1 diabetes or obesity.

PubMed

Wiltshire, Esko J; Peña, Alexia S; MacKenzie, Karen; Bose-Sundernathan, Tulika; Gent, Roger; Couper, Jennifer J

2015-02-01

To determine the effect of polymorphisms in NOS3 and folate pathway enzymes on vascular function and folate status and endothelial response to folate in children with diabetes or obesity. A total of 244 subjects (age 13.8 ± 2.8 years, 125 males) were studied for NOS3 and/or folate pathway polymorphisms using polymerase chain reaction/restriction fragment length polymorphism, including at baseline: 139 with type 1 diabetes; 58 with obesity; and 47 controls. The effect of NOS3 genotype on endothelial response to folate (5 mg) was assessed in 85 subjects with diabetes and 28 obese subjects who received active treatment during intervention trials. Vascular function (flow-mediated dilatation [FMD] and glyceryl trinitrate-mediated dilatation), clinical, and biochemical measurements were assessed at baseline and 8 weeks in folate intervention studies. Folate pathway enzyme and NOS3 polymorphisms did not significantly affect baseline vascular function. The polymorphism in intron 4 of endothelial nitric oxide synthase altered endothelial response to folate significantly: in subjects with diabetes FMD improved by 6.4 ± 5% (insertion carriers) vs 2.3 ± 6.6% (deletion carriers), P = .01; in obese subjects FMD improved by 1.8 ± 5.4% (insertion carriers) and deteriorated by -3.2 ± 7.2% (deletion carriers), P = .05. More subjects carrying the insertion normalized FMD after folate supplementation (insertion 64% vs deletion 28%, χ(2) = 10.14, P = .001). A NOS3 polymorphism predicts endothelial response to folate in children with diabetes or obesity, with implications for vascular risk and folate intervention studies. Copyright © 2015 Elsevier Inc. All rights reserved.

Oral administration of erythrocyte membrane antigen does not suppress anti-Rh(D) antibody responses in humans.

PubMed Central

Barnes, R M; Duguid, J K; Roberts, F M; Risk, J M; Johnson, P M; Finn, R; Hardy, J; Napier, J A; Clarke, C A

1987-01-01

The effects of prior oral administration of erythrocyte membrane preparations (Oral Rh antigen) on the serum anti-Rh(D) antibody response has been evaluated in non-sensitized Rh(D)-negative male volunteers, and in female volunteers sensitized previously by Rh(D)-positive fetal blood during pregnancy. Sixty-one percent (11/18) of males who received oral Rh antigen (either D-positive or D-negative) before intravenous challenge with Rh(D)-positive cells produced detectable antibodies; of these 11, six received oral Rh(D)-negative antigen and five received oral Rh(D)-positive antigen. Seventy-two percent (13/18) of control males, who had received no prior oral Rh antigen, produced antibodies following challenge with Rh(D)-positive cells. Three out of six pre-sensitized females who received oral D-positive or D-negative Rh antigen for 4 weeks, but without intravenous challenge, increased their anti-Rh(D) antibody levels which peaked after 11-18 weeks: two had received Rh(D)-positive antigen, and one Rh(D)-negative antigen. These data indicate that administration of oral Rh antigen before parenteral immunization does not significantly suppress the anti-Rh(D) antibody response. Indeed, oral administration of either Rh(D)-positive or Rh(D)-negative antigen can boost systemic antibody in pre-sensitized females. These results do not support the rationale of treating Rh-sensitized pregnant women with oral Rh antigen. PMID:3113783

Presence of Human T-Cell Responses to the Mycobacterium leprae 45-Kilodalton Antigen Reflects Infection with or Exposure to M. leprae

PubMed Central

Macfarlane, Anne; Mondragon-Gonzalez, Rafael; Vega-Lopez, Francisco; Wieles, Brigitte; de Pena, Josefina; Rodriguez, Obdulia; Suarez y de la Torre, Raul; de Vries, Rene R. P.; Ottenhoff, Tom H. M.; Dockrell, Hazel M.

2001-01-01

The ability of the 45-kDa serine-rich Mycobacterium leprae antigen to stimulate peripheral blood mononuclear cell (PBMC) proliferation and gamma interferon (IFN-γ) production was measured in leprosy patients, household contacts, and healthy controls from areas of endemicity in Mexico. Almost all the tuberculoid leprosy patients gave strong PBMC proliferation responses to the M. leprae 45-kDa antigen (92.8%; n = 14). Responses were lower in lepromatous leprosy patients (60.6%; n = 34), but some responses to the 45-kDa antigen were detected in patients unresponsive to M. leprae sonicate. The proportion of positive responses to the M. leprae 45-kDa antigen was much higher in leprosy contacts (88%; n = 17) than in controls from areas of endemicity (10%; n = 20). None of 15 patients with pulmonary tuberculosis gave a positive proliferation response to the 45-kDa antigen. The 45-kDa antigen induced IFN-γ secretion similar to that induced by the native Mycobacterium tuberculosis 30/31-kDa antigen in tuberculoid leprosy patients and higher responses than those induced by the other recombinant antigens (M. leprae 10- and 65-kDa antigens, thioredoxin, and thioredoxin reductase); in patients with pulmonary tuberculosis it induced lower IFN-γ secretion than the other recombinant antigens. These results suggest that the M. leprae 45-kDa antigen is a potent T-cell antigen which is M. leprae specific in these Mexican donors. This antigen may therefore have diagnostic potential as a new skin test reagent or as an antigen in a simple whole-blood cytokine test. PMID:11329466

Isolation and Characterization of Rat Pituitary Endothelial Cells

PubMed Central

Chaturvedi, Kirti; Sarkar, Dipak K.

2010-01-01

Most previous studies that determined the effect of estradiol on angiogenesis used endothelial cells from nonpituitary sources. Because pituitary tumor tissue receives its blood supply via portal and arterial circulation, it is important to use pituitary-derived endothelial cells in studying pituitary angiogenesis. We have developed a magnetic separation technique to isolate endothelial cells from pituitary tissues and have characterized these cells in primary cultures. Endothelial cells of the pituitary showed the existence of endothelial cell marker, CD31, and of von Willebrand factor protein. These cells in cultures also showed immunore-activity of estrogen receptors alpha and beta. The angiogenic factors, vascular endothelial growth factor and basic fibroblast growth factor, significantly increased proliferation and migration of the pituitary-derived endothelial cells in primary cultures. These results suggest that a magnetic separation technique can be used for enrichment of pituitary-derived endothelial cells for determination of cellular mechanisms governing the vascularization in the pituitary. PMID:17028416

Intraocular and systemic levels of vascular endothelial growth factor in advanced cases of retinopathy of prematurity

PubMed Central

Velez-Montoya, Raul; Clapp, Carmen; Rivera, Jose Carlos; Garcia-Aguirre, Gerardo; Morales-Cantón, Virgilio; Fromow-Guerra, Jans; Guerrero-Naranjo, Jose Luis; Quiroz-Mercado, Hugo

2010-01-01

Purpose: To measure vitreous, aqueous, subretinal fluid and plasma levels of vascular endothelial growth factor in late stages of retinopathy of prematurity. Methods: Interventional study. We enrolled patients with clinical diagnoses of bilateral stage V retinopathy of prematurity, confirmed by b-scan ultrasound and programmed for vitrectomy. During surgery we took samples from blood, aqueous, vitreous, and subretinal fluids. The vascular endothelial growth factor concentration in each sample was measured by ELISA reaction. A control sample of aqueous, vitreous and blood was taken from patients with congenital cataract programmed for phacoemulsification. For statistical analysis, a Mann–Whitney and a Wilcoxon W test was done with a significant P value of 0.05. Results: We took samples of 16 consecutive patients who met the inclusion criteria. The vascular endothelial growth factor levels in the study group were: aqueous, 76.81 ± 61.89 pg/mL; vitreous, 118.53 ± 65.87 pg/mL; subretinal fluid, 1636.58 ± 356.47 pg/mL; and plasma, 74.64 ± 43.94 pg/mL. There was a statistical difference between the study and the control group (P < 0.001) in the aqueous and vitreous samples. Conclusion: Stage 5 retinopathy of prematurity has elevated intraocular levels of vascular endothelial growth factor, which remains high despite severe retinal lesion. There was no statistical difference in plasma levels of the molecule between the control and study group. PMID:20856587

Antigen-specific response of murine immune system toward a yeast beta-glucan preparation, zymosan.

PubMed

Miura, T; Ohno, N; Miura, N N; Adachi, Y; Shimada, S; Yadomae, T

1999-06-01

Zymosan, a particulate beta-glucan preparation from Saccharomyces cerevisiae, shows various biological activities, including anti-tumor activity. We have previously shown that soluble beta-glucan initiated anti-tumor activity was long-lived and was effective even by prophylactic treatment at 1 month prior to tumor challenge. However, the activity by zymosan was relatively short-lived. Antigen-specific responses of mice to zymosan might be a causative mechanism. In this paper, mice were immunized with zymosan and antibody production and antigen-specific responses of lymphocytes to zymosan were analyzed. Sera of zymosan immune mice contained zymosan-specific IgG assessed by enzyme-linked immunosorbent assay and FACS. Spleen and bone marrow cells of zymosan-immune mice showed higher cytokine production in response to zymosan. Specificity of zymosan-specific responses were also analyzed using various derivatives prepared from zymosan. These facts strongly suggested that mice recognize zymosan as antigen in addition to non-specific immune stimulant.

Role of tumour necrosis factor receptor-1 and nuclear factor-κB in production of TNF-α-induced pro-inflammatory microparticles in endothelial cells.

PubMed

Lee, S K; Yang, S-H; Kwon, I; Lee, O-H; Heo, J H

2014-09-02

Tumour necrosis factor-α (TNF-α) is upregulated in many inflammatory diseases and is also a potent agent for microparticle (MP) generation. Here, we describe an essential role of TNF-α in the production of endothelial cell-derived microparticles (EMPs) in vivo and the function of TNF-α-induced EMPs in endothelial cells. We found that TNF-α rapidly increased blood levels of EMPs in mice. Treatment of human umbilical vein endothelial cells (HUVECs) with TNF-α also induced EMP formation in a time-dependent manner. Silencing of TNF receptor (TNFR)-1 or inhibition of the nuclear factor-κB (NF-κB) in HUVECs impaired the production of TNF-α-induced EMP. Incubation of HUVECs with PKH-67-stained EMPs showed that endothelial cells readily engulfed EMPs, and the engulfed TNF-α-induced EMPs promoted the expression of pro-apoptotic molecules and upregulated intercellular adhesion molecule-1 level on the cell surface, which led to monocyte adhesion. Collectively, our findings indicate that the generation of TNF-α-induced EMPs was mediated by TNFR1 or NF-κB and that EMPs can contribute to apoptosis and inflammation of endothelial cells.

Transcriptional responses of human aortic endothelial cells to nanoconstructs used in biomedical applications.

PubMed

Moos, Philip J; Honeggar, Matthew; Malugin, Alexander; Herd, Heather; Thiagarajan, Giridhar; Ghandehari, Hamidreza

2013-08-05

Understanding the potential toxicities of manufactured nanoconstructs used for drug delivery and biomedical applications may help improve their safety. We sought to determine if surface-modified silica nanoparticles and poly(amido amine) dendrimers elicit genotoxic responses on vascular endothelial cells. The nanoconstructs utilized in this study had a distinct geometry (spheres vs worms) and surface charge, which were used to evaluate the contributions of these parameters to any potential adverse effects of these materials. Time-dependent cytotoxicity was found for surfaced-functionalized but geometrically distinct silica materials, while amine-terminated dendrimers displayed time-independent cytotoxicity and carboxylated dendrimers were nontoxic in our assays. Transcriptomic evaluation of human aortic endothelial cell (HAEC) responses indicated time-dependent gene induction following silica exposure, consisting of cell cycle gene repression and pro-inflammatory gene induction. However, the dendrimers did not induce genomic toxicity, despite displaying general cytotoxicity.

Expression of vascular endothelial growth factor in Juvenile Angiofibroma.

PubMed

Hota, Ashutosh; Sarkar, Chitra; Gupta, Siddhartha Datta; Kumar, Rakesh; Bhalla, Ashu Seith; Thakar, Alok

2015-06-01

To examine Juvenile Angiofibroma (JA) tissue for expression of vascular endothelial growth factor (VEGF), and to explore its relationship with puberty status, stage, recurrence and the intraoperative blood loss. Retrospective cohort study of 36 histologically proven cases of JA. Minimum follow up period was 3 years. VEGF expression on tumor cells assessed by immunohistochemistry and graded on two criteria--percentage of cells expressing positivity and the intensity of positivity. These two parameters assessed for impact on puberty status, stage, recurrence, and blood loss. VEGF expression noted on the tumor endothelial cells in 36/36, and on the tumor stromal cells in 34/36. The percentage of cells expressing VEGF and the intensity of expression were not significantly related to puberty status, tumor stage, recurrence, or intra-operative blood loss (p values 0.3-1.0). VEGF expression is near universal in JA. Such expression is independent of puberty status and stage, and does not impact on intra operative blood loss and recurrence. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

Immune responses of B. malayi thioredoxin (TRX) and venom allergen homologue (VAH) chimeric multiple antigen for lymphatic filariasis.

PubMed

Anugraha, Gandhirajan; Jeyaprita, Parasurama Jawaharlal; Madhumathi, Jayaprakasam; Sheeba, Tamilvanan; Kaliraj, Perumal

2013-12-01

Although multiple vaccine strategy for lymphatic filariasis has provided tremendous hope, the choice of antigens used in combination has determined its success in the previous studies. Multiple antigens comprising key vaccine candidates from different life cycle stages would provide a promising strategy if the antigenic combination is chosen by careful screening. In order to analyze one such combination, we have used a chimeric construct carrying the well studied B. malayi antigens thioredoxin (BmTRX) and venom allergen homologue (BmVAH) as a fusion protein (TV) and evaluated its immune responses in mice model. The efficacy of fusion protein vaccine was explored in comparison with the single antigen vaccines and their cocktail. In mice, TV induced significantly high antibody titer of 1,28,000 compared to cocktail vaccine TRX+VAH (50,000) and single antigen vaccine TRX (16,000) or VAH (50,000). Furthermore, TV elicited higher level of cellular proliferative response together with elevated levels of IFN-γ, IL-4 and IL-5 indicating a Th1/Th2 balanced response. The isotype antibody profile showed significantly high level of IgG1 and IgG2b confirming the balanced response elicited by TV. Immunization with TV antigen induced high levels of both humoral and cellular immune responses compared to either cocktail or antigen given alone. The result suggests that TV is highly immunogenic in mice and hence the combination needs to be evaluated for its prophylactic potential.

Tumor necrosis factor-alpha stimulates the production of squamous cell carcinoma antigen in normal squamous cells.

PubMed

Numa, F; Takeda, O; Nakata, M; Nawata, S; Tsunaga, N; Hirabayashi, K; Suminami, Y; Kato, H; Hamanaka, S

1996-01-01

Squamous cell carcinoma (SCC) antigen, a tumor marker of squamous cell carcinoma, is also increased in several nonmalignant skin lesions, e.g. pemphigus. The aim of the present investigation was to determine if tumor necrosis factor-alpha (TNF-alpha), one of the important environmental factors, stimulated the production of SCC antigen in the normal squamous cells. The exposure of normal human epidermal keratinocytes to TNF-alpha (100 IU/ml) for 72 h greatly increased the SCC antigen production. The stimulatory effect of TNF-alpha (1,000 IU/ml) on the production of SCC antigen was also observed in the normal squamous epithelium tissue. These results would be helpful for understanding the increase of SCC antigen in several nonmalignant skin disorders.

Acetylcholine released by endothelial cells facilitates flow‐mediated dilatation

PubMed Central

Wilson, Calum; Lee, Matthew D.

2016-01-01

Key points The endothelium plays a pivotal role in the vascular response to chemical and mechanical stimuli.The endothelium is exquisitely sensitive to ACh, although the physiological significance of ACh‐induced activation of the endothelium is unknown.In the present study, we investigated the mechanisms of flow‐mediated endothelial calcium signalling.Our data establish that flow‐mediated endothelial calcium responses arise from the autocrine action of non‐neuronal ACh released by the endothelium. Abstract Circulating blood generates frictional forces (shear stress) on the walls of blood vessels. These frictional forces critically regulate vascular function. The endothelium senses these frictional forces and, in response, releases various vasodilators that relax smooth muscle cells in a process termed flow‐mediated dilatation. Although some elements of the signalling mechanisms have been identified, precisely how flow is sensed and transduced to cause the release of relaxing factors is poorly understood. By imaging signalling in large areas of the endothelium of intact arteries, we show that the endothelium responds to flow by releasing ACh. Once liberated, ACh acts to trigger calcium release from the internal store in endothelial cells, nitric oxide production and artery relaxation. Flow‐activated release of ACh from the endothelium is non‐vesicular and occurs via organic cation transporters. ACh is generated following mitochondrial production of acetylCoA. Thus, we show ACh is an autocrine signalling molecule released from endothelial cells, and identify a new role for the classical neurotransmitter in endothelial mechanotransduction. PMID:27730645

Vascular endothelial growth factor (VEGF) inhibition--a critical review.

PubMed

Moreira, Irina Sousa; Fernandes, Pedro Alexandrino; Ramos, Maria João

2007-03-01

Angiogenesis, or formation of new blood capillaries from preexisting vessels, plays both beneficial and damaging roles in the organism. It is a result of a complex balance of positive and negative regulators, and vascular endothelial growth factor (VEGF) is one of the most important pro-angiogenic factors involved in tumor angiogenesis. VEGF increases vascular permeability, which might facilitate tumor dissemination via the circulation causing a greater delivery of oxygen and nutrients; it recruits circulating endothelial precursor cells, and acts as a survival factor for immature tumor blood vessels. The endotheliotropic activities of VEGF are mediated through the VEGF-specific tyrosine-kinase receptors: VEGFR-1, VEGFR-2 and VEGFR-3. VEGF and its receptors play a central role in tumor angiogenesis, and therefore the blockade of this pathway is a promising therapeutic strategy for inhibiting angiogenesis and tumor growth. A number of different strategies to inhibit VEGF signal transduction are in development and they include the development of humanized neutralizing anti-VEGF monoclonal antibodies, receptor antagonists, soluble receptors, antagonistic VEGF mutants, and inhibitors of VEGF receptor function. These agents can be divided in two broad classes, namely agents designed to target the VEGF activity and agents designed to target the surface receptor function. The main purpose of this review is to summarize all the available information regarding the importance of the pro-angiogenic factor VEGF in cancer therapy. After an overview of the VEGF family and their respective receptors, we shall focus our attention on the different VEGF-inhibitors existent nowadays. Agents based upon anti-VEGF therapy have provided solid proofs about their success, and therefore we believe that a critical review is of the utmost importance to help researchers in their future work.

Adenovirus-vectored novel African Swine Fever Virus antigens elicit robust immune responses in swine.

PubMed

Lokhandwala, Shehnaz; Waghela, Suryakant D; Bray, Jocelyn; Sangewar, Neha; Charendoff, Chloe; Martin, Cameron L; Hassan, Wisam S; Koynarski, Tsvetoslav; Gabbert, Lindsay; Burrage, Thomas G; Brake, David; Neilan, John; Mwangi, Waithaka

2017-01-01

African Swine Fever Virus (ASFV) is a high-consequence transboundary animal pathogen that often causes hemorrhagic disease in swine with a case fatality rate close to 100%. Lack of treatment or vaccine for the disease makes it imperative that safe and efficacious vaccines are developed to safeguard the swine industry. In this study, we evaluated the immunogenicity of seven adenovirus-vectored novel ASFV antigens, namely A151R, B119L, B602L, EP402RΔPRR, B438L, K205R and A104R. Immunization of commercial swine with a cocktail of the recombinant adenoviruses formulated in adjuvant primed strong ASFV antigen-specific IgG responses that underwent rapid recall upon boost. Notably, most vaccinees mounted robust IgG responses against all the antigens in the cocktail. Most importantly and relevant to vaccine development, the induced antibodies recognized viral proteins from Georgia 2007/1 ASFV-infected cells by IFA and by western blot analysis. The recombinant adenovirus cocktail also induced ASFV-specific IFN-γ-secreting cells that were recalled upon boosting. Evaluation of local and systemic effects of the recombinant adenovirus cocktail post-priming and post-boosting in the immunized animals showed that the immunogen was well tolerated and no serious negative effects were observed. Taken together, these outcomes showed that the adenovirus-vectored novel ASFV antigen cocktail was capable of safely inducing strong antibody and IFN-γ+ cell responses in commercial swine. The data will be used for selection of antigens for inclusion in a multi-antigen prototype vaccine to be evaluated for protective efficacy.

Adenovirus-vectored novel African Swine Fever Virus antigens elicit robust immune responses in swine

PubMed Central

Waghela, Suryakant D.; Bray, Jocelyn; Sangewar, Neha; Charendoff, Chloe; Martin, Cameron L.; Hassan, Wisam S.; Koynarski, Tsvetoslav; Gabbert, Lindsay; Burrage, Thomas G.; Brake, David; Neilan, John; Mwangi, Waithaka

2017-01-01

African Swine Fever Virus (ASFV) is a high-consequence transboundary animal pathogen that often causes hemorrhagic disease in swine with a case fatality rate close to 100%. Lack of treatment or vaccine for the disease makes it imperative that safe and efficacious vaccines are developed to safeguard the swine industry. In this study, we evaluated the immunogenicity of seven adenovirus-vectored novel ASFV antigens, namely A151R, B119L, B602L, EP402RΔPRR, B438L, K205R and A104R. Immunization of commercial swine with a cocktail of the recombinant adenoviruses formulated in adjuvant primed strong ASFV antigen-specific IgG responses that underwent rapid recall upon boost. Notably, most vaccinees mounted robust IgG responses against all the antigens in the cocktail. Most importantly and relevant to vaccine development, the induced antibodies recognized viral proteins from Georgia 2007/1 ASFV-infected cells by IFA and by western blot analysis. The recombinant adenovirus cocktail also induced ASFV-specific IFN-γ-secreting cells that were recalled upon boosting. Evaluation of local and systemic effects of the recombinant adenovirus cocktail post-priming and post-boosting in the immunized animals showed that the immunogen was well tolerated and no serious negative effects were observed. Taken together, these outcomes showed that the adenovirus-vectored novel ASFV antigen cocktail was capable of safely inducing strong antibody and IFN-γ+ cell responses in commercial swine. The data will be used for selection of antigens for inclusion in a multi-antigen prototype vaccine to be evaluated for protective efficacy. PMID:28481911

Polyomavirus Reactivation and Immune Responses to Kidney-Specific Self-Antigens in Transplantation.

PubMed

Seifert, Michael E; Gunasekaran, Muthukumar; Horwedel, Timothy A; Daloul, Reem; Storch, Gregory A; Mohanakumar, Thalachallour; Brennan, Daniel C

2017-04-01

Humoral immune responses against donor antigens are important determinants of long-term transplant outcomes. Reactivation of the polyomavirus BK has been associated with de novo antibodies against mismatched donor HLA antigens in kidney transplantation. The effect of polyomavirus reactivation (BK viremia or JC viruria) on antibodies to kidney-specific self-antigens is unknown. We previously reported excellent 5-year outcomes after minimization of immunosuppression for BK viremia and after no intervention for JC viruria. Here, we report the 10-year results of this trial ( n =193) along with a nested case-control study ( n =40) to explore associations between polyomavirus reactivation and immune responses to the self-antigens fibronectin (FN) and collagen type-IV (Col-IV). Consistent with 5-year findings, subjects taking tacrolimus, compared with those taking cyclosporin, had less acute rejection (11% versus 22%, P =0.05) and graft loss (9% versus 22%, P =0.01) along with better transplant function (eGFR 65±19 versus 50±24 ml/min per 1.73 m 2 , P <0.001) at 10 years. Subjects undergoing immunosuppression reduction for BK viremia had 10-year outcomes similar to those without viremia. In the case-control study, antibodies to FN/Col-IV were more prevalent during year 1 in subjects with polyomavirus reactivation than in those without reactivation (48% versus 11%, P= 0.04). Subjects with antibodies to FN/Col-IV had more acute rejection than did those without these antibodies (38% versus 8%, P =0.02). These data demonstrate the long-term safety and effectiveness of minimizing immunosuppression to treat BK viremia. Furthermore, these results indicate that polyomavirus reactivation associates with immune responses to kidney-specific self-antigens that may increase the risk for acute rejection through unclear mechanisms. Copyright © 2017 by the American Society of Nephrology.

Transfection of the Human Heme Oxygenase Gene Into Rabbit Coronary Microvessel Endothelial Cells: Protective Effect Against Heme and Hemoglobin Toxicity

NASA Astrophysics Data System (ADS)

Abraham, N. G.; Lavrovsky, Y.; Schwartzman, M. L.; Stoltz, R. A.; Levere, R. D.; Gerritsen, M. E.

1995-07-01

Heme oxygenase (HO) is a stress protein and has been suggested to participate in defense mechanisms against agents that may induce oxidative injury such as metals, endotoxin, heme/hemoglobin, and various cytokines. Overexpression of HO in cells might therefore protect against oxidative stress produced by certain of these agents, specifically heme and hemoglobin, by catalyzing their degradation to bilirubin, which itself has antioxidant properties. We report here the successful in vitro transfection of rabbit coronary microvessel endothelial cells with a functioning gene encoding the human HO enzyme. A plasmid containing the cytomegalovirus promoter and the human HO cDNA complexed to cationic liposomes (Lipofectin) was used to transfect rabbit endothelial cells. Cells transfected with human HO exhibited an ≈3.0-fold increase in enzyme activity and expressed a severalfold induction of human HO mRNA as compared with endogenous rabbit HO mRNA. Transfected and nontransfected cells expressed factor VIII antigen and exhibited similar acetylated low-density lipoprotein uptake (two important features that characterize endothelial cells) with >85% of cells staining positive for each marker. Moreover, cells transfected with the human HO gene acquired substantial resistance to toxicity produced by exposure to recombinant hemoglobin and heme as compared with nontransfected cells. The protective effect of HO overexpression against heme/hemoglobin toxicity in endothelial cells shown in these studies provides direct evidence that the inductive response of human HO to such injurious stimuli represents an important tissue adaptive mechanism for moderating the severity of cell damage produced by these blood components.

Endocrine gland-derived vascular endothelial growth factor (EG-VEGF) expression in colorectal cancer.

PubMed

Nagano, Hideki; Goi, Takanori; Koneri, Kenji; Hirono, Yasuo; Katayama, Kanji; Yamaguchi, Akio

2007-12-01

Vascular endothelial growth factor (VEGF) is known as an important factor in the growth and metastasis of cancer cells. In 2001, a novel angiogenesis factor, endocrine gland-derived vascular endothelial growth factor (EG-VEGF), was cloned. In this study, we investigated the expression of EG-VEGF in colorectal cancer, the relationship between its expression and clinicopathological factors, and the in vitro activity of EG-VEGF transfectants. We determined expression levels of EG-VEGF in 113 advanced colorectal cancers resected in our hospital by quantitative PCR, and compared the expression levels and clinicopathological findings by multivariate analyses. The expression of EG-VEGF mRNA was positive in 31 cancers and negative in 82 cancers. We found that compared with the negative expression of the EG-VEGF gene, its positive expression was more frequently associated with hematogenous metastasis, and was associated with a poorer survival rate. In addition, EG-VEGF transfectants showed a higher degree of in vitro tubular formation than control cells. We speculate that, in colorectal cancers, the EG-VEGF gene functions as an important factor in angiogenesis in primary and metastatic lesions, and consider that it is useful as a novel prognostic factor. EG-VEGF molecule-targeted therapy has the potential for improving survival rates.

CD8+ T-cell responses rapidly select for antigen-negative tumor cells in the prostate.

PubMed

Bak, S Peter; Barnkob, Mike Stein; Wittrup, K Dane; Chen, Jianzhu

2013-12-01

Stimulation of patients' immune systems for the treatment of solid tumors is an emerging therapeutic paradigm. The use of enriched autologous T cells for adoptive cell therapy or vaccination with antigen-loaded dendritic cells have shown clinical efficacy in melanoma and prostate cancer, respectively. However, the long-term effects of immune responses on selection and outgrowth of antigen-negative tumor cells in specific tumor types must be determined to understand and achieve long-term therapeutic effects. In this study, we have investigated the expression of a tumor-specific antigen in situ after treatment with tumor-specific CD8(+) T cells in an autochthonous mouse model of prostate cancer. After T-cell treatment, aggregates of dead antigen-positive tumor cells were concentrated in the lumen of the prostate gland and were eventually eliminated from the prostate tissue. Despite the elimination of antigen-positive tumor cells, prostate tumor continued to grow in T-cell-treated mice. Interestingly, the remaining tumor cells were antigen negative and downregulated MHC class I expression. These results show that CD8(+) T cells are effective in eliminating antigen-bearing prostate tumor cells but they also can select for the outgrowth of antigen-negative tumor cells. These findings provide insights into the requirements for an effective cancer immunotherapy within the prostate that not only induces potent immune responses but also avoids selection and outgrowth of antigen-negative tumor cells. ©2013 AACR.

Surface plasmon resonance measurements of plasma antibody avidity during primary and secondary responses to anthrax protective antigen

PubMed Central

Lynch, Heather E.; Stewart, Shelley M.; Kepler, Thomas B.; Sempowski, Gregory D.; Alam, S. Munir

2014-01-01

Establishment of humoral immunity against pathogens is dependent on events that occur in the germinal center and the subsequent induction of high-affinity neutralizing antibodies. Quantitative assays that allow monitoring of affinity maturation and duration of antibody responses can provide useful information regarding the efficacy of vaccines and adjuvants. Using an anthrax protective antigen (rPA) and alum model antigen/adjuvant system, we describe a methodology for monitoring antigen-specific serum antibody concentration and avidity by surface plasmon resonance during primary and secondary immune responses. Our analyses showed that following a priming dose in mice, rPA-specific antibody concentration and avidity increases over time and reaches a maximal response in about six weeks, but gradually declines in the absence of antigenic boost. Germinal center reactions were observed early with maximal development achieved during the primary response, which coincided with peak antibody avidity responses to primary immunization. Boosting with antigen resulted in a rapid increase in rPA-specific antibody concentration and five-fold increase in avidity, which was not dependent on sustained GC development. The described methodology couples surface plasmon resonance-based plasma avidity measurements with germinal center analysis and provides a novel way to monitor humoral responses that can play a role in facilitating vaccine and adjuvant development. PMID:24316020

Bone Morphogenic Protein 4-Smad-Induced Upregulation of Platelet-Derived Growth Factor AA Impairs Endothelial Function.

PubMed

Hu, Weining; Zhang, Yang; Wang, Li; Lau, Chi Wai; Xu, Jian; Luo, Jiang-Yun; Gou, Lingshan; Yao, Xiaoqiang; Chen, Zhen-Yu; Ma, Ronald Ching Wan; Tian, Xiao Yu; Huang, Yu

2016-03-01

Bone morphogenic protein 4 (BMP4) is an important mediator of endothelial dysfunction in cardio-metabolic diseases, whereas platelet-derived growth factors (PDGFs) are major angiogenic and proinflammatory mediator, although the functional link between these 2 factors is unknown. The present study investigated whether PDGF mediates BMP4-induced endothelial dysfunction in diabetes mellitus. We generated Ad-Bmp4 to overexpress Bmp4 and Ad-Pdgfa-shRNA to knockdown Pdgfa in mice through tail intravenous injection. SMAD4-shRNA lentivirus, SMAD1-shRNA, and SMAD5 shRNA adenovirus were used for knockdown in human and mouse endothelial cells. We found that PDGF-AA impaired endothelium-dependent vasodilation in aortas and mesenteric resistance arteries. BMP4 upregulated PDGF-AA in human and mouse endothelial cells, which was abolished by BMP4 antagonist noggin or knockdown of SMAD1/5 or SMAD4. BMP4-impared relaxation in mouse aorta was also ameliorated by PDGF-AA neutralizing antibody. Tail injection of Ad-Pdgfa-shRNA ameliorates endothelial dysfunction induced by Bmp4 overexpression (Ad-Bmp4) in vivo. Serum PDGF-AA was elevated in both diabetic patients and diabetic db/db mice compared with nondiabetic controls. Pdgfa-shRNA or Bmp4-shRNA adenovirus reduced serum PDGF-AA concentration in db/db mice. PDGF-AA neutralizing antibody or tail injection with Pdgfa-shRNA adenovirus improved endothelial function in aortas and mesenteric resistance arteries from db/db mice. The effect of PDGF-AA on endothelial function in mouse aorta was also inhibited by Ad-Pdgfra-shRNA to inhibit PDGFRα. The present study provides novel evidences to show that PDGF-AA impairs endothelium-dependent vasodilation and PDGF-AA mediates BMP4-induced adverse effect on endothelial cell function through SMAD1/5- and SMAD4-dependent mechanisms. Inhibition of PGDF-AA ameliorates vascular dysfunction in diabetic mice. © 2016 American Heart Association, Inc.

Angiogenic Type I Collagen Extracellular Matrix Integrated with Recombinant Bacteriophages Displaying Vascular Endothelial Growth Factors.

PubMed

Yoon, Junghyo; Korkmaz Zirpel, Nuriye; Park, Hyun-Ji; Han, Sewoon; Hwang, Kyung Hoon; Shin, Jisoo; Cho, Seung-Woo; Nam, Chang-Hoon; Chung, Seok

2016-01-21

Here, a growth-factor-integrated natural extracellular matrix of type I collagen is presented that induces angiogenesis. The developed matrix adapts type I collagen nanofibers integrated with synthetic colloidal particles of recombinant bacteriophages that display vascular endothelial growth factor (VEGF). The integration is achieved during or after gelation of the type I collagen and the matrix enables spatial delivery of VEGF into a desired region. Endothelial cells that contact the VEGF are found to invade into the matrix to form tube-like structures both in vitro and in vivo, proving the angiogenic potential of the matrix. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Mechanical Adaptability of the MMP-Responsive Film Improves the Functionality of Endothelial Cell Monolayer.

PubMed

Hu, Mi; Chang, Hao; Zhang, He; Wang, Jing; Lei, Wen-Xi; Li, Bo-Chao; Ren, Ke-Feng; Ji, Jian

2017-07-01

Extracellular matrix and cells are inherent in coordinating and adapting to each other during all physiological and pathological processes. Synthetic materials, however, show rarely reciprocal and spatiotemporal responses to cells, and lacking self-adapting properties as well. Here, a mechanical adaptability based on the matrix metalloproteinase (MMPs) sensitive polyelectrolyte film is reported. Poly-lysine (PLL) and methacrylated hyaluronic acid (HA-MA) nanolayers are employed to build the thin film through the layer-by-layer assembly, and it is further crosslinked using MMP sensitive peptides, which endows the films with changeable mechanical properties in response to MMPs. It is demonstrated that stiffness of the (PLL/HA-MA) films increases with the crosslinking, and then decreases in response to a treatment of enzyme. Consequently, the crosslinked (PLL/HA-MA) films reveal effective growth of endothelial cells (ECs), leading to fast formation of EC monolayer. Importantly, significantly improved endothelial function of the EC monolayer, which is characterized by integrity, biomolecules release, expression of function related gene, and antithrombotic properties, is achieved along with the decrosslinking of the film because of EC-secreted MMPs. These results suggest that mechanical adaptability of substrate in Young's modulus plays a significant role in endothelial progression, which shows great application potential in tissue engineering, regenerative medicine, and organ-on-a-chip. © 2017 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

In vitro leukocyte response of three-spined sticklebacks (Gasterosteus aculeatus) to helminth parasite antigens.

PubMed

Franke, Frederik; Rahn, Anna K; Dittmar, Janine; Erin, Noémie; Rieger, Jennifer K; Haase, David; Samonte-Padilla, Irene E; Lange, Joseph; Jakobsen, Per J; Hermida, Miguel; Fernández, Carlos; Kurtz, Joachim; Bakker, Theo C M; Reusch, Thorsten B H; Kalbe, Martin; Scharsack, Jörn P

2014-01-01

Helminth parasites of teleost fish have evolved strategies to evade and manipulate the immune responses of their hosts. Responsiveness of fish host immunity to helminth antigens may therefore vary depending on the degree of host-parasite counter-adaptation. Generalist parasites, infective for a number of host species, might be unable to adapt optimally to the immune system of a certain host species, while specialist parasites might display high levels of adaptation to a particular host species. The degree of adaptations may further differ between sympatric and allopatric host-parasite combinations. Here, we test these hypotheses by in vitro exposure of head kidney leukocytes from three-spined sticklebacks (Gasterosteus aculeatus) to antigens from parasites with a broad fish host range (Diplostomum pseudospathaceum, Triaenophorus nodulosus), a specific fish parasite of cyprinids (Ligula intestinalis) and parasites highly specific only to a single fish species as second intermediate host (Schistocephalus pungitii, which does not infect G. aculeatus, and Schistocephalus solidus, infecting G. aculeatus). In vitro responses of stickleback leukocytes to S. solidus antigens from six European populations, with S. solidus prevalence from <1% to 66% were tested in a fully crossed experimental design. Leukocyte cultures were analysed by means of flow cytometry and a chemiluminescence assay to quantify respiratory burst activity. We detected decreasing magnitudes of in vitro responses to antigens from generalist to specialist parasites and among specialists, from parasites that do not infect G. aculeatus to a G. aculeatus-infecting species. Generalist parasites seem to maintain their ability to infect different host species at the costs of relatively higher immunogenicity compared to specialist parasites. In a comparison of sympatric and allopatric combinations of stickleback leukocytes and antigens from S. solidus, magnitudes of in vitro responses were dependent on

Kaposi's Sarcoma-Associated Herpesvirus Interleukin-6 Modulates Endothelial Cell Movement by Upregulating Cellular Genes Involved in Migration.

PubMed

Giffin, Louise; West, John A; Damania, Blossom

2015-12-08

Kaposi's sarcoma-associated herpesvirus (KSHV) is the causative agent of human Kaposi's sarcoma, a tumor that arises from endothelial cells, as well as two B cell lymphoproliferative diseases, primary effusion lymphoma and multicentric Castleman's disease. KSHV utilizes a variety of mechanisms to evade host immune responses and promote cellular transformation and growth in order to persist for the life of the host. A viral homolog of human interleukin-6 (hIL-6) named viral interleukin-6 (vIL-6) is encoded by KSHV and expressed in KSHV-associated cancers. Similar to hIL-6, vIL-6 is secreted, but the majority of vIL-6 is retained within the endoplasmic reticulum, where it can initiate functional signaling through part of the interleukin-6 receptor complex. We sought to determine how intracellular vIL-6 modulates the host endothelial cell environment by analyzing vIL-6's impact on the endothelial cell transcriptome. vIL-6 significantly altered the expression of many cellular genes associated with cell migration. In particular, vIL-6 upregulated the host factor carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) at the protein and message levels. CEACAM1 has been implicated in tumor invasion and metastasis and promotes migration and vascular remodeling in endothelial cells. We report that vIL-6 upregulates CEACAM1 by a STAT3-dependent mechanism and that CEACAM1 promotes vIL-6-mediated migration. Furthermore, latent and de novo KSHV infections of endothelial cells also induce CEACAM1 expression. Collectively, our data suggest that vIL-6 modulates endothelial cell migration by upregulating the expression of cellular factors, including CEACAM1. Kaposi's sarcoma-associated herpesvirus (KSHV) is linked with the development of three human malignancies, Kaposi's sarcoma, multicentric Castleman's disease, and primary effusion lymphoma. KSHV expresses many factors that enable the virus to manipulate the host environment in order to persist and induce disease

Skin-Resident T Cells Drive Dermal Dendritic Cell Migration in Response to Tissue Self-Antigen.

PubMed

Ali, Niwa; Zirak, Bahar; Truong, Hong-An; Maurano, Megan M; Gratz, Iris K; Abbas, Abul K; Rosenblum, Michael D

2018-05-01

Migratory dendritic cell (DC) subsets deliver tissue Ags to draining lymph nodes (DLNs) to either initiate or inhibit T cell-mediated immune responses. The signals mediating DC migration in response to tissue self-antigen are largely unknown. Using a mouse model of inducible skin-specific self-antigen expression, we demonstrate that CD103 + dermal DCs (DDCs) rapidly migrate from skin to skin DLN (SDLNs) within the first 48 h after Ag expression. This window of time was characterized by the preferential activation of tissue-resident Ag-specific effector T cells (Teffs), with no concurrent activation of Ag-specific Teffs in SDLNs. Using genetic deletion and adoptive transfer approaches, we show that activation of skin-resident Teffs is required to drive CD103 + DDC migration in response to tissue self-antigen and this Batf3-dependent DC population is necessary to mount a fulminant autoimmune response in skin. Conversely, activation of Ag-specific Teffs in SDLNs played no role in DDC migration. Our studies reveal a crucial role for skin-resident T cell-derived signals, originating at the site of self-antigen expression, to drive DDC migration during the elicitation phase of an autoimmune response. Copyright © 2018 by The American Association of Immunologists, Inc.

Protein Kinase D-dependent Phosphorylation and Nuclear Export of Histone Deacetylase 5 Mediates Vascular Endothelial Growth Factor-induced Gene Expression and Angiogenesis*S⃞

PubMed Central

Ha, Chang Hoon; Wang, Weiye; Jhun, Bong Sook; Wong, Chelsea; Hausser, Angelika; Pfizenmaier, Klaus; McKinsey, Timothy A.; Olson, Eric N.; Jin, Zheng-Gen

2008-01-01

Vascular endothelial growth factor (VEGF) is essential for normal and pathological angiogenesis. However, the signaling pathways linked to gene regulation in VEGF-induced angiogenesis are not fully understood. Here we demonstrate a critical role of protein kinase D (PKD) and histone deacetylase 5 (HDAC5) in VEGF-induced gene expression and angiogenesis. We found that VEGF stimulated HDAC5 phosphorylation and nuclear export in endothelial cells through a VEGF receptor 2-phospholipase Cγ-protein kinase C-PKD-dependent pathway. We further showed that the PKD-HDAC5 pathway mediated myocyte enhancer factor-2 transcriptional activation and a specific subset of gene expression in response to VEGF, including NR4A1, an orphan nuclear receptor involved in angiogenesis. Specifically, inhibition of PKD by overexpression of the PKD kinase-negative mutant prevents VEGF-induced HDAC5 phosphorylation and nuclear export as well as NR4A1 induction. Moreover, a mutant of HDAC5 specifically deficient in PKD-dependent phosphorylation inhibited VEGF-mediated NR4A1 expression, endothelial cell migration, and in vitro angiogenesis. These findings suggest that the PKD-HDAC5 pathway plays an important role in VEGF regulation of gene transcription and angiogenesis. PMID:18332134

Identification of myogenic-endothelial progenitor cells in the interstitial spaces of skeletal muscle.

PubMed

Tamaki, Tetsuro; Akatsuka, Akira; Ando, Kiyoshi; Nakamura, Yoshihiko; Matsuzawa, Hideyuki; Hotta, Tomomitsu; Roy, Roland R; Edgerton, V Reggie

2002-05-13

Putative myogenic and endothelial (myo-endothelial) cell progenitors were identified in the interstitial spaces of murine skeletal muscle by immunohistochemistry and immunoelectron microscopy using CD34 antigen. Enzymatically isolated cells were characterized by fluorescence-activated cell sorting on the basis of cell surface antigen expression, and were sorted as a CD34+ and CD45- fraction. Cells in this fraction were approximately 94% positive for Sca-1, and mostly negative (<3% positive) for CD14, 31, 49, 144, c-kit, and FLK-1. The CD34+/45- cells formed colonies in clonal cell cultures and colony-forming units displayed the potential to differentiate into adipocytes, endothelial, and myogenic cells. The CD34+/45- cells fully differentiated into vascular endothelial cells and skeletal muscle fibers in vivo after transplantation. Immediately after sorting, CD34+/45- cells expressed only c-met mRNA, and did not express any other myogenic cell-related markers such as MyoD, myf-5, myf-6, myogenin, M-cadherin, Pax-3, and Pax-7. However, after 3 d of culture, these cells expressed mRNA for all myogenic markers. CD34+/45- cells were distinct from satellite cells, as they expressed Bcrp1/ABCG2 gene mRNA (Zhou et al., 2001). These findings suggest that myo-endothelial progenitors reside in the interstitial spaces of mammalian skeletal muscles, and that they can potentially contribute to postnatal skeletal muscle growth.

Dairy cows produce cytokine and cytotoxic T cell responses following vaccination with an antigenic fraction from Streptococcus uberis.

PubMed

Wedlock, D Neil; Buddle, Bryce M; Williamson, John; Lacy-Hulbert, S Jane; Turner, Sally-Anne; Subharat, Supatsak; Heiser, Axel

2014-07-15

Streptococcus uberis is a major cause of mastitis in dairy cows worldwide and currently, there is no vaccine commercially available against this form of mastitis. In the current study, cell-free extracts (CFE) were prepared from each of three different S. uberis strains, designated as #3, #24 and #363 representative of the three main sequence types of S. uberis that cause mastitis in New Zealand. These proteins were formulated into vaccines with Emulsigen-D and the immunogenicity of the vaccines was determined in both calves and dairy cows. Two groups of calves (n=5/group) were vaccinated subcutaneously with CFE from strain #24 or strains #3, #24 and #363 formulated with Emulsigen-D, respectively. A third group (n=5) was vaccinated with CFE from the three strains formulated with Emulsigen-D and also containing recombinant bovine granulocyte macrophage colony-stimulating factor while, a control group (n=5) was not vaccinated. Vaccinated animals produced strong antibody responses to the S. uberis antigens and an antigen-specific cytotoxic effect against blood monocytes/macrophages that had phagocytosed S. uberis, with no significant differences in responses observed between the three vaccinated groups. In a second trial, the safety and immunogenicity of the vaccine containing CFE from all three strains of S. uberis and Emulsigen-D was determined in dairy cows. A group of six cows were vaccinated subcutaneously at 3 and 1 week prior to dry off and revaccinated 2-3 weeks before calving. Immune responses in blood and mammary gland secretions (MGS) were monitored during the dry period and in the subsequent lactation. The vaccine was well tolerated with no adverse effect from vaccination observed in any of the cows. Vaccination induced an antigen-specific cytotoxic effect against blood monocytes/macrophages that had phagocytosed S. uberis, moderate antigen-specific IFN-γ responses in blood and strong antibody responses in both blood and MGS. In conclusion, the results

Regulation of human feto-placental endothelial barrier integrity by vascular endothelial growth factors: competitive interplay between VEGF-A165a, VEGF-A165b, PIGF and VE-cadherin.

PubMed

Pang, Vincent; Bates, David O; Leach, Lopa

2017-12-01

The human placenta nourishes and protects the developing foetus whilst influencing maternal physiology for fetal advantage. It expresses several members of the vascular endothelial growth factor (VEGF) family including the pro-angiogenic/pro-permeability VEGF-A 165 a isoform, the anti-angiogenic VEGF-A 165 b, placental growth factor (PIGF) and their receptors, VEGFR1 and VEGFR2. Alterations in the ratio of these factors during gestation and in complicated pregnancies have been reported; however, the impact of this on feto-placental endothelial barrier integrity is unknown. The present study investigated the interplay of these factors on junctional occupancy of VE-cadherin and macromolecular leakage in human endothelial monolayers and the perfused placental microvascular bed. Whilst VEGF-A 165 a (50 ng/ml) increased endothelial monolayer albumin permeability ( P <0.0001), equimolar concentrations of VEGF-A 165 b ( P >0.05) or PlGF ( P >0.05) did not. Moreover, VEGF-A 165 b (100 ng/ml; P <0.001) but not PlGF (100 ng/ml; P >0.05) inhibited VEGF-A 165 a-induced permeability when added singly. PlGF abolished the VEGF-A 165 b-induced reduction in VEGF-A 165 a-mediated permeability ( P >0.05); PlGF was found to compete with VEGF-A 165 b for binding to Flt-1 at equimolar affinity. Junctional occupancy of VE-cadherin matched alterations in permeability. In the perfused microvascular bed, VEGF-A 165 b did not induce microvascular leakage but inhibited and reversed VEGF-A 165 a-induced loss of junctional VE-cadherin and tracer leakage. These results indicate that the anti-angiogenic VEGF-A 165 b isoform does not increase permeability in human placental microvessels or HUVEC primary cells and can interrupt VEGF-A 165 a-induced permeability. Moreover, the interplay of these isoforms with PIGF (and s-flt1) suggests that the ratio of these three factors may be important in determining the placental and endothelial barrier in normal and complicated pregnancies. © 2017 The Author(s).

Carnauba wax nanoparticles enhance strong systemic and mucosal cellular and humoral immune responses to HIV-gp140 antigen

PubMed Central

Arias, Mauricio A.; Loxley, Andrew; Eatmon, Christy; Van Roey, Griet; Fairhurst, David; Mitchnick, Mark; Dash, Philip; Cole, Tom; Wegmann, Frank; Sattentau, Quentin; Shattock, Robin

2011-01-01

Induction of humoral responses to HIV at mucosal compartments without inflammation is important for vaccine design. We developed charged wax nanoparticles that efficiently adsorb protein antigens and are internalized by DC in the absence of inflammation. HIV-gp140-adsorbed nanoparticles induced stronger in vitro T-cell proliferation responses than antigen alone. Such responses were greatly enhanced when antigen was co-adsorbed with TLR ligands. Immunogenicity studies in mice showed that intradermal vaccination with HIV-gp140 antigen-adsorbed nanoparticles induced high levels of specific IgG. Importantly, intranasal immunization with HIV-gp140-adsorbed nanoparticles greatly enhanced serum and vaginal IgG and IgA responses. Our results show that HIV-gp140-carrying wax nanoparticles can induce strong cellular/humoral immune responses without inflammation and may be of potential use as effective mucosal adjuvants for HIV vaccine candidates. PMID:21145913

Inhibition of vascular endothelial growth factor-induced angiogenesis suppresses tumour growth in vivo

NASA Astrophysics Data System (ADS)

Kim, K. Jin; Li, Bing; Winer, Jane; Armanini, Mark; Gillett, Nancy; Phillips, Heidi S.; Ferrara, Napoleone

1993-04-01

THE development of new blood vessels (angiogenesis) is required for many physiological processes including embryogenesis, wound healing and corpus luteum formation1,2. Blood vessel neoformation is also important in the pathogenesis of many disorders1-5, particularly rapid growth and metastasis of solid tumours3-5. There are several potential mediators of tumour angiogenesis, including basic and acidic fibroblast growth factors, tumour necrosis factor-α and transforming factors-α and -β 1,2. But it is unclear whether any of these agents actually mediates angiogenesis and tumour growth in vivo. Vascular endothelial growth factor (VEGF) is an endothelial cell-specific mitogen and an angiogenesis inducer released by a variety of tumour cells and expressed in human tumours in situ. To test whether VEGF may be a tumour angiogenesis factor in vivo, we injected human rhabdomyosar-coma, glioblastoma multiforme or leiomyosarcoma cell lines into nude mice. We report here that treatment with a monoclonal antibody specific for VEGF inhibited the growth of the tumours, but had no effect on the growth rate of the tumour cells In vitro. The density of vessels was decreased in the antibody-treated tumours. These findings demonstrate that inhibition of the action of an angiogenic factor spontaneously produced by tumour cells may suppress tumour growth in vivo.

Endothelial Msx1 transduces hemodynamic changes into an arteriogenic remodeling response

PubMed Central

Vandersmissen, Ine; Craps, Sander; Depypere, Maarten; Coppiello, Giulia; van Gastel, Nick; Maes, Frederik; Carmeliet, Geert; Schrooten, Jan; Jones, Elizabeth A.V.; Umans, Lieve; Devlieger, Roland; Koole, Michel; Gheysens, Olivier; Zwijsen, An; Aranguren, Xabier L.

2015-01-01

Collateral remodeling is critical for blood flow restoration in peripheral arterial disease and is triggered by increasing fluid shear stress in preexisting collateral arteries. So far, no arterial-specific mediators of this mechanotransduction response have been identified. We show that muscle segment homeobox 1 (MSX1) acts exclusively in collateral arterial endothelium to transduce the extrinsic shear stimulus into an arteriogenic remodeling response. MSX1 was specifically up-regulated in remodeling collateral arteries. MSX1 induction in collateral endothelial cells (ECs) was shear stress driven and downstream of canonical bone morphogenetic protein–SMAD signaling. Flow recovery and collateral remodeling were significantly blunted in EC-specific Msx1/2 knockout mice. Mechanistically, MSX1 linked the arterial shear stimulus to arteriogenic remodeling by activating the endothelial but not medial layer to a proinflammatory state because EC but not smooth muscle cellMsx1/2 knockout mice had reduced leukocyte recruitment to remodeling collateral arteries. This reduced leukocyte infiltration in EC Msx1/2 knockout mice originated from decreased levels of intercellular adhesion molecule 1 (ICAM1)/vascular cell adhesion molecule 1 (VCAM1), whose expression was also in vitro driven by promoter binding of MSX1. PMID:26391659

Clay Nanoparticles Elicit Long-Term Immune Responses by Forming Biodegradable Depots for Sustained Antigen Stimulation.

PubMed

Chen, Weiyu; Zuo, Huali; Li, Bei; Duan, Chengcheng; Rolfe, Barbara; Zhang, Bing; Mahony, Timothy J; Xu, Zhi Ping

2018-05-01

Nanomaterials have been widely tested as new generation vaccine adjuvants, but few evoke efficient immunoreactions. Clay nanoparticles, for example, layered double hydroxide (LDH) and hectorite (HEC) nanoparticles, have shown their potent adjuvanticity in generating effective and durable immune responses. However, the mechanism by which clay nanoadjuvants stimulate the immune system is not well understood. Here, it is demonstrated that LDH and HEC-antigen complexes form loose agglomerates in culture medium/serum. They also form nodules with loose structures in tissue after subcutaneous injection, where they act as a depot for up to 35 d. More importantly, clay nanoparticles actively and continuously recruit immune cells into the depot for up to one month, and stimulate stronger immune responses than FDA-approved adjuvants, Alum and QuilA. Sustained antigen release is also observed in clay nanoparticle depots, with 50-60% antigen released after 35 d. In contrast, Alum-antigen complexes show minimal antigen release from the depot. Importantly, LDH and HEC are more effective than QuilA and Alum in promoting memory T-cell proliferation. These findings suggest that both clay nanoadjuvants can serve as active vaccine platforms for sustained and potent immune responses. © 2018 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Polymer nanoparticles for cross-presentation of exogenous antigens and enhanced cytotoxic T-lymphocyte immune response

PubMed Central

Song, Chanyoung; Noh, Young-Woock; Lim, Yong Taik

2016-01-01

Effective induction of an antigen-specific cytotoxic T lymphocyte (CTL) immune response is one of the key goals of cancer immunotherapy. We report the design and fabrication of polyethylenimine (PEI)-coated polymer nanoparticles (NPs) as efficient antigen-delivery carriers that can induce antigen cross-presentation and a strong CTL response. After synthesis of poly(d,l-lactide-co-glycolide) (PLGA) NPs containing ovalbumin (OVA) by the double-emulsion solvent-evaporation method, cationic-charged PLGA NPs were generated by coating them with PEI. In a methyl tetrazolium salt assay, no discernible cytotoxic effect of PEI-coated PLGA (OVA) NPs was observed. The capacity and mechanism of PEI-coated PLGA (OVA) NPs for antigen delivery and cross-presentation on dendritic cells (DCs) were determined by fluorescence microscopy and flow cytometry. PEI-coated PLGA (OVA) NPs were internalized efficiently via phagocytosis or macropinocytosis in DCs and induced efficient cross-presentation of the antigen on MHC class I molecules via both endosome escape and a lysosomal processing mechanism. The DCs treated with PEI-coated PLGA (OVA) NPs induced a release of IL-2 cytokine from OVA-specific CD8-OVA1.3 T cells more efficiently than DCs treated with PLGA (OVA) NPs. Therefore, the PEI-coated PLGA (OVA) NPs can induce antigen cross-presentation and are expected to be used for induction of a strong CTL immune response and for efficient anticancer immunotherapy. PMID:27540289

The role of vascular endothelial growth factor-B in metabolic homoeostasis: current evidence.

PubMed

Zafar, Mohammad Ishraq; Zheng, Juan; Kong, Wen; Ye, Xiaofeng; Gou, Luoning; Regmi, Anita; Chen, Lu-Lu

2017-08-31

It has been shown that adipose tissue and skeletal muscles in lean individuals respond to meal-induced hyperinsulinemia by increase in perfusion, the effect not observed in patients with metabolic syndrome. In conditions of hyperglycaemia and hypertriglyceridemia, this insufficient vascularization leads to the liberation of reactive oxygen species (ROS), and disruption of nitric oxide (NO) synthesis and endothelial signalling responsible for the uptake of circulating fatty acids (FAs), whose accumulation in skeletal muscles and adipose tissue is widely associated with the impairment of insulin signalling. While the angiogenic role of VEGF-A and its increased circulating concentrations in obesity have been widely confirmed, the data related to the metabolic role of VEGF-B are diverse. However, recent discoveries indicate that this growth factor may be a promising therapeutic agent in patients with metabolic syndrome. Preclinical studies agree over two crucial metabolic effects of VEGF-B: (i) regulation of FAs uptake and (ii) regulation of tissue perfusion via activation of VEGF-A/vascular endothelial growth factor receptor (VEGFR) 2 (VEGFR2) pathway. While in some preclinical high-fat diet studies, VEGF-B overexpression reverted glucose intolerance and stimulated fat burning, in others it further promoted accumulation of lipids and lipotoxicity. Data from clinical studies point out the changes in circulating or tissue expression levels of VEGF-B in obese compared with lean patients. Potentially beneficial effects of VEGF-B, achieved through enhanced blood flow (increased availability of insulin and glucose uptake in target organs) and decreased FAs uptake (prevention of lipotoxicity and improved insulin signalling), and its safety for clinical use, remain to be clarified through future translational research. © 2017 The Author(s).

Endothelial cells promote the proliferation of lymphocytes partly through the Wnt pathway via LEF-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Shu-Hong; Nan, Ke-Jun, E-mail: nankj@163.com; Wang, Yao-Chun

The function of T cells and B cells is to recognize specific 'non-self' antigens, during a process known as antigen presentation. Once they have identified an invader, the cells generate specific responses that are tailored to maximally eliminate specific pathogens or pathogen-infected cells. Endothelial cells (ECs) can trigger the activation of T cells through their class I and class II MHC molecules. In this study, we examined the effect of ECs on the proliferation of lymphocytes. We report that the proliferation of T and B cells can be improved by interaction with ECs. LEF-1 is one of the main molecularmore » mediators in this process, and the inhibition of LEF-1 induces apoptosis. These results suggest that LEF-1 modulates positively the proliferation of lymphocytes induced by their interaction with ECs.« less

Ten-fold augmentation of endothelial uptake of vascular endothelial growth factor with ultrasound after systemic administration

NASA Technical Reports Server (NTRS)

Mukherjee, D.; Wong, J.; Griffin, B.; Ellis, S. G.; Porter, T.; Sen, S.; Thomas, J. D.

2000-01-01

OBJECTIVES: In this study, the feasibility of delivering and enhancing the uptake of vascular endothelial growth factor (VEGF) into the intact endothelium by using ultrasound (US) facilitation was determined. BACKGROUND: A limitation of tissue-targeted drug delivery is the need for direct arterial cannulation. We postulate a mechanism by which agents injected intravenously may be targeted to a tissue using US and ultrasonic contrast agents. METHODS: We used a rat model to test the ability of US and an ultrasonic contrast agent perflurocarbon exposed sonicated dextrose albumin (PESDA) to increase uptake of VEGF in the myocardium. Continuous wave Doppler US (0.6 W/cm2 at 1 MHz for 15 min) was applied to the chest wall overlying the myocardium during intravenous injection with either VEGF (100 microg/kg) alone or a combination of VEGF and PESDA (0.1%). Control rats had VEGF infused without US or PESDA. The VEGF uptake was measured quantitatively in the heart, lung, liver and kidneys by enzyme-linked immunosorbent assay (ng/g of tissue) and morphologically by fluorescence microscopy. RESULTS: There was an eight-fold increase in VEGF uptake in the heart by US alone (16.86 +/- 1.56 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) and a 13-fold increase with US + PESDA (26.78 +/- 2.88 vs. 2.11 +/- 0.953 ng/g of tissue, p < 0.0001) compared with control rats. Fluorescence microscopy revealed deposition of VEGF in the endothelium of small intramyocardial arterioles. CONCLUSIONS: These results show a marked increase in endothelial VEGF uptake with US and US + PESDA. Thus, US may be used to augment endothelial VEGF uptake 10-fold to 13-fold.

Bevacizumab, an anti-vascular endothelial growth factor antibody, inhibits osteoarthritis.

PubMed

Nagai, Toshihiro; Sato, Masato; Kobayashi, Miyuki; Yokoyama, Munetaka; Tani, Yoshiki; Mochida, Joji

2014-09-18

Angiogenesis is an important factor in the development of osteoarthritis (OA). We investigated the efficacy of bevacizumab, an antibody against vascular endothelial growth factor and an inhibitor of angiogenesis, in the treatment of OA using a rabbit model of anterior cruciate ligament transection. First, we evaluated the response of gene expression and histology of the normal joint to bevacizumab treatment. Next, in a rabbit model of OA induced by anterior cruciate ligament transection, we used macroscopic and histological evaluations and real-time polymerase chain reaction (PCR) to examine the responses to intravenous (systemic) administration of bevacizumab (OAB IV group). We also investigated the efficacy of intra-articular (local) administration of bevacizumab in OA-induced rabbits (OAB IA group). Histologically, bevacizumab had no negative effect in normal joints. Bevacizumab did not increase the expression of genes for catabolic factors in the synovium, subchondral bone, or articular cartilage, but it increased the expression of collagen type 2 in the articular cartilage. Macroscopically and histologically, the OAB IV group exhibited a reduction in articular cartilage degeneration and less osteophyte formation and synovitis compared with the control group (no bevacizumab; OA group). Real-time PCR showed significantly lower expression of catabolic factors in the synovium in the OAB IV group compared with the OA group. In articular cartilage, expression levels of aggrecan, collagen type 2, and chondromodulin-1 were higher in the OAB IV group than in the OA group. Histological evaluation and assessment of pain behaviour showed a superior effect in the OAB IA group compared with the OAB IV group 12 weeks after administration of bevacizumab, even though the total dosage given to the OAB IA group was half that received by the OAB IV group. Considering the dosage and potential adverse effects of bevacizumab, the local administration of bevacizumab is a more

The adapter protein, Grb10, is a positive regulator of vascular endothelial growth factor signaling.

PubMed

Giorgetti-Peraldi, S; Murdaca, J; Mas, J C; Van Obberghen, E

2001-07-05

Vascular endothelial growth factor (VEGF) is an important regulator of vasculogenesis and angiogenesis. Activation of VEGF receptors leads to the recruitment of SH2 containing proteins which link the receptors to the activation of signaling pathways. Here we report that Grb10, an adapter protein of which the biological role remains unknown, is tyrosine phosphorylated in response to VEGF in endothelial cells (HUVEC) and in 293 cells expressing the VEGF receptor KDR. An intact SH2 domain is required for Grb10 tyrosine phosphorylation in response to VEGF, and this phosphorylation is mediated in part through the activation of Src. In HUVEC, VEGF increases Grb10 mRNA level. Expression of Grb10 in HUVEC or in KDR expressing 293 cells results in an increase in the amount and in the tyrosine phosphorylation of KDR. In 293 cells, this is correlated with the activation of signaling molecules, such as MAP kinase. By expressing mutants of Grb10, we found that the positive action of Grb10 is independent of its SH2 domain. Moreover, these Grb10 effects on KDR seem to be specific since Grb10 has no effect on the insulin receptor, and Grb2, another adapter protein, does not mimic the effect of Grb10 on KDR. In conclusion, we propose that VEGF up-regulates Grb10 level, which in turn increases KDR molecules, suggesting that Grb10 could be involved in a positive feedback loop in VEGF signaling.

Effect of benzo[a]pyrene on the production of vascular endothelial growth factor by human eosinophilic leukemia EoL-1 cells.

PubMed

Gu, Jie; Chan, Lai-Sheung; Wong, Chris Kong-Chu; Wong, Ngok-Shun; Wong, Chun-Kwok; Leung, Kok-Nam; Mak, Naiki K

2011-01-01

Benzo[a]pyrene (BaP) has been shown to affect both the development and response of T and B cells in the immune system. However, the effect of BaP on other immune cells, such as eosionophils, is unknown. In this study, we investigated the effect of BaP on the production of vascular endothelial growth factor (VEGF) using an in vitro eosinophilic EoL-1 cell and human umbilical vein endothelial cell (HUVEC) co-culture system. EoL-1-conditioned medium was found to promote the growth of HUVEC in a time-dependent manner. The growth stimulating activity was due to the production of VEGF by the EoL-1 cells. The production of VEGF was correlated with the enhanced expression of the phosphorylated form of extracellular signal-regulated kinases (p-ERKs) and the upregulated expression of VEGF mRNA. Furthermore, BaP-induced expression of VEGF mRNA was reduced by the ERK inhibitor PD98059. Results from this study suggested that BaP might affect the growth of endothelial cells through the modulation of VEGF production by eosinophils.

Mesenchymal Stem/Multipotent Stromal Cells from Human Decidua Basalis Reduce Endothelial Cell Activation.

PubMed

Alshabibi, Manal A; Al Huqail, Al Joharah; Khatlani, Tanvir; Abomaray, Fawaz M; Alaskar, Ahmed S; Alawad, Abdullah O; Kalionis, Bill; Abumaree, Mohamed Hassan

2017-09-15

Recently, we reported the isolation and characterization of mesenchymal stem cells from the decidua basalis of human placenta (DBMSCs). These cells express a unique combination of molecules involved in many important cellular functions, which make them good candidates for cell-based therapies. The endothelium is a highly specialized, metabolically active interface between blood and the underlying tissues. Inflammatory factors stimulate the endothelium to undergo a change to a proinflammatory and procoagulant state (ie, endothelial cell activation). An initial response to endothelial cell activation is monocyte adhesion. Activation typically involves increased proliferation and enhanced expression of adhesion and inflammatory markers by endothelial cells. Sustained endothelial cell activation leads to a type of damage to the body associated with inflammatory diseases, such as atherosclerosis. In this study, we examined the ability of DBMSCs to protect endothelial cells from activation through monocyte adhesion, by modulating endothelial proliferation, migration, adhesion, and inflammatory marker expression. Endothelial cells were cocultured with DBMSCs, monocytes, monocyte-pretreated with DBMSCs and DBMSC-pretreated with monocytes were also evaluated. Monocyte adhesion to endothelial cells was examined following treatment with DBMSCs. Expression of endothelial cell adhesion and inflammatory markers was also analyzed. The interaction between DBMSCs and monocytes reduced endothelial cell proliferation and monocyte adhesion to endothelial cells. In contrast, endothelial cell migration increased in response to DBMSCs and monocytes. Endothelial cell expression of adhesion and inflammatory molecules was reduced by DBMSCs and DBMSC-pretreated with monocytes. The mechanism of reduced endothelial proliferation involved enhanced phosphorylation of the tumor suppressor protein p53. Our study shows for the first time that DBMSCs protect endothelial cells from activation by

Carnauba wax nanoparticles enhance strong systemic and mucosal cellular and humoral immune responses to HIV-gp140 antigen.

PubMed

Arias, Mauricio A; Loxley, Andrew; Eatmon, Christy; Van Roey, Griet; Fairhurst, David; Mitchnick, Mark; Dash, Philip; Cole, Tom; Wegmann, Frank; Sattentau, Quentin; Shattock, Robin

2011-02-01

Induction of humoral responses to HIV at mucosal compartments without inflammation is important for vaccine design. We developed charged wax nanoparticles that efficiently adsorb protein antigens and are internalized by DC in the absence of inflammation. HIV-gp140-adsorbed nanoparticles induced stronger in vitro T-cell proliferation responses than antigen alone. Such responses were greatly enhanced when antigen was co-adsorbed with TLR ligands. Immunogenicity studies in mice showed that intradermal vaccination with HIV-gp140 antigen-adsorbed nanoparticles induced high levels of specific IgG. Importantly, intranasal immunization with HIV-gp140-adsorbed nanoparticles greatly enhanced serum and vaginal IgG and IgA responses. Our results show that HIV-gp140-carrying wax nanoparticles can induce strong cellular/humoral immune responses without inflammation and may be of potential use as effective mucosal adjuvants for HIV vaccine candidates. Copyright © 2010 Elsevier Ltd. All rights reserved.

T cells bearing a chimeric antigen receptor against prostate-specific membrane antigen mediate vascular disruption and result in tumor regression

PubMed Central

Santoro, Stephen P.; Kim, Soorin; Motz, Gregory T.; Alatzoglou, Dimitrios; Li, Chunsheng; Irving, Melita; Powell, Daniel J.; Coukos, George

2014-01-01

Aberrant blood vessels enable tumor growth, provide a barrier to immune infiltration, and serve as a source of pro-tumorigenic signals. Targeting tumor blood vessels for destruction, or tumor vascular disruption therapy, can therefore provide significant therapeutic benefit. Here we describe the ability of chimeric antigen receptor (CAR)-bearing T cells to recognize human prostate-specific membrane antigen (hPSMA) on endothelial targets in vitro as well as in vivo. CAR T cells were generated using the anti-PSMA scFv, J591, and the intracellular signaling domains: CD3ζ, CD28, and/or CD137/4-1BB. We found that all anti-hPSMA CAR T cells recognized and eliminated PSMA+ endothelial targets in vitro, regardless of the signaling domain. T cells bearing the 3rd generation anti-hPSMA CAR, P28BBζ, were able to recognize and kill primary human endothelial cells isolated from gynecologic cancers. In addition, the P28BBζ CAR T cells mediated regression of hPSMA-expressing vascular neoplasms in mice. Finally, in murine models of ovarian cancers populated by murine vessels expressing hPSMA, the P28BBζ CAR T cells were able to ablate PSMA+ vessels, cause secondary depletion of tumor cells, and reduce tumor burden. Taken together, these results provide strong rationale for the use of CAR T cells as agents of tumor vascular disruption, specifically those targeting PSMA. PMID:25358763

Wine and endothelial function.

PubMed

Caimi, G; Carollo, C; Lo Presti, R

2003-01-01

In recent years many studies have focused on the well-known relationship between wine consumption and cardiovascular risk. Wine exerts its protective effects through various changes in lipoprotein profile, coagulation and fibrinolytic cascades, platelet aggregation, oxidative mechanisms and endothelial function. The last has earned more attention for its implications in atherogenesis. Endothelium regulates vascular tone by a delicate balancing among vasorelaxing (nitric oxide [NO]) and vasoconstrincting (endothelins) factors produced by endothelium in response to various stimuli. In rat models, wine and other grape derivatives exerted an endothelium-dependent vasorelaxing capacity especially associated with the NO-stimulating activity of their polyphenol components. In experimental conditions, reservatrol (a stilbene polyphenol) protected hearts and kidneys from ischemia-reperfusion injury through antioxidant activity and upregulation of NO production. Wine polyphenols are also able to induce the expression of genes involved in the NO pathway within the arterial wall. The effects of wine on endothelial function in humans are not yet clearly understood. A favorable action of red wine or dealcoholized wine extract or purple grape juice on endothelial function has been observed by several authors, but discrimination between ethanol and polyphenol effects is controversial. It is, however likely that regular and prolonged moderate wine drinking positively affects endothelial function. The beneficial effects of wine on cardiovascular health are greater if wine is associated with a healthy diet. The most recent nutritional and epidemiologic studies show that the ideal diet closely resembles the Mediterranean diet.

Antivascular Endothelial Growth Factor Bevacizumab for Radiation Optic Neuropathy: Secondary to Plaque Radiotherapy

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finger, Paul T., E-mail: pfinger@eyecancer.com; Chin, Kimberly J.

2012-02-01

Purpose: To evaluate the intravitreal antivascular endothelial growth factor, bevacizumab, for treatment of radiation optic neuropathy (RON). Methods and Materials: A prospective interventional clinical case series was performed of 14 patients with RON related to plaque radiotherapy for choroidal melanoma. The RON was characterized by optic disc edema, hemorrhages, microangiopathy, and neovascularization. The entry criteria included a subjective or objective loss of vision, coupled with findings of RON. The study subjects received a minimum of two initial injections of intravitreal bevacizumab (1.25 mg in 0.05 mL) every 6-8 weeks. The primary objectives included safety and tolerability. The secondary objectives includedmore » the efficacy as measured using the Early Treatment Diabetic Retinopathy Study chart for visual acuity, fundus photography, angiography, and optical coherence tomography/scanning laser ophthalmoscopy. Results: Reductions in optic disc hemorrhage and edema were noted in all patients. The visual acuity was stable or improved in 9 (64%) of the 14 patients. Of the 5 patients who had lost vision, 2 had relatively large posterior tumors, 1 had had the vision decrease because of intraocular hemorrhage, and 1 had developed optic atrophy. The fifth patient who lost vision was noncompliant. No treatment-related ocular or systemic side effects were observed. Conclusions: Intravitreal antivascular endothelial growth factor bevacizumab was tolerated and generally associated with improved vision, reduced papillary hemorrhage, and resolution of optic disc edema. Persistent optic disc neovascularization and fluorescein angiographic leakage were invariably noted. The results of the present study support additional evaluation of antivascular endothelial growth factor medications as treatment of RON.« less

Impaired Cytokine Responses to Epstein-Barr Virus Antigens in Systemic Lupus Erythematosus Patients

PubMed Central

Draborg, Anette Holck; Sandhu, Noreen; Larsen, Nanna; Lisander Larsen, Janni; Jacobsen, Søren; Houen, Gunnar

2016-01-01

We analyzed cytokine responses against latent and lytic Epstein-Barr virus (EBV) antigens in systemic lupus erythematosus (SLE) patients and healthy controls (HCs) to obtain an overview of the distinctive immune regulatory response in SLE patients and to expand the previously determined impaired EBV-directed T-cell response. The concentrations of 14 cytokines (IL2, IL4, IL5, IL6, IL10, IL12, IL17, IL18, IL1β, IFNγ, TNFα, TNFβ, TGFβ, and GM-CSF) were quantified upon stimulation of whole blood with latent state antigen EBNA1, lytic cycle antigen EBV-EA/D, and the superantigen SEB. To avoid results affected by lack of lymphocytes, we focused on SLE patients with normal levels. Decreased induction of IL12, IFNγ, IL17, and IL6 upon EBNA1 stimulation and that of IFNγ, IL6, TNFβ, IL1β, and GM-CSF upon EBV-EA/D stimulation were detected in SLE patients compared to HCs. IFNγ responses, especially, were shown to be reduced. Induction of several cytokines was furthermore impaired in SLE patients upon SEB stimulation, but no difference was observed in basic levels. Results substantiate the previously proposed impaired regulation of the immune response against latent and lytic cycle EBV infection in SLE patients without lymphopenia. Furthermore, results indicate general dysfunction of leukocytes and their cytokine regulations in SLE patients. PMID:27110576

Isolation and purification of antigenic components of Cryptococcus.

PubMed

Wozniak, Karen L; Levitz, Stuart M

2009-01-01

The encapsulated fungal pathogens Cryptococcus neoformans and Cryptococcus gattii are significant agents of life-threatening infections, particularly in persons with suppressed cell-mediated immunity. This chapter provides detailed methodology for the purification of two of the major antigen fractions of C. neoformans: glucuronoxylomannan (GXM) and mannoprotein (MP). GXM is the primary component of the polysaccharide capsule, which is the major cryptococcal virulence factor. In contrast, MPs have been identified as key antigens that stimulate T-cell responses. Purification of GXM and MP should assist investigators studying the antigenic, biochemical, and virulence properties of Cryptococcus species.

Chronic shear induces caveolae formation and alters ERK and Akt responses in endothelial cells

NASA Technical Reports Server (NTRS)

Boyd, Nolan L.; Park, Heonyong; Yi, Hong; Boo, Yong Chool; Sorescu, George P.; Sykes, Michelle; Jo, Hanjoong

2003-01-01

Caveolae are plasmalemmal domains enriched with cholesterol, caveolins, and signaling molecules. Endothelial cells in vivo are continuously exposed to shear conditions, and their caveolae density and location may be different from that of static cultured cells. Here, we show that chronic shear exposure regulates formation and localization of caveolae and caveolin-1 in bovine aortic endothelial cells (BAEC). Chronic exposure (1 or 3 days) of BAEC to laminar shear increased the total number of caveolae by 45-48% above static control. This increase was due to a rise in the luminal caveolae density without changing abluminal caveolae numbers or increasing caveolin-1 mRNA and protein levels. Whereas some caveolin-1 was found in the plasma membrane in static-cultured cells, it was predominantly localized in the Golgi. In contrast, chronic shear-exposed cells showed intense caveolin-1 staining in the luminal plasma membrane with minimum Golgi association. The preferential luminal localization of caveolae may play an important role in endothelial mechanosensing. Indeed, we found that chronic shear exposure (preconditioning) altered activation patterns of two well-known shear-sensitive signaling molecules (ERK and Akt) in response to a step increase in shear stress. ERK activation was blunted in shear preconditioned cells, whereas the Akt response was accelerated. These results suggest that chronic shear stimulates caveolae formation by translocating caveolin-1 from the Golgi to the luminal plasma membrane and alters cell signaling responses.

No causal impact of serum vascular endothelial growth factor level on temporal changes in body mass index in Japanese male workers: a five-year longitudinal study.

PubMed