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Sample records for ifp angiogenesis hypoxia

  1. Hypoxia independent drivers of melanoma angiogenesis

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    Svenja eMeierjohann

    2015-05-01

    Full Text Available Tumor angiogenesis is a process which is traditionally regarded as the tumor`s response to low nutrient supply occurring under hypoxic conditions. However, hypoxia is not a prerequisite for angiogenesis. The fact that even single tumor cells or small tumor cell aggregates are capable of attracting blood vessels reveals the early metastatic capability of tumor cells. This review sheds light on the hypoxia independent mechanisms of tumor angiogenesis in melanoma.

  2. Hypoxia and Angiogenesis in Endometrioid Endometrial Carcinogenesis

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    Nicole Horrée

    2007-01-01

    Full Text Available Background: Hypoxia-inducible factor 1α (HIF-1α plays an essential role in the adaptive response of cells to hypoxia, triggering biologic events associated with aggressive tumor behavior. Methods: Expression of HIF-1α and proteins in the HIF-1α pathway (Glut-1, CAIX, VEGF in paraffin-embedded specimens of normal (n = 17, premalignant (n = 17 and endometrioid endometrial carcinoma (n = 39 was explored by immunohistochemistry, in relation to microvessel density (MVD. Results: HIF-1α overexpression was absent in inactive endometrium but present in hyperplasia (61% and carcinoma (87%, with increasing expression in a perinecrotic fashion pointing to underlying hypoxia. No membranous expression of Glut-1 and CAIX was noticed in inactive endometrium, in contrast with expression in hyperplasia (Glut-1 0%, CAIX 61%, only focal and diffuse and carcinoma (Glut-1 94.6%, CAIX 92%, both mostly perinecrotically. Diffuse HIF-1α was accompanied by activation of downstream targets. VEGF was significantly higher expressed in hyperplasias and carcinomas compared to inactive endometrium. MVD was higher in hyperplasias and carcinomas than in normal endometrium (p < 0.001. Conclusion: HIF-1α and its downstream genes are increasingly expressed from normal through premalignant to endometrioid adenocarcinoma of the endometrium, paralleled by activation of its downstream genes and increased angiogenesis. This underlines the potential importance of hypoxia and its key regulator HIF-1α in endometrial carcinogenesis.

  3. Hypoxia, hypoxia-inducible transcription factor, and macrophages in human atherosclerotic plaques are correlated with intraplaque angiogenesis

    NARCIS (Netherlands)

    Sluimer, Judith C.; Gasc, Jean-Marie; van Wanroij, Job L.; Kisters, Natasja; Groeneweg, Mathijs; Sollewijn Gelpke, Maarten D.; Cleutjens, Jack P.; van den Akker, Luc H.; Corvol, Pierre; Wouters, Bradly G.; Daemen, Mat J.; Bijnens, Ann-Pascale J.

    2008-01-01

    We sought to examine the presence of hypoxia in human carotid atherosclerosis and its association with hypoxia-inducible transcription factor (HIF) and intraplaque angiogenesis. Atherosclerotic plaques develop intraplaque angiogenesis, which is a typical feature of hypoxic tissue and expression of

  4. Notch-1 mediates hypoxia-induced angiogenesis in rheumatoid arthritis.

    Science.gov (United States)

    Gao, Wei; Sweeney, Catherine; Connolly, Mary; Kennedy, Aisling; Ng, Chin Teck; McCormick, Jennifer; Veale, Douglas J; Fearon, Ursula

    2012-07-01

    To examine the effect of hypoxia on Notch-1 signaling pathway components and angiogenesis in inflammatory arthritis. The expression and regulation of Notch-1, its ligand delta-like protein 4 (DLL-4) and downstream signaling components (hairy-related transcription factor 1 [HRT-1], HRT-2), and hypoxia-inducible factor 1α (HIF-1α) under normoxic and hypoxic conditions (1-3%) were assessed in synovial tissue specimens from patients with inflammatory arthritis and controls and in human dermal microvascular endothelial cells (HDMECs) by immunohistology, dual immunofluorescence staining (Notch-1/factor VIII), Western blotting, and real-time polymerase chain reaction. In vivo synovial tissue oxygen levels (tissue PO2) were measured under direct visualization at arthroscopy. HDMEC activation under hypoxic conditions in the presence of Notch-1 small interfering RNA (siRNA), the γ-secretase inhibitor DAPT, or dimethyloxalylglycine (DMOG) was assessed by Matrigel tube formation assay, migration assay, invasion assay, and matrix metalloproteinase 2 (MMP-2)/MMP-9 zymography. Expression of Notch-1, its ligand DLL-4, and HRT-1 was demonstrated in synovial tissue, with the strongest expression localized to perivascular/vascular regions. Localization of Notch-1 to synovial endothelium was confirmed by dual immunofluorescence staining. Notch-1 intracellular domain (NICD) expression was significantly higher in synovial tissue from patients with tissue PO2 of PO2 of >20 mm Hg (>3% O2). Exposure of HDMECs to 3% hypoxia induced HIF-1α and NICD protein expression and DLL-4, HRT-1, and HRT-2 messenger RNA expression. DMOG directly induced NICD expression, while Notch-1 siRNA inhibited hypoxia-induced HIF-1α expression, suggesting that Notch-1/HIF-1α signaling is bidirectional. Finally, 3% hypoxia-induced angiogenesis, endothelial cell migration, endothelial cell invasion, and proMMP-2 and proMMP-9 activities were inhibited by Notch-1 siRNA and/or the γ-secretase inhibitor DAPT. Our

  5. Hypoxia-driven angiogenesis: role of tip cells and extracellular matrix scaffolding.

    Science.gov (United States)

    Germain, Stéphane; Monnot, Catherine; Muller, Laurent; Eichmann, Anne

    2010-05-01

    Angiogenesis is a highly coordinated tissue remodeling process leading to blood vessel formation. Hypoxia triggers angiogenesis via induction of expression of growth factors such as vascular endothelial growth factor (VEGF). VEGF instructs endothelial cells to form tip cells, which lead outgrowing capillary sprouts, whereas Notch signaling inhibits sprout formation. Basement membrane deposition and mechanical cues from the extracellular matrix (ECM) induced by hypoxia may participate to coordinated vessel sprouting in conjunction with the VEGF and Notch signaling pathways. Hypoxia regulates ECM composition, deposition, posttranslational modifications and rearrangement. In particular, hypoxia-driven vascular remodeling is dynamically regulated through modulation of ECM-modifying enzyme activities that eventually affect both matricellular proteins and growth factor availability. Better understanding of the complex interplay between endothelial cells and soluble growth factors and mechanical factors from the ECM will certainly have significant implications for understanding the regulation of developmental and pathological angiogenesis driven by hypoxia.

  6. [18F]-FMISO PET study of hypoxia in gliomas before surgery: correlation with molecular markers of hypoxia and angiogenesis

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    Bekaert, Lien [CHU de Caen, Department of Neurology, Caen (France); Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Caen, Department of Neurosurgery, Caen (France); CHU de Caen, Service de Neurochirurgie, Caen (France); Valable, Samuel; Collet, Solene; Bordji, Karim; Petit, Edwige; Bernaudin, Myriam [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); Lechapt-Zalcman, Emmanuele [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Caen, Department of Pathology, Caen (France); Ponte, Keven [CHU de Caen, Department of Neurosurgery, Caen (France); Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); Constans, Jean-Marc [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Caen, Department of Neuroradiology, Caen (France); Levallet, Guenaelle [CHU de Caen, Department of Pathology, Caen (France); Branger, Pierre [CHU de Caen, Department of Neurology, Caen (France); Emery, Evelyne [CHU de Caen, Department of Neurosurgery, Caen (France); Manrique, Alain [CHU de Caen, Department of Nuclear Medicine, Caen (France); Barre, Louisa [Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/LDM-TEP group, Caen (France); Guillamo, Jean-Sebastien [CHU de Caen, Department of Neurology, Caen (France); Normandie Univ, UNICAEN, CEA, CNRS, ISTCT/CERVOxy Group, Caen (France); CHU de Nimes, Department of Neurology, Nimes (France)

    2017-08-15

    Hypoxia in gliomas is associated with tumor resistance to radio- and chemotherapy. However, positron emission tomography (PET) imaging of hypoxia remains challenging, and the validation of biological markers is, therefore, of great importance. We investigated the relationship between uptake of the PET hypoxia tracer [18F]-FMISO and other markers of hypoxia and angiogenesis and with patient survival. In this prospective single center clinical study, 33 glioma patients (grade IV: n = 24, III: n = 3, and II: n = 6) underwent [18F]-FMISO PET and MRI including relative cerebral blood volume (rCBV) maps before surgery. Maximum standardized uptake values (SUVmax) and hypoxic volume were calculated, defining two groups of patients based on the presence or absence of [18F]-FMISO uptake. After surgery, molecular quantification of CAIX, VEGF, Ang2 (rt-qPCR), and HIF-1α (immunohistochemistry) were performed on tumor specimens. [18F]-FMISO PET uptake was closely linked to tumor grade, with high uptake in glioblastomas (GB, grade IV). Expression of biomarkers of hypoxia (CAIX, HIF-1α), and angiogenesis markers (VEGF, Ang2, rCBV) were significantly higher in the [18F]-FMISO uptake group. We found correlations between the degree of hypoxia (hypoxic volume and SUVmax) and expression of HIF-1α, CAIX, VEGF, Ang2, and rCBV (p < 0.01). Patients without [18F]-FMISO uptake had a longer survival time than uptake positive patients (log-rank, p < 0.005). Tumor hypoxia as evaluated by [18F]-FMISO PET is associated with the expression of hypoxia markers on a molecular level and is related to angiogenesis. [18F]-FMISO uptake is a mark of an aggressive tumor, almost always a glioblastoma. Our results underline that [18F]-FMISO PET could be useful to guide glioma treatment, and in particular radiotherapy, since hypoxia is a well-known factor of resistance. (orig.)

  7. Low Molecular Weight Fucoidan Inhibits Tumor Angiogenesis through Downregulation of HIF-1/VEGF Signaling under Hypoxia

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    Meng-Chuan Chen

    2015-07-01

    Full Text Available Activation of hypoxia-induced hypoxia-inducible factors-1 (HIF-1 plays a critical role in promoting tumor angiogenesis, growth and metastasis. Low molecular weight fucoidan (LMWF is prepared from brown algae, and exhibits anticancer activity. However, whether LMWF attenuates hypoxia-induced angiogenesis in bladder cancer cells and the molecular mechanisms involved remain unclear. This is the first study to demonstrate that LMWF can inhibit hypoxia-stimulated H2O2 formation, HIF-1 accumulation and transcriptional activity vascular endothelial growth factor (VEGF secretion, and the migration and invasion in hypoxic human bladder cancer cells (T24 cells. LMWF also downregulated hypoxia-activated phosphorylation of PI3K/AKT/mTOR/p70S6K/4EBP-1 signaling in T24 cells. Blocking PI3K/AKT or mTOR activity strongly diminished hypoxia-induced HIF-1α expression and VEGF secretion in T24 cells, supporting the involvement of PI3K/AKT/mTOR in the induction of HIF-1α and VEGF. Additionally, LMWF significantly attenuated angiogenesis in vitro and in vivo evidenced by reduction of tube formation of hypoxic human umbilical vascular endothelial cells and blood capillary generation in the tumor. Similarly, administration of LMWF also inhibited the HIF-1α and VEGF expression in vivo, accompanied by a reduction of tumor growth. In summary, under hypoxia conditions, the antiangiogenic activity of LMWF in bladder cancer may be associated with suppressing HIF-1/VEGF-regulated signaling pathway.

  8. Hypoxia promotes tumor growth in linking angiogenesis to immune escape

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    Salem eCHOUAIB

    2012-02-01

    Full Text Available Despite the impressive progress over the past decade, in the field of tumor immunology, such as the identification of tumor antigens and antigenic peptides as potential targets, there are still many obstacles in eliciting an effective immune response to eradicate cancer. It has become increasingly clear that tumor microenvironment plays a crucial role in the control of immune protection and contains many overlapping mechanisms to evade antigen specific immunotherapy. Obviously, tumors have evolved to utilize hypoxic stress to their own advantage by activating key biochemical and cellular pathways that are important in progression, survival and metastasis. Among the hypoxia-induced genes, hypoxia-inducible factor (HIF-1 and vascular endothelial growth factor (VEGF play a determinant role in promoting tumor cell growth and survival. In this regard, hypoxia is emerging as an attractive target for cancer therapy. How the microenvironmental hypoxia poses both obstacles and opportunities for new therapeutic immune interventions will be discussed.

  9. Cinnamic aldehyde suppresses hypoxia-induced angiogenesis via inhibition of hypoxia-inducible factor-1α expression during tumor progression.

    Science.gov (United States)

    Bae, Woom-Yee; Choi, Jae-Sun; Kim, Ja-Eun; Jeong, Joo-Won

    2015-11-01

    During tumor progression, hypoxia-inducible factor 1 (HIF-1) plays a critical role in tumor angiogenesis and tumor growth by regulating the transcription of several genes in response to a hypoxic environment and changes in growth factors. This study was designed to investigate the effects of cinnamic aldehyde (CA) on tumor growth and angiogenesis and the mechanisms underlying CA's anti-angiogenic activities. We found that CA administration inhibits tumor growth and blocks tumor angiogenesis in BALB/c mice. In addition, CA treatment decreased HIF-1α protein expression and vascular endothelial growth factor (VEGF) expression in mouse tumors and Renca cells exposed to hypoxia in vitro. Interestingly, CA treatment did not affect the stability of von Hippel-Lindau protein (pVHL)-associated HIF-1α and CA attenuated the activation of mammalian target of rapamycin (mTOR) pathway. Collectively, these findings strongly indicate that the anti-angiogenic activity of CA is, at least in part, regulated by the mTOR pathway-mediated suppression of HIF-1α protein expression and these findings suggest that CA may be a potential drug for human cancer therapy. Copyright © 2015 Elsevier Inc. All rights reserved.

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

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    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.

  11. Overexpression of Dimethylarginine Dimethylaminohydrolase Enhances Tumor Hypoxia: An Insight into the Relationship of Hypoxia and Angiogenesis In Vivo

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    Vassiliki Kostourou

    2004-07-01

    Full Text Available The oxygenation status of tumors derived from wild-type C6 glioma cells and clone D27 cells overexpressing dimethylarginine dimethylaminohydrolase (DDAH was assessed in vivo using a variety of direct and indirect assays of hypoxia. Clone D27 tumors exhibit a more aggressive and better-vascularized phenotype compared to wild-type C6 gliomas. Immunohistochemical analyses using the 2-nitroimidazole hypoxia marker pimonidazole, fiber optic OxyLite measurements of tumor pO2, and localized 31P magnetic resonance spectroscopy measurements of tumor bioenergetic status and pH clearly demonstrated that the D27 tumors were more hypoxic compared to C6 wild type. In the tumor extracts, only glucose concentrations were significantly lower in the D27 tumors. Elevated Glut-1 expression, a reliable functional marker for hypoxia-inducible factor-1-mediated metabolic adaptation, was observed in the D27 tumors. Together, the data show that overexpression of DDAH results in C6 gliomas that are more hypoxic compared to wild-type tumors, and point strongly to an inverse relationship of tumor oxygenation and angiogenesis in vivo-a concept now being supported by the enhanced understanding of oxygen sensing at the molecular level.

  12. Hypoxia-Inducible Factor-1 in Physiological and Pathophysiological Angiogenesis: Applications and Therapies

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    Zimna, Agnieszka; Kurpisz, Maciej

    2015-01-01

    The cardiovascular system ensures the delivery of oxygen and nutrients to all cells, tissues, and organs. Under extended exposure to reduced oxygen levels, cells are able to survive through the transcriptional activation of a series of genes that participate in angiogenesis, glucose metabolism, and cell proliferation. The oxygen-sensitive transcriptional activator HIF-1 (hypoxia-inducible factor-1) is a key transcriptional mediator of the response to hypoxic conditions. The HIF-1 pathway was found to be a master regulator of angiogenesis. Whether the process is physiological or pathological, HIF-1 seems to participate in vasculature formation by synergistic correlations with other proangiogenic factors such as VEGF (vascular endothelial growth factor), PlGF (placental growth factor), or angiopoietins. Considering the important contributions of HIF-1 in angiogenesis and vasculogenesis, it should be considered a promising target for treating ischaemic diseases or cancer. In this review, we discuss the roles of HIF-1 in both physiological/pathophysiological angiogenesis and potential strategies for clinical therapy. PMID:26146622

  13. IFP - Annual report 2003; IFP - Rapport annuel 2003

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    NONE

    2003-07-01

    The Institute Francais du Petrole (IFP) is an independent industrial research and development, education and training and information center active in the oil, natural gas and automobile industries. IFP strategy is based on a clear vision of the long term evolution of the world energy sector. IFP strategic positioning is thus aimed at taking advantage of the opportunities that arise and making full use of its scientific and technological strengths. This 2003 annual report presents the IFP strategic positioning, facts and figures, highlights of 2003, IFP executive committee, the IFP as a player in sustainable development, the exploration-reservoir engineering, drilling-production, refining-petrochemicals, engines-energy, education and training activities and the IFP Group. (A.L.B.)

  14. Hypoxia-induced angiogenesis is increased by the controlled release of deferoxiamine from gelatin hydrogels.

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    Saito, Takashi; Tabata, Yasuhiko

    2014-08-01

    The objective of this study is to design biodegradable hydrogels for the controlled release of deferoxiamine (DFO) and evaluate their biological activity. When the DFO was added to human umbilical vein endothelial cells cultured in 5.0% O2, the level of hypoxia-inducible factor-1α and vascular endothelial growth factor significantly increased compared with that without DFO. The expression of angiogenesis-related genes was accordingly increased by the DFO addition. An aqueous solution of mixed gelatin and DFO was freeze-dried, and dehydrothermally treated at 140°C for 24h to prepare a gelatin hydrogel incorporating DFO. In the release test with phosphate-buffered saline solution (PBS) at 37°C, an initial DFO release of 60% was observed, followed by no release. When placed in PBS containing collagenase, the hydrogel was enzymatically degraded with time, and consequently released DFO in a degradation-dependent manner. After the hydrogel incorporating DFO was injected intramuscularly into a mouse model of hind limb ischemia, the number of new blood vessels formed was significantly higher than that with free DFO and DFO-free hydrogel. It is concluded that the DFO-containing hydrogel shows promising for inducing angiogenesis locally. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  15. Systemic administration of thrombin peptide TP508 enhances VEGF-stimulated angiogenesis and attenuates effects of chronic hypoxia

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    Olszewska-Pazdrak, Barbara; Carney, Darrell H.

    2015-01-01

    Revascularization of chronic wounds and ischemic tissue is attenuated by endothelial dysfunction and the inability of angiogenic factors to stimulate angiogenesis. We recently showed that TP508, a nonproteolytic thrombin peptide, increases perfusion and NO-dependent vasodilation in hearts with chronic ischemia and stimulates NO production by endothelial cells. In this study, we investigated systemic in vivo effects of TP508 on VEGF-stimulated angiogenesis in vitro using aortic explants in normoxic and hypoxic conditions. Mice were injected with saline or TP508 and 24h later aortas were removed and cultured to quantify endothelial sprouting. TP508 injection increased endothelial sprouting and potentiated the in vitro response to VEGF. Exposure of control explants to hypoxia inhibited basal and VEGF-stimulated endothelial cell sprouting. This effect of hypoxia was significantly prevented by TP508 injection. Thus, TP508 systemic administration increases responsiveness of aortic endothelial cells to VEGF and diminishes the effect of chronic hypoxia on endothelial cell sprouting. Studies using human endothelial cells in culture suggest that protective effects of TP508 during hypoxia may involve stimulation of endothelial cell NO production. These data suggest potential clinical benefit of using a combination of systemic TP508 and local VEGF as a therapy for revascularization of ischemic tissue. PMID:23594718

  16. Hypoxia-induced mitogenic factor enhances angiogenesis by promoting proliferation and migration of endothelial cells

    International Nuclear Information System (INIS)

    Tong Qiangsong; Zheng Liduan; Li Bo; Wang Danming; Huang Chuanshu; Matuschak, George M.; Li Dechun

    2006-01-01

    Our previous studies have indicated that hypoxia-induced mitogenic factor (HIMF) has angiogenic properties in an in vivo matrigel plug model and HIMF upregulates expression of vascular endothelial growth factor (VEGF) in mouse lungs and cultured lung epithelial cells. However, whether HIMF exerts angiogenic effects through modulating endothelial cell function remains unknown. In this study, mouse aortic rings cultured with recombinant HIMF protein resulted in enhanced vascular sprouting and increased endothelial cell spreading as confirmed by Dil-Ac-LDL uptake, von Willebrand factor and CD31 staining. In cultured mouse endothelial cell line SVEC 4-10, HIMF dose-dependently enhanced cell proliferation, in vitro migration and tubulogenesis, which was not attenuated by SU1498, a VEGFR2/Flk-1 receptor tyrosine kinase inhibitor. Moreover, HIMF stimulation resulted in phosphorylation of Akt, p38 and ERK1/2 kinases in SVEC 4-10 cells. Treatment of mouse aortic rings and SVEC 4-10 cells with LY294002, but not SB203580, PD098059 or U0126, abolished HIMF-induced vascular sprouting and angiogenic responses. In addition, transfection of a dominant-negative mutant of phosphatidylinositol 3-kinase (PI-3K), Δp85, blocked HIMF-induced phosphorylation of Akt, endothelial activation and tubulogenesis. These results indicate that HIMF enhances angiogenesis by promoting proliferation and migration of endothelial cells via activation of the PI-3K/Akt pathways

  17. Increased Umbilical Cord PAI-1 Levels in Placental Insufficiency Are Associated with Fetal Hypoxia and Angiogenesis

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    Maxim D. Seferovic

    2016-01-01

    Full Text Available In intrauterine growth restriction (IUGR, a subset of pregnancies undergoes placental vascular dysregulation resulting in restricted blood flow and fetal hypoxemia. Altered transcription of hypoxic regulated plasminogen activator inhibitor 1 (PAI-1 has been associated with pregnancy complications and angiogenic regulation. Here we assessed circulating PAI-1 as an indicator of placental insufficiency. Venous umbilical PAI-1 of hypoxemic (VpO2 20 versus 35 mmHg, p<0.0001 placental insufficient pregnancies (resistance index 0.9 versus 0.63, p<0.05 (n=18 was compared to controls (n=12. PAI-1 was increased (~10-fold, p<0.001 and had a positive predictive ratio of 6.7. Further, PAI-1 levels correlated to blood oxygen (r=-0.68, p<0.0001. The plasma’s angiogenic potency measured in vitro was associated with umbilical cord blood PAI-1 levels (r=0.65, p<0.01. This association was attenuated by PAI-1 inhibiting antibody (p<0.001. The results demonstrate PAI-1 as a potential marker of placental insufficiency and identify its close association with pathological hypoxia and angiogenesis in a subset of growth restricted pregnancies.

  18. Hypoxia-Inducible Factor-1 as Regulator of Angiogenesis in Rheumatoid Arthritis - Therapeutic Implications

    NARCIS (Netherlands)

    Westra, J.; Molema, G.; Kallenberg, C. G. M.

    Angiogenesis plays an important role in the pathogenesis of inflammatory diseases, including rheumatoid arthritis ( RA). The site and extent of inflammation and subsequent joint destruction in the rheumatoid synovium is dependent on the development of new vasculature. Inhibition of angiogenesis,

  19. IFP. 1998 annual report; IFP. Rapport annuel 1998

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    NONE

    1998-07-01

    This 1998 edition of the annual report of the Institut Francais du Petrole (IFP) presents the main information relative to the institute: highlights, organization, consulting activity, budget, manpower, quality actions, patents and agreements; the research activities: exploration and fields, drilling and production, refining and petrochemistry, engines and energy research, environmental policy, natural gas; the training activities and the industrial partnerships. (J.S.)

  20. IFP. Annual report 2000; IFP. Rapport annuel 2000

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-07-01

    This annual report presents the highlights of the year 2000 activities of the Institut Francais du Petrole (IFP): petroleum exploration, drilling and production, refining and petrochemistry, automotive engines and cogeneration turbines, natural gas technologies, environmental research, training activity, industrial partnerships, industrialization of processes, ISIS group. (J.S.)

  1. Tumor necrosis is an important hallmark of aggressive endometrial cancer and associates with hypoxia, angiogenesis and inflammation responses.

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    Bredholt, Geir; Mannelqvist, Monica; Stefansson, Ingunn M; Birkeland, Even; Bø, Trond Hellem; Øyan, Anne M; Trovik, Jone; Kalland, Karl-Henning; Jonassen, Inge; Salvesen, Helga B; Wik, Elisabeth; Akslen, Lars A

    2015-11-24

    Tumor necrosis is associated with aggressive features of endometrial cancer and poor prognosis. Here, we investigated gene expression patterns and potential treatment targets related to presence of tumor necrosis in primary endometrial cancer lesions. By DNA microarray analysis, expression of genes related to tumor necrosis reflected multiple tumor-microenvironment interactions like tissue hypoxia, angiogenesis and inflammation pathways. A tumor necrosis signature of 38 genes and a related patient cluster (Cluster I, 67% of the cases) were associated with features of aggressive tumors such as type II cancers, estrogen receptor negative tumors and vascular invasion. Further, the tumor necrosis signature was increased in tumor cells grown in hypoxic conditions in vitro. Multiple genes with increased expression are known to be activated by HIF1A and NF-kB. Our findings indicate that the presence of tumor necrosis within primary tumors is associated with hypoxia, angiogenesis and inflammation responses. HIF1A, NF-kB and PI3K/mTOR might be potential treatment targets in aggressive endometrial cancers with presence of tumor necrosis.

  2. Hypoxia precondition promotes adipose-derived mesenchymal stem cells based repair of diabetic erectile dysfunction via augmenting angiogenesis and neuroprotection.

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    XiYou Wang

    Full Text Available The aim of the present study was to examine whether hypoxia preconditioning could improve therapeutic effects of adipose derived mesenchymal stem cells (AMSCs for diabetes induced erectile dysfunction (DED. AMSCs were pretreated with normoxia (20% O2, N-AMSCs or sub-lethal hypoxia (1% O2, H-AMSCs. The hypoxia exposure up-regulated the expression of several angiogenesis and neuroprotection related cytokines in AMSCs, including vascular endothelial growth factor (VEGF and its receptor FIK-1, angiotensin (Ang-1, basic fibroblast growth factor (bFGF, brain-derived neurotrophic factor (BDNF, glial cell-derived neurotrophic factor (GDNF, stromal derived factor-1 (SDF-1 and its CXC chemokine receptor 4 (CXCR4. DED rats were induced via intraperitoneal injection of streptozotocin (60 mg/kg and were randomly divided into three groups-Saline group: intracavernous injection with phosphate buffer saline; N-AMSCs group: N-AMSCs injection; H-AMSCs group: H-AMSCs injection. Ten rats without any treatment were used as normal control. Four weeks after injection, the mean arterial pressure (MAP and intracavernosal pressure (ICP were measured. The contents of endothelial, smooth muscle, dorsal nerve in cavernoursal tissue were assessed. Compared with N-AMSCs and saline, intracavernosum injection of H-AMSCs significantly raised ICP and ICP/MAP (p<0.05. Immunofluorescent staining analysis demonstrated that improved erectile function by MSCs was significantly associated with increased expression of endothelial markers (CD31 and vWF (p<0.01 and smooth muscle markers (α-SMA (p<0.01. Meanwhile, the expression of nNOS was also significantly higher in rats receiving H-AMSCs injection than those receiving N-AMSCs or saline injection. The results suggested that hypoxic preconditioning of MSCs was an effective approach to enhance their therapeutic effect for DED, which may be due to their augmented angiogenesis and neuroprotection.

  3. Down-regulation of hypoxia-inducible factor-1 alpha and vascular endothelial growth factor by HEXIM1 attenuates myocardial angiogenesis in hypoxic mice.

    Science.gov (United States)

    Yoshikawa, Noritada; Shimizu, Noriaki; Ojima, Hidenori; Kobayashi, Hiroshi; Hosono, Osamu; Tanaka, Hirotoshi

    2014-10-24

    Pulmonary hypertension (PH) sustains elevation of pulmonary vascular resistance and ultimately leads to right ventricular (RV) hypertrophy and failure and death. Recently, proangiogenic factors hypoxia-inducible factor-1 alpha (HIF-1α) and vascular endothelial growth factor (VEGF) have been known to promote left ventricular myocardial angiogenesis and lead to cardiac hypertrophy, and this would be involved in RV hypertrophy of PH patients. Previously, we revealed that overexpression of HEXIM1 prevents endothelin-1-induced cardiomyocyte hypertrophy and hypertrophic genes expression, and that cardiomyocyte-specific HEXIM1 transgenic mice ameliorates RV hypertrophy in hypoxia-induced PH model. Given these results, here we analyzed the effect of HEXIM1 on the expression of HIF-1α and VEGF and on myocardial angiogenesis of RV in PH. We revealed that overexpression of HEXIM1 prevented hypoxia-induced expression of HIF-1α protein and its target genes including VEGF in the cultured cardiac myocytes and fibroblasts, and that cardiomyocyte-specific HEXIM1 transgenic mice repressed RV myocardial angiogenesis in hypoxia-induced PH model. Thus, we conclude that HEXIM1 could prevent RV hypertrophy, at least in part, via suppression of myocardial angiogenesis through down-regulation of HIF-1α and VEGF in the myocardium under hypoxic condition. Copyright © 2014 Elsevier Inc. All rights reserved.

  4. Epidermal growth factor receptor inhibition reduces angiogenesis via hypoxia-inducible factor-1α and Notch1 in head neck squamous cell carcinoma.

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    Wei-Ming Wang

    Full Text Available Angiogenesis, a marker of cancer development, affects response to radiotherapy sensibility. This preclinical study aims to understand the receptor tyrosine kinase-mediated angiogenesis in head neck squamous cell carcinoma (HNSCC. The receptor tyrosine kinase activity in a transgenic mouse model of HNSCC was assessed. The anti-tumorigenetic and anti-angiogenetic effects of cetuximab-induced epidermal growth factor receptor (EGFR inhibition were investigated in xenograft and transgenic mouse models of HNSCC. The signaling transduction of Notch1 and hypoxia-inducible factor-1α (HIF-1α was also analyzed. EGFR was overexpressed and activated in the Tgfbr1/Pten deletion (2cKO mouse model of HNSCC. Cetuximab significantly delayed tumor onset by reducing tumor angiogenesis. This drug exerted similar effects on heterotopic xenograft tumors. In the human HNSCC tissue array, increased EGFR expression correlated with increased HIF-1α and micro vessel density. Cetuximab inhibited tumor-induced angiogenesis in vitro and in vivo by significantly downregulating HIF-1α and Notch1. EGFR is involved in the tumor angiogenesis of HNSCC via the HIF-1α and Notch1 pathways. Therefore, targeting EGFR by suppressing hypoxia- and Notch-induced angiogenesis may benefit HNSCC therapy.

  5. A hypoxia-inducible factor (HIF)-3α splicing variant, HIF-3α4 impairs angiogenesis in hypervascular malignant meningiomas with epigenetically silenced HIF-3α4

    Energy Technology Data Exchange (ETDEWEB)

    Ando, Hitoshi [Department of Neurosurgery, Nagoya University School of Medicine, Nagoya (Japan); Department of Neurosurgery, Fukushima Medical University School of Medicine, Fukushima (Japan); Natsume, Atsushi, E-mail: anatsume@med.nagoya-u.ac.jp [Department of Neurosurgery, Nagoya University School of Medicine, Nagoya (Japan); Iwami, Kenichiro; Ohka, Fumiharu [Department of Neurosurgery, Nagoya University School of Medicine, Nagoya (Japan); Kuchimaru, Takahiro; Kizaka-Kondoh, Shinae [Department of Biomolecular Engineering, Tokyo Institute of Technology Graduate School of Bioscience and Biotechnology, Yokohama (Japan); Ito, Kengo [National Center for Geriatrics and Gerontology, Aichi (Japan); Saito, Kiyoshi [Department of Neurosurgery, Fukushima Medical University School of Medicine, Fukushima (Japan); Sugita, Sachi; Hoshino, Tsuneyoshi [MICRON Inc.Medical Facilities Support Department, Aichi (Japan); Wakabayashi, Toshihiko [Department of Neurosurgery, Nagoya University School of Medicine, Nagoya (Japan)

    2013-03-29

    Highlights: ► HIF-3α4 is silenced by DNA methylation in meningiomas. ► Induction of HIF-3α4 impaired angiogenesis in meningiomas. ► Induction of HIF-3α4 impaired proliferation and oxygen-dependent metabolism. -- Abstract: Hypoxia inducible factor is a dominant regulator of adaptive cellular responses to hypoxia and controls the expression of a large number of genes regulating angiogenesis as well as metabolism, cell survival, apoptosis, and other cellular functions in an oxygen level-dependent manner. When a neoplasm is able to induce angiogenesis, tumor progression occurs more rapidly because of the nutrients provided by the neovasculature. Meningioma is one of the most hypervascular brain tumors, making anti-angiogenic therapy an attractive novel therapy for these tumors. HIF-3α has been conventionally regarded as a dominant-negative regulator of HIF-1α, and although alternative HIF-3α splicing variants are extensively reported, their specific functions have not yet been determined. In this study, we found that the transcription of HIF-3α4 was silenced by the promoter DNA methylation in meningiomas, and inducible HIF-3α4 impaired angiogenesis, proliferation, and metabolism/oxidation in hypervascular meningiomas. Thus, HIF-3α4 could be a potential molecular target in meningiomas.

  6. A hypoxia-inducible factor (HIF)-3α splicing variant, HIF-3α4 impairs angiogenesis in hypervascular malignant meningiomas with epigenetically silenced HIF-3α4

    International Nuclear Information System (INIS)

    Ando, Hitoshi; Natsume, Atsushi; Iwami, Kenichiro; Ohka, Fumiharu; Kuchimaru, Takahiro; Kizaka-Kondoh, Shinae; Ito, Kengo; Saito, Kiyoshi; Sugita, Sachi; Hoshino, Tsuneyoshi; Wakabayashi, Toshihiko

    2013-01-01

    Highlights: ► HIF-3α4 is silenced by DNA methylation in meningiomas. ► Induction of HIF-3α4 impaired angiogenesis in meningiomas. ► Induction of HIF-3α4 impaired proliferation and oxygen-dependent metabolism. -- Abstract: Hypoxia inducible factor is a dominant regulator of adaptive cellular responses to hypoxia and controls the expression of a large number of genes regulating angiogenesis as well as metabolism, cell survival, apoptosis, and other cellular functions in an oxygen level-dependent manner. When a neoplasm is able to induce angiogenesis, tumor progression occurs more rapidly because of the nutrients provided by the neovasculature. Meningioma is one of the most hypervascular brain tumors, making anti-angiogenic therapy an attractive novel therapy for these tumors. HIF-3α has been conventionally regarded as a dominant-negative regulator of HIF-1α, and although alternative HIF-3α splicing variants are extensively reported, their specific functions have not yet been determined. In this study, we found that the transcription of HIF-3α4 was silenced by the promoter DNA methylation in meningiomas, and inducible HIF-3α4 impaired angiogenesis, proliferation, and metabolism/oxidation in hypervascular meningiomas. Thus, HIF-3α4 could be a potential molecular target in meningiomas

  7. Relationship of binding specificity and structural property of the technetium-99m complexes for tumor hypoxia and tumor angiogenesis imaging

    International Nuclear Information System (INIS)

    Su, Z.F.

    2005-01-01

    The growth of tumor requires nutrition and oxygen. Tumor cells will become hypoxic when the supply of oxygen is insufficient. Hypoxic tumor cells will not only resist radiation therapy and chemotherapy, but also induce angiogenesis for oxygen supply and for metastasis. Therefore, detection of tumor hypoxia and tumor angiogenesis with high sensitive radio labeled imaging agents is important. Hypoxic tumor cells may display some molecules as tumor markers for the specific binding with radiopharmaceuticals. Radiopharmaceuticals, unlike the non-radioactive drugs, are trace compounds in a given dosage. Due to the extreme low concentration, the non-specific accumulation of the radiotracers by blood cells and proteins, tissues, and organs can be even more serious compared to the non-radioactive drugs. The non-specific accumulation of the radiotracers can make the ratios of tumor/tissue (in terms of i.d.%/g) falling to the range of 2∼7 [1-2]. Non-specific binding of radiopharmaceuticals is common, but detailed studies on it are poor documented. This presentation reports the study of the relationship of non-specific accumulation and the structural property of two type of 99m TC labeled compounds: (a) 99m Tc-(amine o xime) containing either 2-nitroimidazole (2-NI, as hypoxia tumor cells specific agents), or 4-nitro- imidazole (4-NI, as control), or aniline (as reference) groups; (b) 99m Tc-(arginine-glycine- aspartic acid, RGD, as tumor angiogenesis specific agents) and 99m Tc-(arginine-glycine- glutarmic acid, RGE, as control). The 99m Tc-(amine-oxime) complexes, in addition to the 2-NI, 4-NI, and aniline groups, contain methyl-, ethyl-, propyl-, iso-butyl-, t-butyl-, phenyl-, and Benzyl- groups as well to make the radiotracers differing in structure and in lipophilicity , while the lipophilicity of a radiotracer plays an important role in non-specific cellular accumulation and protein binding, The results demonstrated that (1) the complex containing 2-NI showed specific

  8. Silibinin inhibits hypoxia-induced HIF-1α-mediated signaling, angiogenesis and lipogenesis in prostate cancer cells: In vitro evidence and in vivo functional imaging and metabolomics.

    Science.gov (United States)

    Deep, Gagan; Kumar, Rahul; Nambiar, Dhanya K; Jain, Anil K; Ramteke, Anand M; Serkova, Natalie J; Agarwal, Chapla; Agarwal, Rajesh

    2017-03-01

    Hypoxia is associated with aggressive phenotype and poor prognosis in prostate cancer (PCa) patients suggesting that PCa growth and progression could be controlled via targeting hypoxia-induced signaling and biological effects. Here, we analyzed silibinin (a natural flavonoid) efficacy to target cell growth, angiogenesis, and metabolic changes in human PCa, LNCaP, and 22Rv1 cells under hypoxic condition. Silibinin treatment inhibited the proliferation, clonogenicity, and endothelial cells tube formation by hypoxic (1% O 2 ) PCa cells. Interestingly, hypoxia promoted a lipogenic phenotype in PCa cells via activating acetyl-Co A carboxylase (ACC) and fatty acid synthase (FASN) that was inhibited by silibinin treatment. Importantly, silibinin treatment strongly decreased hypoxia-induced HIF-1α expression in PCa cells together with a strong reduction in hypoxia-induced NADPH oxidase (NOX) activity. HIF-1α overexpression in LNCaP cells significantly increased the lipid accumulation and NOX activity; however, silibinin treatment reduced HIF-1α expression, lipid levels, clonogenicity, and NOX activity even in HIF-1α overexpressing LNCaP cells. In vivo, silibinin feeding (200 mg/kg body weight) to male nude mice with 22Rv1 tumors, specifically inhibited tumor vascularity (measured by dynamic contrast-enhanced MRI) resulting in tumor growth inhibition without directly inducing necrosis (as revealed by diffusion-weighted MRI). Silibinin feeding did not significantly affect tumor glucose uptake measured by FDG-PET; however, reduced the lipid synthesis measured by quantitative 1 H-NMR metabolomics. IHC analyses of tumor tissues confirmed that silibinin feeding decreased proliferation and angiogenesis as well as reduced HIF-1α, FASN, and ACC levels. Together, these findings further support silibinin usefulness against PCa through inhibiting hypoxia-induced signaling. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. Schedule-dependent inhibition of hypoxia-inducible factor-1alpha protein accumulation, angiogenesis, and tumor growth by topotecan in U251-HRE glioblastoma xenografts.

    Science.gov (United States)

    Rapisarda, Annamaria; Zalek, Jessica; Hollingshead, Melinda; Braunschweig, Till; Uranchimeg, Badarch; Bonomi, Carrie A; Borgel, Suzanne D; Carter, John P; Hewitt, Stephen M; Shoemaker, Robert H; Melillo, Giovanni

    2004-10-01

    We have previously shown that topotecan, a topoisomerase I poison, inhibits hypoxia-inducible factor (HIF)-1alpha protein accumulation by a DNA damage-independent mechanism. Here, we report that daily administration of topotecan inhibits HIF-1alpha protein expression in U251-HRE glioblastoma xenografts. Concomitant with HIF-1alpha inhibition, topotecan caused a significant tumor growth inhibition associated with a marked decrease of angiogenesis and expression of HIF-1 target genes in tumor tissue. These results provide a compelling rationale for testing topotecan in clinical trials to target HIF-1 in cancer patients.

  10. Transcriptome analysis of the spalax hypoxia survival response includes suppression of apoptosis and tight control of angiogenesis

    Directory of Open Access Journals (Sweden)

    Malik Assaf

    2012-11-01

    Full Text Available Abstract Background The development of complex responses to hypoxia has played a key role in the evolution of mammals, as inadequate response to this condition is frequently associated with cardiovascular diseases, developmental disorders, and cancers. Though numerous studies have used mice and rats in order to explore mechanisms that contribute to hypoxia tolerance, these studies are limited due to the high sensitivity of most rodents to severe hypoxia. The blind subterranean mole rat Spalax is a hypoxia tolerant rodent, which exhibits unique longevity and therefore has invaluable potential in hypoxia and cancer research. Results Using microarrays, transcript abundance was measured in brain and muscle tissues from Spalax and rat individuals exposed to acute and chronic hypoxia for varying durations. We found that Spalax global gene expression response to hypoxia differs from that of rat and is characterized by the activation of functional groups of genes that have not been strongly associated with the response to hypoxia in hypoxia sensitive mammals. Using functional enrichment analysis of Spalax hypoxia induced genes we found highly significant overrepresentation of groups of genes involved in anti apoptosis, cancer, embryonic/sexual development, epidermal growth factor receptor binding, coordinated suppression and activation of distinct groups of transcription factors and membrane receptors, in addition to angiogenic related processes. We also detected hypoxia induced increases of different critical Spalax hub gene transcripts, including antiangiogenic genes associated with cancer tolerance in Down syndrome human individuals. Conclusions This is the most comprehensive study of Spalax large scale gene expression response to hypoxia to date, and the first to use custom Spalax microarrays. Our work presents novel patterns that may underlie mechanisms with critical importance to the evolution of hypoxia tolerance, with special relevance to

  11. The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Hua; Yang, Ying-Hua [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Binmadi, Nada O. [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Department of Oral Basic and Clinical Sciences, King Abdulaziz University, Jeddah 21589 (Saudi Arabia); Proia, Patrizia [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Department of Sports Science (DISMOT), University of Palermo, Via Eleonora Duse 2 90146, Palermo (Italy); Basile, John R., E-mail: jbasile@umaryland.edu [Department of Oncology and Diagnostic Sciences, University of Maryland Dental School, 650W. Baltimore Street, 7-North, Baltimore, MD 21201 (United States); Greenebaum Cancer Center, 22S. Greene Street, Baltimore, MD 21201 (United States)

    2012-08-15

    Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors. -- Highlights: Black-Right-Pointing-Pointer Similar to VEGF, SEMA4D promotes angiogenesis in vitro and in vivo. Black-Right-Pointing-Pointer Both VEGF and SEMA4D are produced by OSCC cells in a HIF-dependent manner. Black-Right-Pointing-Pointer These factors combine to elicit a robust pro-angiogenic phenotype in OSCC. Black-Right-Pointing-Pointer Anti-SEMA4D

  12. The hypoxia-inducible factor-responsive proteins semaphorin 4D and vascular endothelial growth factor promote tumor growth and angiogenesis in oral squamous cell carcinoma

    International Nuclear Information System (INIS)

    Zhou, Hua; Yang, Ying-Hua; Binmadi, Nada O.; Proia, Patrizia; Basile, John R.

    2012-01-01

    Growth and metastasis of solid tumors requires induction of angiogenesis to ensure the delivery of oxygen, nutrients and growth factors to rapidly dividing transformed cells. Through either mutations, hypoxia generated by cytoreductive therapies, or when a malignancy outgrows its blood supply, tumor cells undergo a change from an avascular to a neovascular phenotype, a transition mediated by the hypoxia-inducible factor (HIF) family of transcriptional regulators. Vascular endothelial growth factor (VEGF) is one example of a gene whose transcription is stimulated by HIF. VEGF plays a crucial role in promoting tumor growth and survival by stimulating new blood vessel growth in response to such stresses as chemotherapy or radiotherapy-induced hypoxia, and it therefore has become a tempting target for neutralizing antibodies in the treatment of advanced neoplasms. Emerging evidence has shown that the semaphorins, proteins originally associated with control of axonal growth and immunity, are regulated by changes in oxygen tension as well and may play a role in tumor-induced angiogenesis. Through the use of RNA interference, in vitro and in vivo angiogenesis assays and tumor xenograft experiments, we demonstrate that expression of semaphorin 4D (SEMA4D), which is under the control of the HIF-family of transcription factors, cooperates with VEGF to promote tumor growth and vascularity in oral squamous cell carcinoma (OSCC). We use blocking antibodies to show that targeting SEMA4D function along with VEGF could represent a novel anti-angiogenic therapeutic strategy for the treatment of OSCC and other solid tumors. -- Highlights: ► Similar to VEGF, SEMA4D promotes angiogenesis in vitro and in vivo. ► Both VEGF and SEMA4D are produced by OSCC cells in a HIF-dependent manner. ► These factors combine to elicit a robust pro-angiogenic phenotype in OSCC. ► Anti-SEMA4D blocking antibody inhibits Plexin-B1 activation. ► SEMA4D is a valid anti-angiogenic target in the

  13. Imaging angiogenesis.

    Science.gov (United States)

    Charnley, Natalie; Donaldson, Stephanie; Price, Pat

    2009-01-01

    There is a need for direct imaging of effects on tumor vasculature in assessment of response to antiangiogenic drugs and vascular disrupting agents. Imaging tumor vasculature depends on differences in permeability of vasculature of tumor and normal tissue, which cause changes in penetration of contrast agents. Angiogenesis imaging may be defined in terms of measurement of tumor perfusion and direct imaging of the molecules involved in angiogenesis. In addition, assessment of tumor hypoxia will give an indication of tumor vasculature. The range of imaging techniques available for these processes includes positron emission tomography (PET), dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI), perfusion computed tomography (CT), and ultrasound (US).

  14. Correlation of Hypoxia-Inducible Factor 1α with Angiogenesis in Liver Tumors After Transcatheter Arterial Embolization in an Animal Model

    International Nuclear Information System (INIS)

    Liang Bin; Zheng Chuansheng; Feng, Gan-Sheng; Wu Hanping; Wang Yong; Zhao Hui; Qian Jun; Liang Huimin

    2010-01-01

    This study sought to determine the expression of hypoxia-inducible factor 1α (HIF-1α) and its relation to angiogenesis in liver tumors after transcatheter arterial embolization (TAE) in an animal model. A total of 20 New Zealand White rabbits were implanted with VX2 tumor in liver. TAE-treated group animals (n = 10) received TAE with polyvinyl alcohol particles. Control group animals (n = 10) received sham embolization with distilled water. Six hours or 3 days after TAE, animals were humanely killed, and tumor samples were collected. Immunohistochemical staining was performed to evaluate HIF-1α and vascular endothelial growth factor (VEGF) protein expression and microvessel density (MVD). Real-time polymerase chain reaction was performed to examine VEGF mRNA levels. The levels of HIF-1α protein were significantly higher in TAE-treated tumors than those in the control tumors (P = 0.001). HIF-1α protein was expressed in viable tumor cells that were located predominantly at the periphery of necrotic tumor regions. The levels of VEGF protein and mRNA, and mean MVD were significantly increased in TAE-treated tumors compared with the control tumors (P = 0.001, 0.000, and 0.001, respectively). HIF-1α protein level was significantly correlated with VEGF mRNA (r = 0.612, P = 0.004) and protein (r = 0.554, P = 0.011), and MVD (r = 0.683, P = 0.001). We conclude that HIF-1α is overexpressed in VX2 tumors treated with TAE as a result of intratumoral hypoxia generated by the procedure and involved in activation of the TAE-associated tumor angiogenesis. HIF-1α might represent a promising therapeutic target for antiangiogenesis in combination with TAE against liver tumors.

  15. Angiogenesis and expression of vascular endothelial growth factor, tumour necrosis factor-α and hypoxia inducible factor-1α in canine renal cell carcinoma.

    Science.gov (United States)

    Yhee, J Y; Yu, C H; Kim, J H; Im, K S; Kim, N H; Brodersen, B W; Doster, A R; Sur, J-H

    2012-01-01

    The aim of the present study was to determine the distribution and characteristics of microvessels in various histological types of canine renal cell carcinoma (RCC). The study compared microvessel density (MVD) and distribution of blood vessels according to histological type and evaluated the presence of angiogenesis-related proteins. Nine archival samples of canine RCC were studied. MVD was calculated as the mean number of blood vessels per mm(2). The diameter of blood vessels was calculated by determining either the length of the long axis of blood vessels (diameter(max)) or the mean distance from the centre of each blood vessel to the tunica adventia (diameter(mean)). A significant difference in MVD was evident between RCCs and normal kidneys (46.6 ± 28.0 versus 8.4 ± 2.2 microvessels/mm(2)). Diameter(max) in canine RCCs (34.1 ± 14.7 μm) was also significantly different from normal canine kidney (23.2 ± 3.4 μm). Vascular endothelial growth factor (VEGF) was expressed by tumour cells and vascular endothelial cells and tumour necrosis factor (TNF)-α expression was observed in vascular endothelial cells in both neoplastic and normal kidney. Although VEGF is involved in angiogenesis and correlates with tumour stage of development, no correlation was found between VEGF expression and MVD. Tumour-associated macrophages expressing TNF-α and hypoxia inducible factor 1α were identified in peritumoural tissue and may play an important role in angiogenesis. Copyright © 2011 Elsevier Ltd. All rights reserved.

  16. ANG II type 1 receptor antagonist irbesartan inhibits coronary angiogenesis stimulated by chronic intermittent hypoxia in neonatal rats

    Czech Academy of Sciences Publication Activity Database

    Rakusan, K.; Chvojková, Zuzana; Oliviero, P.; Ošťádalová, Ivana; Kolář, František; Chassagne, C.; Samuel, J. L.; Ošťádal, Bohuslav

    2007-01-01

    Roč. 292, č. 3 (2007), H1237-H1244 ISSN 0363-6135 R&D Projects: GA MŠk 1M0510 Institutional research plan: CEZ:AV0Z50110509 Keywords : angiogenesis neonatal rat * ANG II type 1 receptor antagonist heart * ischemic tolerance Subject RIV: ED - Physiology Impact factor: 3.973, year: 2007

  17. Enzyme 15-lipoxygenase 1 promotes hypoxia-inducible factor 1α turnover and reduces vascular endothelial growth factor expression: implications for angiogenesis

    International Nuclear Information System (INIS)

    Zhong, Hua; Wang, Ruoxiang; Kelavkar, Uddhav; Wang, Christopher Y; Simons, Jonathan

    2014-01-01

    Hypoxia-inducible factor 1α (HIF-1α) is the regulatory subunit of the heterodimeric HIF-1 that plays a critical role in transcriptional regulation of genes in angiogenesis and hypoxic adaptation, while fatty acid metabolism mediated by lipoxygenases has been implicated in a variety of pathogeneses, including cancers. In this study, we report that 15-lipoxygenase 1 (15-LO1), a key member of the lipoxygenase family, promotes HIF-1α ubiquitination and degradation. Altering the level of 15-LO1 yields inverse changes in HIF-1α and HIF-1 transcriptional activity, under both normoxia and hypoxia, and even in CoCl 2 -treated cells where HIF-1α has been artificially elevated. The antagonistic effect of 15-LO1 is mediated by the Pro 564 /hydroxylation/26S proteasome system, while both the enzymatic activity and the intracellular membrane-binding function of 15-LO1 appear to contribute to HIF-1α suppression. Our findings provide a novel mechanism for HIF-1α regulation, in which oxygen-dependent HIF-1 activity is modulated by an oxygen-insensitive lipid metabolic enzyme

  18. Leptin acts on neoplastic behavior and expression levels of genes related to hypoxia, angiogenesis, and invasiveness in oral squamous cell carcinoma.

    Science.gov (United States)

    Sobrinho Santos, Eliane Macedo; Guimarães, Talita Antunes; Santos, Hércules Otacílio; Cangussu, Lilian Mendes Borborema; de Jesus, Sabrina Ferreira; Fraga, Carlos Alberto de Carvalho; Cardoso, Claudio Marcelo; Santos, Sérgio Henrique Souza; de Paula, Alfredo Maurício Batista; Gomez, Ricardo Santiago; Guimarães, André Luiz Sena; Farias, Lucyana Conceição

    2017-05-01

    Leptin, one of the main hormones controlling energy homeostasis, has been associated with different cancer types. In oral cancer, its effect is not well understood. We investigated, through in vitro and in vivo assays, whether leptin can affect the neoplastic behavior of oral squamous cell carcinoma. Expression of genes possibly linked to the leptin pathway was assessed in leptin-treated oral squamous cell carcinoma cells and also in tissue samples of oral squamous cell carcinoma and oral mucosa, including leptin, leptin receptor, hypoxia-inducible factor 1-alpha, E-cadherin, matrix metalloproteinase-2, matrix metalloproteinase-9, Col1A1, Ki67, and mir-210. Leptin treatment favored higher rates of cell proliferation and migration, and reduced apoptosis. Accordingly, leptin-treated oral squamous cell carcinoma cells show decreased messenger RNA caspase-3 expression, and increased levels of E-cadherin, Col1A1, matrix metalloproteinase-2, matrix metalloproteinase-9, and mir-210. In tissue samples, hypoxia-inducible factor 1-alpha messenger RNA and protein expression of leptin and leptin receptor were high in oral squamous cell carcinoma cases. Serum leptin levels were increased in first clinical stages of the disease. In animal model, oral squamous cell carcinoma-induced mice show higher leptin receptor expression, and serum leptin level was increased in dysplasia group. Our findings suggest that leptin seems to exert an effect on oral squamous cell carcinoma cells behavior and also on molecular markers related to cell proliferation, migration, and tumor angiogenesis.

  19. Correlation of matrix metalloproteinases and their inhibitors with hypoxia and angiogenesis in premenopausal patients with adenocarcinoma of the breast.

    Science.gov (United States)

    Vinothini, Govindarajah; Aravindraja, Chairmandurai; Chitrathara, K; Nagini, Siddavaram

    2011-08-01

    The present study was designed to correlate the expression of proteins regulating invasion and angiogenesis in patients with adenocarcinoma of the breast. Seventy-five premenopausal breast cancer patients histologically categorized as grades I, II and III were chosen for the study. We analyzed the expression of MMP-2, and -9 and their inhibitors TIMP-2 and RECK together with HIF-1α and VEGF in tumor, adjacent tissues and serum samples by immunohistochemical and Western blot analysis. The breast tumors analyzed in the present study were characterized by increased expression of MMP-2, -9, HIF-1α and VEGF with differential expression patterns of TIMP-2 and downregulation of RECK. The simultaneous analysis of the expression of these molecular markers is important to understand the intricate network between key molecules involved in invasion and angiogenesis that eventually determines the clinical course of the disease. Copyright © 2011 The Canadian Society of Clinical Chemists. Published by Elsevier Inc. All rights reserved.

  20. Hypoxia-inducible factor-1α, vascular endothelial growth factor, inducible nitric oxide synthase, and endothelin-1 expression correlates with angiogenesis in congenital heart disease

    Directory of Open Access Journals (Sweden)

    Hsin-Ling Yin

    2016-07-01

    Full Text Available In Taiwan, the average prevalence of congenital heart disease (CHD is 13.08/1000 live births. Most children with CHD die before the age of 5 years; therefore, identifying treatment methods to extend the life of CHD patients is an important issue in clinical practice. The objective of this study is to evaluate the roles of hypoxia-inducible factor-1α (HIF-1α, vascular endothelial growth factor (VEGF, inducible nitric oxide synthase (iNOS, endothelin-1 (ET-1, and CD34 in CHD autopsy cases in comparison with autopsy cases without CHD. The study included 19 autopsy cases, which were divided into the following four groups: acyanotic CHD (n = 11, cyanotic CHD (n = 3, CHD associated with chromosomal abnormalities (n = 3, and complex CHD (n = 2. Heart specimens obtained from 10 autopsy cases without CHD were included as controls. Our results indicated that high percentages of HIF-1α (100%, VEGF (89.5%, iNOS (78.9%, and ET-1 (84.2% expressions were observed in CHD autopsy cases and this was found to be significant. HIF-1α induced by hypoxia could play a potential role in relating downstream gene expressions in CHD patients. Upregulation of VEGF by HIF-1α could play an important role in triggering angiogenesis to protect myocardial cell survival in a hypoxic microenvironment. Therefore, HIF-1α could be a significant prognosis marker in CHD and be a prospective candidate in the development of target therapy in cardiovascular diseases.

  1. The IFP and the CO{sub 2}; L'IFP et le CO{sub 2}

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    The IFP (french petroleum institute) developed research programs on the CO{sub 2} emissions decrease. This colloquium presents the IFP research programs in the domain the greenhouse effect fight (regulations framework implementation, the European Union actions); the carbon dioxide emissions fight (motors combustion improvement, the alternative fuels) and the carbon dioxide capture storage. (A.L.B.)

  2. The redox protein thioredoxin-1 (Trx-1) increases hypoxia-inducible factor 1alpha protein expression: Trx-1 overexpression results in increased vascular endothelial growth factor production and enhanced tumor angiogenesis.

    Science.gov (United States)

    Welsh, Sarah J; Bellamy, William T; Briehl, Margaret M; Powis, Garth

    2002-09-01

    Hypoxia-inducible factor 1 (HIF-1), a heterodimer of HIF-1alpha and HIF-1beta subunits, is a transcriptional activator central to the cellular response to low oxygen that includes metabolic adaptation, angiogenesis, metastasis, and inhibited apoptosis. Thioredoxin-1 (Trx-1) is a small redox protein overexpressed in a number of human primary tumors. We have examined the effects of Trx-1 on HIF activity and the activation of downstream genes. Stable transfection of human breast carcinoma MCF-7 cells with human Trx-1 caused a significant increase in HIF-1alpha protein levels under both normoxic (20% oxygen) and hypoxic (1% oxygen) conditions. Trx-1 increased hypoxia-induced HIF-1 transactivation activity measured using a luciferase reporter under the control of the hypoxia response element. Changes in HIF-1alpha mRNA levels did not account for the changes observed at the protein level, and HIF-1beta protein levels did not change. Trx-1 transfection also caused a significant increase in the protein products of hypoxia-responsive genes, including vascular endothelial growth factor (VEGF) and nitric oxide synthase 2 in a number of different cell lines (MCF-7 human breast and HT29 human colon carcinomas and WEHI7.2 mouse lymphoma cells) under both normoxic and hypoxic conditions. The pattern of expression of the different isoforms of VEGF was not changed by Trx-1. Transfection of a redox-inactive Trx-1 (C32S/C35S) markedly decreased levels of HIF-1alpha protein, HIF-1 transactivating activity, and VEGF protein in MCF-7 cells compared with empty vector controls. In vivo studies using WEHI7.2 cells transfected with Trx-1 showed significantly increased tumor VEGF and angiogenesis. The results suggest that Trx-1 increases HIF-1alpha protein levels in cancer cells and increases VEGF production and tumor angiogenesis.

  3. Hydrocarbons and environment: IFP's strategy; hydrocarbures et environnement: la strategie de l'IFP

    Energy Technology Data Exchange (ETDEWEB)

    Mandil, C.; Feugier, A.

    2001-07-01

    This press kit presents the strategy of the French Institute of Petroleum (IFP) in the domain of environment and sustainable development. This strategy concerns the whole R and D activities of IFP: exploration-production, refining-petrochemistry, engines and use of petroleum products. IFP's work in this domain follows three ways of actions: development of energy saving and environmentally friendly technologies of hydrocarbons production, transformation and use, development of methodologies and techniques of remediation of polluted environments, and intensification of the research effort in the domain of greenhouse gases abatement. A set of transparencies and two brochures entitled 'IFP and environment' and 'management of polluted sites' are included. (J.S.)

  4. IFP Energies nouvelles. 2016 Activity Report - Innovating for energy

    International Nuclear Information System (INIS)

    2017-01-01

    IFP Energies Nouvelles is a major research and training player in the fields of energy, transport and the environment. From research to industry, technological innovation is central to all its activities, structured around three strategic priorities: sustainable mobility, new energies and responsible oil and gas. As part of the public-interest mission with which it has been tasked by the public authorities, IFPEN focuses on: - providing solutions to take up the challenges facing society in terms of energy and the climate, promoting the transition towards sustainable mobility and the emergence of a more diversified energy mix; - creating wealth and jobs by supporting French and European economic activity, and the competitiveness of related industrial sectors. An integral part of IFPEN, its graduate engineering school - IFP School - prepares future generations to take up these challenges. IFPEN has proven expertise across the entire value chain, from fundamental research to innovation. It is funded both by a state budget and by its own resources provided by industrial partners. The latter account for over 50% of IFPEN's total budget, a configuration that is quasi unique in France. The aim of IFPEN's R and I programs is to overcome existing scientific and technological challenges in order to develop innovations that can be used by industry. IFPEN's fundamental research program aims to create a bedrock of knowledge essential for the development of innovations. The scientific expertise of IFPEN's researchers is internationally recognized and they are regularly consulted by the public authorities to provide their insight in their specific fields to inform the decision-making process. IFPEN's economic model is based on the transfer to industry of the technologies developed by its researchers. This technology transfer to industry generates jobs and business, fostering the economic development of fields and approaches related to the mobility, energy and eco-industry sectors

  5. Engelhard and IFP/Procatalyse set up worldwide catalysts venture

    International Nuclear Information System (INIS)

    Hunter, D.

    1992-01-01

    The new joint venture between Engelhard (Iselin, N) and Procatalyse (Paris), jointly owned by process licenser Institut Francais de Petrole (IFP; Rueil Malmaison, France) and Rhone-Poulenc (RP; Paris), marks the latest episode in the worldwide catalyst industry's restructuring. The operation will combine Engelhard's catalyst line, apart from its fluid catalytic cracking (FCC) and emission catalysts, with Procatalyse's offering. To be launched at the beginning of 1993, the venture will have annual sales of about $75 million. Reforming catalysts will be the biggest part of the venture's lineup at the outset, making it number three in the US, behind UOP - which dominates the sector - and Criterion. IFP is starting to establish a presence in North America with its reforming technology. But flat gasoline demand and reductions on aromatics in gasoline limit requirements for new reforming units, comments one competitor. Although lower sulfur specifications are putting some new demand into the hydrodesulfurization (HDS) catalyst market, both partners play down their prospects. The sector, whose leaders are Akzo and Crtierion, is continuing to suffer from severe overcapacity. Procatalyse's HDS business is mainly linked to IFP licensees, while Engelhard is due to mothball its Salt Lake City HDS catalyst plant by year-end, transferring output to Elyria

  6. Hypoxic inactivation of glycogen synthase kinase-3β promotes gastric tumor growth and angiogenesis by facilitating hypoxia-inducible factor-1 signaling.

    Science.gov (United States)

    Ko, Young San; Cho, Sung Jin; Park, Jinju; Choi, Yiseul; Lee, Jae-Seon; Youn, Hong-Duk; Kim, Woo Ho; Kim, Min A; Park, Jong-Wan; Lee, Byung Lan

    2016-09-01

    Since the molecular mechanism of hypoxic adaptation in cancer cells is cell-type specific, we investigated whether glycogen synthase kinase-3β (GSK-3β) activation is involved in hypoxia-induced gastric tumor promotion. Stable gastric cancer cell lines (SNU-638, SNU-484, MKN1, and MKN45) were cultured under hypoxic conditions. Cells overexpressing wild-type GSK-3β (WT-GSK-3β) or kinase-dead mutant of GSK-3β (KD-GSK-3β) were generated and used for cell culture and animal studies. In cell culture experiments, hypoxia decreased GSK-3β activation in gastric cancer cells. Cell viability and the expressions of HIF-1α protein and VEGF mRNA in gastric cancer cells were higher in KD-GSK-3β transfectants than in WT-GSK-3β transfectants under hypoxic conditions, but not under normoxic conditions. Gastric cancer xenografts showed that tumor growth, microvessel area, HIF-1α activation, and VEGF expression were higher in KD-GSK-3β tumors than in WT-GSK-3β tumors in vivo. In addition, the expression of hypoxia-induced HIF-1α protein was regulated by GSK-3β at the translational level. Our data suggest that GSK-3β is involved in hypoxic adaptation of gastric cancer cells as an inhibitory upstream regulator of the HIF-1α/VEGF signaling pathway. © 2016 APMIS. Published by John Wiley & Sons Ltd.

  7. Inhibition of hypoxia inducible factor-1alpha by dihydroxyphenylethanol, a product from olive oil, blocks microsomal prostaglandin-E synthase-1/vascular endothelial growth factor expression and reduces tumor angiogenesis.

    Science.gov (United States)

    Terzuoli, Erika; Donnini, Sandra; Giachetti, Antonio; Iñiguez, Miguel A; Fresno, Manuel; Melillo, Giovanni; Ziche, Marina

    2010-08-15

    2-(3,4-dihydroxyphenil)-ethanol (DPE), a polyphenol present in olive oil, has been found to attenuate the growth of colon cancer cells, an effect presumably related to its anti-inflammatory activity. To further explore the effects of DPE on angiogenesis and tumor growth we investigated the in vivo efficacy of DPE in a HT-29 xenograft model and in vitro activities in colon cancer cells exposed to interleukin-1beta (IL-1beta) and prostaglandin E-2 (PGE-2). DPE (10 mg/kg/day for 14 days) inhibited tumor growth, reducing vessel lumina and blood perfusion to tumor, and diminished expression of hypoxia inducible factor-1alpha (HIF-1alpha), vascular endothelial growth factor (VEGF), and microsomal prostaglandin-E synthase-1 (mPGEs-1). In vitro, DPE (100 mumol/L) neither affected cell proliferation nor induced apoptosis in HT-29 and WiDr cells. DPE prevented the IL-1beta-mediated increase of mPGEs-1 expression and PGE-2 generation, as it did the silencing of HIF-1alpha. Moreover, DPE blocked mPGEs-1-dependent expression of VEGF and inhibited endothelial sprouting induced by tumor cells in a coculture system. PGE-2 triggers a feed-forward loop involving HIF-1alpha, which impinges on mPGEs-1 and VEGF expression, events prevented by DPE via extracellular signal-related kinase 1/2. The reduction of PGE-2 and VEGF levels, caused by DPE, was invariably associated with a marked decrease in HIF-1alpha expression and activity, independent of proteasome activity, indicating that the DPE effects on tumor growth and angiogenesis are dependent on the inhibition of HIF-1alpha translation. We show that the in vivo DPE antitumor effect is associated with anti-inflammatory and antiangiogenic activities resulting from the downregulation of the HIF-1alpha/mPGEs-1/VEGF axis.

  8. Biodegradation of 2-ethylhexyl nitrate by Mycobacterium austroafricanum IFP 2173

    International Nuclear Information System (INIS)

    Nicolau, E.

    2008-10-01

    Compounds such as 2-ethylhexyl nitrate (2-EHN) are added to diesel fuel to improve ignition and boost cetane number. The production of 2-EHN reaches around 100000 tons per year in France, principally. Risks associated to its utilization are however poorly known because, in case of accidental release in the environment, nothing is known about its biodegradation. In this study, we aimed at (i) identifying bacterial strains able to degrade 2-EHN and compare their capabilities, (ii) elucidating the degradation pathway, and (iii) identifying the enzymes involved. Biodegradation of 2-EHN was first tested in biphasic cultures under conditions that reduce the toxicity and increase the availability of the hydrophobic substrate. Using optimized culture conditions, we showed that several strains of Mycobacterium austroafricanum were able to degrade 2-EHN. One of the most efficient strain (IFP 2173) which could grow at 2-EHN concentrations up to 6 g.L -1 , was chosen to investigate the degradation pathway. On the basis of carbon balance determination and gas chromatographic (GC) analysis on the culture medium, I found that the degradation of 2-EHN was incomplete and gave rise to the accumulation of a metabolite. This metabolite was identified as β-methyl-γ-butyrolactone by GC-MS and LC-MS/MS analysis. The structure of the lactone indicated that 2-EHN was degraded through a pathway involving the hydroxylation of the methyl group of the main carbon chain, its oxidation into aldehyde an acid and a subsequent cycle of b-oxidation. Enzymes involved in the 2-EHN biodegradation pathway were looked for by a proteomic approach. Analyses by two-dimensional gel electrophoresis showed that, when exposed to 2-EHN, strain IFP 2173 triggered the synthesis of a bunch of enzymes specialized in fatty acid metabolism such as β-oxidation enzymes, as well as alcohol and aldehyde dehydrogenases. An exhaustive analysis of the IFP 2173 proteome resulted in the identification of more than 200

  9. Biodegradation of 2-ethylhexyl nitrate by Mycobacterium austroafricanum IFP 2173; Biodegradation du 2-ethylhexyl nitrate par Mycobacterium austroafricanum IFP 2173

    Energy Technology Data Exchange (ETDEWEB)

    Nicolau, E

    2008-10-15

    Compounds such as 2-ethylhexyl nitrate (2-EHN) are added to diesel fuel to improve ignition and boost cetane number. The production of 2-EHN reaches around 100000 tons per year in France, principally. Risks associated to its utilization are however poorly known because, in case of accidental release in the environment, nothing is known about its biodegradation. In this study, we aimed at (i) identifying bacterial strains able to degrade 2-EHN and compare their capabilities, (ii) elucidating the degradation pathway, and (iii) identifying the enzymes involved. Biodegradation of 2-EHN was first tested in biphasic cultures under conditions that reduce the toxicity and increase the availability of the hydrophobic substrate. Using optimized culture conditions, we showed that several strains of Mycobacterium austroafricanum were able to degrade 2-EHN. One of the most efficient strain (IFP 2173) which could grow at 2-EHN concentrations up to 6 g.L{sup -1}, was chosen to investigate the degradation pathway. On the basis of carbon balance determination and gas chromatographic (GC) analysis on the culture medium, I found that the degradation of 2-EHN was incomplete and gave rise to the accumulation of a metabolite. This metabolite was identified as {beta}-methyl-{gamma}-butyrolactone by GC-MS and LC-MS/MS analysis. The structure of the lactone indicated that 2-EHN was degraded through a pathway involving the hydroxylation of the methyl group of the main carbon chain, its oxidation into aldehyde an acid and a subsequent cycle of b-oxidation. Enzymes involved in the 2-EHN biodegradation pathway were looked for by a proteomic approach. Analyses by two-dimensional gel electrophoresis showed that, when exposed to 2-EHN, strain IFP 2173 triggered the synthesis of a bunch of enzymes specialized in fatty acid metabolism such as {beta}-oxidation enzymes, as well as alcohol and aldehyde dehydrogenases. An exhaustive analysis of the IFP 2173 proteome resulted in the identification of

  10. Hypoxia in Tumor Angiogenesis and Metastasis: Evaluation of VEGF and MMP Over-expression and Down-Regulation of HIF-1alpha with RNAi in Hypoxic Tumor Cells

    Science.gov (United States)

    Shah, Shruti

    Background: As tumor mass grows beyond a few millimeters in diameter, the angiogenic "switch" is turned on leading to recruitment of blood vessels from surrounding artery and veins. However, the tumor mass is poorly perfused and there are pockets of hypoxia or lower oxygen concentrations relative to normal tissue. Hypoxia-inducing factor-1a (HIF-1a), a transcription factor, is activated when the oxygen concentration is low. Upon activation of HIF-1a, a number of other genes also turn on that allows the tumor to become more aggressive and resistant to therapy. Purpose: The main objectives of this study were to evaluate the effect of hypoxia-induced HIF-1a followed by over-expression of angiogenic and metastatic markers in tumor cells and down-regulation of HIF-1a using nanoparticle-delivered RNA interference therapy. Methods: Human ovarian (SKOV3) and breast (MDA-MB-231) adenocarcinoma cells were incubated under normoxic and hypoxic conditions. Following hypoxia treatment of the cells, HIF-1α, vascular endothelial growth factor (VEGF), matrix metalloproteinase 2 (MMP-2), and MMP-9 expression was analyzed qualitatively and quantitatively. For intracellular delivery of HIF-1a gene silencing small interfering RNA (siRNA), type B gelatin nanoparticles were fabricated using the solvent displacement method and the surface was modified with poly(ethylene glycol) (PEG, Mol. wt. 2kDa). Cellular uptake and distribution of the nanoparticles was observed with Cy3-siRNA loaded, FITC-conjugated gelatin nanoparticles. Cytotoxicity of the nanoparticle formulations was evaluated in both the cell lines. siRNA was transfected in the gelatin nanoparticles under hypoxic conditions. Total cellular protein and RNA were extracted for analysis of HIF1a, VEGF, MMP-2 and MMP-9 expression. Results: MDA-MB-231 and SKOV3 cells show increased expression of HIF1a under hypoxic conditions compared to baseline levels at normoxic conditions. ELISA and western blots of VEGF, MMP-2 and MMP-9 appear to

  11. Toll-like Receptor 3 Regulates Angiogenesis and Apoptosis in Prostate Cancer Cell Lines through Hypoxia-Inducible Factor 1α

    Directory of Open Access Journals (Sweden)

    Alessio Paone

    2010-07-01

    Full Text Available Toll-like receptors (TLRs recognize microbial/viral-derived components that trigger innate immune response and conflicting data implicate TLR agonists in cancer, either as protumor or antitumor agents. We previously demonstrated that TLR3 activation mediated by its agonist poly(I:C induces antitumor signaling, leading to apoptosis of prostate cancer cells LNCaP and PC3 with much more efficiency in the former than in the second more aggressive line. The transcription factor hypoxia-induciblefactor 1 (HIF-1regulates several cellular processes, includingapoptosis, in response to hypoxia and to other stimuli also in normoxic conditions. Here we describe a novel protumor machinery triggered by TLR3 activation in PC3 cells consisting of increased expression of the specific 1.3 isoform of HIF-1α and nuclear accumulation of HIF-1 complex in normoxia, resulting in reduced apoptosis and in secretion of functional vascular endothelial growth factor (VEGF. Moreover, we report that, in the less aggressive LNCaP cells, TLR3 activation fails to induce nuclear accumulation of HIF-1α. However, the transfection of 1.3 isoform of hif-1α in LNCaP cells allows poly(I:CI-induced HIF-1 activation, resulting in apoptosis protection and VEGF secretion. Altogether, our findings demonstrate that differences in the basal level of HIF-1α expression in different prostate cancer cell lines underlie their differential response to TLR3 activation, suggesting a correlation between different stages of malignancy, hypoxic gene expression, and beneficial responsiveness to TLR agonists.

  12. EPA/IFP EUROPEAN WORKSHOP ON THE EMISSION ON NITROUS OXIDE FROM FOSSIL FUEL COMBUSTION

    Science.gov (United States)

    The report summarizes the proceedings of an EPA/Institut Francais du Petrole (IFP) cosponsored workshop addressing direct nitrous oxide (N2O) emission from fossil fuel combustion. The third in a series, it was held at the IFP in Rueil-Malmaison, France, on June 1-2, 1988. Increas...

  13. An allometric approach of tumor-angiogenesis.

    Science.gov (United States)

    Szasz, Oliver; Vincze, Gyula; Szigeti, Gyula Peter; Benyo, Zoltan; Szasz, Andras

    2018-07-01

    Angiogenesis is one of the main supporting factors of tumor-progression. It is a complex set of interactions together with hypoxia and inflammation, regulating tumor growth. The objective of this study is to examine the effect of angiogenesis with an allometric approach applied to angiogenesis and the regulating factors. The results show that allometry has the potential to describe this aspect, including the sigmoid-like transport function. There are particular conditions under which the complex control maximizes the relative tumor mass. Linear growth of malignancy diameter with an allometric approach was proven. Copyright © 2018. Published by Elsevier Ltd.

  14. The automobile of the future: engine technologies and automotive fuels developed by IFP; l'automobile du futur: les technologies moteurs et carburants developpes par l'IFP

    Energy Technology Data Exchange (ETDEWEB)

    Appert, O; Pinchon, Ph

    2004-07-01

    In front of the challenges of climate change and depletion of petroleum reserves, in front of the continuous strengthening of pollution regulations applied to automobile (Euro IV and V) and the advances of R and D, several ways of research can be explored to answer the mobility needs of the coming decades. The IFP takes stock of these topics in this press kit which comprises 11 documents: the synthesis of O. Appert and P. Pinchon's talk about 'the cleaner and multi-energies automobile of the future', the slides of this presentation, the future evolutions of automobiles motorizations, the long-term evolutions of engines/fuels (brief for the Panorama 2004 colloquium), diesel fuel in the USA (brief for the Panorama 2004 colloquium), bio-fuels in Europe (brief for the Panorama 2004 colloquium), diesel pollution abatement: efficient results from the IFP's diesel combustion process 'NADI'(TM), the presentation of the IFP scientific meeting of September 22-23, 2004 'which fuels for low CO{sub 2} engines?', the strategic positioning of IFP in the world energy and environmental context, the brochures 'IFP engines and fuels: a competitive advantage' and 'innovating for a sustainable development in the domain of energy'. (J.S.)

  15. IFP Energies Nouvelles. 2014 Activity report - Innovating for energy

    International Nuclear Information System (INIS)

    2015-01-01

    As part of the public-interest mission with which it has been tasked by the public authorities, IFP Energies Nouvelles (IFPEN) focuses on: - providing solutions to take up the challenges facing society in terms of energy and the climate, promoting the emergence of a sustainable energy mix, - creating wealth and jobs by supporting French and European economic activity, and the competitiveness of related industrial sectors. Despite the current economic environment, 2014 was a good year for IFPEN. In the field of renewable energies, major milestones were reached in two significant projects dedicated to the production of second generation biofuels in which IFPEN is very actively involved: processes developed in Futurol TM are already in the pre-marketing phase, while the construction of the two pilot units for the BioTfueL project has just been launched. In the field of ocean energies, IFPEN research has led to the first partnership agreements relating to floating wind turbines anchor technologies and command control systems for wind energy and wave energy conversion. In the transport sector, game-changing concepts are beginning to emerge, such as smart battery charging and a Rankine cycle system for an internal combustion engine transforming combustion heat into energy. In addition, IFPEN have joined forces with innovative SMEs to boost their research in the fields of electric power-trains and power electronics. Finally, IFPEN launched an eco-driving application that has proved extremely popular with the public. Turning now to oil and gas, IFPEN continued to expand its range of basin and reservoir simulation, modeling and characterization software, and it signed several contracts in the field of chemical enhanced recovery solutions with its EOR (Enhanced Oil Recovery) Alliance TM partners. IFPEN also developed new generations of high-performance catalysts and improved the conversion rate of its processes to enable refiners to convert increasingly heavy crudes and

  16. Hypoxia Room

    Data.gov (United States)

    Federal Laboratory Consortium — The Hypoxia Room is a 8x8x8 ft. clear vinyl plastic and aluminum frame construction enclosure located within USAREIM laboratory 028. The Hypoxia Room (manufactured...

  17. Abatement of CO{sub 2} emissions: IFP's solutions; Reduction des emissions de CO{sub 2}: les solutions IFP

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2003-07-01

    In a context of increasing energy consumption and world economic growth, the fight against greenhouse gases has become a major technological challenge for the coming years. The capture and sequestration of CO{sub 2} in the underground is a promising solution in terms of environmental impact, especially in places and sectors characterized by a strong concentration of CO{sub 2} emissions (power generation plants, big industries). However, such a solution requires important R and D efforts to reduce the costs and warrant the long-term reliability of the storage. The French institute of petroleum (IFP) will play an important role in the implementation of the geological sequestration. This press kit comprises 7 documents: a press release from November 4, 2003; a press conference with a series of slides presenting the stakes, solutions and actions proposed by the IFP in collaboration with several foreign partners (CO{sub 2} capture, storage in depleted hydrocarbon deposits, saline aquifers or abandoned coal seams, storage potential, reduction of costs); a summary of the stakes and solutions for CO{sub 2} sequestration in deep underground; a similar document presented at the Panorama 2003 colloquium; the CO{sub 2} constraint in France and in Europe (international consensus on climatic change, Kyoto protocol, European directive about tradable carbon permits, voluntary commitment of companies in the fight against greenhouse effects (AERES)); the European project Castor (CO{sub 2} from capture to storage); and the IFP brochure 'innovating for a sustainable development in the energy domain'. (J.S.)

  18. Role and mechanism of arsenic in regulating angiogenesis.

    Directory of Open Access Journals (Sweden)

    Ling-Zhi Liu

    Full Text Available Arsenic is a wide spread carcinogen associated with several kinds of cancers including skin, lung, bladder, and liver cancers. Lung is one of the major targets of arsenic exposure. Angiogenesis is the pivotal process during carcinogenesis and chronic pulmonary diseases, but the role and mechanism of arsenic in regulating angiogenesis remain to be elucidated. In this study we show that short time exposure of arsenic induces angiogenesis in both human immortalized lung epithelial cells BEAS-2B and adenocarcinoma cells A549. To study the molecular mechanism of arsenic-inducing angiogenesis, we find that arsenic induces reactive oxygen species (ROS generation, which activates AKT and ERK1/2 signaling pathways and increases the expression of hypoxia-inducible factor 1 (HIF-1 and vascular endothelial growth factor (VEGF. Inhibition of ROS production suppresses angiogenesis by decreasing AKT and ERK activation and HIF-1 expression. Inhibition of ROS, AKT and ERK1/2 signaling pathways is sufficient to attenuate arsenic-inducing angiogenesis. HIF-1 and VEGF are downstream effectors of AKT and ERK1/2 that are required for arsenic-inducing angiogenesis. These results shed light on the mechanism of arsenic in regulating angiogenesis, and are helpful to develop mechanism-based intervention to prevent arsenic-induced carcinogenesis and angiogenesis in the future.

  19. R and D status of high-current accelerators at IFP

    International Nuclear Information System (INIS)

    Deng, J. J.; Shi, J. S.; Xie, W. P.

    2011-01-01

    High-current accelerators have many important applications in Z-pinches, high-power microwaves, and free electron lasers, imploding liners and radiography and so on. Research activities on Z-pinches, imploding liners, radiography at the Institute of Fluid Physics (IFP) are introduced. Several main high-current accelerators developed and being developed at IFP are described, such as the Linear Induction Accelerator X-Ray Facility Upgrade (LIAXFU, 12 MeV, 2.5 kA, 90 ns), the Dragon-I linear induction accelerator (20 MeV, 2.5 kA, 60 ns), and the Primary Test Stand for Z-pinch (PTS, 10 MA, 120 ns). The design of Dragon-II linear induction accelerator (20 MeV, 2.5 kA, 3 x 60 ns) to be built will be presented briefly.

  20. IFP Energies nouvelles - 2013 Activity Report. 2013 financial report. Innovating for energy

    International Nuclear Information System (INIS)

    2014-01-01

    IFP Energies nouvelles (IFPEN) is a public research and training player. It has an international scope, covering the fields of energy, transport and the environment. From research to industry, technological innovation is central to all its activities. As part of the public-interest mission with which it has been tasked by the public authorities, IFPEN focuses on: - providing solutions to take up the challenges facing society in terms of energy and the climate, promoting the emergence of a sustainable energy mix; - creating wealth and jobs by supporting French and European economic activity, and the competitiveness of related industrial sectors. IFPEN has proven expertise across the entire value chain, from fundamental research to industrial research and innovation. It is funded both by a state budget and by resources provided by French and foreign international partners. The aim of IFPEN's R and D programs is to overcome existing scientific and technological barriers in order to develop innovations that can be used by industry. Through its research and resulting innovations, IFPEN fosters the economic development of fields related to the energy, transport and eco-industry sectors. In so doing, it also contributes to creating wealth and jobs. IFPEN's innovations are developed industrially through close partnerships with industrial players and IFP Group subsidiaries. In both emerging and mature markets, IFPEN creates companies or acquires stakeholdings in companies of significant potential, either directly or via capital funds. In addition, IFPEN supports the development of SMEs and SMIs as part of collaboration agreements, contributing its technical and legal expertise. Representing over 50 professions, from geological engineers to power-train engineers, IFPEN's employees form a unique body of globally recognized scientific specialists and an unparalleled network of expertise. In order to carry out their research work at the cutting edge of innovation, they have

  1. Hypoxia: From Placental Development to Fetal Programming.

    Science.gov (United States)

    Fajersztajn, Lais; Veras, Mariana Matera

    2017-10-16

    Hypoxia may influence normal and different pathological processes. Low oxygenation activates a variety of responses, many of them regulated by hypoxia-inducible factor 1 complex, which is mostly involved in cellular control of O 2 consumption and delivery, inhibition of growth and development, and promotion of anaerobic metabolism. Hypoxia plays a significant physiological role in fetal development; it is involved in different embryonic processes, for example, placentation, angiogenesis, and hematopoiesis. More recently, fetal hypoxia has been associated directly or indirectly with fetal programming of heart, brain, and kidney function and metabolism in adulthood. In this review, the role of hypoxia in fetal development, placentation, and fetal programming is summarized. Hypoxia is a basic mechanism involved in different pregnancy disorders and fetal health developmental complications. Although there are scientific data showing that hypoxia mediates changes in the growth trajectory of the fetus, modulates gene expression by epigenetic mechanisms, and determines the health status later in adulthood, more mechanistic studies are needed. Furthermore, if we consider that intrauterine hypoxia is not a rare event, and can be a consequence of unavoidable exposures to air pollution, nutritional deficiencies, obesity, and other very common conditions (drug addiction and stress), the health of future generations may be damaged and the incidence of some diseases will markedly increase as a consequence of disturbed fetal programming. Birth Defects Research 109:1377-1385, 2017.© 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  2. Long-term performance of interstial fluid pressure and hypoxia as prognostic factors in cervix cancer

    International Nuclear Information System (INIS)

    Fyles, Anthony; Milosevic, Michael; Pintilie, Melania; Syed, Ami; Levin, Wilf; Manchul, Lee; Hill, Richard P.

    2006-01-01

    Objectives: Hypoxia and high interstitial fluid pressure (IFP) have been shown to independently predict for nodal and distant metastases, as well as survival, in patients with cervix cancer. Using data from our prospective trial, we updated a cohort of patients treated with definitive radiation alone without chemotherapy, to assess the long-term prognostic impact of these microenvironmental features. Methods: Between April 1994 and January 1999, 107 eligible patients with cervix cancer were entered into a prospective study of tumor oxygenation and IFP prior to primary radiation therapy. Oxygenation data are presented as the hypoxic proportion, defined as the percentage of pO 2 readings 5 ). Patients with HP 5 values >50% were considered to have hypoxic tumors. IFP is presented in mm Hg, divided into high and low IFP groups by the median value. Patients ranged in age from 23 to 78 years with a mean of 53 years. The maximum tumor size ranged from 2 to 10 cm, with a median diameter of 5 cm. FIGO stage was IB in 28 patients, IIA in 4, IIB in 42 and IIIB in 33 patients. Twenty-two patients (21%) had evidence of pelvic lymph node involvement on staging CT abdomen/pelvis or MR pelvis. HP 5 ranged from 0% to 99% with a median of 48%. IFP ranged from -3 to 48 mm Hg (median 19 mm Hg). Median follow-up was 6.7 years (range 0.9-10.6). Results: Disease-free survival (DFS) at 5 years was 50%. Five year DFS was 42% for patients with hypoxic tumors (HP 5 > 50%), and 58% in patients with oxygenated tumors (HR 1.01 per %, p = 0.05). DFS at 5 years was 42% for patients with interstitial hypertension (IFP >19 mm Hg), and 63% in patients with IFP ≤19 mm Hg (HR 1.05 per mm Hg, p = 0.001). In a multivariate analysis only tumor size (HR 1.2, p = 0.009) pelvic nodal metastases (HR 3.3, p = 0.0004) and IFP (HR 1.06, p = 0.0005) were predictive of DFS. Because an interaction between nodal status and oxygenation was observed (p = 0.03), further analysis indicated a borderline significant

  3. Hypoxia downregulates Ku70/80 expression in cervical carcinoma tumors

    International Nuclear Information System (INIS)

    Lara, Pedro Carlos; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa Maria; Bordon, Elisa; Rey, Agustin; Falcon, Orlando; Alonso, Ana Ruiz; Belka, Claus

    2008-01-01

    Hypoxia may inhibits the NHEJ DNA repair through downregulating Ku70/80 expression and combined with an increased angiogenesis and altered p53 expression would be responsible for tumor progression in cervical carcinoma

  4. Dietary Proteins and Angiogenesis

    Directory of Open Access Journals (Sweden)

    Miguel Ángel Medina

    2014-01-01

    Full Text Available Both defective and persistent angiogenesis are linked to pathological situations in the adult. Compounds able to modulate angiogenesis have a potential value for the treatment of such pathologies. Several small molecules present in the diet have been shown to have modulatory effects on angiogenesis. This review presents the current state of knowledge on the potential modulatory roles of dietary proteins on angiogenesis. There is currently limited available information on the topic. Milk contains at least three proteins for which modulatory effects on angiogenesis have been previously demonstrated. On the other hand, there is some scarce information on the potential of dietary lectins, edible plant proteins and high protein diets to modulate angiogenesis.

  5. The automobile of the future: engine technologies and automotive fuels developed by IFP; l'automobile du futur: les technologies moteurs et carburants developpes par l'IFP

    Energy Technology Data Exchange (ETDEWEB)

    Appert, O.; Pinchon, Ph.

    2004-07-01

    In front of the challenges of climate change and depletion of petroleum reserves, in front of the continuous strengthening of pollution regulations applied to automobile (Euro IV and V) and the advances of R and D, several ways of research can be explored to answer the mobility needs of the coming decades. The IFP takes stock of these topics in this press kit which comprises 11 documents: the synthesis of O. Appert and P. Pinchon's talk about 'the cleaner and multi-energies automobile of the future', the slides of this presentation, the future evolutions of automobiles motorizations, the long-term evolutions of engines/fuels (brief for the Panorama 2004 colloquium), diesel fuel in the USA (brief for the Panorama 2004 colloquium), bio-fuels in Europe (brief for the Panorama 2004 colloquium), diesel pollution abatement: efficient results from the IFP's diesel combustion process 'NADI'(TM), the presentation of the IFP scientific meeting of September 22-23, 2004 'which fuels for low CO{sub 2} engines?', the strategic positioning of IFP in the world energy and environmental context, the brochures 'IFP engines and fuels: a competitive advantage' and 'innovating for a sustainable development in the domain of energy'. (J.S.)

  6. Angiogenesis in liver fibrosis

    NARCIS (Netherlands)

    Adlia, Amirah

    2017-01-01

    Angiogenesis emerges in parallel with liver fibrosis, but it is still unclear whether angiogenesis is a defense mechanism of the body in response to fibrosis, or whether it aggravates the fibrotic condition. In this thesis, Amirah Adlia applied different approaches to elucidate the role of

  7. Induction of Gastrin Expression in Gastrointestinal Cells by Hypoxia or Cobalt Is Independent of Hypoxia-Inducible Factor (HIF)

    OpenAIRE

    Xiao, Lin; Kovac, Suzana; Chang, Mike; Shulkes, Arthur; Baldwin, Graham S.; Patel, Oneel

    2012-01-01

    Gastrin and its precursors have been shown to promote mitogenesis and angiogenesis in gastrointestinal tumors. Hypoxia stimulates tumor growth, but its effect on gastrin gene regulation has not been examined in detail. Here we have investigated the effect of hypoxia on the transcription of the gastrin gene in human gastric cancer (AGS) cells. Gastrin mRNA was measured by real-time PCR, gastrin peptides were measured by RIA, and gastrin promoter activity was measured by dual-luciferase reporte...

  8. A RNA antagonist of hypoxia-inducible factor-1alpha, EZN-2968, inhibits tumor cell growth

    DEFF Research Database (Denmark)

    Greenberger, Lee M; Horak, Ivan D; Filpula, David

    2008-01-01

    Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that plays a critical role in angiogenesis, survival, metastasis, drug resistance, and glucose metabolism. Elevated expression of the alpha-subunit of HIF-1 (HIF-1alpha), which occurs in response to hypoxia or activation of growth facto...

  9. The Role of Hypoxia in the Tumor Microenvironment: Implications for Ovarian Cancer Therapy

    Science.gov (United States)

    2017-07-01

    Association for Cancer Research Publications ( Peer Reviewed) 1. Sinha S, Thomas D, Chan S, Gao Y, Brunen D, Torabi D, Reinisch A, Hernandez D, Chan A...Symposia, Keystone, CO Teaching 2017 Guest lecturer CBIO 242: Hypoxia and Angiogenesis (Stanford University) 2016 Guest lecturer CBIO 242: Hypoxia...Cancer Biology Journal Club (Stanford University) 2006 Teaching Assistant BIOM 555: Gene Expression (University of Pennsylvania)

  10. Progress toward overcoming hypoxia-induced resistance to solid tumor therapy

    International Nuclear Information System (INIS)

    Karakashev, Sergey V; Reginato, Mauricio J

    2015-01-01

    Hypoxic tumors are associated with poor clinical outcome for multiple types of human cancer. This may be due, in part, to hypoxic cancer cells being resistant to anticancer therapy, including radiation therapy, chemotherapy, and targeted therapy. Hypoxia inducible factor 1, a major regulator of cellular response to hypoxia, regulates the expression of genes that are involved in multiple aspects of cancer biology, including cell survival, proliferation, metabolism, invasion, and angiogenesis. Here, we review multiple pathways regulated by hypoxia/hypoxia inducible factor 1 in cancer cells and discuss the latest advancements in overcoming hypoxia-mediated tumor resistance

  11. [Angiogenesis and endometriose].

    Science.gov (United States)

    Becker, C M; Bartley, J; Mechsner, S; Ebert, A D

    2004-08-01

    Endometriosis is considered a chronic disease of women during their reproductive phase, which resembles many signs of malignancy. So far, therapeutic options for endometriosis-associated pain and infertility are unsatisfactory and often lead to recurrence of disease after termination of treatment. Angiogenesis seems to play an important role in the pathogenesis of endometriosis. The use of angiogenesis inhibitors may add an important new tool to well-established treatment schedules. Therefore, it is very important to thoroughly investigate the role of angiogenesis in endometriosis with respect to the female reproductive system.

  12. Cycling hypoxia: A key feature of the tumor microenvironment.

    Science.gov (United States)

    Michiels, Carine; Tellier, Céline; Feron, Olivier

    2016-08-01

    A compelling body of evidence indicates that most human solid tumors contain hypoxic areas. Hypoxia is the consequence not only of the chaotic proliferation of cancer cells that places them at distance from the nearest capillary but also of the abnormal structure of the new vasculature network resulting in transient blood flow. Hence two types of hypoxia are observed in tumors: chronic and cycling (intermittent) hypoxia. Most of the current work aims at understanding the role of chronic hypoxia in tumor growth, response to treatment and metastasis. Only recently, cycling hypoxia, with spatial and temporal fluctuations in oxygen levels, has emerged as another key feature of the tumor environment that triggers different responses in comparison to chronic hypoxia. Either type of hypoxia is associated with distinct effects not only in cancer cells but also in stromal cells. In particular, cycling hypoxia has been demonstrated to favor, to a higher extent than chronic hypoxia, angiogenesis, resistance to anti-cancer treatments, intratumoral inflammation and tumor metastasis. These review details these effects as well as the signaling pathway it triggers to switch on specific transcriptomic programs. Understanding the signaling pathways through which cycling hypoxia induces these processes that support the development of an aggressive cancer could convey to the emergence of promising new cancer treatments. Copyright © 2016 Elsevier B.V. All rights reserved.

  13. Capturing and storing CO2 to combat the greenhouse effect. What IFP is doing

    International Nuclear Information System (INIS)

    2009-01-01

    The growing awareness of the international community and the convergence of the scientific data concerning climate change make it urgent to deploy, throughout the world, technologies to reduce emissions of greenhouse gases. Indeed, the growth of the world energy demand will prevent any rapid reduction of the use of fossil fuels - oil, natural gas, and coal - that are the main sources of greenhouse gas emissions. To reconcile the use of these resources with control of the emissions responsible for global warming, the capture and storage of CO 2 are a very promising approach; the economic and industrial stakes are high. To meet the objective of reducing CO 2 emissions, IFP is exploring three approaches: The first approach is to reduce energy consumption by improving the efficiency of energy converters, in particular internal combustion engines. A second approach is to reduce the carbon content of energy by favoring the use of natural gas or by incorporating in the fuel recycled carbon (biofuels and synfuels) and by developing hydrogen as an energy carrier. The third approach is to capture the CO 2 from industrial processes used for electricity, steel, and cement production, which emit it in large quantities, then store it underground so as to keep it out of the atmosphere. This approach for reducing the CO 2 emissions consists in capturing the CO 2 (Post-combustion, oxy-combustion), transporting it to the place of storage, then injecting it underground to store it. Storage sites are selected and evaluated prior to injection in order to estimate the injectivity, the propagation of CO 2 in the subsoil and the impact of geochemical and geomechanical transformations on the tightness of the overburden and of the injection well. The injection phase is followed by a phase of monitoring to ensure the safety and long-term viability of CO 2 storage facilities. IFP, through the research it is conducting either alone or in partnership with universities, research centers, and the

  14. Mediators of ocular angiogenesis

    Indian Academy of Sciences (India)

    2016-08-26

    Aug 26, 2016 ... Keywords. ocular angiogenesis; corneal neovascularization; retinal neovascularization; diabetic retinopathy; age-related macular degeneration; retinopathy of prematurity; VEGF; PEDF; Flt-1; Flk-1; endostatin; angiopoietin; erythropoietin; Tie2; inflammation; complement; gene therapy; TLR-3; Robo4.

  15. Angiogenesis in vestibular schwannomas

    DEFF Research Database (Denmark)

    Møller, Martin Nue; Werther, Kim; Nalla, Amarnadh

    2010-01-01

    Vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs) are potent mediators of tumor angiogenesis. It has been demonstrated that vestibular schwannoma VEGF expression correlates with tumor growth pattern, whereas knowledge on the expression of MMPs is lacking. This study...

  16. Cerebral insulin, insulin signaling pathway, and brain angiogenesis.

    Science.gov (United States)

    Zeng, Yi; Zhang, Le; Hu, Zhiping

    2016-01-01

    Insulin performs unique non-metabolic functions within the brain. Broadly speaking, two major areas of these functions are those related to brain endothelial cells and the blood-brain barrier (BBB) function, and those related to behavioral effects, like cognition in disease states (Alzheimer's disease, AD) and in health. Recent studies showed that both these functions are associated with brain angiogenesis. These findings raise interesting questions such as how they are linked to each other and whether modifying brain angiogenesis by targeting certain insulin signaling pathways could be an effective strategy to treat dementia as in AD, or even to help secure healthy longevity. The two canonical downstream pathways involved in mediating the insulin signaling pathway, the phosphoinositide-3 kinase (PI3K), and mitogen-activated protein kinase (MAPK) cascades, in the brain are supposed to be similar to those in the periphery. PI3K and MAPK pathways play important roles in angiogenesis. Both are involved in stimulating hypoxia inducible factor (HIF) in angiogenesis and could be activated by the insulin signaling pathway. This suggests that PI3K and MAPK pathways might act as cross-talk between the insulin signaling pathway and the angiogenesis pathway in brain. But the cerebral insulin, insulin signaling pathway, and the detailed mechanism in the connection of insulin signaling pathway, brain angiogenesis pathway, and healthy aging or dementias are still mostly not clear and need further studies.

  17. Melatonin as an angiogenesis inhibitor to combat cancer: Mechanistic evidence.

    Science.gov (United States)

    Goradel, Nasser Hashemi; Asghari, Mohammad Hossein; Moloudizargari, Milad; Negahdari, Babak; Haghi-Aminjan, Hamed; Abdollahi, Mohammad

    2017-11-15

    Melatonin, a pineal indolamine, participates in different body functions and is shown to possess diverse biological activities such as anti-tumor action. Angiogenesis inhibition is one of the mechanisms by which melatonin exerts its oncostatic effects. Increased angiogenesis is a major feature of tumor progression, thus angiogenesis inhibition is a critical step in cancer therapy. Melatonin employs a variety of mechanisms to target nutrients and oxygen supply to cancer cells. At the transcriptional level, hypoxia induced factor-1α (HIF-1α) and the genes under its control, such as vascular endothelial growth factor (VEGF) are the main targets of melatonin for inhibition of angiogenesis. Melatonin prevents translocation of HIF-1α into the nucleus thereby hindering VEGF expression and also prevents the formation of HIF-1α, phospho-STAT3 and CBP/p300 complex which is involved in the expression of angiogenesis-related genes. Angiostatic properties of melatonin could be also due to its ability to inhibit VEGFR2's activation and expression. Other angiostatic mechanisms of melatonin include the inhibition of endothelial cell migration, invasion, and tube formation. In the present study, we have reviewed the molecular anti-angiogenesis pathways mediated by melatonin and the responsible mechanisms in various types of cancers both in vitro and in vivo. Copyright © 2017 Elsevier Inc. All rights reserved.

  18. A review of fission gas release data within the Nea/IAEA IFPE database

    International Nuclear Information System (INIS)

    Turnbull, J.A.; Menut, P.; Sartori, E.

    2002-01-01

    The paper describes the International Fuel Performance Experimental (IFPE) database on nuclear fuel performance. The aim of the project is to provide a comprehensive and well-qualified database on Zr clad UO 2 fuel for model development and code validation in the public domain. The data encompass both normal and off-normal operation and include prototypic commercial irradiations as well as experiments performed in material testing reactors. To date, the database contains some 380 individual cases, the majority of which provide data on FGR either from in-pile pressure measurements or PIE techniques including puncturing, electron probe microanalysis (EPMA) and X-ray fluorescence (XRF) measurements. The paper outlines parameters affecting fission gas release and highlights individual datasets addressing these issues. (authors)

  19. Matairesinol inhibits angiogenesis via suppression of mitochondrial reactive oxygen species

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Boram; Kim, Ki Hyun; Jung, Hye Jin [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Kwon, Ho Jeong, E-mail: kwonhj@yonsei.ac.kr [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2012-04-27

    Highlights: Black-Right-Pointing-Pointer Matairesinol suppresses mitochondrial ROS generation during hypoxia. Black-Right-Pointing-Pointer Matairesinol exhibits potent anti-angiogenic activity both in vitro and in vivo. Black-Right-Pointing-Pointer Matairesinol could be a basis for the development of novel anti-angiogenic agents. -- Abstract: Mitochondrial reactive oxygen species (mROS) are involved in cancer initiation and progression and function as signaling molecules in many aspects of hypoxia and growth factor-mediated signaling. Here we report that matairesinol, a natural small molecule identified from the cell-based screening of 200 natural plants, suppresses mROS generation resulting in anti-angiogenic activity. A non-toxic concentration of matairesinol inhibited the proliferation of human umbilical vein endothelial cells. The compound also suppressed in vitro angiogenesis of tube formation and chemoinvasion, as well as in vivo angiogenesis of the chorioallantoic membrane at non-toxic doses. Furthermore, matairesinol decreased hypoxia-inducible factor-1{alpha} in hypoxic HeLa cells. These results demonstrate that matairesinol could function as a novel angiogenesis inhibitor by suppressing mROS signaling.

  20. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  1. Vascular grading of angiogenesis

    DEFF Research Database (Denmark)

    Hansen, S; Grabau, D A; Sørensen, Flemming Brandt

    2000-01-01

    The study aimed to evaluate the prognostic value of angiogenesis by vascular grading of primary breast tumours, and to evaluate the prognostic impact of adding the vascular grade to the Nottingham Prognostic Index (NPI). The investigation included 836 patients. The median follow-up time was 11...... years and 4 months. The microvessels were immunohistochemically stained by antibodies against CD34. Angiogenesis was graded semiquantitatively by subjective scoring into three groups according to the expected number of microvessels in the most vascular tumour area. The vascular grading between observers...... impact for 24% of the patients, who had a shift in prognostic group, as compared to NPI, and implied a better prognostic dissemination. We concluded that the angiogenesis determined by vascular grading has independent prognostic value of clinical relevance for patients with breast cancer....

  2. Inhibitors of Angiogenesis.

    Science.gov (United States)

    Büning, H; Hacker, U T

    Angiogenesis plays a pivotal role in malignant, ischemic, inflammatory, infectious and immune disorders. The increasing molecular understanding of angiogenic processes fostered the development of strategies to induce or inhibit angiogenesis for therapeutic purposes. Here, we focus on anti-angiogenic therapies, which represent a standard of care in the treatment of different cancer types and in neovascular age-related macular degeneration. Specifically, strategies related to the blockade of angiogenic proteins and receptors will be outlined covering both preclinical and clinical aspects. Finally, examples of gene therapy based anti-angiogenic approaches are presented.

  3. Angiogenesis inhibition causes hypertension and placental dysfunction in a rat model of preeclampsia

    DEFF Research Database (Denmark)

    Carlström, Mattias; Wentzel, Parri; Skøtt, Ole

    2009-01-01

    in the mesometrial triangle was smaller in the pregnant Suramin-treated rats group than in the pregnant control rats group. CONCLUSION: The inhibition of uterine angiogenesis increases maternal blood pressure and compromises fetal and placental development. Placental hypoxia and subsequent activation of the renin...

  4. Tip Cells in Angiogenesis

    NARCIS (Netherlands)

    M.G. Dallinga (Marchien); S.E.M. Boas (Sonja); I. Klaassen (Ingeborg); R.M.H. Merks (Roeland); C.J.F. van Noorden; R.O. Schlingemann (Reinier)

    2015-01-01

    htmlabstractIn angiogenesis, the process in which blood vessel sprouts grow out from a pre-existing vascular network, the so-called endothelial tip cells play an essential role. Tip cells are the leading cells of the sprouts; they guide following endothelial cells and sense their environment for

  5. Analysis of fuel centre temperatures and fission gas release data from the IFPE Database

    International Nuclear Information System (INIS)

    Schubert, A.; Lassmann, K.; Van Uffelen, P.; Van de Laar, J.; Elenkov, D.; Asenov, S.; Boneva, S.; Djourelov, N.; Georgieva, M.

    2003-01-01

    The present work has continued the analysis of fuel centre temperatures and fission gas release, calculated with standard options of the TRANSURANUS code. The calculations are compared to experimental data from the International Fuel Performance Experiments (IFPE) database. It is reported an analysis regarding UO 2 fuel for Western-type reactors: Fuel centre temperatures measured in the experiments Contact 1 and Contact 2 (in-pile tests of 2 rods performed at the Siloe reactor in Grenoble, France, closely simulating commercial PWR conditions); Fission gas release data derived from post-irradiation examinations of 9 fuel rods belonging to the High-Burnup Effects Programme, task 3 (HBEP3). The results allow for a comparison of predictions by TRANSURANUS for the mentioned Western-type fuels with those done previously for Russian-type WWER fuel. The comparison has been extended to include fuel centre temperatures as well as fission gas release. The present version of TRANSURANUS includes a model that calculates the production of Helium. The amount of produced Helium is compared to the measured and to the calculated release of the fission gases Xenon and Krypton

  6. Hypoxia-Induced Signaling Promotes Prostate Cancer Progression: Exosomes Role as Messenger of Hypoxic Response in Tumor Microenvironment

    Science.gov (United States)

    Deep, Gagan; Panigrahi, Gati K.

    2017-01-01

    Prostate cancer (PCA) is the leading malignancy in men and the second leading cause of cancer-related deaths. Hypoxia (low O2 condition) is considered an early event in prostate carcinogenesis associated with an aggressive phenotype. In fact, clinically, hypoxia and hypoxia-related biomarkers are associated with treatment failure and disease progression. Hypoxia-inducible factor 1 (HIF-1) is the key factor that is activated under hypoxia, and mediates adaptation of cells to hypoxic conditions through regulating the expression of genes associated with angiogenesis, epithelial-to-mesenchymal transition (EMT), metastasis, survival, proliferation, metabolism, stemness, hormone-refractory progression, and therapeutic resistance. Besides HIF-1, several other signaling pathways including PI3K/Akt/mTOR, NADPH oxidase (NOX), Wnt/β-catenin, and Hedgehog are activated in cancer cells under hypoxic conditions, and also contribute in hypoxia-induced biological effects in HIF-1-dependent and -independent manners. Hypoxic cancer cells cause extensive changes in the tumor microenvironment both local and distant, and recent studies have provided ample evidence supporting the crucial role of nanosized vesicles “exosomes” in mediating hypoxia-induced tumor microenvironment remodeling. Exosomes’ role has been reported in hypoxia-induced angiogenesis, stemness, activation of cancer-associated fibroblasts (CAFs), and EMT. Together, existing literature suggests that hypoxia plays a predominant role in PCA growth and progression, and PCA could be effectively prevented and treated via targeting hypoxia/hypoxia-related signaling pathways. PMID:27279239

  7. Unraveling the role of hypoxia-inducible factor (HIF)-1α and HIF-2α in the adaption process of human microvascular endothelial cells (HMEC-1) to hypoxia: Redundant HIF-dependent regulation of macrophage migration inhibitory factor.

    Science.gov (United States)

    Hahne, Martin; Schumann, Peggy; Mursell, Mathias; Strehl, Cindy; Hoff, Paula; Buttgereit, Frank; Gaber, Timo

    2018-03-01

    Hypoxia driven angiogenesis is a prominent feature of tissue regeneration, inflammation and tumor growth and is regulated by hypoxia-inducible factor (HIF)-1 and -2. The distinct functions of HIFs in the hypoxia-induced angiogenesis and metabolic switch of endothelial cells are still unknown and therefore aim of this study. We investigated the role of HIF-1 and -2 in the adaptation of immortalized human microvascular endothelial cells (HMEC-1) to hypoxic conditions (1% O 2 ) in terms of angiogenesis, cytokine secretion, gene expression and ATP/ADP-ratio using shRNA-mediated reduction of the oxygen sensitive α-subunits of either HIF-1 or HIF-2 or the combination of both. Reduction of HIF-1α diminished cellular energy, hypoxia-induced glycolytic gene expression, and angiogenesis not altering pro-angiogenic factors. Reduction of HIF-2α diminished hypoxia-induced pro-angiogenic factors, enhanced anti-angiogenic factors and attenuated angiogenesis not altering glycolytic gene expression. Reduction of both HIFs reduced cell survival, gene expression of glycolytic enzymes and pro-angiogenic factors as compared to the corresponding control. Finally, we identified the macrophage migration inhibitory factor (MIF) to be redundantly regulated by HIF-1 and HIF-2 and to be essential in the process of hypoxia-driven angiogenesis. Our results demonstrate a major impact of HIF-1 and HIF-2 on hypoxia-induced angiogenesis indicating distinct but also overlapping functions of HIF-1 and HIF-2. These findings open new possibilities for therapeutic approaches by specifically targeting the HIF-1 and HIF-2 or their target MIF. Copyright © 2017 Elsevier Inc. All rights reserved.

  8. Hypoxia Promotes Tumor Growth in Linking Angiogenesis to Immune Escape

    OpenAIRE

    Chouaib, Salem; Messai, Yosra; Couve, Sophie; Escudier, Bernard; Hasmim, Meriem; Noman, Muhammad Zaeem

    2012-01-01

    Despite the impressive progress over the past decade, in the field of tumor immunology, such as the identification of tumor antigens and antigenic peptides, there are still many obstacles in eliciting an effective immune response to eradicate cancer. It has become increasingly clear that tumor microenvironment plays a crucial role in the control of immune protection. Tumors have evolved to utilize hypoxic stress to their own advantage by activating key biochemical and cellular pathways that a...

  9. Influence of Levamisole and Other Angiogenesis Inhibitors on Angiogenesis and Endothelial Cell Morphology in Vitro

    Energy Technology Data Exchange (ETDEWEB)

    Friis, Tina; Engel, Anne-Marie; Bendiksen, Christine D.; Larsen, Line S.; Houen, Gunnar, E-mail: gh@ssi.dk [Department of Clinical Biochemistry, Immunology and Genetics, Statens Serum Institut, Artillerivej 5, DK-2300 Copenhagen (Denmark)

    2013-06-24

    Angiogenesis, the formation of new blood vessels from existing vessels is required for many physiological processes and for growth of solid tumors. Initiated by hypoxia, angiogenesis involves binding of angiogenic factors to endothelial cell (EC) receptors and activation of cellular signaling, differentiation, migration, proliferation, interconnection and canalization of ECs, remodeling of the extracellular matrix and stabilization of newly formed vessels. Experimentally, these processes can be studied by several in vitro and in vivo assays focusing on different steps in the process. In vitro, ECs form networks of capillary-like tubes when propagated for three days in coculture with fibroblasts. The tube formation is dependent on vascular endothelial growth factor (VEGF) and omission of VEGF from the culture medium results in the formation of clusters of undifferentiated ECs. Addition of angiogenesis inhibitors to the coculture system disrupts endothelial network formation and influences EC morphology in two distinct ways. Treatment with antibodies to VEGF, soluble VEGF receptor, the VEGF receptor tyrosine kinase inhibitor SU5614, protein tyrosine phosphatase inhibitor (PTPI) IV or levamisole results in the formation of EC clusters of variable size. This cluster morphology is a result of inhibited EC differentiation and levamisole can be inferred to influence and block VEGF signaling. Treatment with platelet factor 4, thrombospondin, rapamycin, suramin, TNP-470, salubrinal, PTPI I, PTPI II, clodronate, NSC87877 or non-steriodal anti-inflammatory drugs (NSAIDs) results in the formation of short cords of ECs, which suggests that these inhibitors have an influence on later steps in the angiogenic process, such as EC proliferation and migration. A humanized antibody to VEGF is one of a few angiogenesis inhibitors used clinically for treatment of cancer. Levamisole is approved for clinical treatment of cancer and is interesting with respect to anti-angiogenic activity

  10. The Harvard angiogenesis story.

    Science.gov (United States)

    Miller, Joan W

    2014-01-01

    I shall discuss the work of researchers at Harvard Medical School who came together in the early 1990s. Scattered across various Harvard-affiliated hospitals and research centers, these individuals were unified by their interest in ocular neovascularization. Together and separately, they investigated models of ocular neovascularization, exploring tumor angiogenesis in eye development and disease. Copyright © 2014 The Author. Published by Elsevier Inc. All rights reserved.

  11. Perlecan and tumor angiogenesis

    DEFF Research Database (Denmark)

    Jiang, Xinnong; Couchman, John R

    2003-01-01

    Perlecan is a major heparan sulfate proteoglycan (HSPG) of basement membranes (BMs) and connective tissues. The core protein of perlecan is divided into five domains based on sequence homology to other known proteins. Commonly, the N-terminal domain I of mammalian perlecan is substituted with thr...... have unwanted promoting effects on tumor cell proliferation and tumor angiogenesis. Understanding of these attributes at the molecular level may offer opportunities for therapeutic intervention....

  12. HIF-2alpha-dependent PAI-1 induction contributes to angiogenesis in hepatocellular carcinoma

    Energy Technology Data Exchange (ETDEWEB)

    Geis, Theresa, E-mail: geis@biochem.uni-frankfurt.de [Institute of Biochemistry I—Pathobiochemistry, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Döring, Claudia, E-mail: C.Doering@em.uni-frankfurt.de [Dr. Senckenberg Institute of Pathology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Popp, Rüdiger, E-mail: popp@vrc.uni-frankfurt.de [Institute for Vascular Signalling, Centre for Molecular Medicine, Faculty of Medicine Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60596 Frankfurt am Main (Germany); Grossmann, Nina, E-mail: grossmann@biochem.uni-frankfurt.de [Institute of Biochemistry I—Pathobiochemistry, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Fleming, Ingrid, E-mail: fleming@vrc.uni-frankfurt.de [Institute for Vascular Signalling, Centre for Molecular Medicine, Faculty of Medicine Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60596 Frankfurt am Main (Germany); Hansmann, Martin-Leo, E-mail: m.l.hansmann@em.uni-frankfurt.de [Dr. Senckenberg Institute of Pathology, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Dehne, Nathalie, E-mail: dehne@biochem.uni-frankfurt.de [Institute of Biochemistry I—Pathobiochemistry, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany); Brüne, Bernhard, E-mail: b.bruene@biochem.uni-frankfurt.de [Institute of Biochemistry I—Pathobiochemistry, Faculty of Medicine, Goethe-University Frankfurt, Theodor-Stern-Kai 7, 60590 Frankfurt am Main (Germany)

    2015-02-01

    Hypoxia promotes progression of hepatocellular carcinoma (HCC), not only affecting tumor cell proliferation and invasion, but also angiogenesis and thus, increasing the risk of metastasis. Hypoxia inducible factors (HIF)-1α and -2α cause adaptation of tumors to hypoxia, still with uncertainties towards the angiogenic switch. We created a stable knockdown of HIF-1α and HIF-2α in HepG2 cells and generated cocultures of HepG2 spheroids with embryonic bodies as an in vitro tumor model mimicking the cancer microenvironment. The naturally occuring oxygen and nutrient gradients within the cocultures allow us to question the role of distinct HIF isoforms in regulating HCC angiogenesis. In cocultures with a HIF-2α knockdown, angiogenesis was attenuated, while the knockdown of HIF-1α was without effect. Microarray analysis identified plasminogen activator inhibitor 1 (PAI-1) as a HIF-2α target gene in HepG2 cells. The knockdown of PAI-1 in HepG2 cells also lowered angiogenesis. Blocking plasmin, the downstream target of PAI-1, with aprotinin in HIF-2α knockdown (k/d) cells proved a cause–effect relation and restored angiogenesis, with no effect on control cocultures. Suggestively, HIF-2α increases PAI-1 to lower concentrations of active plasmin, thereby supporting angiogenesis. We conclude that the HIF-2α target gene PAI-1 favors the angiogenic switch in HCC. - Highlights: • HepG2 were cocultured with stem cells to mimic a cancer microenvironment in vitro. • A knockdown of HIF-2α reduces angiogenesis. • PAI-1 was identified as a HIF-2α target gene in HCC by microarray analysis. • HIF-2α induces the angiogenic switch via inhibition of plasmin.

  13. HIF-2alpha-dependent PAI-1 induction contributes to angiogenesis in hepatocellular carcinoma

    International Nuclear Information System (INIS)

    Geis, Theresa; Döring, Claudia; Popp, Rüdiger; Grossmann, Nina; Fleming, Ingrid; Hansmann, Martin-Leo; Dehne, Nathalie; Brüne, Bernhard

    2015-01-01

    Hypoxia promotes progression of hepatocellular carcinoma (HCC), not only affecting tumor cell proliferation and invasion, but also angiogenesis and thus, increasing the risk of metastasis. Hypoxia inducible factors (HIF)-1α and -2α cause adaptation of tumors to hypoxia, still with uncertainties towards the angiogenic switch. We created a stable knockdown of HIF-1α and HIF-2α in HepG2 cells and generated cocultures of HepG2 spheroids with embryonic bodies as an in vitro tumor model mimicking the cancer microenvironment. The naturally occuring oxygen and nutrient gradients within the cocultures allow us to question the role of distinct HIF isoforms in regulating HCC angiogenesis. In cocultures with a HIF-2α knockdown, angiogenesis was attenuated, while the knockdown of HIF-1α was without effect. Microarray analysis identified plasminogen activator inhibitor 1 (PAI-1) as a HIF-2α target gene in HepG2 cells. The knockdown of PAI-1 in HepG2 cells also lowered angiogenesis. Blocking plasmin, the downstream target of PAI-1, with aprotinin in HIF-2α knockdown (k/d) cells proved a cause–effect relation and restored angiogenesis, with no effect on control cocultures. Suggestively, HIF-2α increases PAI-1 to lower concentrations of active plasmin, thereby supporting angiogenesis. We conclude that the HIF-2α target gene PAI-1 favors the angiogenic switch in HCC. - Highlights: • HepG2 were cocultured with stem cells to mimic a cancer microenvironment in vitro. • A knockdown of HIF-2α reduces angiogenesis. • PAI-1 was identified as a HIF-2α target gene in HCC by microarray analysis. • HIF-2α induces the angiogenic switch via inhibition of plasmin

  14. Experimental data on PCI and PCMI within the IFPE data base

    International Nuclear Information System (INIS)

    Killeen, J.C.; Sartori, E.; Turnbull, J.A.

    2005-01-01

    Following the conclusions reached at the end of the FUMEX-I code comparison exercise, the International Fuel Performance Experimental Database (IFPE) gave priority to collecting and assembling data sets addressing: thermal performance, fission gas release and pellet-clad mechanical interaction (PCMI). The data available that address the last topic are the subject of the current paper. The data on mechanical interaction in fuel rods fall into three broad categories: - Fuel rod diameter changes caused by periods spent at higher than normal power. - The result of power ramp testing to define a failure threshold. - Single effects studies to measure changes in gaseous porosity causing fuel swelling during controlled test conditions. In the first category, the fuel remained un-failed at the end of the test and the resulting permanent clad strain was due to PCMI caused by thermal expansion of the pellet and gaseous fuel swelling. Some excellent data in this category come from the last two Riso Fission Gas Release projects. The second category, namely, failure by pellet-clad interaction (PCI) and stress corrosion cracking (SCC) involves the simultaneous imposition of stress and the availability of corrosive fission products. A comprehensive list of tests carried out in the Swedish Studsvik reactor is included in the database. The third category is a recent acquisition to the database and comprises data on fuel swelling obtained from ramp tests on AGR fuel and carried out in the Halden BWR. This data set contains a wealth of well-qualified data which are invaluable for the development and validation of fuel swelling models. (authors)

  15. How to increase and renew the oil and gas reserves? Technology advances and research strategy of IFP

    International Nuclear Information System (INIS)

    2005-01-01

    Technology progresses made to reach new oil and gas resources (heavy crudes, buried deposits, ultra-deep offshore), to better exploit the available reserves (increase of the recovery ratio) and to reduce the costs will allow to enhance the hydrocarbon reserves and to durably extend the limits of the world energy supply. In a context where geopolitical uncertainties, high price rates and pessimistic declarations increase once again the public fear about petroleum reserves, the French institute of petroleum (IFP) wanted to make a status about the essential role that technology can play in this challenge. This document gathers the transparencies and articles presented at this press conference: how to increase and renew oil and gas reserves, technology advances and research strategy of IFP (O. Appert, J. Lecourtier, G. Fries); how to enhance oil recovery from deposits (primary, secondary and tertiary recovery: polymers injection, CO 2 injection, steam injection, in-situ oxidation and combustion, reservoir modeling, monitoring of uncertainties); the heavy crudes (the Orenoque extra-heavy oil, the tar sands of Alberta, the heavy and extra-heavy crudes of Canada, IFP's research); ultra-deep offshore (the weight challenge: mooring lines and risers, the temperature challenge: paraffins and hydrates deposition, immersion of the treatment unit: economical profitability of satellite fields); fields buried beyond 5000 m (technological challenges: seismic surveys, drilling equipment, well logging, drilling mud; prospects of these fields); oil reserves: data that change with technique and economy (proven, probable and possible reserves, proven and declared reserves, three converging evaluations about the world proven reserves, reserves to be discovered, non-conventional petroleum resources, technical progress and oil prices, production depletion at the end of the century). (J.S.)

  16. Hypoxia-induced metastasis model in embryonic zebrafish

    DEFF Research Database (Denmark)

    Rouhi, Pegah; Jensen, Lasse D.; Cao, Ziquan

    2010-01-01

    Hypoxia facilitates tumor invasion and metastasis by promoting neovascularization and co-option of tumor cells in the peritumoral vasculature, leading to dissemination of tumor cells into the circulation. However, until recently, animal models and imaging technology did not enable monitoring...... of the early events of tumor cell invasion and dissemination in living animals. We recently developed a zebrafish metastasis model to dissect the detailed events of hypoxia-induced tumor cell invasion and metastasis in association with angiogenesis at the single-cell level. In this model, fluorescent Di......I-labeled human or mouse tumor cells are implanted into the perivitelline cavity of 48-h-old zebrafish embryos, which are subsequently placed in hypoxic water for 3 d. Tumor cell invasion, metastasis and pathological angiogenesis are detected under fluorescent microscopy in the living fish. The average...

  17. Synthesis of the objectives contract 2006-2010 between the State and the IFP. Innovate for a controlled energy transition

    International Nuclear Information System (INIS)

    2006-01-01

    The IFP, French Institute of Petroleum, is a public organization of research and formation at the service of the energy, the transport and the environment. It assures the technology transfer between fundamental research, applied research and the industrial development. The contract for 2006-2010 presents three major structural evolutions: the increase development of the new technologies of the energy; a new equilibrium in favor of the downstream researches and more particularly the transports, the increase of the industry competitiveness in the hydrocarbons sector and the automobiles. (A.L.B.)

  18. Urokinase receptor expression on human microvascular endothelial cells is increased by hypoxia: Implications for capillary-like tube formation in a fibrin matrix

    NARCIS (Netherlands)

    Kroon, M.E.; Koolwijk, P.; Vecht, B. van der; Hinsbergh, V.W.M. van

    2000-01-01

    Hypoxia stimulates angiogenesis, the formation of new blood vessels. This study evaluates the direct effect of hypoxia (1% oxygen) on the angiogenic response of human microvascular endothelial cells (hMVECs) seeded on top of a 3-dimensional fibrin matrix, hMVECs stimulated with fibroblast growth

  19. The relevance of the IFPE Database to the modelling of WWER-type fuel behaviour

    International Nuclear Information System (INIS)

    Killeen, J.; Sartori, E.

    2006-01-01

    The aim of the International Fuel Performance Experimental Database (IFPE Database) is to provide, in the public domain, a comprehensive and well-qualified database on zircaloy-clad UO 2 fuel for model development and code validation. The data encompass both normal and off-normal operation and include prototypic commercial irradiations as well as experiments performed in Material Testing Reactors. To date, the Database contains over 800 individual cases, providing data on fuel centreline temperatures, dimensional changes and FGR either from in-pile pressure measurements or PIE techniques, including puncturing, Electron Probe Micro Analysis (EPMA) and X-ray Fluorescence (XRF) measurements. This work in assembling and disseminating the Database is carried out in close co-operation and co-ordination between OECD/NEA and the IAEA. The majority of data sets are dedicated to fuel behaviour under LWR irradiation, and every effort has been made to obtain data representative of BWR, PWR and WWER conditions. In each case, the data set contains information on the pre-characterisation of the fuel, cladding and fuel rod geometry, the irradiation history presented in as much detail as the source documents allow, and finally any in-pile or PIE measurements that were made. The purpose of this paper is to highlight data that are relevant specifically to WWER application. To this end, the NEA and IAEA have been successful in obtaining appropriate data for both WWER-440 and WWER-1000-type reactors. These are: 1) Twelve (12) rods from the Finnish-Russian co-operative SOFIT programme; 2) Kola-3 WWER-440 irradiation; 3) MIR ramp tests on Kola-3 rods; 4) Zaporozskaya WWER-1000 irradiation; 5) Novovoronezh WWER-1000 irradiation. Before reviewing these data sets and their usefulness, the paper touches briefly on recent, more novel additions to the Database and on progress made in the use of the Database for the current IAEA FUMEX II Project. Finally, the paper describes the Computer

  20. Angiogenesis, Cancer, and Vascular Aging

    Directory of Open Access Journals (Sweden)

    Junji Moriya

    2017-10-01

    Full Text Available Several lines of evidence have revealed that the angiogenic response to ischemic injury declines with age, which might account for the increased morbidity and mortality of cardiovascular disease (CVD among the elderly. While impairment of angiogenesis with aging leads to delayed wound healing or exacerbation of atherosclerotic ischemic diseases, it also inhibits the progression of cancer. Age-related changes of angiogenesis have been considered to at least partly result from vascular aging or endothelial cell senescence. There is considerable evidence supporting the hypothesis that vascular cell senescence contributes to the pathogenesis of age-related CVD, suggesting that vascular aging could be an important therapeutic target. Since therapeutic angiogenesis is now regarded as a promising concept for patients with ischemic CVD, it has become even more important to understand the detailed molecular mechanisms underlying impairment of angiogenesis in older patients. To improve the usefulness of therapeutic angiogenesis, approaches are needed that can compensate for impaired angiogenic capacity in the elderly while not promoting the development or progression of malignancy. In this review, we briefly outline the mechanisms of angiogenesis and vascular aging, followed by a description of how vascular aging leads to impairment of angiogenesis. We also examine potential therapeutic approaches that could enhance angiogenesis and/or vascular function in the elderly, as well as discussing the possibility of anti-senescence therapy or reversal of endothelial cell senescence.

  1. Mesenchymal Stem Cells Respond to Hypoxia by Increasing Diacylglycerols.

    Science.gov (United States)

    Lakatos, Kinga; Kalomoiris, Stefanos; Merkely, Béla; Nolta, Jan A; Fierro, Fernando A

    2016-02-01

    Mesenchymal stem cells (MSC) are currently being tested clinically for a plethora of conditions, with most approaches relying on the secretion of paracrine signals by MSC to modulate the immune system, promote wound healing, and induce angiogenesis. Hypoxia has been shown to affect MSC proliferation, differentiation, survival and secretory profile. Here, we investigate changes in the lipid composition of human bone marrow-derived MSC after exposure to hypoxia. Using mass spectrometry, we compared the lipid profiles of MSC derived from five different donors, cultured for two days in either normoxia (control) or hypoxia (1% oxygen). Hypoxia induced a significant increase of total triglycerides, fatty acids and diacylglycerols (DG). Remarkably, reduction of DG levels using the phosphatidylcholine-specific phospholipase C inhibitor D609 inhibited the secretion of VEGF and Angiopoietin-2, but increased the secretion of interleukin-8, without affecting significantly their respective mRNA levels. Functionally, incubation of MSC in hypoxia with D609 inhibited the potential of the cells to promote migration of human endothelial cells in a wound/scratch assay. Hence, we show that hypoxia induces in MSC an increase of DG that may affect the angiogenic potential of these cells. © 2015 Wiley Periodicals, Inc.

  2. Angiogenesis and Endometriosis

    Directory of Open Access Journals (Sweden)

    Ana Luiza L. Rocha

    2013-01-01

    Full Text Available A comprehensive review was performed to survey the role of angiogenesis in the pathogenesis of endometriosis. This is a multifactorial disease in which the development and maintenance of endometriotic implants depend on their invasive capacity and angiogenic potential. The peritoneal fluid of patients with endometriosis is a complex suspension carrying inflammatory cytokines, growth factors, steroid hormones, proangiogenic factors, macrophages, and endometrial and red blood cells. These cells and their signaling products concur to promote the spreading of new blood vessels at the endometriotic lesions and surroundings, which contributes to the endometriotic implant survival. Experimental studies of several antiangiogenic agents demonstrated the regression of endometriotic lesions by reducing their blood supply. Further studies are necessary before these novel agents can be introduced into clinical practice, in particular the establishment of the safety of anti-angiogenic medications in women who are seeking to become pregnant.

  3. Angiogenesis in gliomas.

    Directory of Open Access Journals (Sweden)

    Elzbieta Czykier

    2008-02-01

    Full Text Available Brain gliomas are characterized by invasive growth and neovascularisation potential. Angiogenesis plays a major role in the progression of gliomas and its determination has a great prognostic value. The aim of the study was to assess the vascularisation of chosen brain gliomas and to estimate how it is correlated with tumour histological type, malignancy grade, location and size, and with age and sex of patients. Tumour vascularisation analysis was based on the determination of microvascular proliferation (MVP and microvessel density (MVD. Microvascular proliferation was measured with immunohistochemical methods using mouse monoclonal antibodies to detect cell proliferation antigens. The following antibodies were used Ki-67 and PCNA (DAKO. Identification of vessels was performed by CD31 antibody and anti-human von Willebrand factor (DAKO. The highest microvascular proliferation and microvascular density were observed in multiform glioblastomas and the lowest in oligodendrogliomas. Significant correlation was observed between the vascularisation and malignancy grade.

  4. Hypoxia-induced retinopathy model in adult zebrafish

    DEFF Research Database (Denmark)

    Cao, Ziquan; Jensen, Lasse D.; Rouhi, Pegah

    2010-01-01

    Hypoxia-induced vascular responses, including angiogenesis, vascular remodeling and vascular leakage, significantly contribute to the onset, development and progression of retinopathy. However, until recently there were no appropriate animal disease models recapitulating adult retinopathy available....... In this article, we describe protocols that create hypoxia-induced retinopathy in adult zebrafish. Adult fli1: EGFP zebrafish are placed in hypoxic water for 3-10 d and retinal neovascularization is analyzed using confocal microscopy. It usually takes 11 d to obtain conclusive results using the hypoxia......-induced retinopathy model in adult zebrafish. This model provides a unique opportunity to study kinetically the development of retinopathy in adult animals using noninvasive protocols and to assess therapeutic efficacy of orally active antiangiogenic drugs....

  5. Hypoxia-Inducible Factor-1α in carcinogenesis and progression of breast cancer

    NARCIS (Netherlands)

    Bos, R.

    2004-01-01

    This thesis is primarily focused on the previously hardly explored role of HIF-1 in breast cancer. HIF-1 is a transcription factor induced by hypoxia, but also by some oncogenes, tumor suppressor genes and growth factors. Activated HIF-1 can induce angiogenesis, glycolysis, erythropoiesis, and other

  6. Induction of gastrin expression in gastrointestinal cells by hypoxia or cobalt is independent of hypoxia-inducible factor (HIF).

    Science.gov (United States)

    Xiao, Lin; Kovac, Suzana; Chang, Mike; Shulkes, Arthur; Baldwin, Graham S; Patel, Oneel

    2012-07-01

    Gastrin and its precursors have been shown to promote mitogenesis and angiogenesis in gastrointestinal tumors. Hypoxia stimulates tumor growth, but its effect on gastrin gene regulation has not been examined in detail. Here we have investigated the effect of hypoxia on the transcription of the gastrin gene in human gastric cancer (AGS) cells. Gastrin mRNA was measured by real-time PCR, gastrin peptides were measured by RIA, and gastrin promoter activity was measured by dual-luciferase reporter assay. Exposure to a low oxygen concentration (1%) increased gastrin mRNA concentrations in wild-type AGS cells (AGS) and in AGS cells overexpressing the gastrin receptor (AGS-cholecystokinin receptor 2) by 2.1 ± 0.4- and 4.1 ± 0.3-fold (P factor hypoxia-inducible factor 1 (HIF-1) or knockdown of either the HIF-1α or HIF-1β subunit did not affect gastrin promoter inducibility under hypoxia indicated that the hypoxic activation of the gastrin gene is likely HIF independent. Mutational analysis of previously identified Sp1 regulatory elements in the gastrin promoter also failed to abrogate the induction of promoter activity by hypoxia. The observations that hypoxia up-regulates the gastrin gene in AGS cells by HIF-independent mechanisms, and that this effect is enhanced by the presence of gastrin receptors, provide potential targets for gastrointestinal cancer therapy.

  7. Preventing High Altitude Cerebral Edema in Rats with Repurposed Anti-Angiogenesis Pharmacotherapy.

    Science.gov (United States)

    Tarshis, Samantha; Maltzahn, Joanne; Loomis, Zoe; Irwin, David C

    2016-12-01

    High altitude cerebral edema (HACE) is a fulminant, deadly, and yet still unpredictable brain disease. A new prophylactic treatment for HACE and its predecessor, acute mountain sickness (AMS), needs to be developed without the contraindications or adverse effect profiles of acetazolamide and dexamethasone. Since neovascularization signals are likely key contributors to HACE/AMS, our approach was to examine already existing anti-angiogenic drugs to inhibit potential initiating HACE pathway(s). This approach can also reveal crucial early steps in the frequently debated mechanism of HACE/AMS pathogenesis. We exposed four rat cohorts to hypobaric hypoxia and one to sea level (hyperbaric) conditions. The cohorts were treated with saline controls, an anti-angiogenesis drug (motesanib), a pro-angiogenesis drug (deferoxamine), or an intraperitoneal version of the established AMS prophylaxis drug, acetazolamide (benzolamide). Brain tissue was analyzed for cerebrovascular leak using the Evans Blue Dye (EVBD) protocol. We observed significantly increased EVBD in the altitude control and pro-angiogenesis (deferoxamine) cohorts, and significantly decreased EVBD in the anti-angiogenesis (motesanib), established treatment (benzolamide), and sea-level cohorts. Anti-angiogenesis-treated cohorts demonstrated less cerebrovascular extravasation than the altitude control and pro-angiogenesis treated rats, suggesting promise as an alternative prophylactic HACE/AMS treatment. The leak exacerbation with pro-angiogenesis treatment and improvement with anti-angiogenesis treatment support the hypothesis of early neovascularization signals provoking HACE. We demonstrate statistically significant evidence to guide further investigation for VEGF- and HIF-inhibitors as HACE/AMS prophylaxis, and as elucidators of still unknown HACE pathogenesis.Tarshis S, Maltzahn J, Loomis Z, Irwin DC. Preventing high altitude cerebral edema in rats with repurposed anti-angiogenesis pharmacotherapy. Aerosp Med

  8. Migraine induced by hypoxia

    DEFF Research Database (Denmark)

    Arngrim, Nanna; Schytz, Henrik Winther; Britze, Josefine

    2016-01-01

    in the visual cortex were measured by proton magnetic resonance spectroscopy. The circumference of cranial arteries was measured by 3 T high-resolution magnetic resonance angiography. Hypoxia induced migraine-like attacks in eight patients compared to one patient after sham (P = 0.039), aura in three...... and possible aura in 4 of 15 patients. Hypoxia did not change glutamate concentration in the visual cortex compared to sham, but increased lactate concentration (P = 0.028) and circumference of the cranial arteries (P ... suggests that hypoxia may provoke migraine headache and aura symptoms in some patients. The mechanisms behind the migraine-inducing effect of hypoxia should be further investigated....

  9. Démonstration du procédé IFP de désulfuration des fumées de centrales Demonstration of the Ifp Stack-Gas Desulfurization Process

    Directory of Open Access Journals (Sweden)

    Busson C.

    2006-11-01

    Full Text Available Les produits pétroliers et le charbon continueront à couvrir les besoins énergétiques pendant plusieurs décennies. La pollution par le SOZ, provenant de la combustion de ces combustibles fossiles, devient une préoccupation pour la population et les Pouvoirs publics. La désulfuration des fumées de combustion devrait, à plus ou moins longue échéance, se développer. L'Institut Français du Pétrole (IFP, mettant à profit ses travaux dans le domaine de la désulfuration, a développé un procédé de traitement des fumées. L'IFP, en collaboration avec Électricité de France (EDF, a effectué en 1976 une opération de démonstration à une échelle pilote (30 MW dans la Centrale de Champagne-sur-Oise. Le procédé consiste à éliminer le S02 des fumées par lavage avec une solution ammoniacale, à produire du soufre à partir de la liqueur obtenue et à recycler l'ammoniaque dans l'étape de lavage. Après quelques modifications d'ordre technologique, l'unité de démonstration a fonctionné d'une manière continue pendant une période de trois mois, correspondant à l'objectif fixé. Les résultats obtenus permettent, actuellement, d'envisager une application de cette technique à une échelle de 250 MW. Oil and coal productswill continue to fulfill energy needs for several more decades. Pollution by SO2 coming from the combustion of such fossil fuels is becoming a preoccupation for the population and the public authorities. The desulfurization of combustion fumes should continue ta develop in the more or less long run. Institut Français du Pétrole (IFP has taken advantage of its research in the fixed of desulfurization to develop a stock-gas treating process. In collaboration with Électricite de Fronce (EDF, IFP carried out a demonsiration operation in 1976 on a pilot-plant scale (30MW in a power plant at Champagne-sur-Oise. The process consists in removing S02 from stock gases by scrubbing them with an ammonia solution

  10. Effect of low-frequency low-intensity ultrasound with microbubbles on prostate cancer hypoxia.

    Science.gov (United States)

    Hou, Rui; Xu, Yanjun; Lu, Qijie; Zhang, Yang; Hu, Bing

    2017-10-01

    Angiogenesis plays an important role in tumor growth, invasiveness, and metastasis. It is well established that prostate cancer is exposed to fluctuating oxygen tensions and both acute and chronic hypoxia exist, and these conditions can upregulate angiogenesis-associated proteins such as hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A. Low-frequency low-intensity ultrasound with microbubbles can induce obvious microvessel damage in tumors, cause cell necrosis or apoptosis. However, there is no information about whether the blocking blood effect of low-frequency low-intensity ultrasound with microbubbles has an influence on hypoxia environment of prostate cancer. Therefore, we investigated the impact of different low-frequency low-intensity ultrasound with microbubbles radiation times on prostate tumors, observed the change in the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A protein levels, as well as cell proliferation, apoptosis, and tumor volume. The results indicated that as the radiation was repeated four times on each treatment day, the effects of interruption were durable, the cell proliferation was inhibited, and apoptosis was promoted, and the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were lower in the treatment group than in the control group. When the radiation was carried out once per treatment day, the hypoxia response was stimulated, the hypoxia-inducible factor 1 alpha and vascular endothelial growth factor A expression levels were higher compared with the control group, and cell proliferation was promoted. In addition, the tumor volume increased obviously in the hypoxia-stimulated group, whereas tumors grew slowly in the hypoxia-suppressed group. The results of this work demonstrated that under the same conditions, different radiation times of low-frequency low-intensity ultrasound with microbubbles affect the hypoxia response differently, and the

  11. Selective vulnerability in brain hypoxia

    DEFF Research Database (Denmark)

    Cervos-Navarro, J.; Diemer, Nils Henrik

    1991-01-01

    Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis......Neuropathology, selective vulnerability, brain hypoxia, vascular factors, excitotoxicity, ion homeostasis...

  12. History of research on angiogenesis.

    Science.gov (United States)

    Ribatti, Domenico

    2014-01-01

    Over the past 25 years, the number of Medline publications dealing with angiogenesis has increased in a nonlinear fashion, reflecting the interest among basic scientists and clinicians in this field. Under physiological conditions, angiogenesis is regulated by the local balance between endogenous stimulators and inhibitors of this process. In tumor growth, there is an imbalance between endogenous stimulator and inhibitor levels, leading to an 'angiogenic switch'. Starting with the hypothesis formulated by Judah Folkman that tumor growth is angiogenesis-dependent, this area of research has a solid scientific foundation and inhibition of angiogenesis is a major area of therapeutic development for the treatment of cancer. This paper offers an account of the most relevant discoveries in this field of biomedical research. Copyright © 2014 S. Karger AG, Basel.

  13. Angiogenesis and Its Therapeutic Opportunities

    Directory of Open Access Journals (Sweden)

    So Young Yoo

    2013-01-01

    Full Text Available Angiogenesis plays critical roles in human physiology that range from reproduction and fetal growth to wound healing and tissue repair. The sophisticated multistep process is tightly regulated in a spatial and temporal manner by “on-off switch signals” between angiogenic factors, extracellular matrix components, and endothelial cells. Uncontrolled angiogenesis may lead to several angiogenic disorders, including vascular insufficiency (myocardial or critical limb ischemia and vascular overgrowth (hemangiomas, vascularized tumors, and retinopathies. Thus, numerous therapeutic opportunities can be envisaged through the successful understanding and subsequent manipulation of angiogenesis. Here, we review the clinical implications of angiogenesis and discuss pro- and antiangiogenic agents that offer potential therapy for cancer and other angiogenic diseases.

  14. Celecoxib and octreotide synergistically ameliorate portal hypertension via inhibition of angiogenesis in cirrhotic rats.

    Science.gov (United States)

    Gao, Jin-Hang; Wen, Shi-Lei; Feng, Shi; Yang, Wen-Juan; Lu, Yao-Yao; Tong, Huan; Liu, Rui; Tang, Shi-Hang; Huang, Zhi-Yin; Tang, Ying-Mei; Yang, Jin-Hui; Xie, Hui-Qi; Tang, Cheng-Wei

    2016-10-01

    Abnormal angiogenesis is critical for portal hypertension in cirrhosis. Except for etiological treatment, no efficient medication or regime has been explored to treat the early stage of cirrhosis when angiogenesis is initiated or overwhelming. In this study, we explored an anti-angiogenesis effort through non-cytotoxic drugs octreotide and celecoxib to treat early stage of cirrhotic portal hypertension in an animal model. Peritoneal injection of thioacetamide (TAA) was employed to induce liver cirrhosis in rats. A combination treatment of celecoxib and octreotide was found to relieve liver fibrosis, portal venous pressure, micro-hepatic arterioportal fistulas, intrahepatic and splanchnic angiogenesis. Celecoxib and octreotide exerted their anti-angiogenesis effect via an axis of cyclooxygenase-2/prostaglandin E2/EP-2/somatostatin receptor-2, which consequently down-regulated phosphorylation of extracellular signal-regulated kinase (p-ERK)-hypoxia-inducible factor-1α (HIF-1α)-vascular endothelial growth factor (VEGF) integrated signaling pathways. In conclusions, combination of celecoxib and octreotide synergistically ameliorated liver fibrosis and portal hypertension of the cirrhotic rats induced by TAA via the inhibition of intrahepatic and extrahepatic angiogenesis. The potential mechanisms behind the regimen may due to the inactivation of p-ERK-HIF-1α-VEGF signaling pathway.

  15. Progesterone in Breast Cancer Angiogenesis

    OpenAIRE

    Botelho, Monica C.; Soares, Raquel; Alves, Helena

    2015-01-01

    The involvement of steroid hormones in breast carcinogenesis is well established. Recent evidence suggests that angiogenesis can be regulated by hormones. Both oestrogen and progesterone have been implicated in the angiogenic process of hormone-dependent cancers, such as breast cancer. Vascular Endothelial Growth Factor (VEGF) is a growth factor involved in angiogenesis in breast cancer that is up-regulated by estrogens. In our study we evaluated the role of progesterone in the expression of ...

  16. miR-21 Is Linked to Glioma Angiogenesis

    DEFF Research Database (Denmark)

    Hermansen, Simon Kjær; Nielsen, Boye Schnack; Aaberg-Jessen, Charlotte

    2016-01-01

    MicroRNA-21 (miR-21) is the most consistently over-expressed microRNA (miRNA) in malignant gliomas. We have previously reported that miR-21 is upregulated in glioma vessels and subsets of glioma cells. To better understand the role of miR-21 in glioma angiogenesis and to characterize miR-21......-localized with the hypoxia- and angiogenesis-associated markers HIF-1α (p=0.0020) and VEGF (p=0.0096), whereas the putative miR-21 target, PTEN, was expressed independently of miR-21. Expression of stem cell markers Oct4, Sox2 and CD133 was not associated with miR-21. In six glioblastoma cultures, miR-21 did not correlate...... with the six markers. These findings suggest that miR-21 is linked to glioma angiogenesis, that miR-21 is unlikely to regulate PTEN, and that miR-21-positive tumor cells do not possess stem cell characteristics....

  17. VEGF blockade inhibits angiogenesis and reepithelialization of endometrium.

    Science.gov (United States)

    Fan, Xiujun; Krieg, Sacha; Kuo, Calvin J; Wiegand, Stanley J; Rabinovitch, Marlene; Druzin, Maurice L; Brenner, Robert M; Giudice, Linda C; Nayak, Nihar R

    2008-10-01

    Despite extensive literature on vascular endothelial growth factor (VEGF) expression and regulation by steroid hormones, the lack of clear understanding of the mechanisms of angiogenesis in the endometrium is a major limitation for use of antiangiogenic therapy targeting endometrial vessels. In the current work, we used the rhesus macaque as a primate model and the decidualized mouse uterus as a murine model to examine angiogenesis during endometrial breakdown and regeneration. We found that blockade of VEGF action with VEGF Trap, a potent VEGF blocker, completely inhibited neovascularization during endometrial regeneration in both models but had no marked effect on preexisting or newly formed vessels, suggesting that VEGF is essential for neoangiogenesis but not survival of mature vessels in this vascular bed. Blockade of VEGF also blocked reepithelialization in both the postmenstrual endometrium and the mouse uterus after decidual breakdown, evidence that VEGF has pleiotropic effects in the endometrium. In vitro studies with a scratch wound assay showed that the migration of luminal epithelial cells during repair involved signaling through VEGF receptor 2-neuropilin 1 (VEGFR2-NP1) receptors on endometrial stromal cells. The leading front of tissue growth during endometrial repair was strongly hypoxic, and this hypoxia was the local stimulus for VEGF expression and angiogenesis in this tissue. In summary, we provide novel experimental data indicating that VEGF is essential for endometrial neoangiogenesis during postmenstrual/postpartum repair.

  18. Upregulated copper transporters in hypoxia-induced pulmonary hypertension.

    Directory of Open Access Journals (Sweden)

    Adriana M Zimnicka

    Full Text Available Pulmonary vascular remodeling and increased arterial wall stiffness are two major causes for the elevated pulmonary vascular resistance and pulmonary arterial pressure in patients and animals with pulmonary hypertension. Cellular copper (Cu plays an important role in angiogenesis and extracellular matrix remodeling; increased Cu in vascular smooth muscle cells has been demonstrated to be associated with atherosclerosis and hypertension in animal experiments. In this study, we show that the Cu-uptake transporter 1, CTR1, and the Cu-efflux pump, ATP7A, were both upregulated in the lung tissues and pulmonary arteries of mice with hypoxia-induced pulmonary hypertension. Hypoxia also significantly increased expression and activity of lysyl oxidase (LOX, a Cu-dependent enzyme that causes crosslinks of collagen and elastin in the extracellular matrix. In vitro experiments show that exposure to hypoxia or treatment with cobalt (CoCl2 also increased protein expression of CTR1, ATP7A, and LOX in pulmonary arterial smooth muscle cells (PASMC. In PASMC exposed to hypoxia or treated with CoCl2, we also confirmed that the Cu transport is increased using 64Cu uptake assays. Furthermore, hypoxia increased both cell migration and proliferation in a Cu-dependent manner. Downregulation of hypoxia-inducible factor 1α (HIF-1α with siRNA significantly attenuated hypoxia-mediated upregulation of CTR1 mRNA. In summary, the data from this study indicate that increased Cu transportation due to upregulated CTR1 and ATP7A in pulmonary arteries and PASMC contributes to the development of hypoxia-induced pulmonary hypertension. The increased Cu uptake and elevated ATP7A also facilitate the increase in LOX activity and thus the increase in crosslink of extracellular matrix, and eventually leading to the increase in pulmonary arterial stiffness.

  19. The Eni - IFP/Axens GTL technology. From R and D to a successful scale-up

    Energy Technology Data Exchange (ETDEWEB)

    Zennaro, R. [Eni S.p.A., Milan (Italy); Hugues, F. [Institut Francais du Petrole, Lyon (France); Caprani, E. [Axens, Paris (France)

    2006-07-01

    Proven natural gas reserves had reached about 184 Tscm in 2006 to which 36% is stranded gas far from the final market. Fischer Tropsch based GtL options today represent a viable route to develop such remote gas resources into high quality fuels and specialties. Thus opening different markets for the gas historically linked to the oil. Thanks to R and D successful improvements in the field of catalysis and reactor technology coupled with optimized integration and economies of scale have reduced the investment cost for building a Fischer Tropsch GtL complex. Basically all major Oil and Gas companies are involved in proprietary GtL development, and today several industrial projects have been announced. The most advanced is the Oryx project (QP-Sasol) which has been inaugurated the 6{sup th} of June '06 and currently in the starting up phase. Eni and IFP-Axens have developed a proprietary GtL Fischer-Tropsch and Upgrading technology in a close collaboration between the two groups. The Eni/IFP-Axens technology is based on proprietary catalysts and reactor, designed according to scale-up criteria defined in ten years of R and D activity. Unique large scale hydrodynamic facilities (bubble columns, loops) bench-scale dedicated pilot units, as well as large scale Fischer-Tropsch pilot plant, have been developed and operated to minimize reactor and ancillaries scale-up risks. The large scale Fischer-Tropsch pilot plant has been built and operated since 2001. The plant, located within the Eni refinery of Sannazzaro de' Burgondi (Pavia, Italy) is fully integrated to the refinery utilities and network. It reproduces at 20 bpd scale the overall Fischer Tropsch synthesis section: from slurry handling (loading, make-up, withdrawal), to reactor configuration and products separation units. Today the scale-up basis has been completed and the technology is ready for industrial deployment. (orig.)

  20. Angiogenesis in alkaptonuria.

    Science.gov (United States)

    Millucci, Lia; Bernardini, Giulia; Marzocchi, Barbara; Braconi, Daniela; Geminiani, Michela; Gambassi, Silvia; Laschi, Marcella; Frediani, Bruno; Galvagni, Federico; Orlandini, Maurizio; Santucci, Annalisa

    2016-11-01

    Alkaptonuria (AKU) is a rare genetic disease that affects the entire joint. Current standard of AKU treatment is palliative and little is known about its physiopathology. Neovascularization is involved in the pathogenesis of systemic inflammatory rheumatic diseases, a family of related disorders that includes AKU. Here, we investigated the presence of neoangiogenesis in AKU synovium and healthy controls. Synovium from AKU patients, who had undergone total joint replacement or arthroscopy, or from healthy patients without any history of rheumatic diseases, who underwent surgical operation following sport trauma was subjected to hematoxylin and eosin staining. Histologic grades were assigned for clinical disease activity and synovitis based on cellular content of the synovium. By immunofluorescence microscopy, using different endothelial cell markers, we observed large vascularization in AKU but not in healthy synovium. Moreover, Western blotting and quantification analyses confirmed strong expression of endothelial cell markers in AKU synovial tissues. Importantly, AKU synovium vascular endothelium expressed high levels of β-dystroglycan, a protein previously involved in the regulation of angiogenesis in osteoarthritic synovium. This is the first report providing experimental evidences that new blood vessels are formed in AKU synovial tissues, opening new perspectives for AKU therapy.

  1. TLX controls angiogenesis through interaction with the von Hippel-Lindau protein.

    Science.gov (United States)

    Zeng, Zhao-Jun; Johansson, Erik; Hayashi, Amiko; Chavali, Pavithra L; Akrap, Nina; Yoshida, Takeshi; Kohno, Kimitoshi; Izumi, Hiroto; Funa, Keiko

    2012-06-15

    TLX is known as the orphan nuclear receptor indispensable for maintaining neural stem cells in adult neurogenesis. We report here that neuroblastoma cell lines express high levels of TLX, which further increase in hypoxia to enhance the angiogenic capacity of these cells. The proangiogenetic activity of TLX appears to be induced by its direct binding to the von Hippel-Lindau protein (pVHL), which stabilizes TLX. In turn, TLX competes with hydroxylated hypoxia-inducible factor (HIF-α) for binding to pVHL, which contributes to the stabilization of HIF-2α in neuroblastoma during normoxia. Upon hypoxia, TLX increases in the nucleus where it binds in close proximity of the HIF-response element on the VEGF-promoter chromatin, and, together with HIF-2α, recruits RNA polymerase II to induce VEGF expression. Conversely, depletion of TLX by shRNA decreases the expression of HIF-2α and VEGF as well as the growth-promoting and colony-forming capacity of the neuroblastoma cell lines IMR-32 and SH-SY5Y. On the contrary, silencing HIF-2α will slightly increase TLX, suggesting that TLX acts to maintain a hypoxic environment when HIF-2α is decreasing. Our results demonstrate TLX to play a key role in controlling angiogenesis by regulating HIF-2α. TLX and pVHL might counterbalance each other in important fate decisions such as self-renewal and differentiation, as well as angiogenesis and anti-angiogenesis.

  2. TLX controls angiogenesis through interaction with the von Hippel-Lindau protein

    Directory of Open Access Journals (Sweden)

    Zhao-jun Zeng

    2012-04-01

    TLX is known as the orphan nuclear receptor indispensable for maintaining neural stem cells in adult neurogenesis. We report here that neuroblastoma cell lines express high levels of TLX, which further increase in hypoxia to enhance the angiogenic capacity of these cells. The proangiogenetic activity of TLX appears to be induced by its direct binding to the von Hippel-Lindau protein (pVHL, which stabilizes TLX. In turn, TLX competes with hydroxylated hypoxia-inducible factor (HIF-α for binding to pVHL, which contributes to the stabilization of HIF-2α in neuroblastoma during normoxia. Upon hypoxia, TLX increases in the nucleus where it binds in close proximity of the HIF-response element on the VEGF-promoter chromatin, and, together with HIF-2α, recruits RNA polymerase II to induce VEGF expression. Conversely, depletion of TLX by shRNA decreases the expression of HIF-2α and VEGF as well as the growth-promoting and colony-forming capacity of the neuroblastoma cell lines IMR-32 and SH-SY5Y. On the contrary, silencing HIF-2α will slightly increase TLX, suggesting that TLX acts to maintain a hypoxic environment when HIF-2α is decreasing. Our results demonstrate TLX to play a key role in controlling angiogenesis by regulating HIF-2α. TLX and pVHL might counterbalance each other in important fate decisions such as self-renewal and differentiation, as well as angiogenesis and anti-angiogenesis.

  3. PACAP and VIP inhibit the invasiveness of glioblastoma cells exposed to hypoxia through the regulation of HIFs and EGFR expression

    OpenAIRE

    Grazia eMaugeri; Agata Grazia eD'Amico; Agata Grazia eD'Amico; Rita eReitano; Gaetano eMagro; Sebastiano eCavallaro; Salvatore eSalomone; Velia eD'Agata

    2016-01-01

    Pituitary adenylate cyclase-activating polypeptide (PACAP) and vasoactive intestinal peptide (VIP) through the binding of vasoactive intestinal peptide receptors (VIPRs), perform a wide variety of effects in human cancers, including glioblastoma multiforme (GBM). This tumor is characterized by extensive areas of hypoxia, which triggers the expression of hypoxia-inducible factors (HIFs). HIFs not only mediate angiogenesis but also tumor cell migration and invasion. Furthermore, HIFs activation...

  4. Effect of the micronutrient iodine in thyroid carcinoma angiogenesis.

    Science.gov (United States)

    Daniell, Kayla; Nucera, Carmelo

    2016-12-20

    Iodide is a micronutrient essential for thyroid hormone production. The uptake and metabolism of iodide by thyrocytes is crucial to proper thyroid function. Iodide ions are drawn into the thyroid follicular cell via the sodium-iodide symporter (NIS) in the cell membrane and become integrated into tyrosyl residues to ultimately form thyroid hormones. We sought to learn how an abnormal concentration of iodide within thyrocyte can have significant effects on the thyroid, specifically the surrounding vascular network. Insufficient levels of iodide can lead to increased expression or activity of several pathways, including vascular endothelial growth factor (VEGF). The VEGF protein fuel vessel growth (angiogenesis) and therefore enhances the nutrients available to surrounding cells. Alternatively, normal/surplus iodide levels can have inhibitory effects on angiogenesis. Varying levels of iodide in the thyroid can influence thyroid carcinoma cell proliferation and angiogenesis via regulation of the hypoxia inducible factor-1 (HIF-1) and VEGF-dependent pathway. We have reviewed a number of studies to investigate how the effect of iodide on angiogenic and oxidative stress regulation can affect the viability of thyroid carcinoma cells. The various studies outlined give key insights to the role of iodide in thyroid follicles function and vascular growth, generally highlighting that insufficient levels of iodide stimulate pathways resulting in vascular growth, and viceversa normal/surplus iodide levels inhibit such pathways. Intriguingly, TSH and iodine levels differentially regulate the expression levels of angiogenic factors. All cells, including carcinoma cells, increase uptake of blood nutrients, meaning the vascular profile is influential to tumor growth and progression. Importantly, variation in the iodine concentrations also influence BRAF V600E -mediated oncogenic activity and might deregulate tumor proliferation. Although the mechanisms are not well eluted, iodine

  5. Hypoxia inhibits hypertrophic differentiation and endochondral ossification in explanted tibiae.

    Directory of Open Access Journals (Sweden)

    Jeroen C H Leijten

    Full Text Available Hypertrophic differentiation of growth plate chondrocytes induces angiogenesis which alleviates hypoxia normally present in cartilage. In the current study, we aim to determine whether alleviation of hypoxia is merely a downstream effect of hypertrophic differentiation as previously described or whether alleviation of hypoxia and consequent changes in oxygen tension mediated signaling events also plays an active role in regulating the hypertrophic differentiation process itself.Fetal mouse tibiae (E17.5 explants were cultured up to 21 days under normoxic or hypoxic conditions (21% and 2.5% oxygen respectively. Tibiae were analyzed on growth kinetics, histology, gene expression and protein secretion.The oxygen level had a strong influence on the development of explanted fetal tibiae. Compared to hypoxia, normoxia increased the length of the tibiae, length of the hypertrophic zone, calcification of the cartilage and mRNA levels of hypertrophic differentiation-related genes e.g. MMP9, MMP13, RUNX2, COL10A1 and ALPL. Compared to normoxia, hypoxia increased the size of the cartilaginous epiphysis, length of the resting zone, calcification of the bone and mRNA levels of hyaline cartilage-related genes e.g. ACAN, COL2A1 and SOX9. Additionally, hypoxia enhanced the mRNA and protein expression of the secreted articular cartilage markers GREM1, FRZB and DKK1, which are able to inhibit hypertrophic differentiation.Collectively our data suggests that oxygen levels play an active role in the regulation of hypertrophic differentiation of hyaline chondrocytes. Normoxia stimulates hypertrophic differentiation evidenced by the expression of hypertrophic differentiation related genes. In contrast, hypoxia suppresses hypertrophic differentiation of chondrocytes, which might be at least partially explained by the induction of GREM1, FRZB and DKK1 expression.

  6. Hypoxia and anemia: factors in decreased sensitivity to radiation therapy and chemotherapy?

    Science.gov (United States)

    Harrison, Louis; Blackwell, Kimberly

    2004-01-01

    Hypoxia is a common feature of solid tumors that occurs across a wide variety of malignancies. Hypoxia and anemia (which contributes to tumor hypoxia) can lead to ionizing radiation and chemotherapy resistance by depriving tumor cells of the oxygen essential for the cytotoxic activities of these agents. Hypoxia may also reduce tumor sensitivity to radiation therapy and chemotherapy through one or more indirect mechanisms that include proteomic and genomic changes. These effects, in turn, can lead to increased invasiveness and metastatic potential, loss of apoptosis, and chaotic angiogenesis, thereby further increasing treatment resistance. Investigations of the prognostic significance of pretreatment tumor oxygenation status have shown that hypoxia (oxygen tension [pO(2)] value effect of hypoxia on standard cancer treatment, a variety of hypoxia- and anemia-targeted therapies have been studied in an effort to improve therapeutic effectiveness and patient outcomes. Early evidence from experimental and clinical studies suggests the administration of recombinant human erythropoietin (rHuEPO) may enhance the effectiveness of radiation therapy and chemotherapy by increasing hemoglobin levels and ameliorating anemia in patients with disease- or treatment-related anemia. However, further research is needed in the area of hypoxia-related treatment resistance and its reversal.

  7. Molecular Imaging of Ovarian Carcinoma Angiogenesis

    National Research Council Canada - National Science Library

    Chen, Xiaoyuan

    2007-01-01

    .... Ovarian cancer is angiogenesis dependent. Integrin , a key player in tumor angiogenesis and metastasis, has been identified as a target for diagnostic and therapeutic interventions for several highly proliferative and metastatic tumor types...

  8. Monitoring angiogenesis using a human compatible calibration for broadband near-infrared spectroscopy

    Science.gov (United States)

    Yang, Runze; Zhang, Qiong; Wu, Ying; Dunn, Jeff F.

    2013-01-01

    Angiogenesis is a hallmark of many conditions, including cancer, stroke, vascular disease, diabetes, and high-altitude exposure. We have previously shown that one can study angiogenesis in animal models by using total hemoglobin (tHb) as a marker of cerebral blood volume (CBV), measured using broadband near-infrared spectroscopy (bNIRS). However, the method was not suitable for patients as global anoxia was used for the calibration. Here we determine if angiogenesis could be detected using a calibration method that could be applied to patients. CBV, as a marker of angiogenesis, is quantified in a rat cortex before and after hypoxia acclimation. Rats are acclimated at 370-mmHg pressure for three weeks, while rats in the control group are housed under the same conditions, but under normal pressure. CBV increased in each animal in the acclimation group. The mean CBV (%volume/volume) is 3.49%±0.43% (mean±SD) before acclimation for the experimental group, and 4.76%±0.29% after acclimation. The CBV for the control group is 3.28%±0.75%, and 3.09%±0.48% for the two measurements. This demonstrates that angiogenesis can be monitored noninvasively over time using a bNIRS system with a calibration method that is compatible with human use and less stressful for studies using animals.

  9. Modulation of thioacetamide-induced hepatic inflammations, angiogenesis and fibrosis by andrographolide in mice.

    Science.gov (United States)

    Lee, Tzung-Yan; Chang, Hen-Hong; Wen, Chorng-Kai; Huang, Tse-Hung; Chang, Ya-Shu

    2014-12-02

    Liver fibrosis is a complex disease in which several pathological processes, such as inflammation and angiogenesis, are closely integrated. We hypothesised that treatment with the pharmacological agent, andrographolide (AP), which has multiple mechanisms of action, will provide a greater understanding of the role of AP during the multiple pathological processes that occur in advanced liver disease. Liver fibrogenesis was induced in mice using thioacetamide (TAA), which was administrated for 6 weeks. Andrographolide (5, 20 or 100mg/kg) was then given once daily following TAA injection. Liver collagen was examined using hydroxyproline and α-SMA, while the inflammatory response was quantified by Western blot and RT-PCR assays. Liver angiogenesis, neutrophil infiltration and hypoxia were assessed using CD11b+, vWF and HIF-1α immunostaining. Mice with liver injuries that were treated with andrographolide showed improved inflammatory response and diminished angiogenesis and hepatic fibrosis. Andrographolide treatment inhibited liver neutrophil infiltration, while a decreased in TNF-α and COX-2 signalling indicated macrophage activation. Andrographolide decreased overall liver hypoxia, as shown by the downregulation of hypoxia-inducible cascade genes, such as VEGF. Andrographolide treatment resulted in a significant decrease in hepatic fibrogenesis, α-SMA abundance, and TGF-βR1 expression. The present results suggest that multi-targeted therapies directed against angiogenesis, inflammation, and fibrosis should be considered for the treatment of advanced liver injury. They further suggest that andrographolide treatment may be a novel therapeutic agent for the treatment of liver disease. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

  10. Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Ferreira, N

    2005-11-15

    Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

  11. Catabolism of methyl ter-butyl ether (MTBE): characterization of the enzymes of Mycobacterium austroafricanum IFP 2012 involved in MTBE degradation; Catabolisme du methyl tert-butyl ether (MTBE): caracterisation des enzymes impliquees dans la degradation du MTBE chez Mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Lopes Ferreira, N.

    2005-11-15

    Methyl tert-butyl ether (MTBE) is added to gasoline to meet the octane index requirement. its solubility in water and its poor biodegradability made the use of MTBE a great environmental concern, particularly regarding aquifers. We previously isolated M austroafricanum IFP 2012 able to use MTBE as a sole source of carbon and energy and the MTBE pathway was partially characterized. In the present study, which aimed at isolating the genes involved in MTBE biodegradation in order to use them for estimation of MTBE biodegradation capacities in contaminated environment, we isolated a new M. austroafricanum strain, IFP 2015. A new degradation intermediate, the 2-methyl 1,2-propane-diol (2-M1,2-PD), the product of tert-butanol (TBA) oxidation, was identified. We also determined the enzymes induced during growth of M. austroafricanum IFP 2012 on MTBF. Then, using the tools of protein analysis and of molecular biology, we isolated and cloned the mpd genes cluster in the plasmid pCL4D. Heterologous expression of the recombinant plasmid in M smegmatis tmc2 155, showed the involvement of an 2-M1,2-PD dehydrogenase (MpdB) and a hydroxy-iso-butyr-aldehyde dehydrogenase (MpdC), encoded by mpdB and mpdC, respectively. Both enzymes were responsible for the conversion of 2-M 1,2-PD to hydroxy-isobutyric acid (HIBA). A further survey of different M austroafricanum strains, including IFP 2012, IFP 2015 and JOBS (ex-M vaccae) showed the link between the ability to grow on C{sub 2} to C{sub 16} n-alkanes and the MTBE and TBA degradation capacities. The alkB gene was partially sequenced in all these strains. Expression of alkB was demonstrated in M. austroafricanum IFP 2012 after growth on propane, hexane, hexadecane and TBA. Finally, we identified 2-propanol as the intermediate of HIBA degradation. The gene encoding the 2-propanol:p-N,N'-dimethyl-4-nitroso-aniline (NDMA) oxidoreductase was detected M austroafricanum IFP 2012. (author)

  12. The Role of Hypoxia in Orthodontic Tooth Movement

    Directory of Open Access Journals (Sweden)

    A. Niklas

    2013-01-01

    Full Text Available Orthodontic forces are known to have various effects on the alveolar process, such as cell deformation, inflammation, and circulatory disturbances. Each of these conditions affecting cell differentiation, cell repair, and cell migration, is driven by numerous molecular and inflammatory mediators. As a result, bone remodeling is induced, facilitating orthodontic tooth movement. However, orthodontic forces not only have cellular effects but also induce vascular changes. Orthodontic forces are known to occlude periodontal ligament vessels on the pressure side of the dental root, decreasing the blood perfusion of the tissue. This condition is accompanied by hypoxia, which is known to either affect cell proliferation or induce apoptosis, depending on the oxygen gradient. Because upregulated tissue proliferation rates are often accompanied by angiogenesis, hypoxia may be assumed to fundamentally contribute to bone remodeling processes during orthodontic treatment.

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

    Science.gov (United States)

    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.

  14. Hypoxia targeting copper complexes

    International Nuclear Information System (INIS)

    Dearling, J.L.

    1998-11-01

    The importance and incidence of tumour hypoxia, its measurement and current treatments available, including pharmacological and radiopharmacological methods of targeting hypoxia, are discussed. A variety of in vitro and in vivo methods for imposing hypoxia have been developed and are reviewed. Copper, its chemistry, biochemistry and radiochemistry, the potential for use of copper radionuclides and its use to date in this field is considered with particular reference to the thiosemicarbazones. Their biological activity, metal chelation, in vitro and in vivo studies of their radiocopper complexes and the potential for their use as hypoxia targeting radiopharmaceuticals is described. The reduction of the copper(II) complex to copper(l), its pivotal importance in their biological behaviour, and the potential for manipulation of this to effect hypoxia selectivity are described. An in vitro method for assessing the hypoxia selectivity of radiopharmaceuticals is reported. The rapid deoxygenation and high viability of a mammalian cell culture in this system is discussed and factors which may affect the cellular uptake of a radiopharmaceutical are described. The design, synthesis and complexation with copper and radiocopper of a range of bis(thiosemicarbazones) is reported. Synthesis of these compounds is simple giving high yields of pure products. The characteristics of the radiocopper complexes ( 64 Cu) including lipophilicity and redox activity are reported (reduction potentials in the range -0.314 - -0.590 V). High cellular uptakes of the radiocopper complexes of the ligands, in hypoxic and normoxic EMT6 and CHO320 cells, were observed. Extremes of selectivity are shown ranging from the hypoxia selective 64 Cu(II)ATSM to normoxic cell selective 64 Cu(II)GTS. The selectivities observed are compared with the physico chemical characteristics of the complexes. A good correlation exists between selectivity of the complex and its Cu(II)/Cu(I) reduction potential, with hypoxia

  15. Angiogenesis is induced by airway smooth muscle strain.

    Science.gov (United States)

    Hasaneen, Nadia A; Zucker, Stanley; Lin, Richard Z; Vaday, Gayle G; Panettieri, Reynold A; Foda, Hussein D

    2007-10-01

    Angiogenesis is an important feature of airway remodeling in both chronic asthma and chronic obstructive pulmonary disease (COPD). Airways in those conditions are exposed to excessive mechanical strain during periods of acute exacerbations. We recently reported that mechanical strain of human airway smooth muscle (HASM) led to an increase in their proliferation and migration. Sustained growth in airway smooth muscle in vivo requires an increase in the nutritional supply to these muscles, hence angiogenesis. In this study, we examined the hypothesis that cyclic mechanical strain of HASM produces factors promoting angiogenic events in the surrounding vascular endothelial cells. Our results show: 1) a significant increase in human lung microvascular endothelial cell (HMVEC-L) proliferation, migration, and tube formation following incubation in conditioned media (CM) from HASM cells exposed to mechanical strain; 2) mechanical strain of HASM cells induced VEGF expression and release; 3) VEGF neutralizing antibodies inhibited the proliferation, migration, and tube formations of HMVEC-L induced by the strained airway smooth muscle CM; 4) mechanical strain of HASM induced a significant increase in hypoxia-inducible factor-1alpha (HIF-1alpha) mRNA and protein, a transcription factor required for VEGF gene transcription; and 5) mechanical strain of HASM induced HIF-1alpha/VEGF through dual phosphatidylinositol 3-kinase (PI3K)/Akt/mammalian target of rapamycin (mTOR) and ERK pathways. In conclusion, exposing HASM cells to mechanical strain induces signal transduction pathway through PI3K/Akt/mTOR and ERK pathways that lead to an increase in HIF-1alpha, a transcription factor required for VEGF expression. VEGF release by mechanical strain of HASM may contribute to the angiogenesis seen with repeated exacerbation of asthma and COPD.

  16. Angiogenesis and Tissue Engineering Research

    Science.gov (United States)

    2010-08-01

    Model with the Angiogenesis Inhibitor Sunitinib. American Pediatric Surgical Association – 40th Annual Meeting, Fajardo, Puerto Rico, May 2009...Res 149(1):115-9. 14 5. Ray NF, Denton WG, Thamer M, Henderson SC, Perry S (1998) Abdominal adhesiolysis: inpatient care and expenditures in the...nude mice (n¼ 9). Mice were injected with near- infrared agents and imaged using intravital fluorescence microscope at 0, 7, and 35 days to validate in

  17. Angiogenesis and blood vessel stability in inflammatory arthritis.

    LENUS (Irish Health Repository)

    Kennedy, Aisling

    2012-02-01

    OBJECTIVE: To assess blood vessel stability in inflammatory synovial tissue (ST) and to examine neural cell adhesion molecule (NCAM), oxidative DNA damage, and hypoxia in vivo. METHODS: Macroscopic vascularity and ST oxygen levels were determined in vivo in patients with inflammatory arthritis who were undergoing arthroscopy. Vessel maturity\\/stability was quantified in matched ST samples by dual immunofluorescence staining for factor VIII (FVIII)\\/alpha-smooth muscle actin (alpha-SMA). NCAM and 8-oxo-7,8-dihydro-2\\'-deoxyguanosine (8-oxodG) were examined by immunohistochemistry. Angiogenesis was assessed in vitro, using human dermal endothelial cells (HDECs) in a Matrigel tube formation assay. RESULTS: A significant number of immature vessels (showing no pericyte recruitment) was observed in tissue from patients with inflammatory arthritis (P < 0.001), in contrast to osteoarthritic and normal tissue, which showed complete recruitment of pericytes. Low in vivo PO(2) levels in the inflamed joint (median [range] 22.8 [3.2-54.1] mm Hg) were inversely related to increased macroscopic vascularity (P < 0.04) and increased microscopic expression of FVIII and alpha-SMA (P < 0.04 and P < 0.03, respectively). A significant proportion of vessels showed focal expression of NCAM and strong nuclear 8-oxodG expression, implicating a loss of EC-pericyte contact and increased DNA damage, levels of which were inversely associated with low in vivo PO(2) (P = 0.04 for each comparison). Circulating cells were completely negative for 8-oxodG. Exposure of HDEC to 3% O(2) (reflecting mean ST in vivo measurements) significantly increased EC tube formation (P < 0.05). CONCLUSION: Our findings indicate the presence of unstable vessels in inflamed joints associated with hypoxia, incomplete EC-pericyte interactions, and increased DNA damage. These changes may further contribute to persistent hypoxia in the inflamed joint to further drive this unstable microenvironment.

  18. Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression.

    Science.gov (United States)

    Lara, Pedro C; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa M; Henríquez-Hernández, Luis Alberto; Bordón, Elisa; Fontes, Fausto; Rey, Agustín

    2009-08-06

    Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP), vault poly(ADP-ribose) polymerase, and telomerase associated protein-1 and small untranslated RNA. Over-expression of MVP has been associated with chemotherapy resistance. Also, it has been related to poor outcome in patients treated with radiotherapy alone. The aim of the present study was to assess the relation of Major Vault Protein expression and tumor hypoxia in clinical cervical tumors. MVP, p53 and angiogenesis, together with tumor oxygenation, were determined in forty-three consecutive patients suffering from localized cervix carcinoma. High MVP expression was related to severe hypoxia compared to low MVP expressing tumors (p = 0.022). Tumors over-expressing MVP also showed increased angiogenesis (p = 0.003). Besides it, in this study we show for the first time that severe tumor hypoxia is associated with high MVP expression in clinical cervical tumors. Up-regulation of MVP by hypoxia is of critical relevance as chemotherapy is currently a standard treatment for those patients. From our results it could be suggested that hypoxia not only induces increased genetic instability, oncogenic properties and metastatization, but through the correlation observed with MVP expression, another pathway of chemo and radiation resistance could be developed.

  19. Severe hypoxia induces chemo-resistance in clinical cervical tumors through MVP over-expression

    International Nuclear Information System (INIS)

    Lara, Pedro C; Lloret, Marta; Clavo, Bernardino; Apolinario, Rosa M; Henríquez-Hernández, Luis Alberto; Bordón, Elisa; Fontes, Fausto; Rey, Agustín

    2009-01-01

    Oxygen molecule modulates tumour response to radiotherapy. Higher radiation doses are required under hypoxic conditions to induce cell death. Hypoxia may inhibit the non-homologous end-joining DNA repair through down regulating Ku70/80 expression. Hypoxia induces drug resistance in clinical tumours, although the mechanism is not clearly elucidated. Vaults are ribonucleoprotein particles with a hollow barrel-like structure composed of three proteins: major vault protein (MVP), vault poly(ADP-ribose) polymerase, and telomerase associated protein-1 and small untranslated RNA. Over-expression of MVP has been associated with chemotherapy resistance. Also, it has been related to poor outcome in patients treated with radiotherapy alone. The aim of the present study was to assess the relation of Major Vault Protein expression and tumor hypoxia in clinical cervical tumors. MVP, p53 and angiogenesis, together with tumor oxygenation, were determined in forty-three consecutive patients suffering from localized cervix carcinoma. High MVP expression was related to severe hypoxia compared to low MVP expressing tumors (p = 0.022). Tumors over-expressing MVP also showed increased angiogenesis (p = 0.003). Besides it, in this study we show for the first time that severe tumor hypoxia is associated with high MVP expression in clinical cervical tumors. Up-regulation of MVP by hypoxia is of critical relevance as chemotherapy is currently a standard treatment for those patients. From our results it could be suggested that hypoxia not only induces increased genetic instability, oncogenic properties and metastatization, but through the correlation observed with MVP expression, another pathway of chemo and radiation resistance could be developed

  20. Monitoring angiogenesis using magnetic resonance methods

    DEFF Research Database (Denmark)

    Holm, David Alberg

    2008-01-01

    When a tumor reaches a certain size it can no longer rely on passive perfusion for nutrition. The tumor therefore emits signaling molecules which stimulating surrounding vessels to divide and grow towards the tumor, a process known as angiogenesis. Very little angiogenesis is present in healthy...... adults where it is primaily found in wound healing, pregnancy and during the menstrual cycle. This thesis focus on the negative consequences of angiogenesis in cancer. It consists of a an initial overview followed by four manuscripts. The overview gives a short introduction to the process of angiogenesis...... and the involved signaling molecules. Subsequently, a short review of contrast agents and perfusion measurements is given. Finally, methods for monitoring angiogenesis using magnetic resonance imaging are reviewed. A method for monitoring early stages of angiogenesis as well as the effect of anti...

  1. Oxidative stress in tumor microenvironment——Its role in angiogenesis

    Institute of Scientific and Technical Information of China (English)

    Armando ROJAS; Raúl SILVA; Héctor FIGUEROA; Miguel A MORALES

    2008-01-01

    The tumor angiogenesis process is believed to be dependent on an "angiogenic switch" formed by a cascade of biologic events as a consequence of the "cross-talk" between tumor cells and several components of local microenvironment including endothelial cells, macrophages, mast cells and stromal components. Oxidative stress represents an important stimulus that widely contributes to this angiogenic switch, which is particularly relevant in lungs,where oxidative stress is originated from different sources including the incomplete reduction of oxygen during respiration,exposure to hypoxia/reoxygenation, stimulated resident or chemoattracted immune ceils to lung tissues, as well as by a variety of chemicals compounds. In the present review we highlight the role of oxidative stress in tumor angiogenesis as a key signal linked to other relevant actors in this complex process.

  2. Silver nanoparticles inhibit the function of hypoxia-inducible factor-1 and target genes: insight into the cytotoxicity and antiangiogenesis.

    Science.gov (United States)

    Yang, Tieshan; Yao, Qian; Cao, Fei; Liu, Qianqian; Liu, Binlei; Wang, Xiu-Hong

    Hypoxia-inducible factor-1 (HIF-1) is a transcription factor that is activated upon exposure to hypoxic stress. It modulates a number of cellular responses including proliferation, apoptosis, angiogenesis, and metabolism by activating a panel of target genes in response to hypoxia. The HIF-1 level is often upregulated in the hypoxic microenvironment of solid tumors, which contributes to cancer treatment failure. Here we report that silver nanoparticles (AgNPs), which are widely used as an antimicrobial agent, are an effective inhibitor of HIF-1. AgNPs inhibited the activation of a HIF-dependent reporter construct after the cells were exposed to hypoxic conditions or treated with cobalt chloride, a hypoxia mimetic agent. The AgNPs also interfered with the accumulation of HIF-1α protein and the induction of the endogenous HIF target genes, VEGF-A and GLUT1. Since both HIF-1 and vascular endothelial growth factor-A play an important role in angiogenesis, AgNPs also inhibited angiogenesis in vitro. Our data reveal a new mechanism of how AgNPs act on cellular function, that is, they disrupt HIF signaling pathway. This finding provides a novel insight into how AgNPs can inhibit cancer cell growth and angiogenesis.

  3. Hypoxia signaling pathways: modulators of oxygen-related organelles

    Science.gov (United States)

    Schönenberger, Miriam J.; Kovacs, Werner J.

    2015-01-01

    Oxygen (O2) is an essential substrate in cellular metabolism, bioenergetics, and signaling and as such linked to the survival and normal function of all metazoans. Low O2 tension (hypoxia) is a fundamental feature of physiological processes as well as pathophysiological conditions such as cancer and ischemic diseases. Central to the molecular mechanisms underlying O2 homeostasis are the hypoxia-inducible factors-1 and -2 alpha (HIF-1α and EPAS1/HIF-2α) that function as master regulators of the adaptive response to hypoxia. HIF-induced genes promote characteristic tumor behaviors, including angiogenesis and metabolic reprogramming. The aim of this review is to critically explore current knowledge of how HIF-α signaling regulates the abundance and function of major O2-consuming organelles. Abundant evidence suggests key roles for HIF-1α in the regulation of mitochondrial homeostasis. An essential adaptation to sustained hypoxia is repression of mitochondrial respiration and induction of glycolysis. HIF-1α activates several genes that trigger mitophagy and represses regulators of mitochondrial biogenesis. Several lines of evidence point to a strong relationship between hypoxia, the accumulation of misfolded proteins in the endoplasmic reticulum, and activation of the unfolded protein response. Surprisingly, although peroxisomes depend highly on molecular O2 for their function, there has been no evidence linking HIF signaling to peroxisomes. We discuss our recent findings that establish HIF-2α as a negative regulator of peroxisome abundance and suggest a mechanism by which cells attune peroxisomal function with O2 availability. HIF-2α activation augments peroxisome turnover by pexophagy and thereby changes lipid composition reminiscent of peroxisomal disorders. We discuss potential mechanisms by which HIF-2α might trigger pexophagy and place special emphasis on the potential pathological implications of HIF-2α-mediated pexophagy for human health. PMID:26258123

  4. Vasculogenesis and angiogenesis initiation under normoxic conditions through Wnt/β-catenin pathway in gliomas.

    Science.gov (United States)

    Vallée, Alexandre; Guillevin, Rémy; Vallée, Jean-Noël

    2018-01-26

    The canonical Wnt/β-catenin pathway is up-regulated in gliomas and involved in proliferation, invasion, apoptosis, vasculogenesis and angiogenesis. Nuclear β-catenin accumulation correlates with malignancy. Hypoxia activates hypoxia-inducible factor (HIF)-1α by inhibiting HIF-1α prolyl hydroxylation, which promotes glycolytic energy metabolism, vasculogenesis and angiogenesis, whereas HIF-1α is degraded by the HIF prolyl hydroxylase under normoxic conditions. We focus this review on the links between the activated Wnt/β-catenin pathway and the mechanisms underlying vasculogenesis and angiogenesis through HIF-1α under normoxic conditions in gliomas. Wnt-induced epidermal growth factor receptor/phosphatidylinositol 3-kinase (PI3K)/Akt signaling, Wnt-induced signal transducers and activators of transcription 3 (STAT3) signaling, and Wnt/β-catenin target gene transduction (c-Myc) can activate HIF-1α in a hypoxia-independent manner. The PI3K/Akt/mammalian target of rapamycin pathway activates HIF-1α through eukaryotic translation initiation factor 4E-binding protein 1 and STAT3. The β-catenin/T-cell factor 4 complex directly binds to STAT3 and activates HIF-1α, which up-regulates the Wnt/β-catenin target genes cyclin D1 and c-Myc in a positive feedback loop. Phosphorylated STAT3 by interleukin-6 or leukemia inhibitory factor activates HIF-1α even under normoxic conditions. The activation of the Wnt/β-catenin pathway induces, via the Wnt target genes c-Myc and cyclin D1 or via HIF-1α, gene transactivation encoding aerobic glycolysis enzymes, such as glucose transporter, hexokinase 2, pyruvate kinase M2, pyruvate dehydrogenase kinase 1 and lactate dehydrogenase-A, leading to lactate production, as the primary alternative of ATP, at all oxygen levels, even in normoxic conditions. Lactate released by glioma cells via the monocarboxylate lactate transporter-1 up-regulated by HIF-1α and lactate anion activates HIF-1α in normoxic endothelial cells by

  5. Silver nanoparticles inhibit the function of hypoxia-inducible factor-1 and target genes: insight into the cytotoxicity and antiangiogenesis

    Directory of Open Access Journals (Sweden)

    Yang T

    2016-12-01

    Full Text Available Tieshan Yang,1 Qian Yao,1 Fei Cao,1 Qianqian Liu,1 Binlei Liu,2 Xiu-Hong Wang1 1Laboratory for Biomedical Photonics, Institute of Laser Engineering, Beijing University of Technology, 2Cancer Institute and Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, People’s Republic of China Abstract: Hypoxia-inducible factor-1 (HIF-1 is a transcription factor that is activated upon exposure to hypoxic stress. It modulates a number of cellular responses including proliferation, apoptosis, angiogenesis, and metabolism by activating a panel of target genes in response to hypoxia. The HIF-1 level is often upregulated in the hypoxic microenvironment of solid tumors, which contributes to cancer treatment failure. Here we report that silver nanoparticles (AgNPs, which are widely used as an antimicrobial agent, are an effective inhibitor of HIF-1. AgNPs inhibited the activation of a HIF-dependent reporter construct after the cells were exposed to hypoxic conditions or treated with cobalt chloride, a hypoxia mimetic agent. The AgNPs also interfered with the accumulation of HIF-1α protein and the induction of the endogenous HIF target genes, VEGF-A and GLUT1. Since both HIF-1 and vascular endothelial growth factor-A play an important role in angiogenesis, AgNPs also inhibited angiogenesis in vitro. Our data reveal a new mechanism of how AgNPs act on cellular function, that is, they disrupt HIF signaling pathway. This finding provides a novel insight into how AgNPs can inhibit cancer cell growth and angiogenesis. Keywords: silver nanoparticles (AgNPs, hypoxia-inducible factor, transcriptional activity, vascular endothelial growth factor-A, angiogenesis

  6. Sphingosine kinase-1 is a hypoxia-regulated gene that stimulates migration of human endothelial cells

    International Nuclear Information System (INIS)

    Schwalm, Stephanie; Doell, Frauke; Roemer, Isolde; Bubnova, Svetlana; Pfeilschifter, Josef; Huwiler, Andrea

    2008-01-01

    Sphingosine kinases (SK) catalyze the production of sphingosine-1-phosphate which in turn regulates cell responses such as proliferation and migration. Here, we show that exposure of the human endothelial cell line EA.hy 926 to hypoxia stimulates a increased SK-1, but not SK-2, mRNA, protein expression, and activity. This effect was due to stimulated SK-1 promoter activity which contains two putative hypoxia-inducible factor-responsive-elements (HRE). By deletion of one of the two HREs, hypoxia-induced promoter activation was abrogated. Furthermore, hypoxia upregulated the expression of HIF-1α and HIF-2α, and both contributed to SK-1 gene transcription as shown by selective depletion of HIF-1α or HIF-2α by siRNA. The hypoxia-stimulated SK-1 upregulation was functionally coupled to increased migration since the selective depletion of SK-1, but not of SK-2, by siRNAs abolished the migratory response. In summary, these data show that hypoxia upregulates SK-1 activity and results in an accelerated migratory capacity of endothelial cells. SK-1 may thus serve as an attractive therapeutic target to treat diseases associated with increased endothelial migration and angiogenesis such as cancer growth and progression

  7. The role of hypoxia-inducible factor-2 in digestive system cancers.

    Science.gov (United States)

    Zhao, J; Du, F; Shen, G; Zheng, F; Xu, B

    2015-01-15

    Hypoxia is an all but ubiquitous phenomenon in cancers. Two known hypoxia-inducible factors (HIFs), HIF-1α and HIF-2α, primarily mediate the transcriptional response to hypoxia. Despite the high homology between HIF-1α and HIF-2α, emerging evidence suggests differences between both molecules in terms of transcriptional targets as well as impact on multiple physiological pathways and tumorigenesis. To date, much progress has been made toward understanding the roles of HIF-2α in digestive system cancers. Indeed, HIF-2α has been shown to regulate multiple aspects of digestive system cancers, including cell proliferation, angiogenesis and apoptosis, metabolism, metastasis and resistance to chemotherapy. These findings make HIF-2α a critical regulator of this malignant phenotype. Here we summarize the function of HIF-2 during cancer development as well as its contribution to tumorigenesis in digestive system malignancies.

  8. [Markers of angiogenesis in tumor growth].

    Science.gov (United States)

    Nefedova, N A; Kharlova, O A; Danilova, N V; Malkov, P G; Gaifullin, N M

    2016-01-01

    Angiogenesis is a process of new blood vessels formation. The role of angiogenesis in growth, invasion and metastasis of malignant tumours is nowdays universally recognized. Though, investigation of mechanisms of blood vessels formation and elaboration methods for assessment of tumour angiogenesis are still up-dated. Another important concern are different aspects of usage of immunohistochemical markers of blood vessels endothelium (CD31 and CD34) for assessment of tumour aggressiveness and prognosis. The problems of malignant lymphangiogenesis are also up-to-date. The focus is on methods of immunohistochemical visualization of forming lymphatic vessels, role of podoplanin, the most reliable marker of lymphatic vessels, in their identification, and formulization of the main criteria for lymphangiogenesis estimation, its correlation with metastatic activity and prognostic potential. Studying of angiogenesis and lymph angiogenesis in malignant tumors is important and challenging direction for researching tumour progression and invention of antiangiogenic therapy.

  9. Pathophysiological response to hypoxia - from the molecular mechanisms of malady to drug discovery: epigenetic regulation of the hypoxic response via hypoxia-inducible factor and histone modifying enzymes.

    Science.gov (United States)

    Mimura, Imari; Tanaka, Tetsuhiro; Wada, Youichiro; Kodama, Tatsuhiko; Nangaku, Masaomi

    2011-01-01

    The hypoxia response regulated primarily by hypoxia-inducible factor (HIF) influences metabolism, cell survival, and angiogenesis to maintain biological homeostasis. In addition to the traditional transcriptional regulation by HIF, recent studies have shown that epigenetic modulation such as histone methylation, acetylation, and DNA methylation could change the regulation of the response to hypoxia. Eukaryotic chromatin is known to be modified by multiple post-translational histone methylation and demethylation, which result in the chromatin conformation change to adapt to hypoxic stimuli. Interestingly, some of the histone demethylase enzymes, which have the Jumonji domain-containing family, require oxygen to function and are induced by hypoxia in an HIF-1-dependent manner. Recent studies have demonstrated that histone modifiers play important roles in the hypoxic environment such as that in cancer cells and that they may become new therapeutic targets for cancer patients. It may lead to finding a new therapy for cancer to clarify a new epigenetic mechanism by HIF and histone demethylase such as JMJD1A (KDM3A) under hypoxia.

  10. Differential expression of IL-6/IL-6R and MAO-A regulates invasion/angiogenesis in breast cancer.

    Science.gov (United States)

    Bharti, Rashmi; Dey, Goutam; Das, Anjan Kumar; Mandal, Mahitosh

    2018-04-26

    Monoamine oxidases (MAO) are mitochondrial enzymes functioning in oxidative metabolism of monoamines. The action of MAO-A has been typically described in neuro-pharmacological domains. Here, we have established a co-relation between IL-6/IL-6R and MAO-A and their regulation in hypoxia induced invasion/angiogenesis. We employed various in-vitro and in-vivo techniques and clinical samples. We studied a co-relation among MAO-A and IL-6/IL-6R and tumour angiogenesis/invasion in hypoxic environment in breast cancer model. Activation of IL-6/IL-6R and its downstream was found in hypoxic cancer cells. This elevation of IL-6/IL-6R caused sustained inhibition of MAO-A in hypoxic environment. Inhibition of IL-6R signalling or IL-6R siRNA increased MAO-A activity and inhibited tumour angiogenesis and invasion significantly in different models. Further, elevation of MAO-A with 5-azacytidine (5-Aza) modulated IL-6 mediated angiogenesis and invasive signatures including VEGF, MMPs and EMT in hypoxic breast cancer. High grade invasive ductal carcinoma (IDC) clinical specimen displayed elevated level of IL-6R and depleted MAO-A expression. Expression of VEGF and HIF-1α was unregulated and loss of E-Cadherin was observed in high grade IDC tissue specimen. Suppression of MAO-A by IL-6/IL-6R activation promotes tumour angiogenesis and invasion in hypoxic breast cancer environment.

  11. The tyrosine phosphatase SHP-1 regulates hypoxia inducible factor-1α (HIF-1α protein levels in endothelial cells under hypoxia.

    Directory of Open Access Journals (Sweden)

    Stefan K Alig

    Full Text Available The tyrosine phosphatase SHP-1 negatively influences endothelial function, such as VEGF signaling and reactive oxygen species (ROS formation, and has been shown to influence angiogenesis during tissue ischemia. In ischemic tissues, hypoxia induced angiogenesis is crucial for restoring oxygen supply. However, the exact mechanism how SHP-1 affects endothelial function during ischemia or hypoxia remains unclear. We performed in vitro endothelial cell culture experiments to characterize the role of SHP-1 during hypoxia.SHP-1 knock-down by specific antisense oligodesoxynucleotides (AS-Odn increased cell growth as well as VEGF synthesis and secretion during 24 hours of hypoxia compared to control AS-Odn. This was prevented by HIF-1α inhibition (echinomycin and apigenin. SHP-1 knock-down as well as overexpression of a catalytically inactive SHP-1 (SHP-1 CS further enhanced HIF-1α protein levels, whereas overexpression of a constitutively active SHP-1 (SHP-1 E74A resulted in decreased HIF-1α levels during hypoxia, compared to wildtype SHP-1. Proteasome inhibition (MG132 returned HIF-1α levels to control or wildtype levels respectively in these cells. SHP-1 silencing did not alter HIF-1α mRNA levels. Finally, under hypoxic conditions SHP-1 knock-down enhanced intracellular endothelial reactive oxygen species (ROS formation, as measured by oxidation of H2-DCF and DHE fluorescence.SHP-1 decreases half-life of HIF-1α under hypoxic conditions resulting in decreased cell growth due to diminished VEGF synthesis and secretion. The regulatory effect of SHP-1 on HIF-1α stability may be mediated by inhibition of endothelial ROS formation stabilizing HIF-1α protein. These findings highlight the importance of SHP-1 in hypoxic signaling and its potential as therapeutic target in ischemic diseases.

  12. Hypoxia upregulates Bcl-2 expression and suppresses interferon-gamma induced antiangiogenic activity in human tumor derived endothelial cells.

    LENUS (Irish Health Repository)

    Wang, Jiang Huai

    2012-02-03

    BACKGROUND: Hypoxia in solid tumors potentially stimulates angiogenesis by promoting vascular endothelial growth factor (VEGF) production and upregulating VEGF receptor expression. However, it is unknown whether hypoxia can modulate the effect of anti-angiogenic treatment on tumor-derived endothelium. METHODS: Human tumor-derived endothelial cells (HTDEC) were freshly isolated from surgically removed human colorectal tumors by collagenase\\/DNase digestion and Percol gradient sedimentation. Cell proliferation was assessed by measuring BrdU incorporation, and capillary tube formation was measured using Matrigel. Cell apoptosis was assessed by flow cytometry and ELISA, and Bcl-2 expression was detected by Western blot analysis. RESULTS: Under aerobic culture conditions (5% CO2 plus 21% O2) HTDEC expressed less Bcl-2 and were more susceptible to IFN-gamma-induced apoptosis with significant reductions in both cell proliferation and capillary tube formation, when compared with normal human macrovascular and microvascular EC. Following exposure of HTDEC to hypoxia (5% CO2 plus 2% O2), IFN-gamma-induced cell apoptosis, and antiangiogenic activity (i.e. an inhibition in cell proliferation and capillary tube formation) in HTDEC were markedly attenuated. This finding correlated with hypoxia-induced upregulation of Bcl-2 expression in HTDEC. CONCLUSIONS: These results indicate that hypoxia can protect HTDEC against IFN-gamma-mediated cell death and antiangiogenic activity, and suggest that improvement of tumor oxygenation may potentiate the efficacy of anti-cancer therapies specifically targeting the inhibition of tumor angiogenesis.

  13. Inositol Polyphosphate Multikinase Inhibits Angiogenesis via Inositol Pentakisphosphate-Induced HIF-1α Degradation.

    Science.gov (United States)

    Fu, Chenglai; Tyagi, Richa; Chin, Alfred C; Rojas, Tomas; Li, Ruo-Jing; Guha, Prasun; Bernstein, Isaac A; Rao, Feng; Xu, Risheng; Cha, Jiyoung Y; Xu, Jing; Snowman, Adele M; Semenza, Gregg L; Snyder, Solomon H

    2018-02-02

    Inositol polyphosphate multikinase (IPMK) and its major product inositol pentakisphosphate (IP5) regulate a variety of cellular functions, but their role in vascular biology remains unexplored. We have investigated the role of IPMK in regulating angiogenesis. Deletion of IPMK in fibroblasts induces angiogenesis in both in vitro and in vivo models. IPMK deletion elicits a substantial increase of VEGF (vascular endothelial growth factor), which mediates the regulation of angiogenesis by IPMK. The regulation of VEGF by IPMK requires its catalytic activity. IPMK is predominantly nuclear and regulates gene transcription. However, IPMK does not apparently serve as a transcription factor for VEGF. HIF (hypoxia-inducible factor)-1α is a major determinant of angiogenesis and induces VEGF transcription. IPMK deletion elicits a major enrichment of HIF-1α protein and thus VEGF. HIF-1α is constitutively ubiquitinated by pVHL (von Hippel-Lindau protein) followed by proteasomal degradation under normal conditions. However, HIF-1α is not recognized and ubiquitinated by pVHL in IPMK KO (knockout) cells. IP5 reinstates the interaction of HIF-1α and pVHL. HIF-1α prolyl hydroxylation, which is prerequisite for pVHL recognition, is interrupted in IPMK-deleted cells. IP5 promotes HIF-1α prolyl hydroxylation and thus pVHL-dependent degradation of HIF-1α. Deletion of IPMK in mouse brain increases HIF-1α/VEGF levels and vascularization. The increased VEGF in IPMK KO disrupts blood-brain barrier and enhances brain blood vessel permeability. IPMK, via its product IP5, negatively regulates angiogenesis by inhibiting VEGF expression. IP5 acts by enhancing HIF-1α hydroxylation and thus pVHL-dependent degradation of HIF-1α. © 2017 American Heart Association, Inc.

  14. Epigenetic control of hypoxia inducible factor-1α-dependent expression of placental growth factor in hypoxic conditions.

    Science.gov (United States)

    Tudisco, Laura; Della Ragione, Floriana; Tarallo, Valeria; Apicella, Ivana; D'Esposito, Maurizio; Matarazzo, Maria Rosaria; De Falco, Sandro

    2014-04-01

    Hypoxia plays a crucial role in the angiogenic switch, modulating a large set of genes mainly through the activation of hypoxia-inducible factor (HIF) transcriptional complex. Endothelial cells play a central role in new vessels formation and express placental growth factor (PlGF), a member of vascular endothelial growth factor (VEGF) family, mainly involved in pathological angiogenesis. Despite several observations suggest a hypoxia-mediated positive modulation of PlGF, the molecular mechanism governing this regulation has not been fully elucidated. We decided to investigate if epigenetic modifications are involved in hypoxia-induced PlGF expression. We report that PlGF expression was induced in cultured human and mouse endothelial cells exposed to hypoxia (1% O 2), although DNA methylation at the Plgf CpG-island remains unchanged. Remarkably, robust hyperacetylation of histones H3 and H4 was observed in the second intron of Plgf, where hypoxia responsive elements (HREs), never described before, are located. HIF-1α, but not HIF-2α, binds to identified HREs. Noteworthy, only HIF-1α silencing fully inhibited PlGF upregulation. These results formally demonstrate a direct involvement of HIF-1α in the upregulation of PlGF expression in hypoxia through chromatin remodeling of HREs sites. Therefore, PlGF may be considered one of the putative targets of anti-HIF therapeutic applications.

  15. The expanding universe of hypoxia.

    Science.gov (United States)

    Zhang, Huafeng; Semenza, Gregg L

    2008-07-01

    Reduced oxygen availability (hypoxia) is sensed and transduced into changes in the activity or expression of cellular macromolecules. These responses impact on virtually all areas of biology and medicine. In this meeting report, we summarize major developments in the field that were presented at the 2008 Keystone Symposium on Cellular, Physiological, and Pathogenic Responses to Hypoxia.

  16. Approaches to improve angiogenesis in tissue-engineered skin.

    Science.gov (United States)

    Sahota, Parbinder S; Burn, J Lance; Brown, Nicola J; MacNeil, Sheila

    2004-01-01

    A problem with tissue-engineered skin is clinical failure due to delays in vascularization. The aim of this study was to explore a number of simple strategies to improve angiogenesis/vascularization using a tissue-engineered model of skin to which small vessel human dermal microvascular endothelial cells were added. For the majority of these studies, a modified Guirguis chamber was used, which allowed the investigation of several variables within the same experiment using the same human dermis; cell type, angiogenic growth factors, the influence of keratinocytes and fibroblasts, mechanical penetration of the human dermis, the site of endothelial cell addition, and the influence of hypoxia were all examined. A qualitative scoring system was used to assess the impact of these factors on the penetration of endothelial cells throughout the dermis. Similar results were achieved using freshly isolated small vessel human dermal microvascular endothelial cells or an endothelial cell line and a minimum cell seeding density was identified. Cell penetration was not influenced by the addition of angiogenic growth factors (vascular endothelial growth factor and basic fibroblast growth factor); similarly, including epidermal keratinocytes or dermal fibroblasts did not encourage endothelial cell entry, and neither did mechanical introduction of holes throughout the dermis. Two factors were identified that significantly enhanced endothelial cell penetration into the dermis: hypoxia and the site of endothelial cell addition. Endothelial cells added from the papillary surface entered into the dermis much more effectively than when cells were added to the reticular surface of the dermis. We conclude that this model is valuable in improving our understanding of how to enhance vascularization of tissue-engineered grafts.

  17. Decidualized Human Endometrial Stromal Cells Mediate Hemostasis, Angiogenesis, and Abnormal Uterine Bleeding

    Science.gov (United States)

    Lockwood, Charles J.; Krikun, Graciela; Hickey, Martha; Huang, S. Joseph; Schatz, Frederick

    2011-01-01

    Factor VII binds trans-membrane tissue factor to initiate hemostasis by forming thrombin. Tissue factor expression is enhanced in decidualized human endometrial stromal cells during the luteal phase. Long-term progestin only contraceptives elicit: 1) abnormal uterine bleeding from fragile vessels at focal bleeding sites, 2) paradoxically high tissue factor expression at bleeding sites; 3) reduced endometrial blood flow promoting local hypoxia and enhancing reactive oxygen species levels; and 4) aberrant angiogenesis reflecting increased stromal cell-expressed vascular endothelial growth factor, decreased Angiopoietin-1 and increased endothelial cell-expressed Angiopoietin-2. Aberrantly high local vascular permeability enhances circulating factor VII to decidualized stromal cell-expressed tissue factor to generate excess thrombin. Hypoxia-thrombin interactions augment expression of vascular endothelial growth factor and interleukin-8 by stromal cells. Thrombin, vascular endothelial growth factor and interlerukin-8 synergis-tically augment angiogenesis in a milieu of reactive oxygen species-induced endothelial cell activation. The resulting enhanced vessel fragility promotes abnormal uterine bleeding. PMID:19208784

  18. Advances and challenges in skeletal muscle angiogenesis

    DEFF Research Database (Denmark)

    Olfert, I Mark; Baum, Oliver; Hellsten, Ylva

    2016-01-01

    The role of capillaries is to serve as the interface for delivery of oxygen and removal of metabolites to/from tissues. During the past decade there has been a proliferation of studies that have advanced our understanding of angiogenesis demonstrating tissue capillary supply is under strict control...... rearrangement of capillaries) that identify areas of future research with the greatest potential to expand our understanding of how angiogenesis is normally regulated, and that may also help to better understand conditions of uncontrolled (pathologic) angiogenesis....

  19. Mechanical and Chemical Signaling in Angiogenesis

    CERN Document Server

    2013-01-01

    This volume of Studies in Mechanobiology, Tissue Engineering and Biomaterials describes the most recent advances in angiogenesis research at all biological length scales: molecular, cellular and tissue, in both in vivo and in vitro settings.  Angiogenesis experts from diverse fields including engineering, cell and developmental biology, and chemistry have contributed chapters which focus on the mechanical and chemical signals which affect and promote blood vessel growth. Specific emphasis is given to novel methodologies and biomaterials that have been developed and applied to angiogenesis research. 

  20. Cancer gene therapy targeting angiogenesis: An updated Review

    Science.gov (United States)

    Liu, Ching-Chiu; Shen, Zan; Kung, Hsiang-Fu; Lin, Marie CM

    2006-01-01

    Since the relationship between angiogenesis and tumor growth was established by Folkman in 1971, scientists have made efforts exploring the possibilities in treating cancer by targeting angiogenesis. Inhibition of angiogenesis growth factors and administration of angiogenesis inhibitors are the basics of anti-angiogenesis therapy. Transfer of anti-angiogenesis genes has received attention recently not only because of the advancement of recombinant vectors, but also because of the localized and sustained expression of therapeutic gene product inside the tumor after gene transfer. This review provides the up-to-date information about the strategies and the vectors studied in the field of anti-angiogenesis cancer gene therapy. PMID:17109514

  1. Galectins in angiogenesis: consequences for gestation.

    Science.gov (United States)

    Blois, Sandra M; Conrad, Melanie L; Freitag, Nancy; Barrientos, Gabriela

    2015-04-01

    Members of the galectin family have been shown to exert several roles in the context of reproduction. They contribute to placentation, maternal immune regulation and facilitate angiogenesis encompassing decidualisation and placenta formation during pregnancy. In the context of neo-vascularisation, galectins have been shown to augment signalling pathways that lead to endothelial cell activation, cell proliferation, migration and tube formation in vitro in addition to angiogenesis in vivo. Angiogenesis during gestation ensures not only proper foetal growth and development, but also maternal health. Consequently, restriction of placental blood flow has major consequences for both foetus and mother, leading to pregnancy diseases. In this review we summarise both the established and the emerging roles of galectin in angiogenesis and discuss the possible implications during healthy and pathological gestation. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  2. Applying nanomedicine in maladaptive inflammation and angiogenesis

    NARCIS (Netherlands)

    Alaarg, Amr; Pérez-Medina, Carlos; Metselaar, Josbert M.; Nahrendorf, Matthias; Fayad, Zahi A.; Storm, Gert; Mulder, Willem J. M.

    2017-01-01

    Inflammation and angiogenesis drive the development and progression of multiple devastating diseases such as atherosclerosis, cancer, rheumatoid arthritis, and inflammatory bowel disease. Though these diseases have very different phenotypic consequences, they possess several common

  3. HIF-2α Expression Regulates Sprout Formation into 3D Fibrin Matrices in Prolonged Hypoxia in Human Microvascular Endothelial Cells.

    Science.gov (United States)

    Nauta, Tessa D; Duyndam, Monique C A; Weijers, Ester M; van Hinsbergh, Victor M W; Koolwijk, Pieter

    2016-01-01

    During short-term hypoxia, Hypoxia Inducible Factors (particular their subunits HIF-1α and HIF-2α) regulate the expression of many genes including the potent angiogenesis stimulator VEGF. However, in some pathological conditions chronic hypoxia occurs and is accompanied by reduced angiogenesis. We investigated the effect of prolonged hypoxia on the proliferation and sprouting ability of human microvascular endothelial cells and the involvement of the HIFs and Dll4/Notch signaling. Human microvascular endothelial cells (hMVECs), cultured at 20% oxygen for 14 days and seeded on top of 3D fibrin matrices, formed sprouts when stimulated with VEGF-A/TNFα. In contrast, hMVECs precultured at 1% oxygen for 14 days were viable and proliferative, but did not form sprouts into fibrin upon VEGF-A/TNFα stimulation at 1% oxygen. Silencing of HIF-2α with si-RNA partially restored the inhibition of endothelial sprouting, whereas HIF-1α or HIF-3α by si-RNA had no effect. No involvement of Dll4/Notch pathway in the inhibitory effect on endothelial sprouting by prolonged hypoxia was found. In addition, hypoxia decreased the production of urokinase-type plasminogen activator (uPA), needed for migration and invasion, without a significant effect on its inhibitor PAI-1. This was independent of HIF-2α, as si-HIF-2α did not counteract uPA reduction. Prolonged culturing of hMVECs at 1% oxygen inhibited endothelial sprouting into fibrin. Two independent mechanisms contribute. Silencing of HIF-2α with si-RNA partially restored the inhibition of endothelial sprouting pointing to a HIF-2α-dependent mechanism. In addition, reduction of uPA contributed to reduced endothelial tube formation in a fibrin matrix during prolonged hypoxia.

  4. Diacetoxyscirpenol as a new anticancer agent to target hypoxia-inducible factor 1

    Science.gov (United States)

    Choi, Yong-Joon; Shin, Hyun-Woo; Chun, Yang-Sook; Leutou, Alain Simplice; Son, Byeng Wha; Park, Jong-Wan

    2016-01-01

    Hypoxia activates hypoxia-inducible factor 1, which promotes the progression of malignancy by stimulating angiogenesis and by augmenting the ability of tumors to survive. Thus, HIF-1 is one of the most compelling targets for treating cancers. The aim of this study was to find a small molecule that inhibits HIF-1 under hypoxia in cancer cells. 7,280 compounds in a chemical library were tested in a cancer cell line expressing luciferase HIF-dependently. Through three rounds of screening, we finally picked up a compound that originates from a marine bacterium parasitizing red alga. The antibiotic potently inhibited HIF-1 expression and its transcriptional activity in cancer cells exposed to hypoxia. Through two-step fractionation, diacetoxyscirpenol was purified and identified as a HIF-inhibiting ingredient. Mechanistically, diacetoxyscirpenol inhibits the synthesis of HIF-1α protein and also interferes with the dimerization of HIF-1α and ARNT. It attenuates HIF-mediated gene expression in cancer cells exposed to hypoxia, and by doing so reduces tumorigenic and angiogenic potentials of cancer cells. More importantly, diacetoxyscirpenol retarded tumor growth in mice, and reduced HIF-1α expression and vascular formation in the tumors. Overall, diacetoxyscirpenol is considered a potential drug deregulating the HIF-1 signaling pathway, and it could be beneficially employed for treating malignant tumors with hypoxic microenvironment. PMID:27613833

  5. How to increase and renew the oil and gas reserves? Technology advances and research strategy of IFP; Comment accroitre et renouveler les reserves de petrole et de gaz? Avancees de la technologie et strategie de recherche de l'IFP

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2005-07-01

    Technology progresses made to reach new oil and gas resources (heavy crudes, buried deposits, ultra-deep offshore), to better exploit the available reserves (increase of the recovery ratio) and to reduce the costs will allow to enhance the hydrocarbon reserves and to durably extend the limits of the world energy supply. In a context where geopolitical uncertainties, high price rates and pessimistic declarations increase once again the public fear about petroleum reserves, the French institute of petroleum (IFP) wanted to make a status about the essential role that technology can play in this challenge. This document gathers the transparencies and articles presented at this press conference: how to increase and renew oil and gas reserves, technology advances and research strategy of IFP (O. Appert, J. Lecourtier, G. Fries); how to enhance oil recovery from deposits (primary, secondary and tertiary recovery: polymers injection, CO{sub 2} injection, steam injection, in-situ oxidation and combustion, reservoir modeling, monitoring of uncertainties); the heavy crudes (the Orenoque extra-heavy oil, the tar sands of Alberta, the heavy and extra-heavy crudes of Canada, IFP's research); ultra-deep offshore (the weight challenge: mooring lines and risers, the temperature challenge: paraffins and hydrates deposition, immersion of the treatment unit: economical profitability of satellite fields); fields buried beyond 5000 m (technological challenges: seismic surveys, drilling equipment, well logging, drilling mud; prospects of these fields); oil reserves: data that change with technique and economy (proven, probable and possible reserves, proven and declared reserves, three converging evaluations about the world proven reserves, reserves to be discovered, non-conventional petroleum resources, technical progress and oil prices, production depletion at the end of the century). (J.S.)

  6. miR-181a Targets RGS16 to Promote Chondrosarcoma Growth, Angiogenesis, and Metastasis.

    Science.gov (United States)

    Sun, Xiaojuan; Charbonneau, Cherie; Wei, Lei; Chen, Qian; Terek, Richard M

    2015-09-01

    Chondrosarcoma is the most common primary malignant bone tumor in adults, has no effective systemic treatment, and patients with this disease have poor survival. Altered expression of microRNA (miR) is involved in tumorigenesis; however, its role in chondrosarcoma is undetermined. miR-181a is overexpressed in high-grade chondrosarcoma, is upregulated by hypoxia, and increases VEGF expression. Here, the purpose was to determine the mechanism of miR-181a regulation of VEGF, determine whether miR-181a overexpression promotes tumor progression, and to evaluate an antagomir-based approach for chondrosarcoma treatment. Therapeutic inhibition of miR-181a decreased expression of VEGF and MMP1 in vitro, and angiogenesis, MMP1 activity, tumor growth, and lung metastasis, all by more than 50%, in a xenograft mouse model. A target of miR-181a is a regulator of G-protein signaling 16 (RGS16), a negative regulator of CXC chemokine receptor 4 (CXCR4) signaling. CXCR4 signaling is increased in chondrosarcoma, its expression is also increased by hypoxia, and is associated with angiogenesis and metastasis; however, receptor blockade is only partially effective. RGS16 expression is restored after miR-181a inhibition and partially accounts for the antiangiogenic and antimetastatic effects of miR-181a inhibition. These data establish miR-181a as an oncomiR that promotes chondrosarcoma progression through a new mechanism involving enhancement of CXCR4 signaling by inhibition of RGS16. Targeting miR-181a can inhibit tumor angiogenesis, growth, and metastasis, thus suggesting the possibility of antagomir-based therapy in chondrosarcoma. ©2015 American Association for Cancer Research.

  7. Cannabidiol inhibits angiogenesis by multiple mechanisms.

    Science.gov (United States)

    Solinas, M; Massi, P; Cantelmo, A R; Cattaneo, M G; Cammarota, R; Bartolini, D; Cinquina, V; Valenti, M; Vicentini, L M; Noonan, D M; Albini, A; Parolaro, D

    2012-11-01

    Several studies have demonstrated anti-proliferative and pro-apoptotic actions of cannabinoids on various tumours, together with their anti-angiogenic properties. The non-psychoactive cannabinoid cannabidiol (CBD) effectively inhibits the growth of different types of tumours in vitro and in vivo and down-regulates some pro-angiogenic signals produced by glioma cells. As its anti-angiogenic properties have not been thoroughly investigated to date, and given its very favourable pharmacological and toxicological profile, here, we evaluated the ability of CBD to modulate tumour angiogenesis. Firstly, we evaluated the effect of CBD on human umbilical vein endothelial cell (HUVEC) proliferation and viability - through [3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide] assay and FACS analysis - and in vitro motility - both in a classical Boyden chamber test and in a wound-healing assay. We next investigated CBD effects on different angiogenesis-related proteins released by HUVECs, using an angiogenesis array kit and an ELISA directed at MMP2. Then we evaluated its effects on in vitro angiogenesis in treated HUVECs invading a Matrigel layer and in HUVEC spheroids embedded into collagen gels, and further characterized its effects in vivo using a Matrigel sponge model of angiogenesis in C57/BL6 mice. CBD induced HUVEC cytostasis without inducing apoptosis, inhibited HUVEC migration, invasion and sprouting in vitro, and angiogenesis in vivo in Matrigel sponges. These effects were associated with the down-modulation of several angiogenesis-related molecules. This study reveals that CBD inhibits angiogenesis by multiple mechanisms. Its dual effect on both tumour and endothelial cells supports the hypothesis that CBD has potential as an effective agent in cancer therapy. © 2012 The Authors. British Journal of Pharmacology © 2012 The British Pharmacological Society.

  8. Synthesis of the objectives contract 2006-2010 between the State and the IFP. Innovate for a controlled energy transition; Synthese du contrat d'objectifs 2006-2010 entre l'Etat et l'IFP. Innover pour une transition energetique maitrisee

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-07-01

    The IFP, French Institute of Petroleum, is a public organization of research and formation at the service of the energy, the transport and the environment. It assures the technology transfer between fundamental research, applied research and the industrial development. The contract for 2006-2010 presents three major structural evolutions: the increase development of the new technologies of the energy; a new equilibrium in favor of the downstream researches and more particularly the transports, the increase of the industry competitiveness in the hydrocarbons sector and the automobiles. (A.L.B.)

  9. Coastal hypoxia and sediment biogeochemistry

    Directory of Open Access Journals (Sweden)

    J. J. Middelburg

    2009-07-01

    Full Text Available The intensity, duration and frequency of coastal hypoxia (oxygen concentration <63 μM are increasing due to human alteration of coastal ecosystems and changes in oceanographic conditions due to global warming. Here we provide a concise review of the consequences of coastal hypoxia for sediment biogeochemistry. Changes in bottom-water oxygen levels have consequences for early diagenetic pathways (more anaerobic at expense of aerobic pathways, the efficiency of re-oxidation of reduced metabolites and the nature, direction and magnitude of sediment-water exchange fluxes. Hypoxia may also lead to more organic matter accumulation and burial and the organic matter eventually buried is also of higher quality, i.e. less degraded. Bottom-water oxygen levels also affect the organisms involved in organic matter processing with the contribution of metazoans decreasing as oxygen levels drop. Hypoxia has a significant effect on benthic animals with the consequences that ecosystem functions related to macrofauna such as bio-irrigation and bioturbation are significantly affected by hypoxia as well. Since many microbes and microbial-mediated biogeochemical processes depend on animal-induced transport processes (e.g. re-oxidation of particulate reduced sulphur and denitrification, there are indirect hypoxia effects on biogeochemistry via the benthos. Severe long-lasting hypoxia and anoxia may result in the accumulation of reduced compounds in sediments and elimination of macrobenthic communities with the consequences that biogeochemical properties during trajectories of decreasing and increasing oxygen may be different (hysteresis with consequences for coastal ecosystem dynamics.

  10. Hypoxia and hydrogen sulfide differentially affect normal and tumor-derived vascular endothelium

    Directory of Open Access Journals (Sweden)

    Serena Bianco

    2017-08-01

    Full Text Available Background: endothelial cells play a key role in vessels formation both under physiological and pathological conditions. Their behavior is influenced by blood components including gasotransmitters (H2S, NO and CO. Tumor cells are subjected to a cyclic shift between pro-oxidative and hypoxic state and, in this scenario, H2S can be both cytoprotective and detrimental depending on its concentration. H2S effects on tumors onset and development is scarcely studied, particularly concerning tumor angiogenesis. We previously demonstrated that H2S is proangiogenic for tumoral but not for normal endothelium and this may represent a target for antiangiogenic therapeutical strategies. Methods: in this work, we investigate cell viability, migration and tubulogenesis on human EC derived from two different tumors, breast and renal carcinoma (BTEC and RTEC, compared to normal microvascular endothelium (HMEC under oxidative stress, hypoxia and treatment with exogenous H2S. Results: all EC types are similarly sensitive to oxidative stress induced by hydrogen peroxide; chemical hypoxia differentially affects endothelial viability, that results unaltered by real hypoxia. H2S neither affects cell viability nor prevents hypoxia and H2O2-induced damage. Endothelial migration is enhanced by hypoxia, while tubulogenesis is inhibited for all EC types. H2S acts differentially on EC migration and tubulogenesis. Conclusions: these data provide evidence for a great variability of normal and altered endothelium in response to the environmental conditions. Keywords: Hydrogen sulfide, Human microvascular endothelial cells, Human breast carcinoma-derived EC, Human renal carcinoma-derived EC, Tumor angiogenesis

  11. Peptidyl Prolyl Isomerase PIN1 Directly Binds to and Stabilizes Hypoxia-Inducible Factor-1α.

    Directory of Open Access Journals (Sweden)

    Hyeong-Jun Han

    Full Text Available Peptidyl prolyl isomerase (PIN1 regulates the functional activity of a subset of phosphoproteins through binding to phosphorylated Ser/Thr-Pro motifs and subsequently isomerization of the phosphorylated bonds. Interestingly, PIN1 is overexpressed in many types of malignancies including breast, prostate, lung and colon cancers. However, its oncogenic functions have not been fully elucidated. Here, we report that PIN1 directly interacts with hypoxia-inducible factor (HIF-1α in human colon cancer (HCT116 cells. PIN1 binding to HIF-1α occurred in a phosphorylation-dependent manner. We also found that PIN1 interacted with HIF-1α at both exogenous and endogenous levels. Notably, PIN1 binding stabilized the HIF-1α protein, given that their levels were significantly increased under hypoxic conditions. The stabilization of HIF-1α resulted in increased transcriptional activity, consequently upregulating expression of vascular endothelial growth factor, a major contributor to angiogenesis. Silencing of PIN1 or pharmacologic inhibition of its activity abrogated the angiogenesis. By utilizing a bioluminescence imaging technique, we were able to demonstrate that PIN1 inhibition dramatically reduced the tumor volume in a subcutaneous mouse xenograft model and angiogenesis as well as hypoxia-induced transcriptional activity of HIF-1α. These results suggest that PIN1 interacting with HIF-1α is a potential cancer chemopreventive and therapeutic target.

  12. Inhibitory PAS domain protein is a negative regulator of hypoxia-inducible gene expression

    Science.gov (United States)

    Makino, Yuichi; Cao, Renhai; Svensson, Kristian; Bertilsson, Göran; Asman, Mikael; Tanaka, Hirotoshi; Cao, Yihai; Berkenstam, Anders; Poellinger, Lorenz

    2001-11-01

    Alteration of gene expression is a crucial component of adaptive responses to hypoxia. These responses are mediated by hypoxia-inducible transcription factors (HIFs). Here we describe an inhibitory PAS (Per/Arnt/Sim) domain protein, IPAS, which is a basic helix-loop-helix (bHLH)/PAS protein structurally related to HIFs. IPAS contains no endogenous transactivation function but demonstrates dominant negative regulation of HIF-mediated control of gene expression. Ectopic expression of IPAS in hepatoma cells selectively impairs induction of genes involved in adaptation to a hypoxic environment, notably the vascular endothelial growth factor (VEGF) gene, and results in retarded tumour growth and tumour vascular density in vivo. In mice, IPAS was predominantly expressed in Purkinje cells of the cerebellum and in corneal epithelium of the eye. Expression of IPAS in the cornea correlates with low levels of expression of the VEGF gene under hypoxic conditions. Application of an IPAS antisense oligonucleotide to the mouse cornea induced angiogenesis under normal oxygen conditions, and demonstrated hypoxia-dependent induction of VEGF gene expression in hypoxic corneal cells. These results indicate a previously unknown mechanism for negative regulation of angiogenesis and maintenance of an avascular phenotype.

  13. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    International Nuclear Information System (INIS)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica; Gonzalez Espinosa, Claudia

    2010-01-01

    Research highlights: → Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. → CoCl 2 -induced VEGF secretion in mast cells occurs by a Ca 2+ -insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. → Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits FcεRI-dependent anaphylactic degranulation in mast cells. → Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl 2 ) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl 2 promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl 2 -induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl 2 -induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl 2 in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals-dependent Fyn kinase activation.

  14. Hypoxia modulates the differentiation potential of stem cells of the apical papilla.

    Science.gov (United States)

    Vanacker, Julie; Viswanath, Aiswarya; De Berdt, Pauline; Everard, Amandine; Cani, Patrice D; Bouzin, Caroline; Feron, Olivier; Diogenes, Anibal; Leprince, Julian G; des Rieux, Anne

    2014-09-01

    Stem cells from the apical papilla (SCAP) are a population of mesenchymal stem cells likely involved in regenerative endodontic procedures and have potential use as therapeutic agents in other tissues. In these situations, SCAP are exposed to hypoxic conditions either within a root canal devoid of an adequate blood supply or in a scaffold material immediately after implantation. However, the effect of hypoxia on SCAP proliferation and differentiation is largely unknown. Therefore, the objective of this study was to evaluate the effect of hypoxia on the fate of SCAP. SCAP were cultured under normoxia (21% O2) or hypoxia (1% O2) in basal or differentiation media. Cellular proliferation, gene expression, differentiation, and protein secretion were analyzed by live imaging, quantitative reverse-transcriptase polymerase chain reaction, cellular staining, and enzyme-linked immunosorbent assay, respectively. Hypoxia had no effect on SCAP proliferation, but it evoked the up-regulation of genes specific for osteogenic differentiation (runt-related transcription factor 2, alkaline phosphatase, and transforming growth factor-β1), neuronal differentiation ( 2'-3'-cyclic nucleotide 3' phosphodiesterase, SNAIL, neuronspecific enolase, glial cell-derived neurotrophic factor and neurotrophin 3), and angiogenesis (vascular endothelial growth factor A and B). Hypoxia also increased the sustained production of VEGFa by SCAP. Moreover, hypoxia augmented the neuronal differentiation of SCAP in the presence of differentiation exogenous factors as detected by the up-regulation of NSE, VEGFB, and GDNF and the expression of neuronal markers (PanF and NeuN). This study shows that hypoxia induces spontaneous differentiation of SCAP into osteogenic and neurogenic lineages while maintaining the release of the proangiogenic factor VEGFa. This highlights the potential of SCAP to promote pulp-dentin regeneration. Moreover, SCAP may represent potential therapeutic agents for neurodegenerative

  15. VEGF secretion during hypoxia depends on free radicals-induced Fyn kinase activity in mast cells

    Energy Technology Data Exchange (ETDEWEB)

    Garcia-Roman, Jonathan; Ibarra-Sanchez, Alfredo; Lamas, Monica [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico); Gonzalez Espinosa, Claudia, E-mail: cgonzal@cinvestav.mx [Departamento de Farmacobiologia, Centro de Investigacion y de Estudios Avanzados del IPN (Cinvestav, IPN) (Mexico)

    2010-10-15

    Research highlights: {yields} Bone marrow-derived mast cells (BMMCs) secrete functional VEGF but do not degranulate after Cobalt chloride-induced hypoxia. {yields} CoCl{sub 2}-induced VEGF secretion in mast cells occurs by a Ca{sup 2+}-insensitive but brefeldin A and Tetanus toxin-sensitive mechanism. {yields} Trolox and N-acetylcysteine inhibit hypoxia-induced VEGF secretion but only Trolox inhibits Fc{epsilon}RI-dependent anaphylactic degranulation in mast cells. {yields} Src family kinase Fyn activation after free radical production is necessary for hypoxia-induced VEGF secretion in mast cells. -- Abstract: Mast cells (MC) have an important role in pathologic conditions such as asthma and chronic obstructive pulmonary disease (COPD), where hypoxia conduce to deleterious inflammatory response. MC contribute to hypoxia-induced angiogenesis producing factors such as vascular endothelial growth factor (VEGF), but the mechanisms behind the control of hypoxia-induced VEGF secretion in this cell type is poorly understood. We used the hypoxia-mimicking agent cobalt chloride (CoCl{sub 2}) to analyze VEGF secretion in murine bone marrow-derived mast cells (BMMCs). We found that CoCl{sub 2} promotes a sustained production of functional VEGF, able to induce proliferation of endothelial cells in vitro. CoCl{sub 2}-induced VEGF secretion was independent of calcium rise but dependent on tetanus toxin-sensitive vesicle-associated membrane proteins (VAMPs). VEGF exocytosis required free radicals formation and the activation of Src family kinases. Interestingly, an important deficiency on CoCl{sub 2}-induced VEGF secretion was observed in Fyn kinase-deficient BMMCs. Moreover, Fyn kinase was activated by CoCl{sub 2} in WT cells and this activation was prevented by treatment with antioxidants such as Trolox and N-acetylcysteine. Our results show that BMMCs are able to release VEGF under hypoxic conditions through a tetanus toxin-sensitive mechanism, promoted by free radicals

  16. Clinical Aspects of Hypoxia-inducible Factors in Colorectal Cancer

    DEFF Research Database (Denmark)

    Havelund, Birgitte Mayland; Spindler, Karen-Lise Garm; Sørensen, Flemming Brandt

    Clinical Aspects of Hypoxia-inducible Factors in Colorectal Cancer  Birgitte Mayland Havelund1,4 MD, Karen-Lise Garm Spindler1,4 MD, PhD, Flemming Brandt Sørensen2,4 MD, DMSc, Ivan Brandslund3 MD, DMSc, Anders Jakobsen1,4 MD, DMSc.1Department of Oncology, 2Pathology and 3Biochemistry, Vejle...... activates transcription of numerous genes associated with angiogenesis, ATP-metabolism, cell-proliferation, glycolysis and apoptosis. HIF-1α is over expressed in many malignant tumors and is reported to play an important role in tumor invasion and progression. The aim of this Ph.D. project is to investigate...... the predictive and prognostic value of HIF-1α in colorectal cancer.Materials and MethodsThe project is divided into 3 substudies:1. Biological and methodological aspects. The expression of HIF-1α measured by immunohistochemistry in paraffin embedded tissue is related to single nucleotide polymorphism (SNP...

  17. Chronic Intermittent Hypoxia Induces Atherosclerosis

    OpenAIRE

    Savransky, Vladimir; Nanayakkara, Ashika; Li, Jianguo; Bevans, Shannon; Smith, Philip L.; Rodriguez, Annabelle; Polotsky, Vsevolod Y.

    2007-01-01

    Rationale: Obstructive sleep apnea, a condition leading to chronic intermittent hypoxia (CIH), is associated with hyperlipidemia, atherosclerosis, and a high cardiovascular risk. A causal link between obstructive sleep apnea and atherosclerosis has not been established.

  18. The effects of a picosecond pulsed electric field on angiogenesis in the cervical cancer xenograft models.

    Science.gov (United States)

    Wu, Limei; Yao, Chenguo; Xiong, Zhengai; Zhang, Ruizhe; Wang, Zhiliang; Wu, Yutong; Qin, Qin; Hua, Yuanyuan

    2016-04-01

    The application of picosecond pulsed electric field (psPEF) is a new biomedical engineering technique used in cancer therapy. However, its effects on cervical cancer angiogenesis are not clear. Therefore, the aim of the present study is to investigate the effects of psPEF on angiogenesis in cervical cancer xenograft models. Xenograft tumors were created by subcutaneously inoculating nude mice (athymic BALB/c nu/nu mice) with HeLa cells, then were placed closely between tweezer-type plate electrodes and subjected to psPEF with a gradually increased electric field intensity (0kV/cm, 50kV/cm, 60kV/cm, 70kV/cm). The direct effect on tumor tissue was observed by hematoxylin and eosin (H&E) staining and transmission electron microscopy (TEM). The changes of blood vessels and oxygen saturation (sO2) of tumors were monitored in vivo by photoacoustic tomography (PAT). The microvessel density (MVD), vascular endothelial growth factor (VEGF) and hypoxia-inducible transcription factors (HIF-1α and HIF-2α) were detected by immunohistochemical technique (IHC). Their protein expressions and gene transcription levels were evaluated using western blot (WB) and quantitative reverse transcription and polymerase chain reaction (RT-PCR). PsPEF induced obvious necrosis of cervical cancer tissue; with the increasing of electric field intensity, the MVD, vascular PA signal and sO2 values declined significantly. The protein expression and gene transcription levels of VEGF, HIF1α and HIF2α were significantly decreased at the same time. PsPEF exhibited dramatic anti-tumor and anti-angiogenesis effects in cervical cancer xenograft models by exerting direct effect on cancer cells and vascular endothelial cells and indirect effect on tumor angiogenesis-related factors. Copyright © 2016 Elsevier Inc. All rights reserved.

  19. Hypoxia, Oxidative Stress and Fat

    Directory of Open Access Journals (Sweden)

    Nikolaus Netzer

    2015-06-01

    Full Text Available Metabolic disturbances in white adipose tissue in obese individuals contribute to the pathogenesis of insulin resistance and the development of type 2 diabetes mellitus. Impaired insulin action in adipocytes is associated with elevated lipolysis and increased free fatty acids leading to ectopic fat deposition in liver and skeletal muscle. Chronic adipose tissue hypoxia has been suggested to be part of pathomechanisms causing dysfunction of adipocytes. Hypoxia can provoke oxidative stress in human and animal adipocytes and reduce the production of beneficial adipokines, such as adiponectin. However, time-dose responses to hypoxia relativize the effects of hypoxic stress. Long-term exposure of fat cells to hypoxia can lead to the production of beneficial substances such as leptin. Knowledge of time-dose responses of hypoxia on white adipose tissue and the time course of generation of oxidative stress in adipocytes is still scarce. This paper reviews the potential links between adipose tissue hypoxia, oxidative stress, mitochondrial dysfunction, and low-grade inflammation caused by adipocyte hypertrophy, macrophage infiltration and production of inflammatory mediators.

  20. Hypoxia-induced secretion of TGF-β1 in mesenchymal stem cell promotes breast cancer cell progression.

    Science.gov (United States)

    Hung, Shun-Pei; Yang, Muh-Hwa; Tseng, Kuo-Fung; Lee, Oscar K

    2013-01-01

    In solid tumors, a decreased oxygen and nutrient supply creates a hypoxic microenvironment in the central region. This hypoxic condition induces molecular responses of normal and cancer cells in the local area, including angiogenesis, metabolic changes, and metastasis. In addition, other cells including mesenchymal stem cells (MSCs) have been reported to be recruited into the hypoxic area of solid tumors. In our previous study, we found that hypoxic condition induces the secretion of growth factors and cytokines in MSCs, and here we demonstrate that elevated secretion of transforming growth factor-β1 (TGF-β1) by MSCs under hypoxia promotes the growth, motility, and invasive ability of breast cancer cells. It was found that TGF-β1 promoter activity was regulated by hypoxia, and the major hypoxia-regulated element was located between bp -1030 to -666 in front of the TGF-β1 promoter region. In ChIP assay, the results revealed that HIF-1 was bound to the hypoxia response element (HRE) of TGF-β1 promoter. Collectively, the results indicate that hypoxia microenvironment can enhance cancer cell growth through the paracrine effects of the MSCs by driving their TGF-β1 gene expression and secretion. Therefore, extra caution has to be exercised when considering hypoxia pretreatment of MSCs before cell transplantation into patients for therapeutic purposes, particularly in patients susceptible to tumor growth.

  1. Tumor microenvironment conditions alter Akt and Na+/H+ exchanger NHE1 expression in endothelial cells more than hypoxia alone

    DEFF Research Database (Denmark)

    Pedersen, Anna-Kathrine; Mendes Lopes de Melo, Joana; Mørup, Nina

    2017-01-01

    Background Chronic angiogenesis is a hallmark of most tumors and takes place in a hostile tumor microenvironment (TME) characterized by hypoxia, low nutrient and glucose levels, elevated lactate and low pH. Despite this, most studies addressing angiogenic signaling use hypoxia as a proxy for tumor...... cells, Akt1 most abundantly. Akt1 protein expression was reduced by TME yet unaffected by hypoxia, while Akt phosphorylation was increased by TME. The Akt loss was partly reversed by MCF-7 human breast cancer cell conditioned medium, suggesting that in vivo, the cancer cell secretome may compensate....../inhibition. Conclusions NHE1 and Akt are downregulated by TME conditions, more potently than by hypoxia alone. This inhibits endothelial cell migration and growth in a manner likely modulated by the cancer cell secretome....

  2. Angiogenesis is inhibitory for mammalian digit regeneration

    Science.gov (United States)

    Yu, Ling; Yan, Mingquan; Simkin, Jennifer; Ketcham, Paulina D.; Leininger, Eric; Han, Manjong

    2014-01-01

    Abstract The regenerating mouse digit tip is a unique model for investigating blastema formation and epimorphic regeneration in mammals. The blastema is characteristically avascular and we previously reported that blastema expression of a known anti‐angiogenic factor gene, Pedf, correlated with a successful regenerative response (Yu, L., Han, M., Yan, M., Lee, E. C., Lee, J. & Muneoka, K. (2010). BMP signaling induces digit regeneration in neonatal mice. Development, 137, 551–559). Here we show that during regeneration Vegfa transcripts are not detected in the blastema but are expressed at the onset of differentiation. Treating the amputation wound with vascular endothelial growth factor enhances angiogenesis but inhibits regeneration. We next tested bone morphogenetic protein 9 (BMP9), another known mediator of angiogenesis, and found that BMP9 is also a potent inhibitor of digit tip regeneration. BMP9 induces Vegfa expression in the digit stump suggesting that regenerative failure is mediated by enhanced angiogenesis. Finally, we show that BMP9 inhibition of regeneration is completely rescued by treatment with pigment epithelium‐derived factor. These studies show that precocious angiogenesis is inhibitory for regeneration, and provide compelling evidence that the regulation of angiogenesis is a critical factor in designing therapies aimed at stimulating mammalian regeneration. PMID:27499862

  3. Mesoscopic and continuum modelling of angiogenesis

    KAUST Repository

    Spill, F.

    2014-03-11

    Angiogenesis is the formation of new blood vessels from pre-existing ones in response to chemical signals secreted by, for example, a wound or a tumour. In this paper, we propose a mesoscopic lattice-based model of angiogenesis, in which processes that include proliferation and cell movement are considered as stochastic events. By studying the dependence of the model on the lattice spacing and the number of cells involved, we are able to derive the deterministic continuum limit of our equations and compare it to similar existing models of angiogenesis. We further identify conditions under which the use of continuum models is justified, and others for which stochastic or discrete effects dominate. We also compare different stochastic models for the movement of endothelial tip cells which have the same macroscopic, deterministic behaviour, but lead to markedly different behaviour in terms of production of new vessel cells. © 2014 Springer-Verlag Berlin Heidelberg.

  4. COX-2, VEGF and tumour angiogenesis.

    LENUS (Irish Health Repository)

    Toomey, D P

    2009-06-01

    Epidemiological evidence suggests a protective effective of regular NSAID use against developing cancer. Cyclooxygenase-2, a target of NSAIDs, is upregulated in many cancers and has been associated with increased VEGF production and angiogenesis. Angiogenesis is the formation of new vessels from existing vasculature and as an essential process for tumour development represents an important therapeutic target. Following an extensive review of the literature this article details the current knowledge on the role of COX-2 in tumorigenesis focusing on its relationship to angiogenesis and VEGF production by tumour cells. While COX-2 is clearly detrimental to prognosis and NSAIDs have a beneficial effect, the possibility of COX-2 independent effects being partly or wholly responsible for this benefit cannot be excluded.

  5. Mesoscopic and continuum modelling of angiogenesis

    KAUST Repository

    Spill, F.; Guerrero, P.; Alarcon, T.; Maini, P. K.; Byrne, H. M.

    2014-01-01

    Angiogenesis is the formation of new blood vessels from pre-existing ones in response to chemical signals secreted by, for example, a wound or a tumour. In this paper, we propose a mesoscopic lattice-based model of angiogenesis, in which processes that include proliferation and cell movement are considered as stochastic events. By studying the dependence of the model on the lattice spacing and the number of cells involved, we are able to derive the deterministic continuum limit of our equations and compare it to similar existing models of angiogenesis. We further identify conditions under which the use of continuum models is justified, and others for which stochastic or discrete effects dominate. We also compare different stochastic models for the movement of endothelial tip cells which have the same macroscopic, deterministic behaviour, but lead to markedly different behaviour in terms of production of new vessel cells. © 2014 Springer-Verlag Berlin Heidelberg.

  6. Vasculogenesis and Angiogenesis: Molecular and Cellular Controls

    Science.gov (United States)

    Kubis, N.; Levy, B.I.

    2003-01-01

    Summary Angiogenesis characterizes embryonic development, but also occurs in adulthood in physiological situations such as adaptation to muscle exercise, and in pathological conditions like cancer. Major advances have been made in understanding the molecular mechanisms responsible for vasculogenesis and angiogenesis, largely due to the use of “knock-out mice”, i.e. mice in which the gene coding for the protein under investigation has been inactivated. Interestingly, the same growth factors and their receptors are equally involved in the different aspects of vasculogenesis and angiogenesis during development and in adulthood. This review aims to describe in detail their respective roles and how interactions between them lead to a newly formed vessel. PMID:20591248

  7. A Role for PPAR/ in Ocular Angiogenesis

    Directory of Open Access Journals (Sweden)

    David Bishop-Bailey

    2008-01-01

    Full Text Available The uses of highly selective PPAR/ ligands and PPAR/ knockout mice have shown a direct ability of PPAR/ to regulate angiogenesis in vitro and in vivo in animal models. PPAR/ ligands induce the proangiogenic growth factor VEGF in many cells and tissues, though its actions in the eye are not known. However, virtually, all tissue components of the eye express PPAR/. Both angiogenesis and in particular VEGF are not only critical for the development of the retina, but they are also a central component in many common pathologies of the eye, including diabetic retinopathy and age-related macular degeneration, the most common causes of blindness in the Western world. This review, therefore, will discuss the recent evidence of PPAR/-mediated angiogenesis and VEGF release in the context of ocular disorders.

  8. Nitroimidazoles and imaging hypoxia

    International Nuclear Information System (INIS)

    Nunn, A.; Linder, K.; Strauss, H.W.

    1995-01-01

    A class of compounds known to undergo different intracellular metabolism depending on the availability of oxygen in tissue, the nitroimidazoles, have been advocated for imaging hypoxic tissue. In the presence of normal oxygen levels the molecule is immediately reoxidized. In hypoxic tissue the low oxygen concentration is not able to effectively compete to reoxidize the molecule and further reduction appears to take place. The association is not irreversible. Nitroimidazoles for in vivo imaging using radiohalogenated derivatives of misonidazole have recently been employed in patients. Two major problems with fluoromisonidazole are its relatively low concentration within the lesion and the need to wait several hours to permit clearance of the agent from the normoxic background tissue. Even with high-resolution positron emission tomographic imaging, this combination of circumstances makes successful evaluation of hypoxic lesions a challenge. Single-photon agents, with their longer half-lives and comparable biological properties, offer a greater opportunity for successful imaging. In 1992 technetium-99m labeled nitroimidazoles were described that seem to have at least comparable in vivo characteristics. Laboratory studies have demonstrated preferential binding of these agents to hypoxic tissue in the myocardium, in the brain, and in tumors. These investigations indicate that imaging can provide direct evidence of tissue with low oxygen levels that is viable. Even from this early vantage point the utility of measuring tissue oxygen levels with external imaging suggests that hypoxia imaging could play a major role in clinical decision making. (orig./MG)

  9. Hypoxia-induced aggressiveness of pancreatic cancer cells is due to increased expression of VEGF, IL-6 and miR-21, which can be attenuated by CDF treatment.

    Directory of Open Access Journals (Sweden)

    Bin Bao

    Full Text Available Hypoxia is known to play critical roles in cell survival, angiogenesis, tumor invasion, and metastasis. Hypoxia mediated over-expression of hypoxia-inducible factor (HIF has been shown to be associated with therapeutic resistance, and contributes to poor prognosis of cancer patients. Emerging evidence suggest that hypoxia and HIF pathways contributes to the acquisition of epithelial-to-mesenchymal transition (EMT, maintenance of cancer stem cell (CSC functions, and also maintains the vicious cycle of inflammation-all which lead to therapeutic resistance. However, the precise molecular mechanism(s by which hypoxia/HIF drives these events are not fully understood. Here, we show, for the first time, that hypoxia leads to increased expression of VEGF, IL-6, and CSC signature genes Nanog, Oct4 and EZH2 consistent with increased cell migration/invasion and angiogenesis, and the formation of pancreatospheres, concomitant with increased expression of miR-21 and miR-210 in human pancreatic cancer (PC cells. The treatment of PC cells with CDF, a novel synthetic compound inhibited the production of VEGF and IL-6, and down-regulated the expression of Nanog, Oct4, EZH2 mRNAs, as well as miR-21 and miR-210 under hypoxia. CDF also led to decreased cell migration/invasion, angiogenesis, and formation of pancreatospheres under hypoxia. Moreover, CDF decreased gene expression of miR-21, miR-210, IL-6, HIF-1α, VEGF, and CSC signatures in vivo in a mouse orthotopic model of human PC. Collectively, these results suggest that the anti-tumor activity of CDF is in part mediated through deregulation of tumor hypoxic pathways, and thus CDF could become a novel, and effective anti-tumor agent for PC therapy.

  10. Angiogenesis and vascular targeting: Relevance for hyperthermia

    DEFF Research Database (Denmark)

    Horsman, Michael R

    2008-01-01

    The creation of a functional blood supply from the normal tissue vasculature via the process of angiogenesis is critical for the continued growth and development of solid tumours. This importance has led to the concept of targeting the tumour vasculature as a therapeutic strategy, and two major...... types of vascular targeting agents (VTAs) have developed; those that inhibit the angiogenic process-angiogenesis inhibiting agents (AIAs)-and those that specifically damage the already established neovasculature-vascular disrupting agents (VDAs). The tumour vasculature also plays a critical role...

  11. Functional inhibition of UQCRB suppresses angiogenesis in zebrafish

    Energy Technology Data Exchange (ETDEWEB)

    Cho, Yoon Sun; Jung, Hye Jin [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of); Seok, Seung Hyeok [Department of Microbiology and Immunology, Institute for Experimental Animals, Seoul National University College of Medicine, Seoul 110-799 (Korea, Republic of); Payumo, Alexander Y.; Chen, James K. [Department of Chemical and Systems Biology, Stanford University School of Medicine, Stanford, CA 94305 (United States); Kwon, Ho Jeong, E-mail: kwonhj@yonsei.ac.kr [Chemical Genomics National Research Laboratory, Department of Biotechnology, Translational Research Center for Protein Function Control, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749 (Korea, Republic of)

    2013-04-19

    Highlights: ► This is the first functional characterization of UQCRB in vivo model. ► Angiogenesis is inhibited with UQCRB loss of function in zebrafish. ► UQCRB is introduced as a prognostic marker for mitochondria- and angiogenesis-related diseases. -- Abstract: As a subunit of mitochondrial complex III, UQCRB plays an important role in complex III stability, electron transport, and cellular oxygen sensing. Herein, we report UQCRB function regarding angiogenesis in vivo with the zebrafish (Danio rerio). UQCRB knockdown inhibited angiogenesis in zebrafish leading to the suppression of VEGF expression. Moreover, the UQCRB-targeting small molecule terpestacin also inhibited angiogenesis and VEGF levels in zebrafish, supporting the role of UQCRB in angiogenesis. Collectively, UQCRB loss of function by either genetic and pharmacological means inhibited angiogenesis, indicating that UQCRB plays a key role in this process and can be a prognostic marker of angiogenesis- and mitochondria-related diseases.

  12. Functional inhibition of UQCRB suppresses angiogenesis in zebrafish

    International Nuclear Information System (INIS)

    Cho, Yoon Sun; Jung, Hye Jin; Seok, Seung Hyeok; Payumo, Alexander Y.; Chen, James K.; Kwon, Ho Jeong

    2013-01-01

    Highlights: ► This is the first functional characterization of UQCRB in vivo model. ► Angiogenesis is inhibited with UQCRB loss of function in zebrafish. ► UQCRB is introduced as a prognostic marker for mitochondria- and angiogenesis-related diseases. -- Abstract: As a subunit of mitochondrial complex III, UQCRB plays an important role in complex III stability, electron transport, and cellular oxygen sensing. Herein, we report UQCRB function regarding angiogenesis in vivo with the zebrafish (Danio rerio). UQCRB knockdown inhibited angiogenesis in zebrafish leading to the suppression of VEGF expression. Moreover, the UQCRB-targeting small molecule terpestacin also inhibited angiogenesis and VEGF levels in zebrafish, supporting the role of UQCRB in angiogenesis. Collectively, UQCRB loss of function by either genetic and pharmacological means inhibited angiogenesis, indicating that UQCRB plays a key role in this process and can be a prognostic marker of angiogenesis- and mitochondria-related diseases

  13. Capturing and storing CO{sub 2} to combat the greenhouse effect. What IFP is doing; Capter et stocker le CO{sub 2} pour lutter contre l'effet de serre. L'action de l'IFP

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2009-07-01

    The growing awareness of the international community and the convergence of the scientific data concerning climate change make it urgent to deploy, throughout the world, technologies to reduce emissions of greenhouse gases. Indeed, the growth of the world energy demand will prevent any rapid reduction of the use of fossil fuels - oil, natural gas, and coal - that are the main sources of greenhouse gas emissions. To reconcile the use of these resources with control of the emissions responsible for global warming, the capture and storage of CO{sub 2} are a very promising approach; the economic and industrial stakes are high. To meet the objective of reducing CO{sub 2} emissions, IFP is exploring three approaches: The first approach is to reduce energy consumption by improving the efficiency of energy converters, in particular internal combustion engines. A second approach is to reduce the carbon content of energy by favoring the use of natural gas or by incorporating in the fuel recycled carbon (biofuels and synfuels) and by developing hydrogen as an energy carrier. The third approach is to capture the CO{sub 2} from industrial processes used for electricity, steel, and cement production, which emit it in large quantities, then store it underground so as to keep it out of the atmosphere. This approach for reducing the CO{sub 2} emissions consists in capturing the CO{sub 2} (Post-combustion, oxy-combustion), transporting it to the place of storage, then injecting it underground to store it. Storage sites are selected and evaluated prior to injection in order to estimate the injectivity, the propagation of CO{sub 2} in the subsoil and the impact of geochemical and geomechanical transformations on the tightness of the overburden and of the injection well. The injection phase is followed by a phase of monitoring to ensure the safety and long-term viability of CO{sub 2} storage facilities. IFP, through the research it is conducting either alone or in partnership with

  14. PPARδ deficiency disrupts hypoxia-mediated tumorigenic potential of colon cancer cells.

    Science.gov (United States)

    Jeong, Eunshil; Koo, Jung Eun; Yeon, Sang Hyeon; Kwak, Mi-Kyoung; Hwang, Daniel H; Lee, Joo Young

    2014-11-01

    Peroxisome proliferator-activated receptor (PPAR) δ is highly expressed in colon epithelial cells and closely linked to colon carcinogenesis. However, the role of PPARδ in colon cancer cells in a hypoxic tumor microenvironment is not fully understood. We found that expression of the tumor-promoting cytokines, IL-8 and VEGF, induced by hypoxia (colon cancer cells. Consequently, PPARδ-knockout colon cancer cells exposed to hypoxia and deferoxamine failed to stimulate endothelial cell vascularization and macrophage migration/proliferation, whereas wild-type cells were able to induce angiogenesis and macrophage activation in response to hypoxic stress. Hypoxic stress induced transcriptional activation of PPARδ, but not its protein expression, in HCT116 cells. Exogenous expression of p300 potentiated deferoxamine-induced PPARδ transactivation, while siRNA knockdown of p300 abolished hypoxia- and deferoxamine-induced PPARδ transactivation. PPARδ associated with p300 upon hypoxic stress as demonstrated by coimmunoprecipitation studies. PI3K inhibitors or siRNA knockdown of Akt suppressed the PPARδ transactivation induced by hypoxia and deferoxamine in HCT116 cells, leading to decreased expression of IL-8 and VEGF. Collectively, these results reveal that PPARδ is required for hypoxic stress-mediated cytokine expression in colon cancer cells, resulting in promotion of angiogenesis, macrophage recruitment, and macrophage proliferation in the tumor microenvironment. p300 and the PI3K/Akt pathway play a role in the regulation of PPARδ transactivation induced by hypoxic stress. Our results demonstrate the positive crosstalk between PPARδ in tumor cells and the hypoxic tumor microenvironment and provide potential therapeutic targets for colon cancer. © 2014 Wiley Periodicals, Inc.

  15. Physiological determinants of human acute hypoxia tolerance.

    Science.gov (United States)

    2013-11-01

    AbstractIntroduction. We investigated possible physiological determinants of variability in hypoxia tolerance in subjects given a 5-minute normobaric exposure to 25,000 ft equivalent. Physiological tolerance to hypoxia was defined as the magnitude of...

  16. Hypoxia-Inducible Factor-1 as a Therapeutic Target in Endometrial Cancer Management

    Directory of Open Access Journals (Sweden)

    Laura M. S. Seeber

    2010-01-01

    Full Text Available In the Western world, endometrial cancer (EC is the most common malignant tumor of the female genital tract. Solid tumors like EC outgrow their vasculature resulting in hypoxia. Tumor hypoxia is important because it renders an aggressive phenotype and leads to radio- and chemo-therapy resistance. Hypoxia-inducible factor-1 (HIF-1 plays an essential role in the adaptive cellular response to hypoxia and is associated with poor clinical outcome in EC. Therefore, HIF-1 could be an attractive therapeutic target. Selective HIF-1 inhibitors have not been identified. A number of nonselective inhibitors which target signaling pathways upstream or downstream HIF-1 are known to decrease HIF-1 protein levels. In clinical trials for the treatment of advanced and/or recurrent EC are the topoisomerase I inhibitor Topotecan, mTOR-inhibitor Rapamycin, and angiogenesis inhibitor Bevacizumab. Preliminary data shows encouraging results for these agents. Further work is needed to identify selective HIF-1 inhibitors and to translate these into clinical trials.

  17. Angiogenesis in prostate cancer : onset, progression and imaging

    NARCIS (Netherlands)

    Russo, G.; Mischi, M.; Scheepens, W.; Rosette, de la J.J.M.C.H.; Wijkstra, H.

    2012-01-01

    Today, angiogenesis is known to play a key role in cancer growth and development. Emerging cancer treatments are based on the suppression of angiogenesis, and modern imaging techniques investigate changes in the microvasculature that are caused by angiogenesis. As for other forms of cancers,

  18. Fibromodulin Enhances Angiogenesis during Cutaneous Wound Healing

    Directory of Open Access Journals (Sweden)

    Zhong Zheng, PhD

    2014-12-01

    Conclusions: Altogether, we demonstrated that in addition to reducing scar formation, FMOD also promotes angiogenesis. As blood vessels organize and regulate wound healing, its potent angiogenic properties will further expand the clinical application of FMOD for cutaneous healing of poorly vascularized wounds.

  19. Their function on angiogenesis and cellular signalling

    Indian Academy of Sciences (India)

    Copper, although known as a micronutrient, has a pivotal role in modulating the cellular metabolism. Many studieshave reported the role of copper in angiogenesis. Copper chaperones are intracellular proteins that mediate coppertrafficking to various cell organelles. However, the role and function of copper chaperones in ...

  20. Teleosts in hypoxia : Aspects of anaerobic metabolism

    NARCIS (Netherlands)

    Van den Thillart, G.; van Waarde, Aren

    1985-01-01

    Moderate hypoxia can be tolerated by many fish species, while only some species survive severe hypoxia or anoxia. Hypoxia usually activates anaerobic glycolysis, which may be temporary when the animals are able to improve their oxygen extraction capacity. Switching over to aerobic metabolism allows

  1. Over-expression of p53 mutants in LNCaP cells alters tumor growth and angiogenesis in vivo

    International Nuclear Information System (INIS)

    Perryman, L.A.; Blair, J.M.; Kingsley, E.A.; Szymanska, B.; Ow, K.T.; Wen, V.W.; MacKenzie, K.L.; Vermeulen, P.B.; Jackson, P.; Russell, P.J.

    2006-01-01

    This study has investigated the impact of three specific dominant-negative p53 mutants (F134L, M237L, and R273H) on tumorigenesis by LNCaP prostate cancer cells. Mutant p53 proteins were associated with an increased subcutaneous 'take rate' in NOD-SCID mice, and increased production of PSA. Tumors expressing F134L and R273H grew slower than controls, and were associated with decreased necrosis and apoptosis, but not hypoxia. Interestingly, hypoxia levels were increased in tumors expressing M237L. There was less proliferation in F134L-bearing tumors compared to control, but this was not statistically significant. Angiogenesis was decreased in tumors expressing F134L and R273H compared with M237L, or controls. Conditioned medium from F134L tumors inhibited growth of normal human umbilical-vein endothelial cells but not telomerase-immortalized bone marrow endothelial cells. F134L tumor supernatants showed lower levels of VEGF and endostatin compared with supernatants from tumors expressing other mutants. Our results support the possibility that decreased angiogenesis might account for reduced growth rate of tumor cells expressing the F134L p53 mutation

  2. Impact of hypoxia and the metabolic microenvironment on radiotherapy of solid tumors. Introduction of a multiinstitutional research project

    International Nuclear Information System (INIS)

    Zips, D.; Petersen, C.; Adam, M.; Molls, M.; Philbrook, C.; Flentje, M.; Haase, A.; Schmitt, P.; Mueller-Klieser, W.; Thews, O.; Walenta, S.; Baumann, M.

    2004-01-01

    Background: recent developments in imaging technology and tumor biology have led to new techniques to detect hypoxia and related alterations of the metabolic microenvironment in tumors. However, whether these new methods can predict radiobiological hypoxia and outcome after fractionated radiotherapy still awaits experimental evaluation. Material and methods: the present article will introduce a multiinstitutional research project addressing the impact of hypoxia and the metabolic microenvironment on radiotherapy of solid tumors. The four laboratories involved are situated at the universities of Dresden, Mainz, Munich and Wuerzburg, Germany. Results: the joint scientific project started to collect data obtained on a set of ten different human tumor xenografts growing in nude mice by applying various imaging techniques to detect tumor hypoxia and related parameters of the metabolic microenvironment. These techniques include magnetic resonance imaging and spectroscopy, metabolic mapping with quantitative bioluminescence and single-photon imaging, histological multiparameter analysis of biochemical hypoxia, perfusion and vasculature, and immunohistochemistry of factors related to angiogenesis, invasion and metastasis. To evaluate the different methods, baseline functional radiobiological data including radiobiological hypoxic fraction and outcome after fractionated irradiation will be determined. Conclusion: besides increasing our understanding of tumor biology, the project will focus on new, clinically applicable strategies for microenvironment profiling and will help to identify those patients that might benefit from targeted interventions to improve tumor oxygenation. (orig.)

  3. Plasma volume in acute hypoxia

    DEFF Research Database (Denmark)

    Poulsen, T D; Klausen, T; Richalet, J P

    1998-01-01

    Exposure to acute hypoxia is associated with changes in body fluid homeostasis and plasma volume (PV). This study compared a dye dilution technique using Evans' blue (PV[Evans']) with a carbon monoxide (CO) rebreathing method (PV[CO]) for measurements of PV in ten normal subjects at sea level...

  4. Preeclampsia, Hypoxia, Thrombosis, and Inflammation

    Directory of Open Access Journals (Sweden)

    Amir A. Shamshirsaz

    2012-01-01

    Full Text Available Reductions in uteroplacental flow initiate a cascade of molecular effects leading to hypoxia, thrombosis, inflammation, and endothelial cell dysfunction resulting in untoward pregnancy outcomes. In this review, we detail these effects and their relationship to preeclampsia (PE and intrauterine growth restriction (IUGR.

  5. Hepcidin: A Critical Regulator Of Iron Metabolism During Hypoxia

    Science.gov (United States)

    2011-01-01

    inducible factor (HIF)/hypoxia response element ( HRE ) system, as well as recent evidence indicating that localized adipose hypoxia due to obesity may...mechanisms by which hypoxia affects hepcidin expression, to include a review of the hypoxia inducible factor (HIF)/hypoxia response element ( HRE ) system, as...a battery of genes are induced by the hypoxia inducible factor (HIF)/hypoxia response element ( HRE ) system. The HIF system senses O2 levels through

  6. Extracellular matrix metalloproteinase inducer (EMMPRIN) is a potential biomarker of angiogenesis in proliferative diabetic retinopathy.

    Science.gov (United States)

    Abu El-Asrar, Ahmed M; Ahmad, Ajmal; Alam, Kaiser; Siddiquei, Mohammad Mairaj; Mohammad, Ghulam; Hertogh, Gert De; Mousa, Ahmed; Opdenakker, Ghislain

    2017-11-01

    Extracellular matrix metalloproteinase inducer (EMMPRIN) promotes angiogenesis through matrix metalloproteinases (MMPs) and vascular endothelial growth factor (VEGF) production. We investigated the expression levels of EMMPRIN and correlated these levels with VEGF, MMP-1 and MMP-9 in proliferative diabetic retinopathy (PDR). In addition, we examined the expression of EMMPRIN in the retinas of diabetic rats and the effect of EMMPRIN on the induction of angiogenesis regulatory factors in human retinal microvascular endothelial cells (HRMECs). Vitreous samples from 40 PDR and 19 non-diabetic patients, epiretinal membranes from 12 patients with PDR, retinas of rats and HRMECs were studied by enzyme-linked immunosorbent assay (ELISA), immunohistochemistry, Western blot analysis, zymography analysis and RT-PCR. We showed a significant increase in the expression of EMMPRIN, VEGF, MMP-1 and MMP-9 in vitreous samples from PDR patients compared with non-diabetic controls (p EMMPRIN and the levels of VEGF (r = 0.38; p = 0.003), MMP-1 (r = 0.36; p = 0.005) and MMP-9 (r = 0.46; p = 0.003). In epiretinal membranes, EMMPRIN was expressed in vascular endothelial cells and stromal cells. Significant increase of EMMPRIN mRNA was detected in rat retinas after induction of diabetes. EMMPRIN induced hypoxia-inducible factor-1α, VEGF and MMP-1 expression in HRMEC. These results suggest that EMMPRIN/MMPs/VEGF pathway is involved in PDR angiogenesis. © 2016 Acta Ophthalmologica Scandinavica Foundation. Published by John Wiley & Sons Ltd.

  7. Oxygen-Induced Retinopathy from Recurrent Intermittent Hypoxia Is Not Dependent on Resolution with Room Air or Oxygen, in Neonatal Rats.

    Science.gov (United States)

    Beharry, Kay D; Cai, Charles L; Skelton, Jacqueline; Siddiqui, Faisal; D'Agrosa, Christina; Calo, Johanna; Valencia, Gloria B; Aranda, Jacob V

    2018-05-01

    Preterm infants often experience intermittent hypoxia (IH) with resolution in room air (RA) or hyperoxia (Hx) between events. Hypoxia is a major inducer of vascular endothelial growth factor, which plays a key role in normal and aberrant retinal angiogenesis. This study tested the hypothesis that neonatal IH which resolved with RA is less injurious to the immature retina than IH resolved by Hx between events. Newborn rats were exposed to: (1) Hx (50% O₂) with brief hypoxia (12% O₂); (2) RA with 12% O₂; (3) Hx with RA; (4) Hx only; or (5) RA only, from P0 to P14. Pups were examined at P14 or placed in RA until P21. Retinal vascular and astrocyte integrity; retinal layer thickness; ocular and systemic biomarkers of angiogenesis; and somatic growth were determined at P14 and P21. All IH paradigms resulted in significant retinal vascular defects, disturbances in retinal astrocyte template, retinal thickening, and photoreceptor damage concurrent with elevations in angiogenesis biomarkers. These data suggest that the susceptibility of the immature retina to changes in oxygen render no differences in the outcomes between RA or O₂ resolution. Interventions and initiatives to curtail O₂ variations should remain a high priority to prevent severe retinopathy.

  8. Oxygen-Induced Retinopathy from Recurrent Intermittent Hypoxia Is Not Dependent on Resolution with Room Air or Oxygen, in Neonatal Rats

    Directory of Open Access Journals (Sweden)

    Kay D. Beharry

    2018-05-01

    Full Text Available Preterm infants often experience intermittent hypoxia (IH with resolution in room air (RA or hyperoxia (Hx between events. Hypoxia is a major inducer of vascular endothelial growth factor, which plays a key role in normal and aberrant retinal angiogenesis. This study tested the hypothesis that neonatal IH which resolved with RA is less injurious to the immature retina than IH resolved by Hx between events. Newborn rats were exposed to: (1 Hx (50% O2 with brief hypoxia (12% O2; (2 RA with 12% O2; (3 Hx with RA; (4 Hx only; or (5 RA only, from P0 to P14. Pups were examined at P14 or placed in RA until P21. Retinal vascular and astrocyte integrity; retinal layer thickness; ocular and systemic biomarkers of angiogenesis; and somatic growth were determined at P14 and P21. All IH paradigms resulted in significant retinal vascular defects, disturbances in retinal astrocyte template, retinal thickening, and photoreceptor damage concurrent with elevations in angiogenesis biomarkers. These data suggest that the susceptibility of the immature retina to changes in oxygen render no differences in the outcomes between RA or O2 resolution. Interventions and initiatives to curtail O2 variations should remain a high priority to prevent severe retinopathy.

  9. Maternal hemoglobin concentration and hematocrit values may affect fetus development by influencing placental angiogenesis.

    Science.gov (United States)

    Stangret, Aleksandra; Wnuk, Anna; Szewczyk, Grzegorz; Pyzlak, Michał; Szukiewicz, Dariusz

    2017-01-01

    Vasculogenesis and angiogenesis are crucial for maintaining proper placental perfusion and optimal fetal development. Among other physical and chemical factors, hypoxia is known to stimulate angiogenic processes. Preplacental type of hypoxia is often associated with maternal anemia and is thought to enhance vascularization within the fetoplacental unit. The goal of this study was to establish the correlation between the local expression of vascular endothelial growth factor (VEGF) and placenta growth factor (PlGF) receptors (flt-1, flk-1) with maternal hemoglobin (Hb) concentration, hematocrit (Ht) values and the infant birthweight. In total, 43 specimens of term placentas obtained from normal course pregnancies delivered at term were included in the study. The expression of flt-1 and flk-1 receptors was analyzed by immunohistochemical staining. Vascular/extravascular tissular index (V/EVTI) was measured by assessing a total vascular area. Nonparametric Mann-Whitney U-test and Spearman's rank correlation were used to compare the various parameters and their differences between the groups. Among the patients with low Hb concentration, nearly 2-fold greater expression of the flt-1 receptor was positively correlated with infants birthweight (p = 0.028). Increased placental vascular density (increased flt-1 expression), during a physiological course of gestation, may be an adaptive response to lowered maternal Hb concentration and Ht values encountered during pregnancy.

  10. Cytokines and Angiogenesis in the Corpus Luteum

    Directory of Open Access Journals (Sweden)

    António M. Galvão

    2013-01-01

    Full Text Available In adults, physiological angiogenesis is a rare event, with few exceptions as the vasculogenesis needed for tissue growth and function in female reproductive organs. Particularly in the corpus luteum (CL, regulation of angiogenic process seems to be tightly controlled by opposite actions resultant from the balance between pro- and antiangiogenic factors. It is the extremely rapid sequence of events that determines the dramatic changes on vascular and nonvascular structures, qualifying the CL as a great model for angiogenesis studies. Using the mare CL as a model, reports on locally produced cytokines, such as tumor necrosis factor α (TNF, interferon gamma (IFNG, or Fas ligand (FASL, pointed out their role on angiogenic activity modulation throughout the luteal phase. Thus, the main purpose of this review is to highlight the interaction between immune, endothelial, and luteal steroidogenic cells, regarding vascular dynamics/changes during establishment and regression of the equine CL.

  11. PACAP and VIP inhibit the invasiveness of glioblastoma cells exposed to hypoxia through the regulation of HIFs and EGFR expression

    Directory of Open Access Journals (Sweden)

    Grazia eMaugeri

    2016-05-01

    Full Text Available Pituitary adenylate cyclase-activating polypeptide (PACAP and vasoactive intestinal peptide (VIP through the binding of vasoactive intestinal peptide receptors (VIPRs, perform a wide variety of effects in human cancers, including glioblastoma multiforme (GBM. This tumor is characterized by extensive areas of hypoxia, which triggers the expression of hypoxia-inducible factors (HIFs. HIFs not only mediate angiogenesis but also tumor cell migration and invasion. Furthermore, HIFs activation is linked to epidermal growth factor receptor (EGFR overexpression. Previous studies have shown that VIP interferes with the invasive nature of gliomas by regulating cell migration. However, the role of VIP family members in GBM infiltration under low oxygen tension has not been clarified yet. Therefore, in the present study we have investigated, for the first time, the molecular mechanisms involved in the anti-invasive effect of PACAP or VIP in U87MG glioblastoma cells exposed to hypoxia induced by treatment with desferrioxamine (DFX. The results suggest that either PACAP or VIP exert an anti-infiltrative effect under low oxygen tension by modulating HIFs and EGFR expression, key elements involved in cell migration and angiogenesis. These peptides act through the inhibition of PI3K/Akt and MAPK/ERK signaling pathways, which are known to have a crucial role in HIFs regulation. In conclusion, the modulation of hypoxic event and the anti-invasive effect exerted by some VIP family members might open new insights in the therapeutic approach to GBM.

  12. Sorafenib Increases Tumor Hypoxia in Cervical Cancer Patients Treated With Radiation Therapy: Results of a Phase 1 Clinical Study

    Energy Technology Data Exchange (ETDEWEB)

    Milosevic, Michael F., E-mail: mike.milosevic@rmp.uhn.ca [Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Townsley, Carol A. [Department of Medical Oncology, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Chaudary, Naz [Department of Advanced Molecular Oncology, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Clarke, Blaise [Department of Pathology, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Department of Laboratory Medicine and Pathology, University of Toronto, Toronto (Canada); Pintilie, Melania [Department of Clinical Study Coordination and Biostatistics, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Fan, Stacy; Glicksman, Rachel [Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Haider, Masoom [Department of Medical Imaging, Sunnybrook Health Sciences Centre, Toronto (Canada); Department of Medical Imaging, University of Toronto, Toronto (Canada); Kim, Sunmo [Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); MacKay, Helen [Department of Medical Oncology, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Department of Medicine, University of Toronto, Toronto (Canada); Yeung, Ivan [Radiation Medicine Program, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Department of Radiation Oncology, University of Toronto, Toronto (Canada); Hill, Richard P. [Department of Radiation Oncology, University of Toronto, Toronto (Canada); Department of Advanced Molecular Oncology, Princess Margaret Cancer Center, University Health Network, Toronto (Canada); Department of Medical Biophysics, University of Toronto, Toronto (Canada); and others

    2016-01-01

    Purpose: Preclinical studies have shown that angiogenesis inhibition can improve response to radiation therapy (RT). The purpose of this phase 1 study was to examine the angiogenesis inhibitor sorafenib in patients with cervical cancer receiving radical RT and concurrent cisplatin (RTCT). Methods and Materials: Thirteen patients with stage IB to IIIB cervical cancer participated. Sorafenib was administered daily for 7 days before the start of standard RTCT in patients with early-stage, low-risk disease and also during RTCT in patients with high-risk disease. Biomarkers of tumor vascularity, perfusion, and hypoxia were measured at baseline and again after 7 days of sorafenib alone before the start of RTCT. The median follow-up time was 4.5 years. Results: Initial complete response was seen in 12 patients. One patient died without achieving disease control, and 4 experienced recurrent disease. One patient with an extensive, infiltrative tumor experienced pelvic fistulas during treatment. The 4-year actuarial survival was 85%. Late grade 3 gastrointestinal toxicity developed in 4 patients. Sorafenib alone produced a reduction in tumor perfusion/permeability and an increase in hypoxia, which resulted in early closure of the study. Conclusions: Sorafenib increased tumor hypoxia, raising concern that it might impair rather than improve disease control when added to RTCT.

  13. The β3-Integrin Binding Protein β3-Endonexin Is a Novel Negative Regulator of Hypoxia-Inducible Factor-1

    Science.gov (United States)

    Kračun, Damir; Rieß, Florian; Kanchev, Ivan; Gawaz, Meinrad

    2014-01-01

    Abstract Aims: Integrins are multifunctional heterodimeric adhesion receptors that mediate the attachment between a cell and the extracellular matrix or other surrounding cells. In endothelial cells, integrins can modulate cell migration and motility. In particular, β3-integrin is expressed in angiogenic vessels. Signal transduction by β3-integrins requires the recruitment of intracellular signaling molecules. β3-endonexin is a highly spliced molecule that has been identified as a β3-integrin binding protein. β3-endonexin isoforms are expressed in endothelial cells and have been suggested to act as shuttle proteins between the membrane and the nucleus. However, their functional role in angiogenesis is unclear. In this study, we investigated whether β3-endonexin isoforms are involved in endothelial angiogenic processes under hypoxia. Results: The overexpression of β3-endonexin isoforms decreased endothelial proliferation and tube formation under hypoxia, while the depletion of β3-endonexin by RNAi promoted angiogenic responses in vitro and in vivo. In hypoxia, β3-endonexin accumulated in the nucleus, and prevention of this response by depletion of β3-endonexin increased hypoxic activation and induction of the hypoxia-inducible factor (HIF)-1 and its target genes VEGF and PAI-1. β3-endonexin diminished nuclear factor kappa B (NFκB) activation and decreased NFκB binding to the HIF-1α promoter under hypoxia, subsequently diminishing NFκB-dependent transcription of HIF-1α under hypoxia. Innovation: Our results indicate for the first time that the overexpression of β3-endonexin can decrease hypoxic induction and activation of HIF-1α and can prevent hypoxic endothelial proliferation and angiogenic responses. Conclusion: β3-endonexin can act as a novel anti-angiogenic factor specifically in the response to hypoxia due to its negative impact on the activation of HIF-1. Antioxid. Redox Signal. 20, 1964–1976. PMID:24386901

  14. Astroglial Activation by an Enriched Environment after Transplantation of Mesenchymal Stem Cells Enhances Angiogenesis after Hypoxic-Ischemic Brain Injury

    Directory of Open Access Journals (Sweden)

    Sung-Rae Cho

    2016-09-01

    Full Text Available Transplantation of mesenchymal stem cells (MSCs has paracrine effects; however, the effects are known to be largely limited. Here we investigated the combination effects of cell transplantation and enriched environment (EE in a model of hypoxic-ischemic brain injury. Brain damage was induced in seven-day-old mice by unilateral carotid artery ligation and exposure to hypoxia (8% O2 for 90 min. At six weeks of age, the mice were randomly assigned to four groups: phosphate-buffered saline (PBS-control (CON, PBS-EE, MSC-CON, and MSC-EE. Rotarod and grip strength tests were performed to evaluate neurobehavioral functions. Histologic evaluations were also performed to confirm the extent of astrocyte activation and endogenous angiogenesis. An array-based multiplex ELISA and Western blot were used to identify growth factors in vivo and in vitro. Two weeks after treatment, levels of astrocyte density and angiogenic factors were increased in MSC-EE mice, but glial scarring was not increased. Eight weeks after treatment, angiogenesis was increased, and behavioral outcomes were synergistically improved in the MSC-EE group. Astrocytes co-cultured with MSCs expressed higher levels of angiogenic factors than astrocytes cultured alone. The mechanisms of this synergistic effect included enhanced repair processes, such as increased endogenous angiogenesis and upregulation of angiogenic factors released from activated astrocytes.

  15. Angiogenesis in Chronic Obstructive Pulmonary Disease

    OpenAIRE

    Góralczyk, Barbara; Drela, Ewelina; Góralczyk, Krzysztof; Szczypiorska, Anna; Rość, Danuta

    2012-01-01

    Angiogenesis is a very important process that occurs in both physiological and pathological states. The new blood vessels formation is characteristic for cancers, ischemic diseases and inflammatory diseases. The process is controlled by factors that stimulate and inhibit neovascularization. The next stages of the neovascularization are known as well as the role of the extracellular matrix, cells and cytokines/factors growth modulating this process. The cells of the endothelium and proangiogen...

  16. Wars2 is a determinant of angiogenesis

    Czech Academy of Sciences Publication Activity Database

    Wang, M.; Sips, P.; Khin, E.; Rotival, M.; Sun, X.; Ahmed, R.; Widjaja, A. A.; Schafer, S.; Yusoff, P.; Choksi, P. K.; Ko, N. S. J.; Singh, M. K.; Epstein, D.; Guan, Y.; Houštěk, Josef; Mráček, Tomáš; Nůsková, Hana; Mikell, B.; Tan, J.; Pesce, F.; Kolář, František; Bottolo, L.; Mancini, M.; Hubner, N.; Pravenec, Michal; Petretto, E.; MacRae, C.; Cook, S. A.

    2016-01-01

    Roč. 7, Jul (2016), s. 12061 ISSN 2041-1723 R&D Projects: GA MŠk(CZ) LL1204; GA ČR(CZ) GB14-36804G; GA MZd(CZ) NT12370 Institutional support: RVO:67985823 Keywords : Wars2 mutant gene * angiogenesis * coronary flow * spontaneously hypertensive rat Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 12.124, year: 2016

  17. Molecular Therapeutic Targets for Glioma Angiogenesis

    Directory of Open Access Journals (Sweden)

    Shingo Takano

    2010-01-01

    Full Text Available Due to the prominent angiogenesis that occurs in malignant glioma, antiangiogenic therapy has been attempted. There have been several molecular targets that are specific to malignant gliomas, as well as more broadly in systemic cancers. In this review, I will focus on some topics related to molecular therapeutic targets for glioma angiogenesis. First, important angiogenic factors that could be considered molecular targets are VEGF, VEGF-induced proteins on endothelial cells, tissue factor, osteopontin, v3 integrin, and thymidine phosphorylase as well as endogenous inhibitors, soluble Flt1, and thrombospondin 1. Second, hypoxic areas are also decreased by metronomic CPT11 treatment as well as temozolomide. Third, glioma-derived endothelial cells that are genetically and functionally distinct from normal endothelial cells should be targeted, for example, with SDF-1 and CXCR7 chemokine. Fourth, endothelial progenitor cells (EPCs likely contribute towards glioma angiogenesis in the brain and could be useful as a drug delivery tool. Finally, blockade of delta-like 4 (Dll4 results in a nonfunctioning vasculature and could be another important target distinct from VEGF.

  18. Statins and angiogenesis: Is it about connections?

    International Nuclear Information System (INIS)

    Khaidakov, Magomed; Wang, Wenze; Khan, Junaid A.; Kang, Bum-Yong; Hermonat, Paul L.; Mehta, Jawahar L.

    2009-01-01

    Statins, inhibitors of 3-hydroxy-3-methyl-glutaryl-coenzyme A reductase, have been shown to induce both angiogenic and angiostatic responses. We attempted to resolve this controversy by studying the effects of two different statins, rosuvastatin and simvastatin, in two different assay systems. In the matrigel angiogenesis assay, both statins enhanced tube formation by human umbilical vein endothelial cells (HUVECs, p < 0.01 vs. control). In the ex vivo mouse aortic ring sprouting assay, both statins virtually abolished new vessel formation (p < 0.01). As a basic difference between the two models of angiogenesis is dispersed state of endothelial cells vs. compact monolayer, we analyzed influence of statins on endothelial junction proteins. RT-PCR analysis and cytoimmunostaining of HUVECs treated with simvastatin revealed increased expression of VE-cadherin (p < 0.05). The blockade of VE-cadherin with a specific antibody reversed simvastatin-induced tube formation (p < 0.002). These data suggest that statins through VE-cadherin stimulation modulate cell-cell adhesion and diminish the ability of cells to proliferate and migrate. The observations of reduced angiogenesis in the intact vessel may relate to anti-atherosclerotic and anti-cancer effects of statins, and provide a feasible explanation for conflicting data under different experimental conditions.

  19. Wogonin inhibits tumor angiogenesis via degradation of HIF-1α protein

    International Nuclear Information System (INIS)

    Song, Xiuming; Yao, Jing; Wang, Fei; Zhou, Mi; Zhou, Yuxin; Wang, Hu; Wei, Libin; Zhao, Li; Li, Zhiyu; Lu, Na; Guo, Qinglong

    2013-01-01

    Wogonin, a plant-derived flavone, has been shown recently to have antitumor effects. However, the mechanisms that wogonin inhibits tumor angiogenesis are not well known. In this study, we investigated the effects of wogonin on expression of hypoxia-inducible factor-1α (HIF-1α) and secretion of vascular endothelial growth factor (VEGF) in tumor cells. We found that wogonin decreased the expression of HIF-1α by affecting its stability and reduced the secretion of VEGF, which suppressed angiogenesis in cancer. Wogonin promoted the degradation of HIF-1α by increasing its prolyl hydroxylation, which depended on prolyl hydroxylase (PHD) and the von Hippel–Lindau tumor suppressor (VHL). Intriguingly, wogonin impeded the binding between heat-shock protein 90 (Hsp90) and HIF-1α. In addition, wogonin down-regulated the Hsp90 client proteins EGFR, Cdk4 and survivin, but did not affect the level of Hsp90. Wogonin also increased ubiquitination of HIF-1α and promoted its degradation in proteasome. We also found that wogonin could inhibit nuclear translocation of HIF-1α. Electrophoresis mobility shift assay (EMSA) showed that wogonin decreased the binding activity of exogenous consensus DNA oligonucleotide with HIF-1α in nuclear extracts from MCF-7 cells. Chromatin immunoprecipitation (ChIP) assay also revealed that HIF-1α directly binded to endogenous hypoxia-responsive element (HRE) and this binding was significantly decreased in MCF-7 cells treated with wogonin. Preliminary results indicated in vivo activity of wogonin against xenograft-induced angiogenesis in nude mice. Taken together, the results suggested that wogonin was a potent inhibitor of HIF-1α and provided a new insight into the mechanisms of wogonin against cancers. - Highlights: • Wogonin is an all around inhibitor of VEGF signaling. • We firstly demonstrate that wogonin inhibits secretion of VEGF by decreasing HIF-1α. • Wogonin enhances PDH and VHL expression and inhibits Hsp90 function.

  20. Wogonin inhibits tumor angiogenesis via degradation of HIF-1α protein

    Energy Technology Data Exchange (ETDEWEB)

    Song, Xiuming; Yao, Jing; Wang, Fei; Zhou, Mi; Zhou, Yuxin; Wang, Hu; Wei, Libin; Zhao, Li; Li, Zhiyu; Lu, Na, E-mail: luna555@163.com; Guo, Qinglong, E-mail: anticancer_drug@yahoo.com.cn

    2013-09-01

    Wogonin, a plant-derived flavone, has been shown recently to have antitumor effects. However, the mechanisms that wogonin inhibits tumor angiogenesis are not well known. In this study, we investigated the effects of wogonin on expression of hypoxia-inducible factor-1α (HIF-1α) and secretion of vascular endothelial growth factor (VEGF) in tumor cells. We found that wogonin decreased the expression of HIF-1α by affecting its stability and reduced the secretion of VEGF, which suppressed angiogenesis in cancer. Wogonin promoted the degradation of HIF-1α by increasing its prolyl hydroxylation, which depended on prolyl hydroxylase (PHD) and the von Hippel–Lindau tumor suppressor (VHL). Intriguingly, wogonin impeded the binding between heat-shock protein 90 (Hsp90) and HIF-1α. In addition, wogonin down-regulated the Hsp90 client proteins EGFR, Cdk4 and survivin, but did not affect the level of Hsp90. Wogonin also increased ubiquitination of HIF-1α and promoted its degradation in proteasome. We also found that wogonin could inhibit nuclear translocation of HIF-1α. Electrophoresis mobility shift assay (EMSA) showed that wogonin decreased the binding activity of exogenous consensus DNA oligonucleotide with HIF-1α in nuclear extracts from MCF-7 cells. Chromatin immunoprecipitation (ChIP) assay also revealed that HIF-1α directly binded to endogenous hypoxia-responsive element (HRE) and this binding was significantly decreased in MCF-7 cells treated with wogonin. Preliminary results indicated in vivo activity of wogonin against xenograft-induced angiogenesis in nude mice. Taken together, the results suggested that wogonin was a potent inhibitor of HIF-1α and provided a new insight into the mechanisms of wogonin against cancers. - Highlights: • Wogonin is an all around inhibitor of VEGF signaling. • We firstly demonstrate that wogonin inhibits secretion of VEGF by decreasing HIF-1α. • Wogonin enhances PDH and VHL expression and inhibits Hsp90 function.

  1. Regulation of Membrane-Type 4 Matrix Metalloproteinase by SLUG Contributes to Hypoxia-Mediated Metastasis

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    Chi-Hung Huang

    2009-12-01

    Full Text Available The hypoxic tumor environment has been shown to be critical to cancer metastasis through the promotion of angiogenesis, induction of epithelial-mesenchymal transition (EMT, and acquisition of invasive potential. However, the impact of hypoxia on the expression profile of the proteolytic enzymes involved in invasiveness is relatively unknown. Membrane-type 4 matrix metalloproteinase (MT4-MMP is a glycosyl-phosphatidyl inositol-anchored protease that has been shown to be overexpressed in human cancers. However, detailed mechanisms regarding the regulation and function of MT4-MMP expression in tumor cells remain unknown. Here, we demonstrate that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α induced MT4-MMP expression in human cancer cells. Activation of SLUG, a transcriptional factor regulating the EMT process of human cancers, by HIF-1α was critical for the induction of MT4-MMP under hypoxia. SLUG regulated the transcription of MT4-MMP through direct binding to the E-box located in its proximal promoter. Short-interference RNA-mediated knockdown of MT4-MMP attenuated in vitro invasiveness and in vivo pulmonary colonization of tumor cells without affecting cell migratory ability. MT4-MMP promoted invasiveness and pulmonary colonization through modulation of the expression profile of MMPs and angiogenic factors. Finally, coexpression of HIF-1α and MT4-MMP in human head and neck cancer was predictive of a worse clinical outcome. These findings establish a novel signaling pathway for hypoxia-mediated metastasis and elucidate the underlying regulatory mechanism and functional significance of MT4-MMP in cancer metastasis.

  2. Fetal blood vessel count increases in compensation of hypoxia in premature placentas

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    K. Kartini

    2015-04-01

    Full Text Available Background Prematurity refers to live births before 37 weeks of gestation, wherein the baby is born before the body and its organ systems achieve perfect maturity, and this disorder is still a global problem. The high incidence of prematurity is a problem in developing and also in developed countries. Certain conditions accompanying pregnancies like preeclampsia, infection, and placental insufficiency, may trigger uterine hypoxia, causing premature birth. The placental condition is related to the intra-uterine fetal condition. In prolonged placental hypoxia, there occurs a compensatory mechanism, i.e. an increase in placental angiogenesis. This study aimed to evaluate the effect of hypoxia on fetal blood vessel count as compensatory mechanism for tissue hypoxia. Methods An observational-analytical cross-sectional design using paraffin blocks of conserved premature placentas, comprising 31 samples of hypoxic premature placentas and 28 samples of non-hypoxic premature placentas, selected using non-random consecutive sampling. The samples were made into slides and stained with hematoxylin-eosin for assessment of histological structure, including fetal blood vessel count and integrity, villus conditions, syncytiotrophoblastic nuclear changes, and syncytiotrophoblastic nuclear aggregation. Mann-Whitney test was used to compare the difference of blood vessel count between groups. Results Assessment of histological structure showed a significant increase in fetal blood vessel count in the hypoxic group [8.00 (5-15] as compared with the non-hypoxic group [7.50 (3-15]. Conclusion The hypoxia in premature placentas caused an increase in the number of fetal blood vessels as a form of compensation for disturbed oxygen homeostasis.

  3. Fetal blood vessel count increases in compensation of hypoxia in premature placentas

    Directory of Open Access Journals (Sweden)

    K Kartini

    2016-02-01

    Full Text Available BACKGROUND Prematurity refers to live births before 37 weeks of gestation, wherein the baby is born before the body and its organ systems achieve perfect maturity, and this disorder is still a global problem. The high incidence of prematurity is a problem in developing and also in developed countries. Certain conditions accompanying pregnancies like preeclampsia, infection, and placental insufficiency, may trigger uterine hypoxia, causing premature birth. The placental condition is related to the intra-uterine fetal condition. In prolonged placental hypoxia, there occurs a compensatory mechanism, i.e. an increase in placental angiogenesis. This study aimed to evaluate the effect of hypoxia on fetal blood vessel count as compensatory mechanism for tissue hypoxia. METHODS An observational-analytical cross-sectional design using paraffin blocks of conserved premature placentas, comprising 31 samples of hypoxic premature placentas and 28 samples of non-hypoxic premature placentas, selected using non-random consecutive sampling. The samples were made into slides and stained with hematoxylin-eosin for assessment of histological structure, including fetal blood vessel count and integrity, villus conditions, syncytiotrophoblastic nuclear changes, and syncytiotrophoblastic nuclear aggregation. Mann-Whitney test was used to compare the difference of blood vessel count between groups. RESULTS Assessment of histological structure showed a significant increase in fetal blood vessel count in the hypoxic group [8.00 (5-15] as compared with the non-hypoxic group [7.50 (3-15]. CONCLUSION The hypoxia in premature placentas caused an increase in the number of fetal blood vessels as a form of compensation for disturbed oxygen homeostasis.

  4. Investigation of an angiogenesis-promoting topical treatment for diabetic wounds using multimodal microscopy (Conference Presentation)

    Science.gov (United States)

    Li, Joanne; Bower, Andrew J.; Arp, Zane A.; Olson, Eric; Holland, Claire; Chaney, Eric J.; Marjanovic, Marina; Boppart, Stephen A.

    2016-02-01

    Impaired skin wound healing is a significant co-morbid condition of diabetes that is caused by poor microcirculation among other factors. Hypoxia-inducible factors (HIFs) are transcription factors that mediate the effects of decreased levels of oxygen in biological environments. Inducing mild hypoxia in the tissue could promote angiogenesis, a critical step in the wound healing process in diabetic wounds. To investigate the relationship between hypoxia and diabetic wound healing, a topical treatment consisting of a HIF-activating prolyl-hydroxylase inhibitor was administered to the wounded skin of diabetic (db/db) mice. Studies were conducted in accordance with the GSK Policy on the Care, Welfare and Treatment of Laboratory Animals and were reviewed at GSK or by the ethical review process at the institution where the work was performed. The wounded area was tracked in vivo for 28 days utilizing a custom-built multimodal microscopy system. An increase in vascular density around the wounds of treated animals was observed using phase-variance optical coherence tomography (PV-OCT), in comparison to normal controls. In addition, second harmonic generation (SHG) and fluorescence lifetime imaging microscopy (FLIM) were utilized to examine the collagen regeneration and cellular metabolic activity, respectively, in the wounded skin. The utilization of these light based methods can follow metabolic and morphologic changes in the wound healing process in ways not possible with current evaluation processes. Insights demonstrated in these studies could lead to new endpoints for evaluation of the efficacy of drugs and lead to more direct ways of detecting patient response to treatment.

  5. Ageing and cardiorespiratory response to hypoxia.

    Science.gov (United States)

    Lhuissier, François J; Canouï-Poitrine, Florence; Richalet, Jean-Paul

    2012-11-01

    The risk of severe altitude-induced diseases is related to ventilatory and cardiac responses to hypoxia and is dependent on sex, age and exercise training status. However, it remains unclear how ageing modifies these physiological adaptations to hypoxia. We assessed the physiological responses to hypoxia with ageing through a cross-sectional 20 year study including 4675 subjects (2789 men, 1886 women; 14-85 years old) and a longitudinal study including 30 subjects explored at a mean 10.4 year interval. The influence of sex, training status and menopause was evaluated. The hypoxia-induced desaturation and the ventilatory and cardiac responses to hypoxia at rest and exercise were measured. In men, ventilatory response to hypoxia increased (P ageing. Cardiac response to hypoxia was blunted with ageing in both sexes (P ageing. These adaptive responses were less pronounced or absent in post-menopausal women (P ageing in men while cardiac response is blunted with ageing in both sexes. Training aggravates desaturation at exercise in hypoxia, improves the ventilatory response and limits the ageing-induced blunting of cardiac response to hypoxia. Training limits the negative effects of menopause in cardiorespiratory adaptations to hypoxia.

  6. Exercise Improves Mood State in Normobaric Hypoxia.

    Science.gov (United States)

    Seo, Yongsuk; Fennell, Curtis; Burns, Keith; Pollock, Brandon S; Gunstad, John; McDaniel, John; Glickman, Ellen

    2015-11-01

    The purpose of this study was to quantify the efficacy of using exercise to alleviate the impairments in mood state associated with hypoxic exposure. Nineteen young, healthy men completed Automated Neuropsychological Assessment Metrics-4(th) Edition (ANAM4) versions of the mood state test before hypoxia exposure, after 60 min of hypoxia exposure (12.5% O(2)), and during and after two intensities of cycling exercise (40% and 60% adjusted Vo(2max)) under the same hypoxic conditions. Peripheral oxygen saturation (Spo(2)) and regional cerebral oxygen saturation (rSo(2)) were continuously monitored. At rest in hypoxia, Total Mood Disturbance (TMD) was significantly increased compared to baseline in both the 40% and 60% groups. TMD was significantly decreased during exercise compared to rest in hypoxia. TMD was also significantly decreased during recovery compared to rest in hypoxia. Spo(2) significantly decreased at 60 min rest in hypoxia, during exercise, and recovery compared to baseline. Regional cerebral oxygen saturation was also reduced at 60 min rest in hypoxia, during exercise, and recovery compared to baseline. The current study demonstrated that exercise at 40% and 60% of adjusted Vo(2max) attenuated the adverse effects of hypoxia on mood. These findings may have significant applied value, as negative mood states are known to impair performance in hypoxia. Further studies are needed to replicate the current finding and to clarify the possible mechanisms associated with the potential benefits of exercise on mood state in normobaric hypoxia.

  7. Approximate Simulation of Acute Hypobaric Hypoxia with Normobaric Hypoxia

    Science.gov (United States)

    Conkin, J.; Wessel, J. H., III

    2011-01-01

    INTRODUCTION. Some manufacturers of reduced oxygen (O2) breathing devices claim a comparable hypobaric hypoxia (HH) training experience by providing F(sub I) O2 pO2) of the target altitude. METHODS. Literature from investigators and manufacturers indicate that these devices may not properly account for the 47 mmHg of water vapor partial pressure that reduces the inspired partial pressure of O2 (P(sub I) O2). Nor do they account for the complex reality of alveolar gas composition as defined by the Alveolar Gas Equation. In essence, by providing iso-pO2 conditions for normobaric hypoxia (NH) as for HH exposures the devices ignore P(sub A)O2 and P(sub A)CO2 as more direct agents to induce signs and symptoms of hypoxia during acute training exposures. RESULTS. There is not a sufficient integrated physiological understanding of the determinants of P(sub A)O2 and P(sub A)CO2 under acute NH and HH given the same hypoxic pO2 to claim a device that provides isohypoxia. Isohypoxia is defined as the same distribution of hypoxia signs and symptoms under any circumstances of equivalent hypoxic dose, and hypoxic pO2 is an incomplete hypoxic dose. Some devices that claim an equivalent HH experience under NH conditions significantly overestimate the HH condition, especially when simulating altitudes above 10,000 feet (3,048 m). CONCLUSIONS. At best, the claim should be that the devices provide an approximate HH experience since they only duplicate the ambient pO2 at sea level as at altitude (iso-pO2 machines). An approach to reduce the overestimation is to at least provide machines that create the same P(sub I)O2 (iso-P(sub I)O2 machines) conditions at sea level as at the target altitude, a simple software upgrade.

  8. Specific inhibition of hypoxia-inducible factor (HIF)-1 alpha activation and of vascular endothelial growth factor (VEGF) production by flavonoids.

    Science.gov (United States)

    Hasebe, Yuki; Egawa, Kiyoshi; Yamazaki, Yoko; Kunimoto, Setsuko; Hirai, Yasuaki; Ida, Yoshiteru; Nose, Kiyoshi

    2003-10-01

    Screening using a reporter under the control of the hypoxia-response element (HRE) identified several flavonoids and homoisoflavonoids that inhibit the activation of HRE under hypoxic conditions. Among various compounds, isorhamnetin, luteolin, quercetin, and methyl ophiopogonanone B (MOB) were effective at 3 to 9 microg/ml in inhibiting the reporter activity. The expression of vascular endothelial growth factor (VEGF) mRNA during hypoxia was also inhibited by MOB in HepG2 cells, but the effective doses were 10 to 20 microg/ml. MOB caused destabilization of hypoxia-inducible factor (HIF)-1alpha, as revealed by Western blotting, that was dependent on proteasome activity and the tumor suppressor, p53. The tubular formation and migration of human umbilical vein endothelial cells was also inhibited by MOB. MOB is expected to act as an inhibitor of angiogenesis.

  9. Ifp's New Flexible Hydrocracking Process Combines Maximum Conversion with Production of High Viscosity, High Vi Lube Stocks Le nouveau procédé IFP d'hydrocraquage à haute flexibilité combine conversion maximum et production de bases, huile à haute viscosité et à indice de viscosité élevé

    Directory of Open Access Journals (Sweden)

    Hennico A.

    2006-11-01

    Full Text Available Institut Français du Pétrole (IFP has developed a new dual catalytic system for its hydrocracking process that enables high conversion to middle distillates and production of high viscosity, high VI lube stocks. Although the hydrocracking process is mainly devoted to the conversion of vacuum distillates, deasphalted oil or mixture of both into high quality middle distillates, it can also produce a residue, that after dewaxing will be a very high VI lube base oil. In this presentation major emphasis is put on the possibility to produce very high VI lubes with high viscosity thanks to the development of the new catalytic system. Large flexibility in feedstock selection and easy control of operating variables allow the production of all grades of lube oils associated with high quality middle distillates for a large range of conversion levels. L'Institut Français du Pétrole (IFP a mis au point, pour son procédé d'hydrocraquage, un nouveau système catalytique à 2 catalyseurs qui permet une forte conversion en distillats moyens et la production de fractions lubrifiantes à haute viscosité et indice de viscosité élevé. Si le procédé d'hydrocraquage est essentiellement utilisé pour la conversion de distillats sous vide, d'huile désasphaltée ou d'un mélange des deux en distillats moyens de haute qualité, il peut aussi produire un résidu qui, après déparaffinage, fournira une base pour lubrifiant à indice de viscosité très élevé. Cet article souligne particulièrement la possibilité de produire des lubrifiants à indice de viscosité très élevé et haute viscosité, grâce à ce nouveau système catalytique. Une grande flexibilité dans le choix des produits à traiter et la facilité de contrôle des paramètres opératoires permet la production de toutes les qualités d'huiles lubrifiantes associées à des distillats moyens de haute qualité, pour une large gamme de niveaux de conversion.

  10. Adiponectin promotes VEGF-A-dependent angiogenesis in human chondrosarcoma through PI3K, Akt, mTOR, and HIF-α pathway.

    Science.gov (United States)

    Lee, Hsiang-Ping; Lin, Chih-Yang; Shih, Jhao-Sheng; Fong, Yi-Chin; Wang, Shih-Wei; Li, Te-Mao; Tang, Chih-Hsin

    2015-11-03

    Chondrosarcoma is a type of highly malignant tumor with a potent capacity to invade locally and cause distant metastasis. Adiponectin is a protein hormone secreted predominantly by differentiated adipocytes. On the other hand, angiogenesis is a critical step in tumor growth and metastasis. However, the relationship of adiponectin with vascular endothelial growth factor-A (VEGF-A) expression and angiogenesis in human chondrosarcoma is mostly unknown. In this study we first demonstrated that the expression of adiponectin was correlated with tumor stage of human chondrosarcoma tissues. In addition, we also found that adiponectin increased VEGF-A expression in human chondrosarcoma cells and subsequently induced migration and tube formation in human endothelial progenitor cells (EPCs). Adiponectin promoted VEGF-A expression through adiponectin receptor (AdipoR), phosphoinositide 3 kinase (PI3K), Akt, mammalian target of rapamycin (mTOR), and hypoxia-inducible factor-1α (HIF)-1α signaling cascades. Knockdown of adiponectin decreased VEGF-A expression and also abolished chondrosarcoma conditional medium-mediated tube formation in EPCs in vitro as well as angiogenesis effects in the chick chorioallantoic membrane and Matrigel plug nude mice model in vivo. Therefore, adiponectin is crucial for tumor angiogenesis and growth, which may represent a novel target for anti-angiogenic therapy in human chondrosarcoma.

  11. The role of hypoxia inducible factor 1 (HIF-1) in hypoxia induced apoptosis

    NARCIS (Netherlands)

    Greijer, A.E.; Wall, E. van der

    2004-01-01

    Apoptosis can be induced in response to hypoxia. The severity of hypoxia determines whether cells become apoptotic or adapt to hypoxia and survive. A hypoxic environment devoid of nutrients prevents the cell undergoing energy dependent apoptosis and cells become necrotic. Apoptosis regulatory

  12. Hypoxia-Inducible Factors: Mediators of Cancer Progression; Prognostic and Therapeutic Targets in Soft Tissue Sarcomas

    International Nuclear Information System (INIS)

    Sadri, Navid; Zhang, Paul J.

    2013-01-01

    Soft-tissue sarcomas remain aggressive tumors that result in death in greater than a third of patients due to either loco-regional recurrence or distant metastasis. Surgical resection remains the main choice of treatment for soft tissue sarcomas with pre- and/or post-operational radiation and neoadjuvant chemotherapy employed in more advanced stage disease. However, in recent decades, there has been little progress in the average five-year survival for the majority of patients with high-grade soft tissue sarcomas, highlighting the need for improved targeted therapeutic agents. Clinical and preclinical studies demonstrate that tumor hypoxia and up-regulation of hypoxia-inducible factors (HIFs) is associated with decreased survival, increased metastasis, and resistance to therapy in soft tissue sarcomas. HIF-mediated gene expression regulates many critical aspects of tumor biology, including cell survival, metabolic programming, angiogenesis, metastasis, and therapy resistance. In this review, we discuss HIFs and HIF-mediated genes as potential prognostic markers and therapeutic targets in sarcomas. Many pharmacological agents targeting hypoxia-related pathways are in development that may hold therapeutic potential for treating both primary and metastatic sarcomas that demonstrate increased HIF expression

  13. Angiogenesis and anti-angiogenesis: Perspectives for the treatment of solid tumors

    NARCIS (Netherlands)

    Hinsbergh, V.W.M. van; Collen, A.; Koolwijk, P.

    1999-01-01

    Angiogenesis is the formation of new blood vessels from preexisting ones. Many solid tumors depend on an extensive newly formed vascular network to become nourished and to expand. Tumor cells induce the formation of an extensive but aberrant vascular network by the secretion of angiogenic factors. A

  14. Mature and progenitor endothelial cells perform angiogenesis also under protease inhibition: the amoeboid angiogenesis.

    Science.gov (United States)

    Chillà, Anastasia; Margheri, Francesca; Biagioni, Alessio; Del Rosso, Mario; Fibbi, Gabriella; Laurenzana, Anna

    2018-04-03

    Controlling vascular growth is a challenging aim for the inhibition of tumor growth and metastasis. The amoeboid and mesenchymal types of invasiveness are two modes of migration interchangeable in cancer cells: the Rac-dependent mesenchymal migration requires the activity of proteases; the Rho-ROCK-dependent amoeboid motility is protease-independent and has never been described in endothelial cells. A cocktail of physiologic inhibitors (Ph-C) of serine-proteases, metallo-proteases and cysteine-proteases, mimicking the physiological environment that cells encounter during their migration within the angiogenesis sites was used to induce amoeboid style migration of Endothelial colony forming cells (ECFCs) and mature endothelial cells (ECs). To evaluate the mesenchymal-ameboid transition RhoA and Rac1 activation assays were performed along with immunofluorescence analysis of proteins involved in cytoskeleton organization. Cell invasion was studied in Boyden chambers and Matrigel plug assay for the in vivo angiogenesis. In the present study we showed in both ECFCs and ECs, a decrease of activated Rac1 and an increase of activated RhoA upon shifting of cells to the amoeboid conditions. In presence of Ph-C inhibitors both cell lines acquired a round morphology and Matrigel invasion was greatly enhanced with respect to that observed in the absence of protease inhibition. We also observed that the urokinase-plasminogen-activator (uPAR) receptor silencing and uPAR-integrin uncoupling with the M25 peptide abolished both mesenchymal and amoeboid angiogenesis of ECFCs and ECs in vitro and in vivo, indicating a role of the uPAR-integrin-actin axis in the regulation of amoeboid angiogenesis. Furthermore, under amoeboid conditions endothelial cells seem to be indifferent to VEGF stimulation, which induces an amoeboid signaling pattern also in mesenchymal conditions. Here we first provide a data set disclosing that endothelial cells can move and differentiate into vascular

  15. Signaling and molecular basis of bone marrow niche angiogenesis in leukemia

    NARCIS (Netherlands)

    Shirzad, R.; Shahrabi, S.; Ahmadzadeh, A.; Kampen, K. R.; Shahjahani, M.; Saki, N.

    2016-01-01

    Angiogenesis, the process of blood vessel formation, is necessary for tissue survival in normal and pathologic conditions. Increased angiogenesis in BM niche is correlated with leukemia progression and resistance to treatment. Angiogenesis can interfere with disease progression and several

  16. Probable Chemical Hypoxia Effects on Progress of CNV Through Induction of Promoter CpG Demethylation and Overexpression of IL17RC in Human RPE Cells.

    Science.gov (United States)

    Alivand, Mohammad Reza; Sabouni, Farzaneh; Soheili, Zahra-Soheila

    2016-09-01

    To survey the changes of promoter CpG methylation status and mRNA expression of IL17RC (interleukin 17 receptor C) gene in retinal pigment epithelium (RPE) cells under chemical hypoxia condition for choroidal neovascularization (CNV) modeling in vitro. RPE cells were cultured in both untreated as a control group and treated by cobalt chloride media as a hypoxia group for various concentrations (100-150μM) and times (24-36 hrs.) To confirm chemical hypoxia condition, mRNA expression of HIF (Hypoxia Inducible Factor) -1α, -2α, and Vascular Endothelial Growth Factor (VEGF) was compared between two groups by Real-time PCR. Also, in normoxia and hypoxia conditions, IL17RC expression changes and promoter CpG methylation status were evaluated by Real-time PCR and methylation-specific PCR (MSP) techniques, respectively. Overexpression of HIF-1α, HIF-2α, and VEGF was significant in hypoxia versus normoxia conditions. Our data showed overexpression of IL17RC (2.1- to 6.3-fold) and decreasing of its promoter methylation in comparison with hypoxia and normoxia conditions. It was found that there are significant association between promoter methylation status and expression of IL17RC in chemical hypoxia condition. Therefore, methylation of IL17RC could play as a marker in CNV and degeneration of RPE cells in vitro. Additionally, HIF-α and methylation phenomena may be considered as critical targets for blocking in angiogenesis of age-related degeneration in future studies.

  17. Expression of angiopoietin-1 in hypoxic pericytes: Regulation by hypoxia-inducible factor-2α and participation in endothelial cell migration and tube formation.

    Science.gov (United States)

    Park, Yoon Shin; Kim, Gyungah; Jin, Yoon Mi; Lee, Jee Young; Shin, Jong Wook; Jo, Inho

    2016-01-08

    We previously reported that hypoxia increases angiopoietin-1 (Ang1), but not Ang2, mRNA expression in bovine retinal pericytes (BRP). However, the mechanism underlying Ang1 expression is unknown. Here, we report that Ang1 protein expression increased in hypoxic BRP in a dose- and time-dependent manner. This increase was accompanied by an increase in hypoxia-inducible factor-2α (HIF2α) expression. Transfection with an antisense oligonucleotide for HIF2α partially inhibited the hypoxia-induced increase in Ang1 expression. HIF2α overexpression further potentiated hypoxia-stimulated Ang1 expression, suggesting that HIF2α plays an important role in Ang1 regulation in BRP. When fused the Ang1 promoter (-3040 to +199) with the luciferase reporter gene, we found that hypoxia significantly increased promoter activity by 4.02 ± 1.68 fold. However, progressive 5'-deletions from -3040 to -1799, which deleted two putative hypoxia response elements (HRE), abolished the hypoxia-induced increase in promoter activity. An electrophoretic mobility shift assay revealed that HIF2α was predominantly bound to a HRE site, located specifically at nucleotides -2715 to -2712. Finally, treatment with conditioned medium obtained from hypoxic pericytes stimulated endothelial cell migration and tube formation, which was completely blocked by co-treatment with anti-Ang1 antibody. This study is the first to demonstrate that hypoxia upregulates Ang1 expression via HIF2α-mediated transcriptional activation in pericytes, which plays a key role in angiogenesis. Copyright © 2015 Elsevier Inc. All rights reserved.

  18. The amphibious fish Kryptolebias marmoratus uses different strategies to maintain oxygen delivery during aquatic hypoxia and air exposure.

    Science.gov (United States)

    Turko, Andy J; Robertson, Cayleih E; Bianchini, Kristin; Freeman, Megan; Wright, Patricia A

    2014-11-15

    Despite the abundance of oxygen in atmospheric air relative to water, the initial loss of respiratory surface area and accumulation of carbon dioxide in the blood of amphibious fishes during emersion may result in hypoxemia. Given that the ability to respond to low oxygen conditions predates the vertebrate invasion of land, we hypothesized that amphibious fishes maintain O2 uptake and transport while emersed by mounting a co-opted hypoxia response. We acclimated the amphibious fish Kryptolebias marmoratus, which are able to remain active for weeks in both air and water, for 7 days to normoxic brackish water (15‰, ~21kPa O2; control), aquatic hypoxia (~3.6kPa), normoxic air (~21 kPa) or aerial hypoxia (~13.6kPa). Angiogenesis in the skin and bucco-opercular chamber was pronounced in air- versus water-acclimated fish, but not in response to hypoxia. Aquatic hypoxia increased the O2-carrying capacity of blood via a large (40%) increase in red blood cell density and a small increase in the affinity of hemoglobin for O2 (P50 decreased 11%). In contrast, air exposure increased the hemoglobin O2 affinity (decreased P50) by 25% without affecting the number of red blood cells. Acclimation to aerial hypoxia both increased the O2-carrying capacity and decreased the hemoglobin O2 affinity. These results suggest that O2 transport is regulated both by O2 availability and also, independently, by air exposure. The ability of the hematological system to respond to air exposure independent of O2 availability may allow extant amphibious fishes, and may also have allowed primitive tetrapods to cope with the complex challenges of aerial respiration during the invasion of land. © 2014. Published by The Company of Biologists Ltd.

  19. Subchronic inhalation of soluble manganese induces expression of hypoxia-associated angiogenic genes in adult mouse lungs

    International Nuclear Information System (INIS)

    Bredow, Sebastian; Falgout, Melanie M.; March, Thomas H.; Yingling, Christin M.; Malkoski, Stephen P.; Aden, James; Bedrick, Edward J.; Lewis, Johnnye L.; Divine, Kevin K.

    2007-01-01

    Although the lung constitutes the major exposure route for airborne manganese (Mn), little is known about the potential pulmonary effects and the underlying molecular mechanisms. Transition metals can mimic a hypoxia-like response, activating the hypoxia inducible factor-1 (HIF-1) transcription factor family. Through binding to the hypoxia-response element (HRE), these factors regulate expression of many genes, including vascular endothelial growth factor (VEGF). Increases in VEGF, an important biomarker of angiogenesis, have been linked to respiratory diseases, including pulmonary hypertension. The objective of this study was to evaluate pulmonary hypoxia-associated angiogenic gene expression in response to exposure of soluble Mn(II) and to assess the genes' role as intermediaries of potential pulmonary Mn toxicity. In vitro, 0.25 mM Mn(II) altered morphology and slowed the growth of human pulmonary epithelial cell lines. Acute doses between 0.05 and 1 mM stimulated VEGF promoter activity up to 3.7-fold in transient transfection assays. Deletion of the HRE within the promoter had no effect on Mn(II)-induced VEGF expression but decreased cobalt [Co(II)]-induced activity 2-fold, suggesting that HIF-1 may not be involved in Mn(II)-induced VEGF gene transcription. Nose-only inhalation to 2 mg Mn(II)/m 3 for 5 days at 6 h/day produced no significant pulmonary inflammation but induced a 2-fold increase in pulmonary VEGF mRNA levels in adult mice and significantly altered expression of genes associated with murine angiogenesis. These findings suggest that even short-term exposures to soluble, occupationally relevant Mn(II) concentrations may alter pulmonary gene expression in pathways that ultimately could affect the lungs' susceptibility to respiratory disease

  20. Angiogenesis stimulated by novel nanoscale bioactive glasses

    International Nuclear Information System (INIS)

    Mao, Cong; Chen, Xiaofeng; Miao, Guohou; Lin, Cai

    2015-01-01

    The ability of biomaterials to induce rapid vascular formation is critical in tissue regeneration. Combining recombinant angiogenic growth factors with bioengineered constructs have proven to be difficult due to several issues, including the instability of recombinant proteins, the need for sustained delivery and the dosage of factors. New formulations of bioactive glass, 58S nanosized bioactive glass (58S-NBG), have been reported to enhance wound healing in animal models better than the first generation of 45S5 Bioglass. Therefore, we investigated the effects of extracts of 58S-NBG and 80S-NBG on cultures of human umbilical vein endothelial cells (HUVECs). Cell viability was assessed by MTS assay. In vitro angiogenesis was measured using an ECM gel tube formation assay, and levels of mRNAs for five angiogenic related genes were measured by qRT-PCR. Extracts of 58S-NBG and 80S-NBG stimulated the proliferation of HUVECs, accelerated cell migration, up-regulated expression of the vascular endothelial growth factor, basic fibroblast growth factor, their receptors, and endothelial nitric oxide synthase, resulting in enhanced tube formation in vitro. The enhanced angiogenic response correlated with increased levels of Ca and Si in the extracts of 58S-NBG and 80S-NBG. The ability of 58S-NBG and 80S-NBG to stimulate angiogenesis in vitro provides alternative approaches for stimulating neovascularization of tissue-engineered constructs. (paper)

  1. Cell-Oriented Modeling of Angiogenesis

    Directory of Open Access Journals (Sweden)

    Diego Guidolin

    2011-01-01

    Full Text Available Due to its significant involvement in various physiological and pathological conditions, angiogenesis (the development of new blood vessels from an existing vasculature represents an important area of the actual biological research and a field in which mathematical modeling proved particularly useful in supporting the experimental work. In this paper, we focus on a specific modeling strategy, known as “cell-centered” approach. This type of mathematical models work at a “mesoscopic scale,” assuming the cell as the natural level of abstraction for computational modeling of development. They treat cells phenomenologically, considering their essential behaviors to study how tissue structure and organization emerge from the collective dynamics of multiple cells. The main contributions of the cell-oriented approach to the study of the angiogenic process will be described. From one side, they have generated “basic science understanding” about the process of capillary assembly during development, growth, and pathology. On the other side, models were also developed supporting “applied biomedical research” for the purpose of identifying new therapeutic targets and clinically relevant approaches for either inhibiting or stimulating angiogenesis.

  2. Cell-oriented modeling of angiogenesis.

    Science.gov (United States)

    Guidolin, Diego; Rebuffat, Piera; Albertin, Giovanna

    2011-01-01

    Due to its significant involvement in various physiological and pathological conditions, angiogenesis (the development of new blood vessels from an existing vasculature) represents an important area of the actual biological research and a field in which mathematical modeling proved particularly useful in supporting the experimental work. In this paper, we focus on a specific modeling strategy, known as "cell-centered" approach. This type of mathematical models work at a "mesoscopic scale," assuming the cell as the natural level of abstraction for computational modeling of development. They treat cells phenomenologically, considering their essential behaviors to study how tissue structure and organization emerge from the collective dynamics of multiple cells. The main contributions of the cell-oriented approach to the study of the angiogenic process will be described. From one side, they have generated "basic science understanding" about the process of capillary assembly during development, growth, and pathology. On the other side, models were also developed supporting "applied biomedical research" for the purpose of identifying new therapeutic targets and clinically relevant approaches for either inhibiting or stimulating angiogenesis.

  3. Human embryo-conditioned medium stimulates in vitro endometrial angiogenesis

    NARCIS (Netherlands)

    Kapiteijn, K.; Koolwijk, P.; Weiden, R.M.F. van der; Nieuw Amerongen, G. van; Plaisier, M.; Hinsbergh, V.W.M. van; Helmerhorst, F.M.

    2006-01-01

    Objective: Successful implantation and placentation depend on the interaction between the endometrium and the embryo. Angiogenesis is crucial at this time. In this article we investigate the direct influence of the human embryo on in vitro endometrial angiogenesis. Design: In vitro study. Setting:

  4. Acetaminophen hepatotoxicity and HIF-1α induction in acetaminophen toxicity in mice occurs without hypoxia

    International Nuclear Information System (INIS)

    Chaudhuri, Shubhra; McCullough, Sandra S.; Hennings, Leah; Letzig, Lynda; Simpson, Pippa M.; Hinson, Jack A.; James, Laura P.

    2011-01-01

    HIF-1α is a nuclear factor important in the transcription of genes controlling angiogenesis including vascular endothelial growth factor (VEGF). Both hypoxia and oxidative stress are known mechanisms for the induction of HIF-1α. Oxidative stress and mitochondrial permeability transition (MPT) are mechanistically important in acetaminophen (APAP) toxicity in the mouse. MPT may occur as a result of oxidative stress and leads to a large increase in oxidative stress. We previously reported the induction of HIF-1α in mice with APAP toxicity and have shown that VEGF is important in hepatocyte regeneration following APAP toxicity. The following study was performed to examine the relative contribution of hypoxia versus oxidative stress to the induction of HIF-1α in APAP toxicity in the mouse. Time course studies using the hypoxia marker pimonidazole showed no staining for pimonidazole at 1 or 2 h in B6C3F1 mice treated with APAP. Staining for pimonidazole was present in the midzonal to periportal regions at 4, 8, 24 and 48 h and no staining was observed in centrilobular hepatocytes, the sites of the toxicity. Subsequent studies with the MPT inhibitor cyclosporine A showed that cyclosporine A (CYC; 10 mg/kg) reduced HIF-1α induction in APAP treated mice at 1 and 4 h and did not inhibit the metabolism of APAP (depletion of hepatic non-protein sulfhydryls and hepatic protein adduct levels). The data suggest that HIF-1α induction in the early stages of APAP toxicity is secondary to oxidative stress via a mechanism involving MPT. In addition, APAP toxicity is not mediated by a hypoxia mechanism.

  5. The Clinical Importance of Assessing Tumor Hypoxia: Relationship of Tumor Hypoxia to Prognosis and Therapeutic Opportunities

    Science.gov (United States)

    Walsh, Joseph C.; Lebedev, Artem; Aten, Edward; Madsen, Kathleen; Marciano, Liane

    2014-01-01

    I. Introduction II. The Clinical Importance of Tumor Hypoxia A. Pathophysiology of hypoxia B. Hypoxia's negative impact on the effectiveness of curative treatment 1. Hypoxic tumors accumulate and propagate cancer stem cells 2. Hypoxia reduces the effectiveness of radiotherapy 3. Hypoxia increases metastasis risk and reduces the effectiveness of surgery 4. Hypoxic tumors are resistant to the effects of chemotherapy and chemoradiation C. Hypoxia is prognostic for poor patient outcomes III. Diagnosis of Tumor Hypoxia A. Direct methods 1. Oxygen electrode—direct pO2 measurement most used in cancer research 2. Phosphorescence quenching—alternative direct pO2 measurement 3. Electron paramagnetic resonance 4. 19F-magnetic resonance spectroscopy 5. Overhauser-enhanced MRI B. Endogenous markers of hypoxia 1. Hypoxia-inducible factor-1α 2. Carbonic anhydrase IX 3. Glucose transporter 1 4. Osteopontin 5. A combined IHC panel of protein markers for hypoxia 6. Comet assay C. Physiologic methods 1. Near-infrared spectroscopy/tomography—widely used for pulse oximetry 2. Photoacoustic tomography 3. Contrast-enhanced color duplex sonography 4. MRI-based measurements 5. Blood oxygen level-dependent MRI 6. Pimonidazole 7. EF5 (pentafluorinated etanidazole) 8. Hypoxia PET imaging—physiologic hypoxia measurement providing tomographic information a. 18F-fluoromisonidazole b. 18F-fluoroazomycinarabinofuranoside c. 18F-EF5 (pentafluorinated etanidazole) d. 18F-flortanidazole e. Copper (II) (diacetyl-bis (N4-methylthiosemicarbazone)) f. 18F-FDG imaging of hypoxia IV. Modifying Hypoxia to Improve Therapeutic Outcomes A. Use of hypoxia information in radiation therapy planning B. Use of hypoxia assessment for selection of patients responsive to nimorazole C. Use of hypoxia assessment for selection of patients responsive to tirapazamine D. Use of hypoxia assessment for selection of patients

  6. Ecosystem impacts of hypoxia: thresholds of hypoxia and pathways to recovery

    International Nuclear Information System (INIS)

    Steckbauer, A; Duarte, C M; Vaquer-Sunyer, R; Carstensen, J; Conley, D J

    2011-01-01

    Coastal hypoxia is increasing in the global coastal zone, where it is recognized as a major threat to biota. Managerial efforts to prevent hypoxia and achieve recovery of ecosystems already affected by hypoxia are largely based on nutrient reduction plans. However, these managerial efforts need to be informed by predictions on the thresholds of hypoxia (i.e. the oxygen levels required to conserve biodiversity) as well as the timescales for the recovery of ecosystems already affected by hypoxia. The thresholds for hypoxia in coastal ecosystems are higher than previously thought and are not static, but regulated by local and global processes, being particularly sensitive to warming. The examination of recovery processes in a number of coastal areas managed for reducing nutrient inputs and, thus, hypoxia (Northern Adriatic; Black Sea; Baltic Sea; Delaware Bay; and Danish Coastal Areas) reveals that recovery timescales following the return to normal oxygen conditions are much longer than those of loss following the onset of hypoxia, and typically involve decadal timescales. The extended lag time for ecosystem recovery from hypoxia results in non-linear pathways of recovery due to hysteresis and the shift in baselines, affecting the oxygen thresholds for hypoxia through time.

  7. Hypoxia induces cancer-associated cAMP/PKA signalling through HIF-mediated transcriptional control of adenylyl cyclases VI and VII.

    Science.gov (United States)

    Simko, Veronika; Iuliano, Filippo; Sevcikova, Andrea; Labudova, Martina; Barathova, Monika; Radvak, Peter; Pastorekova, Silvia; Pastorek, Jaromir; Csaderova, Lucia

    2017-08-31

    Hypoxia is a phenomenon often arising in solid tumours, linked to aggressive malignancy, bad prognosis and resistance to therapy. Hypoxia-inducible factor-1 has been identified as a key mediator of cell and tissue adaptation to hypoxic conditions through transcriptional activation of many genes involved in glucose metabolism and other cancer-related processes, such as angiogenesis, cell survival and cell invasion. Cyclic adenosine 3'5'-monophosphate is one of the most ancient and evolutionarily conserved signalling molecules and the cAMP/PKA signalling pathway plays an important role in cellular adaptation to hypoxia. We have investigated possible new mechanisms behind hypoxic activation of the cAMP/PKA pathway. For the first time, we have shown that hypoxia induces transcriptional up-regulation of the system of adenylyl cyclases, enzymes responsible for cAMP production, in a panel of carcinoma cell lines of various origin. Our data prove functional relevance of the hypoxic increase of adenylyl cyclases VI and VII at least partially mediated by HIF-1 transcription factor. We have identified adenylyl cyclase VI and VII isoforms as mediators of cellular response to hypoxia, which led to the elevation of cAMP levels and enhanced PKA activity, with an impact on cell migration and pH regulation.

  8. Menadione and ethacrynic acid inhibit the hypoxia-inducible factor (HIF) pathway by disrupting HIF-1α interaction with p300.

    Science.gov (United States)

    Na, Yu-Ran; Han, Ki-Cheol; Park, Hyunsung; Yang, Eun Gyeong

    2013-05-17

    Hypoxia is a general characteristic of most solid malignancies and intimately related to neoplastic diseases and cancer progression. Homeostatic response to hypoxia is primarily mediated by hypoxia inducible factor (HIF)-1α that elicits transcriptional activity through recruitment of the CREB binding protein (CBP)/p300 coactivator. Targeted blockade of HIF-1α binding to CBP/p300 would thus constitute a novel approach for cancer treatment by suppressing tumor angiogenesis and metastasis. Here, we identified inhibitors against the interaction between HIF-1α and p300 by a fluorescence polarization-based assay employing a fluorescently-labeled peptide containing the C-terminal activation domain of HIF-1α. Two small molecule inhibitors, menadione (MD) and ethacrynic acid (EA), were found to decrease expression of luciferase under the control of hypoxia-responsive elements in hypoxic cells as well as to efficiently block the interaction between the full-length HIF-1α and p300. While these compounds did not alter the expression level of HIF-1α, they down-regulated expression of a HIF-1α target vascular endothelial growth factor (VEGF) gene. Considering hypoxia-induced VEGF expression leading to highly aggressive tumor growth, MD and EA may provide new scaffolds for development of tumor therapeutic reagents as well as tools for a better understanding of HIF-1α-mediated hypoxic regulation. Copyright © 2013 Elsevier Inc. All rights reserved.

  9. Positron emission tomography tracers for imaging angiogenesis

    International Nuclear Information System (INIS)

    Haubner, Roland; Beer, Ambros J.; Wang, Hui; Chen, Xiaoyuan

    2010-01-01

    Position emission tomography imaging of angiogenesis may provide non-invasive insights into the corresponding molecular processes and may be applied for individualized treatment planning of antiangiogenic therapies. At the moment, most strategies are focusing on the development of radiolabelled proteins and antibody formats targeting VEGF and its receptor or the ED-B domain of a fibronectin isoform as well as radiolabelled matrix metalloproteinase inhibitors or α v β 3 integrin antagonists. Great efforts are being made to develop suitable tracers for different target structures. All of the major strategies focusing on the development of radiolabelled compounds for use with positron emission tomography are summarized in this review. However, because the most intensive work is concentrated on the development of radiolabelled RGD peptides for imaging α v β 3 expression, which has successfully made its way from bench to bedside, these developments are especially emphasized. (orig.)

  10. Melatonin Reduces Angiogenesis in Serous Papillary Ovarian Carcinoma of Ethanol-Preferring Rats

    Science.gov (United States)

    Zonta, Yohan Ricci; Martinez, Marcelo; Camargo, Isabel Cristina C.; Domeniconi, Raquel F.; Lupi Júnior, Luiz Antonio; Pinheiro, Patricia Fernanda F.; Reiter, Russel J.; Martinez, Francisco Eduardo; Chuffa, Luiz Gustavo A.

    2017-01-01

    Angiogenesis is a hallmark of ovarian cancer (OC); the ingrowth of blood vessels promotes rapid cell growth and the associated metastasis. Melatonin is a well-characterized indoleamine that possesses important anti-angiogenic properties in a set of aggressive solid tumors. Herein, we evaluated the role of melatonin therapy on the angiogenic signaling pathway in OC of an ethanol-preferring rat model that mimics the same pathophysiological conditions occurring in women. OC was chemically induced with a single injection of 7,12-dimethylbenz(a)anthracene (DMBA) under the ovarian bursa. After the rats developed serous papillary OC, half of the animals received intraperitoneal injections of melatonin (200 µg/100 g body weight/day) for 60 days. Melatonin-treated animals showed a significant reduction in OC size and microvessel density. Serum levels of melatonin were higher following therapy, and the expression of its receptor MT1 was significantly increased in OC-bearing rats, regardless of ethanol intake. TGFβ1, a transforming growth factor-beta1, was reduced only after melatonin treatment. Importantly, vascular endothelial growth factor (VEGF) was severely reduced after melatonin therapy in animals given or not given ethanol. Conversely, the levels of VEGF receptor 1 (VEGFR1) was diminished after ethanol consumption, regardless of melatonin therapy, and VEGFR2 was only reduced following melatonin. Hypoxia-inducible factor (HIF)-1α was augmented with ethanol consumption, and, notably, melatonin significantly reduced their levels. Collectively, our results suggest that melatonin attenuates angiogenesis in OC in an animal model of ethanol consumption; this provides a possible complementary therapeutic opportunity for concurrent OC chemotherapy. PMID:28398226

  11. Tympanomastoid cholesterol granulomas: Immunohistochemical evaluation of angiogenesis.

    Science.gov (United States)

    Iannella, Giannicola; Di Gioia, Cira; Carletti, Raffaella; Magliulo, Giuseppe

    2017-08-01

    This study investigates the immunohistochemical expression of vascular endothelial growth factor (VEGF) and CD34 in patients treated for middle ear and mastoid cholesterol granulomas to evaluate the angiogenesis and vascularization of this type of lesion. A correlation between the immunohistochemical data and the radiological and intraoperative evidence of temporal bone marrow invasion and blood source connection was performed to validate this hypothesis. Retrospective study. Immunohistochemical expression of VEGF and CD34 in a group of 16 patients surgically treated for cholesterol granuloma was examined. Middle ear cholesteatomas with normal middle ear mucosa and external auditory canal skin were used as the control groups. The radiological and intraoperative features of cholesterol granulomas were also examined. In endothelial cells, there was an increased expression of angiogenetic growth factor receptors in all the cholesterol granulomas in this study. The quantitative analysis of VEGF showed a mean value of 37.5, whereas the CD34 quantitative analysis gave a mean value of 6.8. Seven patients presented radiological or intraoperative evidence of bone marrow invasion, hematopoietic potentialities, or blood source connections that might support the bleeding theory. In all of these cases there was computed tomography or intraoperative evidence of bone erosion of the middle ear and/or temporal bone structures. The mean values of VEGF and CD34 were 41.1 and 7.7, respectively. High values of VEGF and CD34 are present in patients with cholesterol granulomas. Upregulation of VEGF and CD34 is indicative of a remarkable angiogenesis and a widespread vascular concentration in cholesterol granulomas. 3b. Laryngoscope, 127:E283-E290, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  12. Proinflammatory mediators stimulate neutrophil-directed angiogenesis.

    LENUS (Irish Health Repository)

    McCourt, M

    2012-02-03

    BACKGROUND: Vascular endothelial growth factor (VEGF; vascular permeability factor) is one of the most potent proangiogenic cytokines, and it plays a central role in mediating the process of angiogenesis or new blood vessel formation. Neutrophils (PMNs) recently have been shown to produce VEGF. HYPOTHESIS: The acute inflammatory response is a potent stimulus for PMN-directed angiogenesis. METHODS: Neutrophils were isolated from healthy volunteers and stimulated with lipopolysaccharide (LPS), tumor necrosis factor alpha (TNF-alpha), interleukin 6 (IL-6), and anti-human Fas monoclonal antibody. Culture supernatants were assayed for VEGF using enzyme-linked immunosorbent assays. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs were then added to human umbilical vein endothelial cells and human microvessel endothelial cells and assessed for endothelial cell proliferation using 5-bromodeoxyuridine labeling. Tubule formation was also assessed on MATRIGEL basement membrane matrix. Neutrophils were lysed to measure total VEGF release, and VEGF expression was detected using Western blot analysis. RESULTS: Lipopolysaccharide and TNF-alpha stimulation resulted in significantly increased release of PMN VEGF (532+\\/-49 and 484+\\/-80 pg\\/mL, respectively; for all, presented as mean +\\/- SEM) compared with control experiments (32+\\/-4 pg\\/mL). Interleukin 6 and Fas had no effect. Culture supernatants from LPS- and TNF-alpha-stimulated PMNs also resulted in significant increases (P<.005) in macrovascular and microvascular endothelial cell proliferation and tubule formation. Adding anti-human VEGF-neutralizing polyclonal antibody to stimulated PMN supernatant inhibited these effects. Total VEGF release following cell lysis and Western blot analysis suggests that the VEGF is released from an intracellular store. CONCLUSION: Activated human PMNs are directly angiogenic by releasing VEGF, and this has important implications for inflammation, capillary leak syndrome

  13. Hypoxic stress simultaneously stimulates vascular endothelial growth factor via hypoxia-inducible factor-1α and inhibits stromal cell-derived factor-1 in human endometrial stromal cells.

    Science.gov (United States)

    Tsuzuki, Tomoko; Okada, Hidetaka; Cho, Hisayuu; Tsuji, Shoko; Nishigaki, Akemi; Yasuda, Katsuhiko; Kanzaki, Hideharu

    2012-02-01

    Hypoxia of the human endometrium is a physiologic event occurring during the perimenstrual period and the local stimulus for angiogenesis. The aim of this study was to investigate the effects of hypoxic stress on the regulation of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1/CXCL12), and the potential role of hypoxia-inducible factor-1α (HIF-1α) in the endometrium. Human endometrial stromal cells (ESCs, n= 22 samples) were studied in vitro. ESCs were cultured under hypoxic and normoxic conditions and treated with cobalt chloride (CoCl₂; a hypoxia-mimicking agent) and/or echinomycin, a small-molecule inhibitor of HIF-1α activity. The mRNA levels and production of VEGF and SDF-1 were assessed by real-time PCR and ELISA, respectively. The HIF-1α protein levels were measured using western blot analysis. Hypoxia simultaneously induced the expression of mRNA and production of VEGF and attenuated the expression and production of SDF-1 from ESCs in a time-dependent manner. Similar changes were observed in the ESCs after stimulation with CoCl₂ in a dose-dependent manner. CoCl₂ significantly induced the expression of HIF-1α protein, and its highest expression was observed at 6 h. Echinomycin inhibited hypoxia-induced VEGF production without affecting the HIF-1α protein level and cell toxicity and had no effect on SDF-1 secretion (P hypoxic conditions that could influence angiogenesis in the human endometrium.

  14. Role of the Norrie disease pseudoglioma gene in sprouting angiogenesis during development of the retinal vasculature.

    Science.gov (United States)

    Luhmann, Ulrich F O; Lin, Jihong; Acar, Niyazi; Lammel, Stefanie; Feil, Silke; Grimm, Christian; Seeliger, Mathias W; Hammes, Hans-Peter; Berger, Wolfgang

    2005-09-01

    To characterize developmental defects and the time course of Norrie disease in retinal and hyaloid vasculature during retinal development and to identify underlying molecular angiogenic pathways that may be affected in Norrie disease, exudative vitreoretinopathy, retinopathy of prematurity, and Coats' disease. Norrie disease pseudoglioma homologue (Ndph)-knockout mice were studied during retinal development at early postnatal (p) stages (p5, p10, p15, and p21). Histologic techniques, quantitative RT-PCR, ELISA, and Western blot analyses provided molecular data, and scanning laser ophthalmoscopy (SLO) angiography and electroretinography (ERG) were used to obtain in vivo data. The data showed that regression of the hyaloid vasculature of Ndph-knockout mice occurred but was drastically delayed. The development of the superficial retinal vasculature was strongly delayed, whereas the deep retinal vasculature did not form because of the blockage of vessel outgrowth into the deep retinal layers. Subsequently, microaneurysm-like lesions formed. Several angiogenic factors were differentially transcribed during retinal development. Increased levels of hypoxia inducible factor-1alpha (HIF1alpha) and VEGFA, as well as a characteristic ERG pattern, confirmed hypoxic conditions in the inner retina of the Ndph-knockout mouse. These data provide evidence for a crucial role of Norrin in hyaloid vessel regression and in sprouting angiogenesis during retinal vascular development, especially in the development of the deep retinal capillary networks. They also suggest an early and a late phase of Norrie disease and may provide an explanation for similar phenotypic features of allelic retinal diseases in mice and patients as secondary consequences of pathologic hypoxia.

  15. LincRNA-p21 Impacts Prognosis in Resected Non-Small Cell Lung Cancer Patients through Angiogenesis Regulation.

    Science.gov (United States)

    Castellano, Joan J; Navarro, Alfons; Viñolas, Nuria; Marrades, Ramon M; Moises, Jorge; Cordeiro, Anna; Saco, Adela; Muñoz, Carmen; Fuster, Dolors; Molins, Laureano; Ramirez, Josep; Monzo, Mariano

    2016-12-01

    Long intergenic noncoding RNA-p21 (lincRNA-p21) is a long noncoding RNA transcriptionally activated by tumor protein p53 (TP53) and hypoxia inducible factor 1 alpha subunit (HIF1A). It is involved in the regulation of TP53-dependent apoptosis and the Warburg effect. We have investigated the role of lincRNA-p21 in NSCLC. LincRNA-p21 expression was assessed in tumor and normal tissue from 128 patients with NSCLC and correlated with time to relapse and cancer-specific survival (CSS). H23, H1299, and HCC-44 cell lines were cultured in hypoxic conditions after silencing of lincRNA-p21. The TaqMan human angiogenesis array was used to explore angiogenesis-related gene expression. Levels of the protein vascular endothelial growth factor A were measured by enzyme-linked immunosorbent assay in the cell supernatants. Angiogenic capability was measured by human umbilical vein endothelial cell tube formation assay. Microvascular density in tumor samples was analyzed by immunohistochemistry. LincRNA-p21 was down-regulated in tumor tissue, but no association was observed with TP53 mutational status. High lincRNA-p21 levels were associated with poor CSS in all patients (p = 0.032). When patients were classified according to histological subtypes, the impact of lincRNA-p21 was confined to patients with adenocarcinoma in both time to relapse (p = 0.006) and CSS (p < 0.001). To explain the poor outcome of patients with high lincRNA-p21 expression, we studied the role of lincRNA-p21 in angiogenesis in vitro and observed a global downregulation in the expression of angiogenesis-related genes when lincRNA-p21 was inhibited. Moreover, supernatants from lincRNA-p21-inhibited cells were significantly less angiogenic and had lower levels of secreted vascular endothelial growth factor A than controls did. Finally, tumor samples with high lincRNA-p21 levels had higher microvascular density. Our findings suggest that lincRNA-p21 affects outcome in patients with NSCLC adenocarcinoma through

  16. Kinetic modeling in PET imaging of hypoxia

    DEFF Research Database (Denmark)

    Li, Fan; Jørgensen, Jesper Tranekjær; Hansen, Anders E

    2014-01-01

    be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET......Tumor hypoxia is associated with increased therapeutic resistance leading to poor treatment outcome. Therefore the ability to detect and quantify intratumoral oxygenation could play an important role in future individual personalized treatment strategies. Positron Emission Tomography (PET) can...... analysis for PET imaging of hypoxia....

  17. QUANTIFICATION OF ANGIOGENESIS IN THE CHICKEN CHORIOALLANTOIC MEMBRANE (CAM

    Directory of Open Access Journals (Sweden)

    Silvia Blacher

    2011-05-01

    Full Text Available The chick chorioallantoic membrane (CAM provides a suitable in vivo model to study angiogenesis and evaluate several pro- and anti-angiogenic factors and compounds. In the present work, new developments in image analysis are used to quantify CAM angiogenic response from optical microscopic observations, covering all vascular components, from the large supplying and feeding vessels down to the capillary plexus. To validate our methodology angiogenesis is quantified during two phases of CAM development (day 7 and 13 and after treatment with an antiangiogenic modulator of the angiogenesis. Our morphometric analysis emphasizes that an accurate quantification of the CAM vasculature needs to be performed at various scales.

  18. Aromatic Hydrocarbon Receptor Suppresses Prostate Cancer Bone Metastasis Cells-Induced Vasculogenesis of Endothelial Progenitor Cells under Hypoxia

    Directory of Open Access Journals (Sweden)

    Shuai Huang

    2016-07-01

    Full Text Available Background/Aims: Hypoxia leads to the development of neovascularization in solid tumor by regulating VEGF expression. Aromatic hydrocarbon receptor (AHR, a receptor for dioxin-like compounds, functions as a transcription factor through dimerization with hypoxia-inducible factors 1β (HIF-1β and inhibits the secretion of vascular endothelial growth factor (VEGF. The purpose of this study was to explore whether AHR can suppress hypoxia-induced VEGF production in prostate bone metastasis cells and repress neovascularization in endothelial progenitor cells (EPCs, and, if so, through what mechanisms. Methods: PC-3 or LNCaP cells induced angiogenesis was detected by Matrigel-based tube formation assay, mRNA expression levels was measured by qRT-PCR, VEGF secretion level was determined by ELISA assay, respectively. Results: AHR activation inhibits hypoxia-induced adhesiveness and vasculogenesis of EPCs induced by PC-3 or LNCaP cells under hypoxia. Moreover, AHR activation suppressed hypoxia-induced VEGF production in PC-3 and LNCaP cells (48 ± 14% in PC-3, p = 0.000; 41 ± 14% in LNCaP, p = 0.000 by attenuating HIF-1α and HIF-1β level that in turn diminished the angiogenic ability of EPCs in vitro. Furthermore, we found the mRNA level of hypoxia-inducible factors 1α (HIF-1α (1.54 ± 0.13 fold in PC-3, p = 0.002, 1.62 ± 0.12 fold in LNCaP, p = 0.001 and HIF-1β (1.67 ± 0.23 fold in PC-3, p = 0.007; 1.75 ± 0.26 fold in LNCaP, p=0.008 were upregulated in prostate cancer bone metastasis PC-3 and LNCaP cell lines in response to hypoxia, and revealed that the regulation of VEGF by HIF-1α and HIF-1β was possibly mediated by the activation of phosphatidylinositol 3-kinase pathway. Conclusion: By providing a mechanistic insight into the modulation of neovascularization by AHR ligand, we suggest that AHR ligand has a strong potential of being a new therapeutic agent with applications in the field of bone metastatic prostate cancer.

  19. Human erythropoietin response to hypocapnic hypoxia, normocapnic hypoxia, and hypocapnic normoxia

    DEFF Research Database (Denmark)

    Klausen, T; Christensen, H; Hansen, J M

    1996-01-01

    exposed to 2 h each of hypocapnic hypoxia, normocapnic hypoxia, hypocapnic normoxia, and normal breathing of room air (control experiment). During the control experiment, serum-EPO showed significant variations (ANOVA P = 0.047) with a 15% increase in mean values. The serum-EPO measured in the other...... (10% Co2 with 10% O2) to the hypoxic gas mixture. This elicited an increased ventilation, unaltered arterial pH and haemoglobin oxygen affinity, a lower degree of hypoxia than during hypocapnic hypoxia, and no significant changes in serum-EPO (ANOVA P > 0.05). Hypocapnic normoxia, produced...

  20. Hypoxia Inducible Factor 1α Promotes Endogenous Adaptive Response in Rat Model of Chronic Cerebral Hypoperfusion

    Directory of Open Access Journals (Sweden)

    Ying Yang

    2017-01-01

    Full Text Available Hypoxia inducible factor 1α (HIF-1α, a pivotal regulator of gene expression in response to hypoxia and ischemia, is now considered to regulate both pro-survival and pro-death responses depending on the duration and severity of the stress. We previously showed that chronic global cerebral hypoperfusion (CCH triggered long-lasting accumulation of HIF-1α protein in the hippocampus of rats. However, the role of the stabilized HIF-1α in CCH is obscure. Here, we knock down endogenous HIF-1α to determine whether and how HIF-1α affects the disease processes and phenotypes of CCH. Lentivirus expressing HIF-1α small hairpin RNA was injected into the bilateral hippocampus and bilateral ventricles to knock down HIF-1α gene expression in the hippocampus and other brain areas. Permanent bilateral common carotid artery occlusions, known as 2-vessel occlusions (2VOs, were used to induce CCH in rats. Angiogenesis, oxidative stress, histopathological changes of the brain, and cognitive function were tested. Knockdown of HIF-1α prior to 2VO significantly exacerbates the impairment of learning and memory after four weeks of CCH. Mechanically, reduced cerebral angiogenesis, increased oxidative damage, and increased density of astrocytes and microglia in the cortex and some subregions of hippocampus are also shown after four weeks of CCH. Furthermore, HIF-1α knockdown also disrupts upregulation of regulated downstream genes. Our findings suggest that HIF-1α-protects the brain from oxidative stress and inflammation response in the disease process of CCH. Accumulated HIF-1α during CCH mediates endogenous adaptive processes to defend against more severe hypoperfusion injury of the brain, which may provide a therapeutic benefit.

  1. Regulation of Membrane-Type 4 Matrix Metalloproteinase by SLUG Contributes to Hypoxia-Mediated Metastasis12

    Science.gov (United States)

    Huang, Chi-Hung; Yang, Wen-Hao; Chang, Shyue-Yih; Tai, Shyh-Kuan; Tzeng, Cheng-Hwei; Kao, Jung-Yie; Wu, Kou-Juey; Yang, Muh-Hwa

    2009-01-01

    The hypoxic tumor environment has been shown to be critical to cancer metastasis through the promotion of angiogenesis, induction of epithelial-mesenchymal transition (EMT), and acquisition of invasive potential. However, the impact of hypoxia on the expression profile of the proteolytic enzymes involved in invasiveness is relatively unknown. Membrane-type 4 matrix metalloproteinase (MT4-MMP) is a glycosyl-phosphatidyl inositol-anchored protease that has been shown to be overexpressed in human cancers. However, detailed mechanisms regarding the regulation and function of MT4-MMP expression in tumor cells remain unknown. Here, we demonstrate that hypoxia or overexpression of hypoxia-inducible factor-1α (HIF-1α) induced MT4-MMP expression in human cancer cells. Activation of SLUG, a transcriptional factor regulating the EMT process of human cancers, by HIF-1α was critical for the induction of MT4-MMP under hypoxia. SLUG regulated the transcription of MT4-MMP through direct binding to the E-box located in its proximal promoter. Short-interference RNA-mediated knockdown of MT4-MMP attenuated in vitro invasiveness and in vivo pulmonary colonization of tumor cells without affecting cell migratory ability. MT4-MMP promoted invasiveness and pulmonary colonization through modulation of the expression profile of MMPs and angiogenic factors. Finally, coexpression of HIF-1α and MT4-MMP in human head and neck cancer was predictive of a worse clinical outcome. These findings establish a novel signaling pathway for hypoxia-mediated metastasis and elucidate the underlying regulatory mechanism and functional significance of MT4-MMP in cancer metastasis. PMID:20019845

  2. Hypoxia and the heart of poikilotherms

    Czech Academy of Sciences Publication Activity Database

    Ošťádal, Bohuslav

    2014-01-01

    Roč. 1, č. 1 (2014), s. 28-32 Institutional support: RVO:67985823 Keywords : blood supply heart * poikilotherms * tolerance to hypoxia Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery

  3. Redox signaling during hypoxia in mammalian cells

    Directory of Open Access Journals (Sweden)

    Kimberly A. Smith

    2017-10-01

    Full Text Available Hypoxia triggers a wide range of protective responses in mammalian cells, which are mediated through transcriptional and post-translational mechanisms. Redox signaling in cells by reactive oxygen species (ROS such as hydrogen peroxide (H2O2 occurs through the reversible oxidation of cysteine thiol groups, resulting in structural modifications that can change protein function profoundly. Mitochondria are an important source of ROS generation, and studies reveal that superoxide generation by the electron transport chain increases during hypoxia. Other sources of ROS, such as the NAD(PH oxidases, may also generate oxidant signals in hypoxia. This review considers the growing body of work indicating that increased ROS signals during hypoxia are responsible for regulating the activation of protective mechanisms in diverse cell types.

  4. Hypoxia, HIF-1 Regulation and Cancer Therapy

    NARCIS (Netherlands)

    Groot, A.J.

    2008-01-01

    Oxygen insufficiency (hypoxia) is a common feature of human cancer and associated with tumor aggressiveness and poor clinical outcome. Furthermore, hypoxic tumors are more resistant to ionizing radiation and chemotherapy contributing to their unfavorable prognosis. The oxygen sensing pathway is

  5. 2007 Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  6. 2004 Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  7. 2005 Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  8. 2002 Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  9. 2003 Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  10. 2001 Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  11. Surgical revascularization induces angiogenesis in orthotopic bone allograft

    NARCIS (Netherlands)

    Willems, Wouter F.; Kremer, Thomas; Friedrich, Patricia; Bishop, Allen T.

    2012-01-01

    Remodeling of structural bone allografts relies on adequate revascularization, which can theoretically be induced by surgical revascularization. We developed a new orthotopic animal model to determine the technical feasibility of axial arteriovenous bundle implantation and resultant angiogenesis. We

  12. Angiogenesis and Therapeutic Approaches to NF1 Tumors

    National Research Council Canada - National Science Library

    Muir, David F

    2007-01-01

    .... Invivo and in vitro models were used to firmly conclude that Nf1 haploinsufficiency in endothelial cells results inexaggerated proliferation and angiogenesis in response to key pro-angiogenic factors...

  13. Molecular targeting of angiogenesis for imaging and therapy

    International Nuclear Information System (INIS)

    Brack, Simon S.; Neri, Dario; Dinkelborg, Ludger M.

    2004-01-01

    Angiogenesis, i.e. the proliferation of new blood vessels from pre-existing ones, is an underlying process in many human diseases, including cancer, blinding ocular disorders and rheumatoid arthritis. The ability to selectively target and interfere with neovascularisation would potentially be useful in the diagnosis and treatment of angiogenesis-related diseases. This review presents the authors' views on some of the most relevant markers of angiogenesis described to date, as well as on specific ligands which have been characterised in pre-clinical animal models and/or clinical studies. Furthermore, we present an overview on technologies which are likely to have an impact on the way molecular targeting of angiogenesis is performed in the future. (orig.)

  14. Cognition Effects of Low-Grade Hypoxia

    Science.gov (United States)

    2016-07-01

    human short-term memory . Br J Anaesth. 1971; 43(6):548–552. 3. Crow TJ, Kelman GR. Psychological effects of mild acute hypoxia. Br J Anaesth. 1973; 45...Journal Article 3. DATES COVERED (From – To) Jan 2003 – Sep 2005 4. TITLE AND SUBTITLE Cognition Effects of Low-Grade Hypoxia 5a. CONTRACT NUMBER... cognitive function are reported in this paper. The study compared cognitive function during short exposures at four different altitudes. Ninety-one

  15. Allogeneic transplantation of programmable cells of monocytic origin (PCMO) improves angiogenesis and tissue recovery in critical limb ischemia (CLI): a translational approach.

    Science.gov (United States)

    Berndt, Rouven; Hummitzsch, Lars; Heß, Katharina; Albrecht, Martin; Zitta, Karina; Rusch, Rene; Sarras, Beke; Bayer, Andreas; Cremer, Jochen; Faendrich, Fred; Groß, Justus

    2018-04-27

    Employing growth factor-induced partial reprogramming in vitro, peripheral human blood monocytes can acquire a state of plasticity along with expression of various markers of pluripotency. These so-called programmable cells of monocytic origin (PCMO) hold great promise in regenerative therapies. The aim of this translational study was to explore and exploit the functional properties of PCMO for allogeneic cell transplantation therapy in critical limb ischemia (CLI). Using our previously described differentiation protocol, murine and human monocytes were differentiated into PCMO. We examined paracrine secretion of pro-angiogenic and tissue recovery-associated proteins under hypoxia and induction of angiogenesis by PCMO in vitro. Allogeneic cell transplantation of PCMO was performed in a hind limb ischemia mouse model in comparison to cell transplantation of native monocytes and a placebo group. Moreover, we analyzed retrospectively four healing attempts with PCMO in patients with peripheral artery disease (PAD; Rutherford classification, stage 5 and 6). Statistical analysis was performed by using one-way ANOVA, Tukey's test or the Student's t test, p < 0.05. Cell culture experiments revealed good resilience of PCMO under hypoxia, enhanced paracrine release of pro-angiogenic and tissue recovery-associated proteins and induction of angiogenesis in vitro by PCMO. Animal experiments demonstrated significantly enhanced SO 2 saturation, blood flow, neoangiogenesis and tissue recovery after treatment with PCMO compared to treatment with native monocytes and placebo. Finally, first therapeutic application of PCMO in humans demonstrated increased vascular collaterals and improved wound healing in patients with chronic CLI without exaggerated immune response, malignant processes or extended infection after 12 months. In all patients minor and/or major amputations of the lower extremity could be avoided. In summary, PCMO improve angiogenesis and tissue recovery in chronic

  16. Leptin and its cardiovascular effects: Focus on angiogenesis

    Directory of Open Access Journals (Sweden)

    Zoya Tahergorabi

    2015-01-01

    Full Text Available Leptin is an endocrine hormone synthesized by adipocytes. It plays a key role in the energy homeostasis in central and peripheral tissues and has additional roles are attributed to it, such as the regulation of reproduction, immune function, bone homeostasis, and angiogenesis. The plasma concentration of leptin significantly increases in obese individuals. In the present review, we give an introduction concerning leptin, its receptors, signaling pathways, and its effect on cardiovascular system, especially on angiogenesis.

  17. Gene therapy and angiogenesis in patients with coronary artery disease

    DEFF Research Database (Denmark)

    Kastrup, Jens

    2010-01-01

    Not all patients with severe coronary artery disease can be treated satisfactorily with current recommended medications and revascularization techniques. Various vascular growth factors have the potential to induce angiogenesis in ischemic tissue. Clinical trials have only evaluated the effect...... of VEGF and FGF in patients with coronary artery disease. The initial small and unblinded studies with either recombinant growth factor proteins or genes encoding growth factors were encouraging, demonstrating both clinical improvement and evidence of angiogenesis. However, subsequent larger double...

  18. VEGF blockade inhibits angiogenesis and reepithelialization of endometrium

    OpenAIRE

    Fan, Xiujun; Krieg, Sacha; Kuo, Calvin J.; Wiegand, Stanley J.; Rabinovitch, Marlene; Druzin, Maurice L.; Brenner, Robert M.; Giudice, Linda C.; Nayak, Nihar R.

    2008-01-01

    Despite extensive literature on vascular endothelial growth factor (VEGF) expression and regulation by steroid hormones, the lack of clear understanding of the mechanisms of angiogenesis in the endometrium is a major limitation for use of antiangiogenic therapy targeting endometrial vessels. In the current work, we used the rhesus macaque as a primate model and the decidualized mouse uterus as a murine model to examine angiogenesis during endometrial breakdown and regeneration. We found that ...

  19. Novel endogenous angiogenesis inhibitors and their therapeutic potential.

    Science.gov (United States)

    Rao, Nithya; Lee, Yu Fei; Ge, Ruowen

    2015-10-01

    Angiogenesis, the formation of new blood vessels from the pre-existing vasculature is essential for embryonic development and tissue homeostasis. It also plays critical roles in diseases such as cancer and retinopathy. A delicate balance between pro- and anti-angiogenic factors ensures normal physiological homeostasis. Endogenous angiogenesis inhibitors are proteins or protein fragments that are formed in the body and have the ability to limit angiogenesis. Many endogenous angiogenesis inhibitors have been discovered, and the list continues to grow. Endogenous protein/peptide inhibitors are relatively less toxic, better tolerated and have a lower risk of drug resistance, which makes them attractive as drug candidates. In this review, we highlight ten novel endogenous protein angiogenesis inhibitors discovered within the last five years, including ISM1, FKBPL, CHIP, ARHGAP18, MMRN2, SOCS3, TAp73, ZNF24, GPR56 and JWA. Although some of these proteins have been well characterized for other biological functions, we focus on their new and specific roles in angiogenesis inhibition and discuss their potential for therapeutic application.

  20. Fascin 1 is dispensable for developmental and tumour angiogenesis

    Directory of Open Access Journals (Sweden)

    Yafeng Ma

    2013-09-01

    The actin bundling protein fascin 1 is not expressed in adult epithelial tissues, but during development it is transiently expressed in many different cell types, and later in adults it is expressed in a subset of immune cells, nervous tissues, endothelial cells, smooth muscle cells and pericytes. In contrast to the wealth of knowledge about the role of fascin 1 in cancer cell migration and invasion, little is known about the involvement of fascin 1 in angiogenesis. We speculated that as angiogenesis involves migration and invasion of tissues by endothelial cells, fascin 1 might have a role in both normal and tumour angiogenesis. Here, we provide evidence that loss of fascin 1 causes relatively minor reductions to angiogenesis during embryonic, postnatal and cancerous development by examining E12.5 hindbrains, postnatal retinas and B16F0 tumour cell allografts in fascin 1-null mice. We also find that in fascin 1 null tissues, endothelial cells display reduced filopodia formation during sprouting. We thus propose that fascin 1 expression promotes angiogenesis via filopodia formation, but is largely dispensable for both normal and tumour angiogenesis.

  1. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  2. Degradation of a recalcitrant xenobiotic compound: methyl tert-butyl ether (MTBE) metabolism by mycobacterium austroafricanum; Degradation d'un compose xenobiotique recalcitrant: metabolisme du methyl tert-butyl ether (MTBE) par mycobacterium austroafricanum IFP 2012

    Energy Technology Data Exchange (ETDEWEB)

    Francois, A.

    2002-11-01

    Methyl tert-butyl ether (MTBE) is introduced up to 15% (vol/vol) in gasoline in order to obtain a good octane number and to prevent carbon monoxide emissions. However, as a consequence of storage tanks leakage, MTBE became one of the major pollutants of aquifers because of its very low biodegradability. The present study aimed at investigating the biodegradation of MTBE by Mycobacterium austroafricanum IFP 2012. The MTBE metabolic pathway was partially elucidated owing to the identification of some intermediates (tert-butyl formate (TBF), tert-butyl alcohol (TBA), a-hydroxy-isobutyric acid and acetone) and some enzymatic activities (MTBE/TBA monooxygenase (non hemic and inducible), TBF esterase, 2-propanol: NDMA oxidoreductase and another monooxygenase involved in acetone degradation). The involvement of TBF and the requirement of cobalt could be explanations for the low natural attenuation of MTBE; whereas the methoxy group does not seem to be implicated. (author)

  3. The histone deacetylase inhibitor, Vorinostat, represses hypoxia inducible factor 1 alpha expression through translational inhibition.

    Directory of Open Access Journals (Sweden)

    Darren M Hutt

    Full Text Available Hypoxia inducible factor 1α (HIF-1α is a master regulator of tumor angiogenesis being one of the major targets for cancer therapy. Previous studies have shown that Histone Deacetylase Inhibitors (HDACi block tumor angiogenesis through the inhibition of HIF-1α expression. As such, Vorinostat (Suberoylanilide Hydroxamic Acid/SAHA and Romidepsin, two HDACis, were recently approved by the Food and Drug Administration (FDA for the treatment of cutaneous T cell lymphoma. Although HDACis have been shown to affect HIF-1α expression by modulating its interactions with the Hsp70/Hsp90 chaperone axis or its acetylation status, the molecular mechanisms by which HDACis inhibit HIF-1α expression need to be further characterized. Here, we report that the FDA-approved HDACi Vorinostat/SAHA inhibits HIF-1α expression in liver cancer-derived cell lines, by a new mechanism independent of p53, prolyl-hydroxylases, autophagy and proteasome degradation. We found that SAHA or silencing of HDAC9 mechanism of action is due to inhibition of HIF-1α translation, which in turn, is mediated by the eukaryotic translation initiation factor--eIF3G. We also highlighted that HIF-1α translation is dramatically inhibited when SAHA is combined with eIF3H silencing. Taken together, we show that HDAC activity regulates HIF-1α translation, with HDACis such as SAHA representing a potential novel approach for the treatment of hepatocellular carcinoma.

  4. Tetrandrine Suppresses Cancer Angiogenesis and Metastasis in 4T1 Tumor Bearing Mice

    Directory of Open Access Journals (Sweden)

    Jian-Li Gao

    2013-01-01

    Full Text Available Metastasis remains the most deadly aspect of cancer and still evades direct treatment. Thus, there is a great need to develop new treatment regimens to suppress tumor cells that have escaped surgical removal or that may have already disseminated. We have found that tetrandrine (TET exhibits anticolon cancer activity. Here, we investigate the inhibition effect of TET to breast cancer metastasis, angiogenesis and its molecular basis underlying TET’s anticancer activity. We compare TET with chemotherapy drug doxorubicin in 4T1 tumor bearing BALB/c mice model and find that TET exhibits an anticancer metastatic and antiangiogenic activities better than those of doxorubicin. The lung metastatic sites were decreased by TET, which is confirmed by bioluminescence imaging in vivo. On the other hand, laser doppler perfusion imaging (LDI was used for measuring the blood flow of tumor in 4T1-tumor bearing mice. As a result, the local blood perfusion of tumor was markedly decreased by TET after 3 weeks. Mechanistically, TET treatment leads to a decrease in p-ERK level and an increase in NF-κB levels in HUVECs. TET also regulated metastatic and angiogenic related proteins, including vascular endothelial growth factor, hypoxia-inducible factor-1α, integrin β5, endothelial cell specific molecule-1, and intercellular adhesion molecule-1 in vivo.

  5. Tumor angiogenesis in advanced stage ovarian carcinoma.

    Science.gov (United States)

    Hollingsworth, H C; Kohn, E C; Steinberg, S M; Rothenberg, M L; Merino, M J

    1995-07-01

    Tumor angiogenesis has been found to have prognostic significance in many tumor types for predicting an increased risk of metastasis. We assessed tumor vascularity in 43 cases of advanced stage (International Federation of Gynecologists and Obstetricians stages III and IV) ovarian cancer by using the highly specific endothelial cell marker CD34. Microvessel counts and stage were associated with disease-free survival and with overall survival by Kaplan-Meier analysis. The plots show that higher stage, higher average vessel count at 200x (200x avg) and 400x (400x avg) magnification and highest vessel count at 400x (400x high) magnification confer a worse prognosis for disease-free survival. Average vessel count of less than 16 (400x avg, P2 = 0.01) and less than 45 (200x avg, P2 = 0.026) suggested a better survival. Similarly, a high vessel count of less than 20 (400x high, P2 = 0.019) conferred a better survival as well. The plots suggest that higher stage, higher average vessel count at 200x and 400x, and highest vessel count at 200x and 400x show a trend to worse overall survival as well. With the Cox proportional hazards model, stage was the best predictor of overall survival, however, the average microvessel count at 400x was found to be the best predictor of disease-free survival. These results suggest that analysis of neovascularization in advanced stage ovarian cancer may be a useful prognostic factor.

  6. Mast cells and angiogenesis in wound healing.

    Science.gov (United States)

    Gaber, Mohamed A; Seliet, Iman A; Ehsan, Nermin A; Megahed, Mohamed A

    2014-02-01

    To investigate the role of mast cells and vascular endothelial growth factor (VEGF) as a mediator of angiogenesis to promote wound healing in surgical and pathological scars. The study was carried out on 40 patients who presented with active scar lesions. They were subdivided into 4 groups. They included granulation tissue (10 cases), surgical scar (10 cases), hypertrophic scar (10 cases), and keloid scar (10 cases). Also 10 healthy volunteers of the same age and sex were selected as a control group. Skin biopsies were taken from the patients and the control group. Skin biopsies from clinically assessed studied groups were processed for routine histology and embedded in paraffin. Four sections were prepared from each paraffin block. The first section was stained with hematoxylin and eosin for histological evaluation. The second and third sections were processed for immunostaining of mast cells that contain chymase (MCCs) and mast cells that contain tryptase (MCTs). The fourth section was processed for immunostaining of VEGF. MCCs exhibited mild expression in normal tissue, granulation tissue, and surgical, hypertrophic and keloid scars. MCTs exhibited mild expression in normal tissue, granulation tissue and keloid, whereas moderate expression was exhibited in hypertrophic and surgical scars. VEGF expression was absent in normal tissue, mild in keloid, surgical and hypertrophic scars, and moderate in keloids and granulation tissue. Mast cell expression variation among different scar types signals the pathological evolution of the lesion, and hence may guide the need for therapeutic intervention.

  7. Gastric angiogenesis and Helicobacter pylori infection

    Directory of Open Access Journals (Sweden)

    I. D. Pousa

    Full Text Available The formation of new blood vessels seen in conditions commonly associated with Helicobacter pylori (H. pylori infection, including gastritis, peptic ulcer, and gastric carcinoma, prompts consideration of a potential relationship between mucosal colonization by this organism and the angiogenic process. H. pylori directly or indirectly damages endothelial cells, which induces a number of changes in the microvasculature of the gastric mucosa. In H. pylori-associated conditions, that is, in gastritis, peptic ulcer and gastric carcinoma, there is an increased concentration of angiogenic factors, and subsequently a formation of new blood vessels. However, this early angiogenesis -which is activated to repair the gastric mucosa- is subsequently inhibited in patients with peptic ulcer, and ulcer healing is thus delayed. This may be due to the antiproliferative action of this organism on endothelial cells. While the angiogenic process becomes inhibited in infected patients with peptic ulcer, it remains seemingly active in those with gastritis or gastric cancer. This fact is in support of the notion suggested by various studies that peptic ulcer and gastric cancer are mutually excluding conditions. In the case of gastric cancer, neoangiogenesis would enhance nutrient and oxygen supply to cancer cells, and thus tumor growth and metastatic spread.

  8. VASCULAR REMODELING IN HYPERTENSION: ANGIOGENESIS FEATURES

    Directory of Open Access Journals (Sweden)

    L. A. Haisheva

    2014-07-01

    Full Text Available Aim — cross-sectional study of changes in various segments of the vascular bed in arterial hypertension (AH, defining the role of inducers and inhibitors of angiogenesis in these processes.Materials and methods. The study included 99 patients with arterial hypertension of I–II degree, average age of 63.2 ± 2.6 years, diseaseduration 9.2 ± 7.2 years.Results. It was found that patients with arterial hypertension have disorders in all segments of vascular bed: endothelial dysfunction (highvWF, microcirculatory disorders, and increased pulse wave velocity (PWV of elastic-type vessels. The level of angioginesis factors doesnot depend on such parameters as gender, age, body mass index. Smoking and duration of hypertension influence on vascular endothelialgrowth factor raise and endostatin levels are higher in patients with family history of cardiovascular diseases. Duration of disease is directlycorrelated with microcirculatory disorders and the PWV, correlation between microcirculatory disorders and pulse wave velocity indicatetheir common processes.

  9. Upregulation of angiogenesis in oral lichen planus.

    Science.gov (United States)

    Al-Hassiny, A; Friedlander, L T; Parachuru, V P B; Seo, B; Hussaini, H M; Rich, A M

    2018-02-01

    As angiogenesis is fundamental to the pathogenesis of many chronic inflammatory disorders, this study investigated the expression of various vascular markers in oral lichen planus and non-specific oral mucosal inflammatory tissues. Archival specimens of oral lichen planus (n = 15) and inflamed tissues (n = 13) were stained using immunohistochemistry with antibodies to CD34, vascular endothelial growth factor, vascular endothelial growth factor receptor and vasohibin. Nine representative sites at the epithelial-connective tissue junction and through the fibrous connective tissue were selected, and automated analysis techniques were used to determine the extent of positivity expressed as the percentage of positive cells. Significance was denoted when P lichen planus samples compared with inflamed controls. A higher level of CD34 was observed in the deeper parts of the connective tissue of Oral lichen planus (OLP) (P = .04), whereas VEGF and VEGFR2 expressions were higher all through the tissues (respectively, P lichen planus in all sites evaluated (P oral lichen planus compared with inflamed controls, with increased expression of pro-angiogenic factors and decreased anti-angiogenic expression. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

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

    Energy Technology Data Exchange (ETDEWEB)

    Tandle, Anita T. [Tumor Angiogenesis Section, Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892 (United States); Calvani, Maura; Uranchimeg, Badarch [DTP-Tumor Hypoxia Laboratory, SAIC Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702 (United States); Zahavi, David [Tumor Angiogenesis Section, Surgery Branch, Center for Cancer Research, National Cancer Institute, Bethesda, Maryland 20892 (United States); Melillo, Giovanni [DTP-Tumor Hypoxia Laboratory, SAIC Frederick, Inc., National Cancer Institute, Frederick, Maryland 21702 (United States); Libutti, Steven K., E-mail: slibutti@montefiore.org [Department of Surgery, Montefiore-Einstein Center for Cancer Care, Albert Einstein College of Medicine, Greene Medical Arts Pavilion, 4th Floor 3400, Bainbridge Avenue, Bronx, New York 10467 (United States)

    2009-07-01

    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-II 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.

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

    International Nuclear Information System (INIS)

    Tandle, Anita T.; Calvani, Maura; Uranchimeg, Badarch; Zahavi, David; Melillo, Giovanni; Libutti, Steven K.

    2009-01-01

    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-II binds to the cell surface α5β1 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-1α) degradation under hypoxic conditions. The degradation results in the inhibition of HIF-1α mediated transcriptional activity as well as HIF-1α mediated angiogenic sprouting of ECs. HIF-1α 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-1α activities.

  12. The role of hypoxia in oral cancer and potentially malignant disorders: a review.

    Science.gov (United States)

    Kujan, Omar; Shearston, Kate; Farah, Camile S

    2017-04-01

    Oral and oropharyngeal cancer are major health problems globally with over 500 000 new cases diagnosed annually. Despite the fact that oral cancer is a preventable disease and has the potential for early detection, the overall survival rate remains at around 50%. Most oral cancer cases are preceded by a group of clinical lesions designated 'potentially malignant disorders'. It is difficult to predict if and when these lesions may transform to malignancy, and in turn it is difficult to agree on appropriate management strategies. Understanding underlying molecular pathways would help in predicting the malignant transformation of oral potentially malignant disorders and ultimately identifying effective methods for early detection and prevention of oral cancer. Reprogramming energy metabolism is an emerging hallmark of cancer that is predominantly controlled by hypoxia-induced genes regulating angiogenesis, tumour vascularization, invasion, drug resistance and metastasis. This review aims to highlight the role of hypoxia in oral carcinogenesis and to suggest future research implications in this arena. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  13. Prenatal hypoxia induces increased cardiac contractility on a background of decreased capillary density

    Directory of Open Access Journals (Sweden)

    Ousley Victoria

    2009-01-01

    Full Text Available Abstract Background Chronic hypoxia in utero (CHU is one of the most common insults to fetal development and may be associated with poor cardiac recovery from ischaemia-reperfusion injury, yet the effects on normal cardiac mechanical performance are poorly understood. Methods Pregnant female wistar rats were exposed to hypoxia (12% oxygen, balance nitrogen for days 10–20 of pregnancy. Pups were born into normal room air and weaned normally. At 10 weeks of age, hearts were excised under anaesthesia and underwent retrograde 'Langendorff' perfusion. Mechanical performance was measured at constant filling pressure (100 cm H2O with intraventricular balloon. Left ventricular free wall was dissected away and capillary density estimated following alkaline phosphatase staining. Expression of SERCA2a and Nitric Oxide Synthases (NOS proteins were estimated by immunoblotting. Results CHU significantly increased body mass (P in utero. Conclusion These data offer potential mechanisms for poor recovery following ischaemia, including decreased coronary flow reserve and impaired angiogenesis with subsequent detrimental effects of post-natal cardiac performance.

  14. Manipulating Endothelial Progenitor Cell Homing with Sphingosine-1-Phosphate for Terapeutic Angiogenesis

    Science.gov (United States)

    Williams, Priscilla Anne

    Ischemic vascular diseases are the main cause of mortality worldwide and yet current therapies only delay disease progression and improve quality of life without addressing the fundamental problem of tissue loss. Within the field of tissue engineering, therapeutic angiogenesis provides a promising approach to alternatively provide new blood vessel formation via spatiotemporally controlled delivery of proangiogenic agents. Sphingosine-1-phosphate (S1P), a bioactive lysophospholipid that is upregulated under ischemic conditions, has recently gained great enthusiasm as a potential mediator in neovascularization strategies given its essential roles in promoting both neovessel formation and stabilization, and cellular trafficking along highly regulated endogenous gradients. Herein, the governing hypothesis guiding this dissertation is that local biomaterial-controlled delivery of S1P may be used to enhance migration and recruitment of vascular progenitor cells for enhanced therapeutic angiogenesis within ischemic tissue. The initial work in this dissertation investigated the effect of hypoxia on the angiogenic response of both mature and progenitor endothelial cells to S1P stimulation in vitro. Outgrowth endothelial cells (OECs) were isolated from human umbilical cord blood to provide a clinically relevant source of vascular progenitor cells for the studies conducted within this dissertation. S1P stimulation promoted angiogenic activity of both ECs and OECs under both ambient and hypoxic (1%) oxygen tensions. Furthermore, dual therapy with the combination of S1P and vascular endothelial growth factor (VEGF) further enhanced cellular responses. Interestingly, hypoxia substantially augmented the functional response of OECs to S1P, resulting in 25-fold and 6.5-fold increases in directed migration and sprouting, respectively. Thus, these studies highlighted the potential for S1P as a therapeutic agent for treatment of ischemic diseases. An injectable biomaterial system

  15. Tumor Hypoxia: Causative Mechanisms, Microregional Heterogeneities, and the Role of Tissue-Based Hypoxia Markers.

    Science.gov (United States)

    Vaupel, Peter; Mayer, Arnulf

    Tumor hypoxia is a hallmark of solid malignant tumor growth, profoundly influences malignant progression and contributes to the development of therapeutic resistance. Pathogenesis of tumor hypoxia is multifactorial, with contributions from both acute and chronic factors. Spatial distribution of hypoxia within tumors is markedly heterogeneous and often changes over time, e.g., during a course of radiotherapy. Substantial changes in the oxygenation status can occur within the distance of a few cell layers, explaining the inability of currently used molecular imaging techniques to adequately assess this crucial trait. Due to the possible importance of tumor hypoxia for clinical decision-making, there is a great demand for molecular tools which may provide the necessary resolution down to the single cell level. Exogenous and endogenous markers of tumor hypoxia have been investigated for this purpose. Their potential use may be greatly enhanced by multiparametric in situ methods in experimental and human tumor tissue.

  16. Hypoxia and hypoxia inducible factor-1α are required for normal endometrial repair during menstruation.

    Science.gov (United States)

    Maybin, Jacqueline A; Murray, Alison A; Saunders, Philippa T K; Hirani, Nikhil; Carmeliet, Peter; Critchley, Hilary O D

    2018-01-23

    Heavy menstrual bleeding (HMB) is common and debilitating, and often requires surgery due to hormonal side effects from medical therapies. Here we show that transient, physiological hypoxia occurs in the menstrual endometrium to stabilise hypoxia inducible factor 1 (HIF-1) and drive repair of the denuded surface. We report that women with HMB have decreased endometrial HIF-1α during menstruation and prolonged menstrual bleeding. In a mouse model of simulated menses, physiological endometrial hypoxia occurs during bleeding. Maintenance of mice under hyperoxia during menses decreases HIF-1α induction and delays endometrial repair. The same effects are observed upon genetic or pharmacological reduction of endometrial HIF-1α. Conversely, artificial induction of hypoxia by pharmacological stabilisation of HIF-1α rescues the delayed endometrial repair in hypoxia-deficient mice. These data reveal a role for HIF-1 in the endometrium and suggest its pharmacological stabilisation during menses offers an effective, non-hormonal treatment for women with HMB.

  17. Deriving mechanisms responsible for the lack of correlation between hypoxia and acidity in solid tumors.

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    Hamid R Molavian

    Full Text Available Hypoxia and acidity are two main microenvironmental factors intimately associated with solid tumors and play critical roles in tumor growth and metastasis. The experimental results of Helmlinger and colleagues (Nature Medicine 3, 177, 1997 provide evidence of a lack of correlation between these factors on the micrometer scale in vivo and further show that the distribution of pH and pO(2 are heterogeneous. Here, using computational simulations, grounded in these experimental results, we show that the lack of correlation between pH and pO(2 and the heterogeneity in their shapes are related to the heterogeneous concentration of buffers and oxygen in the blood vessels, further amplified by the network of blood vessels and the cell metabolism. We also demonstrate that, although the judicious administration of anti-angiogenesis agents (normalization process in tumors may lead to recovery of the correlation between hypoxia and acidity, it may not normalize the pH throughout the whole tumor. However, an increase in the buffering capacity inside the blood vessels does appear to increase the extracellular pH throughout the whole tumor. Based on these results, we propose that the application of anti-angiogenic agents and at the same time increasing the buffering capacity of the tumor extracellular environment may be the most efficient way of normalizing the tumor microenvironment. As a by-product of our simulation we show that the recently observed lack of correlation between glucose consumption and hypoxia in cells which rely on respiration is related to the inhomogeneous consumption of glucose to oxygen concentration. We also demonstrate that this lack of correlation in cells which rely on glycolysis could be related to the heterogeneous concentration of oxygen inside the blood vessels.

  18. Potent inhibition of tumoral hypoxia-inducible factor 1α by albendazole

    International Nuclear Information System (INIS)

    Pourgholami, Mohammad H; Cai, Zhao Y; Badar, Samina; Wangoo, Kiran; Poruchynsky, Marianne S; Morris, David L

    2010-01-01

    Emerging reports suggest resistance, increased tumor invasiveness and metastasis arising from treatment with drugs targeting vascular endothelial growth factor (VEGF). It is believed that increased tumoral hypoxia plays a prominent role in the development of these phenomena. Inhibition of tumoral hypoxia inducible factor (HIF-1α) is thus becoming an increasingly attractive therapeutic target in the treatment of cancer. We hypothesized that the anti-VEGF effect of albendazole (ABZ) could be mediated through inhibition of tumoral HIF-1α. In vitro, the effects of ABZ on HIF-1α levels in human ovarian cancer cells (OVCAR-3) were investigated using hypoxic chamber or desferrioxamine (DFO) induced-hypoxia. In vivo, the effects of ABZ (150 mg/kg, i.p., single dose) on the tumor levels of HIF-1α and VEGF protein and mRNA were investigated by western blotting, RT-PCR and real time-PCR. In vitro, ABZ inhibited cellular HIF-1α protein accumulation resulting from placement of cells under hypoxic chamber or exposure to DFO. In vivo, tumors excised from vehicle treated mice showed high levels of both HIF-1α and VEGF. Whereas, tumoral HIF-1α and VEGF protein levels were highly suppressed in ABZ treated mice. Tumoral VEGFmRNA (but not HIF-1αmRNA) was also found to be highly suppressed by ABZ. These results demonstrate for the first time the effects of an acute dose of ABZ in profoundly suppressing both HIF-1α and VEGF within the tumor. This dual inhibition may provide additional value in inhibiting angiogenesis and be at least partially effective in inhibiting tumoral HIF-1α surge, tumor invasiveness and metastasis

  19. Hypoxia training: symptom replication in experienced military aircrew.

    Science.gov (United States)

    Johnston, Ben J; Iremonger, Gareth S; Hunt, Sheena; Beattie, Elizabeth

    2012-10-01

    Military aircrew are trained to recognize the signs and symptoms of hypoxia in a safe environment using a variety of methods to simulate altitude. In order to investigate the effectiveness of hypoxia training, this study compared the recall of hypoxia symptoms in military aircrew between two consecutive hypobaric chamber hypoxia training sessions conducted, on average, 4.5 yr apart. Previously trained subjects completed a questionnaire immediately before and after they underwent refresher hypoxia training and recorded the occurrence, order, and severity of symptoms experienced. Responses from refresher training were compared with their recall of symptoms experienced during previous training. There was no difference in the recall of most hypoxia symptoms between training sessions. Slurred speech was recalled more frequently from previous training compared to refresher training (14 vs. 4 subjects), whereas hot/cold flushes were recalled less frequently from previous training compared to refresher training (5 vs. 17 subjects). There was a statistically significant difference in overall hypoxia score (10.3 vs. 8.3), suggesting that from memory subjects may underestimate the level of hypoxia experienced in previous training. A high level of similarity between the recall of previously experienced hypoxia symptoms and recent experience supports the effectiveness of hypoxia training. These results replicate the finding of a 'hypoxia signature' reported by a previous study. Small differences in the recall of some symptoms and in overall hypoxia score highlight the importance of drawing attention to the more subtle symptoms of early hypoxia, and of using training techniques which optimize aircrew recall.

  20. The role of hypoxia-induced factor in the regulation of oxygen homeostasis during reparative regeneration in compromised microcirculation

    Directory of Open Access Journals (Sweden)

    S. G. Izmaylov

    2017-01-01

    Full Text Available The aim of the present review is to find an answer to the clinically important question on the mechanisms regulating the activity of reparative regeneration in hypoxic conditions and potential ways to modify this process. In the recent studies, compensated hypoxia is characterized as a trigger for the regeneration, with the central regulating factor being the member of the cytokine family, hypoxia-inducible factor-1 (HIF-1. Changes in the concentration of this protein modulates cell migration, angiogenesis and epithelialmesenchymal integration; it also stimulates the proliferation of endothelial cells and fibroblasts, playing a  major role in the stimulation of wound healing, especially with compromised microcirculation, for example, diabetes mellitus. 

  1. Probiotic yeast inhibits VEGFR signaling and angiogenesis in intestinal inflammation.

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    Xinhua Chen

    Full Text Available Saccharomyces boulardii (Sb can protect against intestinal injury and tumor formation, but how this probiotic yeast controls protective mucosal host responses is unclear. Angiogenesis is an integral process of inflammatory responses in inflammatory bowel diseases (IBD and required for mucosal remodeling during restitution. The aim of this study was to determine whether Sb alters VEGFR (vascular endothelial growth factor receptor signaling, a central regulator of angiogenesis.HUVEC were used to examine the effects of Sb on signaling and on capillary tube formation (using the ECMatrix™ system. The effects of Sb on VEGF-mediated angiogenesis were examined in vivo using an adenovirus expressing VEGF-A(164 in the ears of adult nude mice (NuNu. The effects of Sb on blood vessel volume branching and density in DSS-induced colitis was quantified using VESsel GENeration (VESGEN software.1 Sb treatment attenuated weight-loss (p<0.01 and histological damage (p<0.01 in DSS colitis. VESGEN analysis of angiogenesis showed significantly increased blood vessel density and volume in DSS-treated mice compared to control. Sb treatment significantly reduced the neo-vascularization associated with acute DSS colitis and accelerated mucosal recovery restoration of the lamina propria capillary network to a normal morphology. 2 Sb inhibited VEGF-induced angiogenesis in vivo in the mouse ear model. 3 Sb also significantly inhibited angiogenesis in vitro in the capillary tube assay in a dose-dependent manner (p<0.01. 4 In HUVEC, Sb reduced basal VEGFR-2 phosphorylation, VEGFR-2 phosphorylation in response to VEGF as well as activation of the downstream kinases PLCγ and Erk1/2.Our findings indicate that the probiotic yeast S boulardii can modulate angiogenesis to limit intestinal inflammation and promote mucosal tissue repair by regulating VEGFR signaling.

  2. Green tea and its anti-angiogenesis effects.

    Science.gov (United States)

    Rashidi, Bahman; Malekzadeh, Mehrnoush; Goodarzi, Mohammad; Masoudifar, Aria; Mirzaei, Hamed

    2017-05-01

    The development of new blood vessels from a pre-existing vasculature (also known as angiogenesis) is required for many physiological processes including embryogenesis and post-natal growth. However, pathological angiogenesis is also a hallmark of cancer and many ischaemic and inflammatory diseases. The pro-angiogenic members of the VEGF family (vascular endothelial growth factor family), VEGF-A, VEGF-B, VEGF-C, VEGF-D and placental growth factor (PlGF), and the related receptors, VEGFR-1, VEGFR-2 and VEGFR-3 have a central and decisive role in angiogenesis. Indeed, they are the targets for anti-angiogenic drugs currently approved. Green tea (from the Camellia sinensis plant) is one of the most popular beverages in the world. It is able to inhibit angiogenesis by different mechanisms such as microRNAs (miRNAs). Green tea and its polyphenolic substances (like catechins) show chemo-preventive and chemotherapeutic features in various types of cancer and experimental models for human cancers. The tea catechins, including (-)-epigallocatechin-3-gallate (EGCG), have multiple effects on the cellular proteome and signalome. Note that the polyphenolic compounds from green tea are able to change the miRNA expression profile associated with angiogenesis in various cancer types. This review focuses on the ability of the green tea constituents to suppress angiogenesis signaling and it summarizes the mechanisms by which EGCG might inhibit the VEGF family. We also highlighted the miRNAs affected by green tea which are involved in anti-angiogenesis. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  3. Heme oxygenase-1 accelerates tumor angiogenesis of human pancreatic cancer.

    Science.gov (United States)

    Sunamura, Makoto; Duda, Dan G; Ghattas, Maivel H; Lozonschi, Lucian; Motoi, Fuyuhiko; Yamauchi, Jun-Ichiro; Matsuno, Seiki; Shibahara, Shigeki; Abraham, Nader G

    2003-01-01

    Angiogenesis is necessary for the continued growth of solid tumors, invasion and metastasis. Several studies clearly showed that heme oxygenase-1 (HO-1) plays an important role in angiogenesis. In this study, we used the vital microscope system, transparent skinfold model, lung colonization model and transduced pancreatic cancer cell line (Panc-1)/human heme oxygenase-1 (hHO-1) cells, to precisely analyze, for the first time, the effect of hHO-1 gene on tumor growth, angiogenesis and metastasis. Our results revealed that HO-1 stimulates angiogenesis of pancreatic carcinoma in severe combined immune deficient mice. Overexpression of human hHO-1 after its retroviral transfer into Panc-1 cells did not interfere with tumor growth in vitro. While in vivo the development of tumors was accelerated upon transfection with hHO-1. On the other hand, inhibition of heme oxygenase (HO) activity by stannous mesoporphyrin was able transiently to delay tumor growth in a dose dependent manner. Tumor angiogenesis was markedly increased in Panc-1/hHO-1 compared to mock transfected and wild type. Lectin staining and Ki-67 proliferation index confirmed these results. In addition hHO-1 stimulated in vitro tumor angiogenesis and increased endothelial cell survival. In a lung colonization model, overexpression of hHO-1 increased the occurrence of metastasis, while inhibition of HO activity by stannous mesoporphyrin completely inhibited the occurrence of metastasis. In conclusion, overexpression of HO-1 genes potentiates pancreatic cancer aggressiveness, by increasing tumor growth, angiogenesis and metastasis and that the inhibition of the HO system may be of useful benefit for the future treatment of the disease.

  4. Upregulation of CREM/ICER suppresses wound endothelial CRE-HIF-1α-VEGF-dependent signaling and impairs angiogenesis in type 2 diabetes

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    Milad S. Bitar

    2015-01-01

    Full Text Available Impaired angiogenesis and endothelial dysfunction in type 2 diabetes constitute dominant risk factors for non-healing wounds and most forms of cardiovascular disease. We propose that diabetes shifts the ‘angiogenic balance’ in favor of an excessive anti-angiogenic phenotype. Herein, we report that diabetes impairs in vivo sponge angiogenic capacity by decreasing VEGF expression and fibrovascular invasion, and reciprocally enhances the formation of angiostatic molecules, such as thrombospondins, NFκB and FasL. Defective in vivo angiogenesis prompted cellular studies in cultured endothelial cells derived from subcutaneous sponge implants (SIECs of control and Goto-Kakizaki rats. Ensuing data from diabetic SIECs demonstrated a marked upregulation in cAMP-PKA-CREB signaling, possibly stemming from increased expression of adenylyl cyclase isoforms 3 and 8, and decreased expression of PDE3. Mechanistically, we found that oxidative stress and PKA activation in diabetes enhanced CREM/ICER expression. This reduces IRS2 cellular content by inhibiting cAMP response element (CRE transcriptional activity. Consequently, a decrease in the activity of Akt-mTOR ensued with a concomitant reduction in the total and nuclear protein levels of HIF-1α. Limiting HIF-1α availability for the specific hypoxia response elements in diabetic SIECs elicited a marked reduction in VEGF expression, both at the mRNA and protein levels. These molecular abnormalities were illustrated functionally by a defect in various pro-angiogenic properties, including cell proliferation, migration and tube formation. A genetic-based strategy in diabetic SIECs using siRNAs against CREM/ICER significantly augmented the PKA-dependent VEGF expression. To this end, the current data identify the importance of CREM/ICER as a negative regulator of endothelial function and establish a link between CREM/ICER overexpression and impaired angiogenesis during the course of diabetes. Moreover, it could

  5. Inhibition of tumor angiogenesis and tumor growth by the DSL domain of human Delta-like 1 targeted to vascular endothelial cells.

    Science.gov (United States)

    Zhao, Xing-Cheng; Dou, Guo-Rui; Wang, Li; Liang, Liang; Tian, Deng-Mei; Cao, Xiu-Li; Qin, Hong-Yan; Wang, Chun-Mei; Zhang, Ping; Han, Hua

    2013-07-01

    The growth of solid tumors depends on neovascularization. Several therapies targeting tumor angiogenesis have been developed. However, poor response in some tumors and emerging resistance necessitate further investigations of new drug targets. Notch signal pathway plays a pivotal role in vascular development and tumor angiogenesis. Either blockade or forced activation of this pathway can inhibit angiogenesis. As blocking Notch pathway results in the formation of vascular neoplasm, activation of Notch pathway to prevent tumor angiogenesis might be an alternative choice. However, an in vivo deliverable reagent with highly efficient Notch-activating capacity has not been developed. Here, we generated a polypeptide, hD1R, which consists of the Delta-Serrate-Lag-2 fragment of the human Notch ligand Delta-like 1 and an arginine-glycine-aspartate (RGD) motif targeting endothelial cells (ECs). We showed that hD1R could bind to ECs specifically through its RGD motif and effectively triggered Notch signaling in ECs. We demonstrated both in vitro and in vivo that hD1R inhibited angiogenic sprouting and EC proliferation. In tumor-bearing mice, the injection of hD1R effectively repressed tumor growth, most likely through increasing tumor hypoxia and tissue necrosis. The amount and width of vessels reduced remarkably in tumors of mice treated with hD1R. Moreover, vessels in tumors of mice treated with hD1R recruited more NG2(+) perivascular cells and were better perfused. Combined application of hD1R and chemotherapy with cisplatin and teniposide revealed that these two treatments had additive antitumor effects. Our study provided a new strategy for antiangiogenic tumor therapy.

  6. Inhibition of Tumor Angiogenesis and Tumor Growth by the DSL Domain of Human Delta-Like 1 Targeted to Vascular Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Xing-Cheng Zhao

    2013-07-01

    Full Text Available The growth of solid tumors depends on neovascularization. Several therapies targeting tumor angiogenesis have been developed. However, poor response in some tumors and emerging resistance necessitate further investigations of newdrug targets. Notch signal pathway plays a pivotal role in vascular development and tumor angiogenesis. Either blockade or forced activation of this pathway can inhibit angiogenesis. As blocking Notch pathway results in the formation of vascular neoplasm, activation of Notch pathway to prevent tumor angiogenesis might be an alternative choice. However, an in vivo deliverable reagent with highly efficient Notch-activating capacity has not been developed. Here, we generated a polypeptide, hD1R, which consists of the Delta-Serrate-Lag-2 fragment of the human Notch ligand Delta-like 1 and an arginine-glycine-aspartate (RGD motif targeting endothelial cells (ECs. We showed that hD1R could bind to ECs specifically through its RGD motif and effectively triggered Notch signaling in ECs. We demonstrated both in vitro and in vivo that hD1R inhibited angiogenic sprouting and EC proliferation. In tumor-bearing mice, the injection of hD1R effectively repressed tumor growth, most likely through increasing tumor hypoxia and tissue necrosis. The amount and width of vessels reduced remarkably in tumors of mice treated with hD1R. Moreover, vessels in tumors of mice treated with hD1R recruited more NG2+ perivascular cells and were better perfused. Combined application of hD1R and chemotherapy with cisplatin and teniposide revealed that these two treatments had additive antitumor effects. Our study provided a new strategy for antiangiogenic tumor therapy.

  7. Hacking macrophage-associated immunosuppression for regulating glioblastoma angiogenesis.

    Science.gov (United States)

    Cui, Xin; Morales, Renee-Tyler Tan; Qian, Weiyi; Wang, Haoyu; Gagner, Jean-Pierre; Dolgalev, Igor; Placantonakis, Dimitris; Zagzag, David; Cimmino, Luisa; Snuderl, Matija; Lam, Raymond H W; Chen, Weiqiang

    2018-04-01

    Glioblastoma (GBM) is the most lethal primary adult brain tumor and its pathology is hallmarked by distorted neovascularization, diffuse tumor-associated macrophage infiltration, and potent immunosuppression. Reconstituting organotypic tumor angiogenesis models with biomimetic cell heterogeneity and interactions, pro-/anti-inflammatory milieu and extracellular matrix (ECM) mechanics is critical for preclinical anti-angiogenic therapeutic screening. However, current in vitro systems do not accurately mirror in vivo human brain tumor microenvironment. Here, we engineered a three-dimensional (3D), microfluidic angiogenesis model with controllable and biomimetic immunosuppressive conditions, immune-vascular and cell-matrix interactions. We demonstrate in vitro, GL261 and CT-2A GBM-like tumors steer macrophage polarization towards a M2-like phenotype for fostering an immunosuppressive and proangiogenic niche, which is consistent with human brain tumors. We distinguished that GBM and M2-like immunosuppressive macrophages promote angiogenesis, while M1-like pro-inflammatory macrophages suppress angiogenesis, which we coin "inflammation-driven angiogenesis." We observed soluble immunosuppressive cytokines, predominantly TGF-β1, and surface integrin (α v β 3 ) endothelial-macrophage interactions are required in inflammation-driven angiogenesis. We demonstrated tuning cell-adhesion receptors using an integrin (α v β 3 )-specific collagen hydrogel regulated inflammation-driven angiogenesis through Src-PI3K-YAP signaling, highlighting the importance of altered cell-ECM interactions in inflammation. To validate the preclinical applications of our 3D organoid model and mechanistic findings of inflammation-driven angiogenesis, we screened a novel dual integrin (α v β 3 ) and cytokine receptor (TGFβ-R1) blockade that suppresses GBM tumor neovascularization by simultaneously targeting macrophage-associated immunosuppression, endothelial-macrophage interactions, and

  8. Angiogenic and angiostatic factors in the molecular control of angiogenesis.

    Science.gov (United States)

    Distler, J H W; Hirth, A; Kurowska-Stolarska, M; Gay, R E; Gay, S; Distler, O

    2003-09-01

    The vascular system that ensures an adequate blood flow is required to provide the cells with sufficient supply of nutrients and oxygen. Two different mechanisms of the formation of new vessels can be distinguished: vasculogenesis, the formation of the first primitive vascular plexus de novo and angiogenesis, the formation of new vessels from preexisting ones. Both processes are regulated by a delicate balance of pro- and anti-angiogenic factors. Physiologically, angiostatic mediators outweigh the angiogenic molecules and angiogenesis does not occur. Under certain conditions such as tumor formation or wound healing, the positive regulators of angiogenesis predominate and the endothelium becomes activated. Angiogenesis is initiated by vasodilatation and an increased permeability. After destabilization of the vessel wall, endothelial cells proliferate, migrate and form a tube, which is finally stabilized by pericytes and smooth muscle cells. Numerous soluble growth factors and inhibitors, cytokines and proteases as well as extracellular matrix proteins and adhesion molecules strictly control this multi-step process. The properties and interactions of angiogenic molecules such as VEGFs, FGFs, angiopoietins, PDGF, angiogenin, angiotropin, HGF, CXC chemokines with ELR motif, PECAM-1, integrins and VE-cadherin as well as angiostatic key players such as angiostatin, endostatin, thrombospondin, CXC chemokines without ELR motif, PEDF are discussed in this review with respect to their molecular impact on angiogenesis.

  9. Friends Turned Foes: Angiogenic Growth Factors beyond Angiogenesis.

    Science.gov (United States)

    Matkar, Pratiek N; Ariyagunarajah, Ramya; Leong-Poi, Howard; Singh, Krishna K

    2017-10-02

    Angiogenesis, the formation of new blood vessels from pre-existing ones is a biological process that ensures an adequate blood flow is maintained to provide the cells with a sufficient supply of nutrients and oxygen within the body. Numerous soluble growth factors and inhibitors, cytokines, proteases as well as extracellular matrix proteins and adhesion molecules stringently regulate the multi-factorial process of angiogenesis. The properties and interactions of key angiogenic molecules such as vascular endothelial growth factors (VEGFs), fibroblast growth factors (FGFs) and angiopoietins have been investigated in great detail with respect to their molecular impact on angiogenesis. Since the discovery of angiogenic growth factors, much research has been focused on their biological actions and their potential use as therapeutic targets for angiogenic or anti-angiogenic strategies in a context-dependent manner depending on the pathologies. It is generally accepted that these factors play an indispensable role in angiogenesis. However, it is becoming increasingly evident that this is not their only role and it is likely that the angiogenic factors have important functions in a wider range of biological and pathological processes. The additional roles played by these molecules in numerous pathologies and biological processes beyond angiogenesis are discussed in this review.

  10. Folate Deficiency Could Restrain Decidual Angiogenesis in Pregnant Mice

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    Yanli Li

    2015-08-01

    Full Text Available The mechanism of birth defects induced by folate deficiency was focused on mainly in fetal development. Little is known about the effect of folate deficiency on the maternal uterus, especially on decidual angiogenesis after implantation which establishes vessel networks to support embryo development. The aim of this study was to investigate the effects of folate deficiency on decidual angiogenesis. Serum folate levels were measured by electrochemiluminescence. The status of decidual angiogenesis was examined by cluster designation 34 (CD34 immunohistochemistry and the expression of angiogenic factors, including vascular endothelial growth factor A (VEGFA, placental growth factor (PLGF, and VEGF receptor 2 (VEGFR2 were also tested. Serum levels of homocysteine (Hcy, follicle stimulating hormone (FSH, luteinizing hormone (LH, prolactin (PRL, progesterone (P4, and estradiol (E2 were detected by Enzyme-linked immunosorbent assay. The folate-deficient mice had a lower folate level and a higher Hcy level. Folate deficiency restrained decidual angiogenesis with significant abnormalities in vascular density and the enlargement and elongation of the vascular sinus. It also showed a reduction in the expressions of VEGFA, VEGFR2, and PLGF. In addition, the serum levels of P4, E2, LH, and PRL were reduced in folate-deficient mice, and the expression of progesterone receptor (PR and estrogen receptor α (ERα were abnormal. These results indicated that folate deficiency could impaire decidual angiogenesis and it may be related to the vasculotoxic properties of Hcy and the imbalance of the reproductive hormone.

  11. Angiogenesis-Related Pathways in the Pathogenesis of Ovarian Cancer

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    Aristotle Bamias

    2013-07-01

    Full Text Available Ovarian Cancer represents the most fatal type of gynecological malignancies. A number of processes are involved in the pathogenesis of ovarian cancer, especially within the tumor microenvironment. Angiogenesis represents a hallmark phenomenon in cancer, and it is responsible for tumor spread and metastasis in ovarian cancer, among other tumor types, as it leads to new blood vessel formation. In recent years angiogenesis has been given considerable attention in order to identify targets for developing effective anti-tumor therapies. Growth factors have been identified to play key roles in driving angiogenesis and, thus, the formation of new blood vessels that assist in “feeding” cancer. Such molecules include the vascular endothelial growth factor (VEGF, the platelet derived growth factor (PDGF, the fibroblast growth factor (FGF, and the angiopoietin/Tie2 receptor complex. These proteins are key players in complex molecular pathways within the tumor cell and they have been in the spotlight of the development of anti-angiogenic molecules that may act as stand-alone therapeutics, or in concert with standard treatment regimes such as chemotherapy. The pathways involved in angiogenesis and molecules that have been developed in order to combat angiogenesis are described in this paper.

  12. Inflammation and hypoxia in the kidney: friends or foes?

    Science.gov (United States)

    Haase, Volker H

    2015-08-01

    Hypoxic injury is commonly associated with inflammatory-cell infiltration, and inflammation frequently leads to the activation of cellular hypoxia response pathways. The molecular mechanisms underlying this cross-talk during kidney injury are incompletely understood. Yamaguchi and colleagues identify CCAAT/enhancer-binding protein δ as a cytokine- and hypoxia-regulated transcription factor that fine-tunes hypoxia-inducible factor-1 signaling in renal epithelial cells and thus provide a novel molecular link between hypoxia and inflammation in kidney injury.

  13. Modification of bacterial cell survival by postirradiation hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Vexler, F B; Eidus, L Kh

    1986-01-27

    It is shown that postirradiation hypoxia affects the survival of E.coli. Hypoxic conditions immediately after a single-dose irradiation diminish cell survival in nutrient medium. Increasing time intervals between irradiation and hypoxia decrease the efficiency of the latter, while 1 h after irradiation hypoxia does not modify the survival of irradiated cells. These findings reveal that the mechanisms of action of postirradiation hypoxia on eu- and prokaryotic cells are similar.

  14. OSU-A9 inhibits angiogenesis in human umbilical vein endothelial cells via disrupting Akt–NF-κB and MAPK signaling pathways

    Energy Technology Data Exchange (ETDEWEB)

    Omar, Hany A. [Division of Medicinal Chemistry, College of Pharmacy, The Ohio State University, Columbus, OH 43210 (United States); Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Arafa, El-Shaimaa A. [Department of Pharmacology, Faculty of Pharmacy, Beni-Suef University, Beni-Suef 62514 (Egypt); Salama, Samir A. [Department of Biochemistry, Faculty of Pharmacy, Al-Azhar University, Cairo 11511 (Egypt); Arab, Hany H. [Department of Biochemistry, Faculty of Pharmacy, Cairo University, Cairo 11562 (Egypt); Wu, Chieh-Hsi, E-mail: chhswu@mail.cmu.edu.tw [School of Pharmacy, China Medical University, Taichung 40402, Taiwan (China); Weng, Jing-Ru, E-mail: columnster@gmail.com [Department of Biological Science and Technology, China Medical University, Taichung 40402, Taiwan (China)

    2013-11-01

    Since the introduction of angiogenesis as a useful target for cancer therapy, few agents have been approved for clinical use due to the rapid development of resistance. This problem can be minimized by simultaneous targeting of multiple angiogenesis signaling pathways, a potential strategy in cancer management known as polypharmacology. The current study aimed at exploring the anti-angiogenic activity of OSU-A9, an indole-3-carbinol-derived pleotropic agent that targets mainly Akt–nuclear factor-kappa B (NF-κB) signaling which regulates many key players of angiogenesis such as vascular endothelial growth factor (VEGF) and matrix metalloproteinases (MMPs). Human umbilical vein endothelial cells (HUVECs) were used to study the in vitro anti-angiogenic effect of OSU-A9 on several key steps of angiogenesis. Results showed that OSU-A9 effectively inhibited cell proliferation and induced apoptosis and cell cycle arrest in HUVECs. Besides, OSU-A9 inhibited angiogenesis as evidenced by abrogation of migration/invasion and Matrigel tube formation in HUVECs and attenuation of the in vivo neovascularization in the chicken chorioallantoic membrane assay. Mechanistically, Western blot, RT-PCR and ELISA analyses showed the ability of OSU-A9 to inhibit MMP-2 production and VEGF expression induced by hypoxia or phorbol-12-myristyl-13-acetate. Furthermore, dual inhibition of Akt–NF-κB and mitogen-activated protein kinase (MAPK) signaling, the key regulators of angiogenesis, was observed. Together, the current study highlights evidences for the promising anti-angiogenic activity of OSU-A9, at least in part through the inhibition of Akt–NF-κB and MAPK signaling and their consequent inhibition of VEGF and MMP-2. These findings support OSU-A9's clinical promise as a component of anticancer therapy. - Highlights: • The antiangiogenic activity of OSU-A9 in HUVECs was explored. • OSU-A9 inhibited HUVECs proliferation, migration, invasion and tube formation. • OSU-A9

  15. Overexpression of Hypoxia-Inducible Factor-1α Exacerbates Endothelial Barrier Dysfunction Induced by Hypoxia

    Directory of Open Access Journals (Sweden)

    Pei Wang

    2013-09-01

    Full Text Available Background/Aims: The mechanisms involved in endothelial barrier dysfunction induced by hypoxia are incompletely understood. There is debate about the role of hypoxia-inducible factor-1α (HIF-1α in endothelial barrier disruption. The aim of this study was to investigate the effect of genetic overexpression of HIF-1α on barrier function and the underlying mechanisms in hypoxic endothelial cells. Methods: The plasmid pcDNA3.1/V5-His-HIF-1α was stably transfected into human endothelial cells. The cells were exposed to normoxia or hypoxia. The mRNA and protein expressions of HIF-1α were detected by RT-PCR and Western blot respectively. The barrier function was assessed by measuring the transendothelial electrical resistance (TER. The Western blot analysis was used to determine the protein expression of glucose transporter-1 (GLUT-1, zonular occludens-1 (ZO-1, occludin, and myosin light chain kinase (MLCK in endothelial cells. The mRNA expression of proinflammatory cytokines was detected by qRT-PCR. Results: Genetic overexpression of HIF-1α significantly increased the mRNA and protein expression of HIF-1α in endothelial cells. The overexpression of HIF-1α enhanced the hypoxia-induced increase of HIF-1α and GLUT-1 protein expression. HIF-1α overexpression not only exacerbated hypoxia-induced endothelial barrier dysfunction but also augmented hypoxia-induced up-regulation of MLCK protein expression. HIF-1α overexpression also enhanced IL-1β, IL-6 and TNF-α mRNA expression. Conclusion: We provide evidence that genetic overexpression of HIF-1α aggravates the hypoxia-induced endothelial barrier dysfunction via enhancing the up-regulation of MLCK protein expression caused by hypoxia, suggesting a potential role for HIF-1α in the pathogenesis of endothelial barrier dysfunction in hypoxia.

  16. Analysis of hypoxia and hypoxia-like states through metabolite profiling.

    Directory of Open Access Journals (Sweden)

    Julie E Gleason

    Full Text Available In diverse organisms, adaptation to low oxygen (hypoxia is mediated through complex gene expression changes that can, in part, be mimicked by exposure to metals such as cobalt. Although much is known about the transcriptional response to hypoxia and cobalt, little is known about the all-important cell metabolism effects that trigger these responses.Herein we use a low molecular weight metabolome profiling approach to identify classes of metabolites in yeast cells that are altered as a consequence of hypoxia or cobalt exposures. Key findings on metabolites were followed-up by measuring expression of relevant proteins and enzyme activities. We find that both hypoxia and cobalt result in a loss of essential sterols and unsaturated fatty acids, but the basis for these changes are disparate. While hypoxia can affect a variety of enzymatic steps requiring oxygen and heme, cobalt specifically interferes with diiron-oxo enzymatic steps for sterol synthesis and fatty acid desaturation. In addition to diiron-oxo enzymes, cobalt but not hypoxia results in loss of labile 4Fe-4S dehydratases in the mitochondria, but has no effect on homologous 4Fe-4S dehydratases in the cytosol. Most striking, hypoxia but not cobalt affected cellular pools of amino acids. Amino acids such as aromatics were elevated whereas leucine and methionine, essential to the strain used here, dramatically decreased due to hypoxia induced down-regulation of amino acid permeases.These studies underscore the notion that cobalt targets a specific class of iron proteins and provide the first evidence for hypoxia effects on amino acid regulation. This research illustrates the power of metabolite profiling for uncovering new adaptations to environmental stress.

  17. Effects of intermittent hypoxia on running economy.

    Science.gov (United States)

    Burtscher, M; Gatterer, H; Faulhaber, M; Gerstgrasser, W; Schenk, K

    2010-09-01

    We investigated the effects of two 5-wk periods of intermittent hypoxia on running economy (RE). 11 male and female middle-distance runners were randomly assigned to the intermittent hypoxia group (IHG) or to the control group (CG). All athletes trained for a 13-wk period starting at pre-season until the competition season. The IHG spent additionally 2 h at rest on 3 days/wk for the first and the last 5 weeks in normobaric hypoxia (15-11% FiO2). RE, haematological parameters and body composition were determined at low altitude (600 m) at baseline, after the 5 (th), the 8 (th) and the 13 (th) week of training. RE, determined by the relative oxygen consumption during submaximal running, (-2.3+/-1.2 vs. -0.3+/-0.7 ml/min/kg, Ptraining phase. Georg Thieme Verlag KG Stuttgart . New York.

  18. Kinetic modeling in PET imaging of hypoxia

    Science.gov (United States)

    Li, Fan; Joergensen, Jesper T; Hansen, Anders E; Kjaer, Andreas

    2014-01-01

    Tumor hypoxia is associated with increased therapeutic resistance leading to poor treatment outcome. Therefore the ability to detect and quantify intratumoral oxygenation could play an important role in future individual personalized treatment strategies. Positron Emission Tomography (PET) can be used for non-invasive mapping of tissue oxygenation in vivo and several hypoxia specific PET tracers have been developed. Evaluation of PET data in the clinic is commonly based on visual assessment together with semiquantitative measurements e.g. standard uptake value (SUV). However, dynamic PET contains additional valuable information on the temporal changes in tracer distribution. Kinetic modeling can be used to extract relevant pharmacokinetic parameters of tracer behavior in vivo that reflects relevant physiological processes. In this paper, we review the potential contribution of kinetic analysis for PET imaging of hypoxia. PMID:25250200

  19. Response of skeletal muscle mitochondria to hypoxia.

    Science.gov (United States)

    Hoppeler, Hans; Vogt, Michael; Weibel, Ewald R; Flück, Martin

    2003-01-01

    This review explores the current concepts relating the structural and functional modifications of skeletal muscle mitochondria to the molecular mechanisms activated when organisms are exposed to a hypoxic environment. In contrast to earlier assumptions it is now established that permanent or long-term exposure to severe environmental hypoxia decreases the mitochondrial content of muscle fibres. Oxidative muscle metabolism is shifted towards a higher reliance on carbohydrates as a fuel, and intramyocellular lipid substrate stores are reduced. Moreover, in muscle cells of mountaineers returning from the Himalayas, we find accumulations of lipofuscin, believed to be a mitochondrial degradation product. Low mitochondrial contents are also observed in high-altitude natives such as Sherpas. In these subjects high-altitude performance seems to be improved by better coupling between ATP demand and supply pathways as well as better metabolite homeostasis. The hypoxia-inducible factor 1 (HIF-1) has been identified as a master regulator for the expression of genes involved in the hypoxia response, such as genes coding for glucose transporters, glycolytic enzymes and vascular endothelial growth factor (VEGF). HIF-1 achieves this by binding to hypoxia response elements in the promoter regions of these genes, whereby the increase of HIF-1 in hypoxia is the consequence of a reduced degradation of its dominant subunit HIF-1a. A further mechanism that seems implicated in the hypoxia response of muscle mitochondria is related to the formation of reactive oxygen species (ROS) in mitochondria during oxidative phosphorylation. How exactly ROS interfere with HIF-1a as well as MAP kinase and other signalling pathways is debated. The current evidence suggests that mitochondria themselves could be important players in oxygen sensing.

  20. The impact of hypoxia on oncolytic virotherapy

    Directory of Open Access Journals (Sweden)

    Guo ZS

    2011-11-01

    Full Text Available Z Sheng GuoUniversity of Pittsburgh Cancer Institute and Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, PA, USAAbstract: The hypoxic tumor microenvironment plays significant roles in tumor cell metabolism and survival, tumor growth, and progression. Hypoxia modulates target genes in target cells mainly through an oxygen-sensing signaling pathway mediated by hypoxia-inducible factor of transcription factors. As a result, hypoxic tumor cells are resistant to conventional therapeutics such as radiation and chemotherapy. Oncolytic virotherapy may be a promising novel therapeutic for hypoxic cancer. Some oncolytic viruses are better adapted than others to the hypoxic tumor environment. Replication of adenoviruses from both groups B and C is inhibited, yet replication of herpes simplex virus is enhanced. Hypoxia seems to exert little or no effect on the replication of other oncolytic viruses. Vaccinia virus displayed increased cytotoxicity in some hypoxic cancer cells even though viral protein synthesis and transgene expression were not affected. Vesicular stomatitis virus replicated to similar levels in both hypoxic and normoxic conditions, and is effective for killing hypoxic cancer cells. However, vesicular stomatitis virus and reovirus, but not encephalomyocarditis virus, are sensitive to elevated levels of hypoxia-inducible factor-1α in renal cancer cells with the loss of von Hippel–Lindau tumor suppressor protein, because elevated hypoxia-inducible factor activity confers dramatically enhanced resistance to cytotoxicity mediated by vesicular stomatitis virus or reovirus. A variety of hypoxia-selective and tumor-type-specific oncolytic adenoviruses, generated by incorporating hypoxia-responsive elements into synthetic promoters to control essential genes for viral replication or therapeutic genes, have been shown to be safe and efficacious. Hypoxic tumor-homing macrophages can function effectively as carrier

  1. Nanobodies As Novel Agents for Targeting Angiogenesis in Solid Cancers

    Directory of Open Access Journals (Sweden)

    Roghaye Arezumand

    2017-12-01

    Full Text Available Solid cancers are dependent on angiogenesis for sustenance. The FDA approval of Bevacizumab in 2004 inspired many scientists to develop more inhibitors of angiogenesis. Although several monoclonal antibodies (mAbs are being administered to successfully combat various pathologies, the complexity and large size of mAbs seem to narrow the therapeutic applications. To improve the performance of cancer therapeutics, including those blocking tumor angiogenesis, attractive strategies such as miniaturization of the antibodies have been introduced. Nanobodies (Nbs, small single-domain antigen-binding antibody fragments, are becoming promising therapeutic and diagnostic proteins in oncology due to their favorable unique structural and functional properties. This review focuses on the potential and state of the art of Nbs to inhibit the angiogenic process for therapy and the use of labeled Nbs for non-invasive in vivo imaging of the tumors.

  2. Angiogenesis in Schistosoma haematobium-associated urinary bladder cancer.

    Science.gov (United States)

    Dematei, Anderson; Fernandes, Rúben; Soares, Raquel; Alves, Helena; Richter, Joachim; Botelho, Monica C

    2017-12-01

    Schistosoma haematobium, a parasitic flatworm that infects more than 100 million people, mostly in the developing world, is the causative agent of urogenital schistosomiasis, and is associated with a high incidence of squamous cell carcinoma (SCC) of the bladder. During infection, eggs are deposited in the bladder causing an intense inflammatory reaction. Angiogenesis is defined as the formation of new blood vessels from preexisting ones and is recognized as a key event in cell proliferation and carcinogenesis and spread of malignant lesions. A growing amount of evidence points to angiogenesis playing a key role in schistosomiasis-associated bladder cancer. Thus, identifying biomarkers of this process plays an important role in the study of cancer. Here, we review recent findings on the role of angiogenesis in bladder cancer and the growth factors that induce and assist in their development, particularly SCC of the bladder associated to urogenital schistosomiasis. © 2017 APMIS. Published by John Wiley & Sons Ltd.

  3. Syndecan-4 shedding impairs macrovascular angiogenesis in diabetes mellitus

    Energy Technology Data Exchange (ETDEWEB)

    Li, Ran; Xie, Jun; Wu, Han; Li, Guannan; Chen, Jianzhou; Chen, Qinhua; Wang, Lian; Xu, Biao, E-mail: xubiao@medmail.com.cn

    2016-05-20

    Purpose: Syndecan-4 (synd4) is a ubiquitous heparan sulfate proteoglycan cell surface receptor that modulates cell proliferation, migration, mechanotransduction, and endocytosis. The extracellular domain of synd4 sheds heavily in acute inflammation, but the shedding of synd4 in chronic inflammation, such as diabetes mellitus (DM), is still undefined. We investigated the alterations of synd4 endothelial expression in DM and the influence of impaired synd4 signaling on angiogenesis in human umbilical vein endothelial cells (HUVECs), diabetic rats, synd4 null mice, and db/db mice. Material and methods: HUVECs were incubated with advanced glycation end products (AGEs). Western blot analysis was used to determine synd4 protein expression and ELISA was used to detect soluble synd4 fragments. The concentration of synd4 in the aortic endothelia of diabetic rats was detected by immunohistochemical staining. Aortic ring assays were performed to study the process of angiogenesis in the diabetic rats and in synd4 null and db/db mice. Recombinant adenoviruses containing the synd4 gene or null were constructed to enhance synd4 aortic expression in db/db mice. Results: Western blot analysis showed decreased expression of the synd4 extracellular domain in HUVECs, and ELISA detected increased soluble fragments of synd4 in the media. Synd4 endothelial expression in the aortas of diabetic rats was decreased. Aortic ring assay indicated impaired angiogenesis in synd4 null and db/db mice, which was partially reversed by synd4 overexpression in db/db mice. Conclusion: Synd4 shedding from vascular endothelial cells played an important role in the diabetes-related impairment of angiogenesis. -- Highlights: •Synd4 shedding from endothelial cells is accelerated under the stimulation of AGEs. •Extracellular domain of synd4 is diminished in the endothelium of DM rats. •Aortic rings of synd4 null mice showed impaired angiogenesis. •Overexpression of synd4 partly rescues macrovascular

  4. Prognostic implication of apoptosis and angiogenesis in cervical uteri cancer

    International Nuclear Information System (INIS)

    Zaghloul, Mohamed S.; El Naggar, Mervat; El Deeb, Amany; Khaled, Hussein; Mokhtar, Nadia

    2000-01-01

    Purpose: A retrospective study was performed to investigate the relationship between spontaneous apoptosis and angiogenesis uterine cervix squamous cell carcinoma patients. The prognostic value of each (and both) of these biologic parameters was also tested. Methods and Materials: The pathologic materials of 40 cervical uteri squamous cell carcinoma patients were examined and immunohistochemically stained to determine the tumor angiogenesis (tumor microvascular score), using factor VIII-related antigen, and their tumor apoptotic index (AI), using the TdT-mediated dUTP nick end-labeling (TUNEL) method. Three patients were Stage I, 18 were Stage II, 15 were Stage III, and 4 were Stage IV (FIGO classification). All patients were treated with radical radiotherapy and all had follow-up for more than 2 years. Results: The mean AI was 15.1 ± 12.8, with a median of 8.3. The mean tumor microvascular score was 3 9.7 ± 14.4, with a median of 3 8. The patients' age and tumor grade did not seem to significantly affect the prognosis. On the other hand, AI and angiogenesis (tumor microvascular score) were of high prognostic significance. The 3-year disease-free survival (DFS) rate for the patients having AI above the median was 78% (confidence interval [CI] 69-87%), compared to 32% (CI 22-42%) for those having AI below the median. The DFS was 18% (CI 9-27%) for patients having an angiogenesis score above the median, while it was 86% (CI 78-94%) for those patients having a score below the median. Conclusion: Determination of both tumor microvascular score and AI can identify patients with the best prognosis of 100% DFS (with low angiogenesis score and high AI). Women with a high score and low AI had the worst prognosis (DFS = 3%, CI 1-5%). Moreover, high AI can compensate partially for the aggressive behavior of tumors showing a high rate of angiogenesis.

  5. An interesting case of angiogenesis in cavernous hemangioma

    Directory of Open Access Journals (Sweden)

    Dipankar Das

    2016-01-01

    Full Text Available Cavernous hemangioma is the most common orbital tumor in adult. There is lot of literatures for clinicopathological features of this tumor. These tumors had been studied for the model of angiogenesis in many of the experimental setups. We present a case of 34-year-old male with this tumor in the left eye with computerized tomography evidence. Postsurgical laboratory findings gave interesting evidence of tumor angiogenesis with tumor endothelial cells and sprouting of the small vessels endothelial cells. Podosome rosette could be conceptualized from the characteristic patterns seen in the tumor.

  6. Skeletal Muscle Angiogenesis and Its Relation to Insulin Sensitivity

    DEFF Research Database (Denmark)

    Lindqvist, Anna Maria Charlotte K

    mediator of angiogenesis) are reduced in insulin resistant individuals. Exercise training can improve skeletal muscle capillarization and the angiogenic potential and physical activity has also been proven to enhance muscle insulin sensitivity. Increased skeletal muscle capillarization is associated......) or by overexpression of VEGF-A in the tibialis anterior muscle (transfection; study II) and the effect of the increased muscle capillarization on muscle insulin sensitivity was examined. In study I skeletal muscle specific angiogenesis was induced by administering an α1-adrenergic antagonist (prazosin) to healthy...

  7. Intermittent Hypoxia Influences Alveolar Bone Proper Microstructure via Hypoxia-Inducible Factor and VEGF Expression in Periodontal Ligaments of Growing Rats

    Directory of Open Access Journals (Sweden)

    Shuji Oishi

    2016-09-01

    Full Text Available Intermittent hypoxia (IH recapitulates morphological changes in the maxillofacial bones in children with obstructive sleep apnea (OSA. Recently, we found that IH increased bone mineral density (BMD in the inter-radicular alveolar bone (reflecting enhanced osteogenesis in the mandibular first molar (M1 region in the growing rats, but the underlying mechanism remains unknown. In this study, we focused on the hypoxia-inducible factor (HIF pathway to assess the effect of IH by testing the null hypothesis of no significant differences in the mRNA-expression levels of relevant factors associated with the HIF pathway, between control rats and growing rats with IH. To test the null hypothesis, we investigated how IH enhances mandibular osteogenesis in the alveolar bone proper with respect to HIF-1α and vascular endothelial growth factor (VEGF in periodontal ligament (PDL tissues. Seven-week-old male Sprague–Dawley rats were exposed to IH for 3 weeks. The microstructure and BMD in the alveolar bone proper of the distal root of the mandibular M1 were evaluated using micro-computed tomography (micro-CT. Expression of HIF-1α and VEGF mRNA in PDL tissues were measured, whereas osteogenesis was evaluated by measuring mRNA levels for alkaline phosphatase (ALP and bone morphogenetic protein-2 (BMP-2. The null hypothesis was rejected: we found an increase in the expression of all of these markers after IH exposure. The results provided the first indication that IH enhanced osteogenesis of the mandibular M1 region in association with PDL angiogenesis during growth via HIF-1α in an animal model.

  8. Role of hypoxia and hypoxia inducible factor in physiological and pathological conditions

    Directory of Open Access Journals (Sweden)

    Mozhgan Jahani

    2017-11-01

    Full Text Available Introduction: Organisms are exposed to oxygen deprivation (Hypoxia in various physiological and pathological conditions. There are different conserve evolutionary responses to counterview with this stress that primary transcriptional response to stress related to hypoxia is interceded by hypoxia-inducible factor (HIF-1 in mammals. This factor can regulate different genes that have essential roles in adaptation to this condition. In this review, the role of this factor in physiological and pathological conditions under hypoxic condition has been evaluated after examining structural features and regulation characteristics of HIF-1. Methods: First, articles related to the keywords of hypoxia and HIF-1 (from 1991-2016 were searched from valid databases such as Springer Link, Google Scholar, PubMed and Science direct. Then, the articles correlated with hypoxia, HIF-1 and their roles in physiological and pathological conditions (120 articles were searched and just 64 articles were selected for this study. Result: According to studies, there are different genes in cells and organs that can be regulated by HIF-1. Activation of genes expression by this protein occurs through its linkage to cis-acting of 50 base pair hypoxia response element (HRE region located in their promotor and enhancer. Depending on circumstances, activation of these genes can be beneficial or harmful. Conclusion: Activation of different genes in hypoxia by HIF-1 has different effects on physiological and pathological conditions. Therefore, HIF-1, as a hypoxia-inducible factor in hypoxic conditions, plays an essential role in the adaptation of cells and organs to changes related to the presence of oxygen.

  9. [The level of superoxide dismutase expression in primary and metastatic colorectal cancer cells in hypoxia and tissue normoxia].

    Science.gov (United States)

    Skrzycki, Michał; Czeczot, Hanna; Chrzanowska, Alicja; Otto-Ślusarczyk, Dagmara

    2015-11-01

    Superoxide oxidase (SOD) is a key antioxidant enzyme protecting cells against oxidative stress, which might induce cancerogenesis. In tumor cells SOD influences the level of the reactive oxygen species (ROS) allowing for survival and proliferation. High rate of cells proliferation in tumor leads to their temporary hypoxia due to lower rate of angiogenesis. Therefore during tumor development, cancer cells function in conditions of hypoxia or tissue normoxia. The aim of study was to evaluate of SOD isoenzymes (SOD1 and SOD2) expression level in cell lines of primary (SW 480) and metastatic (SW 620) colorectal cancer, cultured in hypoxia (1% oxygen), tissue normoxia (10% oxygen), and atmospheric normoxia (21% oxygen). Cells were cultured in MEM medium in different oxygen concentrations (1%, 10%, 21%) in hypoxic chamber with oxygenation regulator. The number of living cells in lines SW 480 and 620 was determined by trypan blue method. Expression of SOD1 and SOD2 at the mRNA level was determined by RT-PCR and PCR. In both studied cell lines (SW 480 and SW 620), the number of living cells (viability) was increased in hypoxia and atmospheric normoxia. The expression level of SOD1 and SOD2 in studied cell lines was different. The lowest level of expression of both SOD isoenzymes was observed in hypoxia. In conditions of atmospheric normoxia the expression level of SOD1 in SW480 cell line was increased, and similar in SW620 cell line comparing to tissue normoxia. Whereas the SOD2 expression level in atmospheric normoxia conditions in both cell lines was significantly increased. Observed differences were statistically significant (p ≤ 0,05). The profile of expression of SOD1 and SOD2 in cell lines SW480 and SW620 indicates differentiated response of tumor cells depending on access to oxygen. Low level of SOD isoenzymes expression in SW480 and SW620 cells in hypoxia indicates decreased production of ROS. Differences of SOD isoenzymes expression level in tissue normoxia

  10. Frequently asked questions in hypoxia research

    Directory of Open Access Journals (Sweden)

    Wenger RH

    2015-09-01

    Full Text Available Roland H Wenger,1,2 Vartan Kurtcuoglu,1,2 Carsten C Scholz,1,2 Hugo H Marti,3 David Hoogewijs1,2,4 1Institute of Physiology and Zurich Center for Human Physiology (ZIHP, University of Zurich, 2National Center of Competence in Research “Kidney.CH”, Zurich, Switzerland; 3Institute of Physiology and Pathophysiology, University of Heidelberg, Heidelberg, 4Institute of Physiology, University of Duisburg-Essen, Essen, Germany Abstract: “What is the O2 concentration in a normoxic cell culture incubator?” This and other frequently asked questions in hypoxia research will be answered in this review. Our intention is to give a simple introduction to the physics of gases that would be helpful for newcomers to the field of hypoxia research. We will provide background knowledge about questions often asked, but without straightforward answers. What is O2 concentration, and what is O2 partial pressure? What is normoxia, and what is hypoxia? How much O2 is experienced by a cell residing in a culture dish in vitro vs in a tissue in vivo? By the way, the O2 concentration in a normoxic incubator is 18.6%, rather than 20.9% or 20%, as commonly stated in research publications. And this is strictly only valid for incubators at sea level. Keywords: gas laws, hypoxia-inducible factor, Krogh tissue cylinder, oxygen diffusion, partial pressure, tissue oxygen levels

  11. Hypoxanthine as a measurement of hypoxia.

    Science.gov (United States)

    Saugstad, O D

    1975-04-01

    The hypoxanthine concentration in plasma was found to be a sensitive parameter of hypoxia of the fetus and the newborn infant. The plasma level of hypoxanthine in the umbilical cord in 29 newborn infants with normal delivery varied between 0 and 11.0 mumol/liter with a mean of 5.8 mumol/liter, SD 3.0 mumol/liter. Compared with this reference group the hypoxanthine concentration in plasma of the umbilical cord in 10 newborn infants with clinical signs of intrauterine hypoxia during labor was found to be significantly higher, with a range of 11.0-61.5 mumol/liter, with a mean of 25.0 mumol/liter, SD 18.0 mumol/liter. The plasma level of hypoxanthine in two premature babies developing an idiopathic respiratory distress syndrome was monitored. The metabolite was found to be considerably increased, in one of them more than 24 hr after a period of hypoxia necessitating artificial ventilation. The hypoxanthine level in plasma of umbilical arterial blood was followed about 2 hr postpartum in three newborn infants with clinical signs of intrauterine hypoxia. The decrease of the plasma concentration of the metabolite seemed to be with a constant velocity, as it was about 10 mumol/liter/hr in these cases. A new method was used for the determination of hypoxanthine in plasma, based on the principle that PO2 decreased when hypoxanthine is oxidized to uric acid.

  12. Signaling hypoxia by hypoxia-inducible factor protein hydroxylases: a historical overview and future perspectives

    Science.gov (United States)

    Bishop, Tammie; Ratcliffe, Peter J

    2014-01-01

    By the early 1900s, the close matching of oxygen supply with demand was recognized to be a fundamental requirement for physiological function, and multiple adaptive responses to environment hypoxia had been described. Nevertheless, the widespread operation of mechanisms that directly sense and respond to levels of oxygen in animal cells was not appreciated for most of the twentieth century with investigators generally stressing the regulatory importance of metabolic products. Work over the last 25 years has overturned that paradigm. It has revealed the existence of a set of “oxygen-sensing” 2-oxoglutarate dependent dioxygenases that catalyze the hydroxylation of specific amino acid residues and thereby control the stability and activity of hypoxia-inducible factor. The hypoxia-inducible factor hydroxylase pathway regulates a massive transcriptional cascade that is operative in essentially all animal cells. It transduces a wide range of responses to hypoxia, extending well beyond the classical boundaries of hypoxia physiology. Here we review the discovery and elucidation of these pathways, and consider the opportunities and challenges that have been brought into focus by the findings, including new implications for the integrated physiology of hypoxia and therapeutic approaches to ischemic/hypoxic disease. PMID:27774477

  13. Hepcidin: A Critical Regulator of Iron Metabolism during Hypoxia

    Directory of Open Access Journals (Sweden)

    Korry J. Hintze

    2011-01-01

    Full Text Available Iron status affects cognitive and physical performance in humans. Recent evidence indicates that iron balance is a tightly regulated process affected by a series of factors other than diet, to include hypoxia. Hypoxia has profound effects on iron absorption and results in increased iron acquisition and erythropoiesis when humans move from sea level to altitude. The effects of hypoxia on iron balance have been attributed to hepcidin, a central regulator of iron homeostasis. This paper will focus on the molecular mechanisms by which hypoxia affects hepcidin expression, to include a review of the hypoxia inducible factor (HIF/hypoxia response element (HRE system, as well as recent evidence indicating that localized adipose hypoxia due to obesity may affect hepcidin signaling and organismal iron metabolism.

  14. Imaging of hypoxia in mouse atherosclerotic plaques with 64Cu-ATSM

    International Nuclear Information System (INIS)

    Nie, Xingyu; Randolph, Gwendalyn J.; Elvington, Andrew; Bandara, Nilantha; Zheleznyak, Alexander; Gropler, Robert J.; Woodard, Pamela K.; Lapi, Suzanne E.

    2016-01-01

    Introduction: Cardiovascular disease is the leading cause of death in the United States. The identification of vulnerable plaque at risk of rupture has been a major focus of research. Hypoxia has been identified as a potential factor in the formation of vulnerable plaque, and it is clear that decreased oxygen plays a role in the development of plaque angiogenesis leading to plaque destabilization. The purpose of this study is to demonstrate the feasibility of copper-64 labeled diacetyl-bis (N 4 -methylthiosemicarbazone) ( 64 Cu-ATSM), a positron-emitting radiopharmaceutical taken up in low-oxygen-tension cells, for the identification of hypoxic and potentially unstable atherosclerotic plaque in a mouse model. Methods: 64 Cu-ATSM PET was performed in 21 atherosclerotic apolipoprotein E knockout (ApoE −/− ) mice, 6 of which were fed high-fat diet (HFD) while the others received standard-chow diet (SCD), and 13 control wild type mice fed SCD. 4 SCD ApoE −/− mice and 4 SCD wild type mice also underwent 18 F-fluorodeoxyglucose ( 18 F-FDG) positron emission tomography (PET) imaging one day prior to 64 Cu-ATSM PET. Results: 64 Cu-ATSM uptake was increased in the aortic arch in SCD ApoE −/− mice (average aortic arch/muscle (A/M) standardized uptake value ratio 7.5–30 min post injection: (5.66 ± 0.23) compared to control mice (A/M SUV ratio 7.5–30 min post injection (3.87 ± 0.22), p < 0.0001). HFD ApoE −/− mice also showed similarly increased aortic arch uptake on PET imaging in comparison to control mice. Immunohistochemistry in both HFD and SCD ApoE −/− mice revealed noticeable hypoxia by pimonidazole stain in atherosclerosis which was co-localized to macrophage by CD68 staining. Autoradiography assessment demonstrated the presence of hypoxia by 64 Cu-ATSM uptake correlated with pimonidazole uptake within the ex vivo atherosclerotic aortic arch specimens. A significant increase in 18 F-FDG uptake in the SCD ApoE −/− mice in comparison to

  15. Pimonidazole: a novel hypoxia marker for complementary study of tumor hypoxia and tumor biology

    International Nuclear Information System (INIS)

    Varia, Mahesh A.; Kennedy, Andrew S.; Calkins-Adams, Dennise P.; Rinker, Lillian; Novotny, Debra; Fowler, Wesley C.; Raleigh, James A.

    1997-01-01

    Purpose/Objectives: Tumor hypoxia appears to be associated with treatment resistance and with gene expression that may lead to hypoxia-mediated selection of tumor cells as a source for cell growth and metastases. The objective of this study was to develop complementary techniques of hypoxia detection with molecular markers of cell proliferation and metastases in order to investigate the role of tumor hypoxia in tumor biology. Materials and Methods: Pimonidazole is a 2-nitroimidazole which is reductively-activated and becomes covalently bound to thiol-containing proteins only in hypoxic cells. These adducts can be detected using immunohistochemistry, enzyme linked immunosorbent assay or flow cytometry as a measure of hypoxia in tumors. Quantitative immunohistochemical analysis has been completed for five patients with squamous cell carcinoma of the cervix who were given pimonidazole hydrochloride (0.5 g/m 2 intravenously) followed by cervical biopsies 24 hours later. Informed consent was obtained according to a protocol approved by the Institutional Review Board. A minimum of 3 random biopsies were obtained from the tumors and at least four sections examined from each biopsy site. Formalin fixed, paraffin embedded tissue sections were immunostained for pimonidazole binding using a mouse monoclonal antibody. Commercially available monoclonal antibodies were used to detect cell proliferation markers MIB-1 (Ki-67) and to detect vascular endothelial growth factor (VEGF) in tumor cells in contiguous sections. The extent of immunostaining was expressed as the percent of immunostained to total tumor cells as determined by Chalkley point counting. Results: No clinical toxicities were associated with pimonidazole infusion. Immunostaining with pimonidazole antibody was observed in all patients indicating the presence of tumor hypoxia. Qualitatively there is little or no overlap between the areas of hypoxia and proliferation. Quantitative data tabulated below show the

  16. Regulation of mRNA translation influences hypoxia tolerance

    International Nuclear Information System (INIS)

    Koritzinsky, M.; Wouters, B.G.; Koumenis, C.

    2003-01-01

    Hypoxia is a heterogenous but common characteristic of human tumours and poor oxygenation is associated with poor prognosis. We believe that the presence of viable hypoxic tumor cells reflects in part an adaptation and tolerance of these cells to oxygen deficiency. Since oxidative phosphorylation is compromized during hypoxia, adaptation may involve both the upregulation of glycolysis as well as downregulation of energy consumption. mRNA translation is one of the most energy costly cellular processes, and we and others have shown that global mRNA translation is rapidly inhibited during hypoxia. However, some mRNAs, including those coding for HIF-1 α and VEGF, remain efficiently translated during hypoxia. Clearly, the mechanisms responsible for the overall inhibition of translation during hypoxia does not compromize the translation of certain hypoxia-induced mRNA species. We therefore hypothesize that the inhibition of mRNA translation serves to promote hypoxia tolerance in two ways: i) through conservation of energy and ii) through differential gene expression involved in hypoxia adaptation. We have recently identified two pathways that are responsible for the global inhibition of translation during hypoxia. The phosphorylation of the eukaryotic initiation factor eIF2 α by the ER resident kinase PERK results in down-regulation of protein synthesis shortly after the onset of hypoxia. In addition, the initiation complex eIF4F is disrupted during long lasting hypoxic conditions. The identification of the molecular pathways responsible for the inhibition of overall translation during hypoxia has rendered it possible to investigate their importance for hypoxia tolerance. We have found that mouse embryo fibroblasts that are knockout for PERK and therefore not able to inhibit protein synthesis efficiently during oxygen deficiency are significantly less tolerant to hypoxia than their wildtype counterparts. We are currently also investigating the functional significance

  17. Protein Structure in Context: The Molecular Landscape of Angiogenesis

    Science.gov (United States)

    Span, Elise A.; Goodsell, David S.; Ramchandran, Ramani; Franzen, Margaret A.; Herman, Tim; Sem, Daniel S.

    2013-01-01

    A team of students, educators, and researchers has developed new materials to teach cell signaling within its cellular context. Two nontraditional modalities are employed: physical models, to explore the atomic details of several of the proteins in the angiogenesis signaling cascade, and illustrations of the proteins in their cellular environment,…

  18. Angiogenesis in calcium phosphate scaffolds by inorganic copper ion release

    NARCIS (Netherlands)

    Barralet, Jake E.; Gbureck, Uwe; Habibovic, Pamela; Vorndran, Elke; Gerard, Catherine; Doillon, Charles J.

    2009-01-01

    Angiogenesis in a tissue-engineered device may be induced by incorporating growth factors (e.g., vascular endothelial growth factor [VEGF]), genetically modified cells, and/or vascular cells. It represents an important process during the formation and repair of tissue and is essential for

  19. Angiogenesis in urinary bladder carcinoma as defined by ...

    African Journals Online (AJOL)

    Background: Among the patients with bladder cancer, a group is still at risk of disease recurrence, progression, and death from their cancer after curative treatment. Angiogenesis is a crucial pathogenic mechanism for this type of urothelial carcinoma and is a potential therapeutic target. Objectives: To quantify tumor ...

  20. Angiogenesis and lymphangiogenesis are downregulated in primary breast cancer

    Science.gov (United States)

    Boneberg, E-M; Legler, D F; Hoefer, M M; Öhlschlegel, C; Steininger, H; Füzesi, L; Beer, G M; Dupont-Lampert, V; Otto, F; Senn, H-J; Fürstenberger, G

    2009-01-01

    Background: Angiogenesis and lymphangiogenesis are considered to play key roles in tumour growth, progression and metastasis. However, targeting tumour angiogenesis in clinical trials showed only modest efficacy. We therefore scrutinised the concept of tumour angiogenesis and lymphangiogenesis by analysing the expression of crucial markers involved in these processes in primary breast cancer. Methods: We analysed the expression of angiogenic, lymphangiogenic or antiangiogenic factors, their respective receptors and specific markers for endothelial and lymphendothelial cells by quantitative real-time RT-PCR in primary breast cancer and compared the expression profiles to non-cancerous, tumour-adjacent tissues and breast tissues from healthy women. Results: We found decreased mRNA amounts of major angiogenic and lymphangiogenic factors in tumour compared to healthy tissues, whereas antiangiogenic factors were upregulated. Concomitantly, angiogenic and lymphangiogenic receptors were downregulated in breast tumours. This antiangiogenic, antilymphangiogenic microenvironment was even more pronounced in aggressive tumours and accompanied by reduced amounts of endothelial and lymphatic endothelial cell markers. Conclusion: Primary breast tumours are not a site of highly active angiogenesis and lymphangiogenesis. Selection for tumour cells that survive with minimal vascular supply may account for this observation in clinical apparent tumours. PMID:19672262

  1. Thyroidal angiogenesis in zebrafish ( Danio rerio ) exposed to high ...

    African Journals Online (AJOL)

    As a well known environmental contaminant, perchlorate inhibits thyroidal iodide uptake and reduces thyroid hormone levels. In zebrafish (Danio rerio) exposed to high concentrations of sodium perchlorate (200, 350 and 500 mg/L) for 10 days, remarkable angiogenesis was identified, not only histopathologically but also ...

  2. Aspartame induces angiogenesis in vitro and in vivo models.

    Science.gov (United States)

    Yesildal, F; Aydin, F N; Deveci, S; Tekin, S; Aydin, I; Mammadov, R; Fermanli, O; Avcu, F; Acikel, C H; Ozgurtas, T

    2015-03-01

    Angiogenesis is the process of generating new blood vessels from preexisting vessels and is considered essential in many pathological conditions. The purpose of the present study is to evaluate the effect of aspartame on angiogenesis in vivo chick chorioallantoic membrane (CAM) and wound-healing models as well as in vitro 2,3-bis-2H-tetrazolium-5-carboxanilide (XTT) and tube formation assays. In CAM assay, aspartame increased angiogenesis in a concentration-dependent manner. Compared with the control group, aspartame has significantly increased vessel proliferation (p aspartame group had better healing than control group, and this was statistically significant at p aspartame on human umbilical vein endothelial cells on XTT assay in vitro, but it was not statistically significant; and there was no antiangiogenic effect of aspartame on tube formation assay in vitro. These results provide evidence that aspartame induces angiogenesis in vitro and in vivo; so regular use may have undesirable effect on susceptible cases. © The Author(s) 2015.

  3. Visualising and quantifying angiogenesis in metastatic colorectal cancer

    DEFF Research Database (Denmark)

    Hansen, Torben Frøstrup; Nielsen, Boye Schnack; Jakobsen, Anders

    2013-01-01

    Angiogenesis plays an important role in tumour growth and dissemination. We have recently shown that blood vessel density, determined by image analysis based on microRNA-126 (miRNA-126) in situ hybridization (ISH) in the primary tumours of metastatic colorectal cancers (mCRC), is predictive...

  4. In vivo monitoring of angiogenesis within Matrigel chambers using MRI

    DEFF Research Database (Denmark)

    Holm, David; Ley, Carsten Dan; Søgaard, Lise Vejby

    2006-01-01

    Angiogenesis is a critical process in tumour development and presents an important target for the development of a range of anti-cancer agents . To assess the in vivo efficacy of these ‘angiotherapeutics', a simple and reproducible in vivo model would be of significant value. Here we show...

  5. Thyroidal angiogenesis in zebrafish (Danio rerio) exposed to high ...

    African Journals Online (AJOL)

    STORAGESEVER

    2009-04-20

    Apr 20, 2009 ... As a well known environmental contaminant, perchlorate inhibits thyroidal iodide uptake and reduces thyroid hormone levels. In zebrafish (Danio rerio) exposed to high concentrations of sodium perchlorate (200, 350 and 500 mg/L) for 10 days, remarkable angiogenesis was identified, not only.

  6. Vascular endothelial growth factors and angiogenesis in eye disease

    NARCIS (Netherlands)

    Witmer, A. N.; Vrensen, G. F. J. M.; van Noorden, C. J. F.; Schlingemann, R. O.

    2003-01-01

    The vascular endothelial growth factor (VEGF) family of growth factors controls pathological angiogenesis and increased vascular permeability in important eye diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD). The purpose of this review is to develop new insights

  7. Hypoxia regulates the expression and localization of CCAAT/enhancer binding protein α by hypoxia inducible factor-1α in bladder transitional carcinoma cells.

    Science.gov (United States)

    Xue, Mei; Li, Xu; Chen, Wei

    2015-08-01

    Hypoxia inducible factor-1α (HIF-1α) is overexpressed in various types of solid tumor in humans, including bladder cancer. HIF-1α regulates the expression of a series of genes, which are involved in cell proliferation, differentiation, apoptosis, angiogenesis, migration and invasion and represents a potential therapeutic target for the treatment of human cancer. Despite extensive investigation of the effects of HIF-1α in the progression and metastasis of bladder cancer, the possible regulatory mechanisms underlying the effects of HIF-1α on bladder cancer cell proliferation and differentiation remain to be elucidated. It has been suggested that the transcription factor CCAAT/enhancer binding protein α (C/EBPα) acts as a tumor suppressor in several types of cancer cell, which are involved in regulating cell differentiation, proliferation and apoptosis. The present study confirmed that, in bladder cancer cells, the expression and localization of C/EBPα was regulated by hypoxia through an HIF-1α -dependent mechanism, which may be significant in bladder cancer cell proliferation and differentiation. The 5637 and T24 bladder cancer cell lines were incubated under normoxic and hypoxic conditions. The expression levels of HIF-1α and C/EBPα were detected by reverse transcription-quantitative polymerase chain reaction, western blotting and immunofluorescence analysis. The results revealed that, under hypoxic conditions, the protein expression levels of HIF-1α were markedly upregulated, but the mRNA levels were not altered. However, the mRNA and protein levels of C/EBPα were significantly reduced. The present study further analyzed the subcellular localization of C/EBPα, which was markedly decreased in the nuclei under hypoxic conditions. Following HIF-1α small interference RNA silencing of HIF-1α, downregulation of C/EBPα was prevented in the bladder cancer cells cultured under hypoxic conditions. In addition, groups of cells treated with 3-(5'-hydroxymethyl

  8. Celecoxib ameliorates portal hypertension of the cirrhotic rats through the dual inhibitory effects on the intrahepatic fibrosis and angiogenesis.

    Science.gov (United States)

    Gao, Jin-Hang; Wen, Shi-Lei; Yang, Wen-Juan; Lu, Yao-Yao; Tong, Huan; Huang, Zhi-Yin; Liu, Zhang-Xu; Tang, Cheng-Wei

    2013-01-01

    Increased intra-hepatic resistance to portal blood flow is the primary factor leading to portal hypertension in cirrhosis. Up-regulated expression of cyclooxygenase-2 (COX-2) in the cirrhotic liver might be a potential target to ameliorate portal hypertension. To verify the effect of celecoxib, a selective inhibitor of COX-2, on portal hypertension and the mechanisms behind it. Cirrhotic liver model of rat was established by peritoneal injection of thiacetamide (TAA). 36 rats were randomly assigned to control, TAA and TAA+celecoxib groups. Portal pressures were measured by introduction of catheters into portal vein. Hepatic fibrosis was assessed by the visible hepatic fibrotic areas and mRNAs for collagen III and α-SMA. The neovasculature was determined by hepatic vascular areas, vascular casts and CD31 expression. Expressions of COX-2, vascular endothelial growth factor (VEGF), VEGF receptor-2 (VEGFR-2) and related signal molecules were quantitated. Compared with TAA group, the portal pressure in TAA+celecoxib group was significantly decreased by 17.8%, pportal venules. The data of fibrotic areas, CD31expression, mRNA levels of α-SMA and collagen III in TAA+celecoxib group were much lower than those in TAA group, pprotein levels of VEGF, VEGFR-2 and COX-2 induced by TAA was significantly inhibited after celecoxib treatment. The expressions of prostaglandin E2 (PGE2), phosphorylated extracellular signal-regulated kinase (p-ERK), hypoxia-inducible factor-1α (HIF-1α), and c-fos were also down-regulated after celecoxib treatment. Long term administration of celecoxib can efficiently ameliorate portal hypertension in TAA rat model by its dual inhibitory effects on the intrahepatic fibrosis and angiogenesis. The anti-angiogenesis effect afforded by celecoxib may attribute to its modulation on VEGF/VEGFR-2 through the down-regulation of integrated signal pathways involving PGE2- HIF-1α- VEGF and p-ERK- c-fos- VEGFR-2.

  9. Effects of maternal smoking on the placental expression of genes related to angiogenesis and apoptosis during the first trimester.

    Directory of Open Access Journals (Sweden)

    Akihiro Kawashima

    Full Text Available Maternal cigarette smoking is reportedly associated with miscarriage, fetal growth restriction and placental abruption, and is paradoxically associated with a decreased risk of developing preeclampsia. In the present study, we investigated the gene expression levels of villous tissues in early gestation. We compared the expression levels of the genes related to angiogenesis and apoptosis in the villous tissues obtained from smoking and non-smoking pregnant women.We collected villous tissue samples from 57 women requesting surgical termination due to non-medical reasons at 6-8 weeks of gestation. The maternal cigarette smoking status was evaluated by the level of serum cotinine and patients were divided into active smokers and non-smokers by the serum cotinine level. The placental levels of VEGFA, PGF, FLT1, HIF1A, TP53, BAX and BCL2 mRNA were quantified by real time PCR.The gene expression level of PGF and HIF1A in the active smoker group was significantly higher than that in the non-smoker group. We did not observe any significant differences in the VEGFA or FLT1 expression between the groups. In active smoker group, the gene expression levels of TP53 and BAX were significantly higher than those in the non-smoker group. The ratio of BAX/BCL2 mRNA in the active smoker group was significantly higher than that in the non-smoker group.Our findings revealed that smoking might affect the placenta during early pregnancy. Maternal cigarette smoking in early pregnancy may be associated with villus hypoxia, which may influence angiogenesis and apoptosis.

  10. Abnormalities in alternative splicing of angiogenesis-related genes and their role in HIV-related cancers

    Directory of Open Access Journals (Sweden)

    Mthembu NN

    2017-03-01

    Full Text Available Nonkululeko N Mthembu,1 Zukile Mbita,2 Rodney Hull,1 Zodwa Dlamini1 1Research, Innovation and Engagements, Mangosuthu University of Technology, Durban, 2Department of Biochemistry, Microbiology and Biotechnology, University of Limpopo, Sovenga, South Africa Abstract: Alternative splicing of mRNA leads to an increase in proteome biodiversity by allowing the generation of multiple mRNAs, coding for multiple protein isoforms of various structural and functional properties from a single primary pre-mRNA transcript. The protein isoforms produced are tightly regulated in normal development but are mostly deregulated in various cancers. In HIV-infected individuals with AIDS, there is an increase in aberrant alternative splicing, resulting in an increase in HIV/AIDS-related cancers, such as Kaposi’s sarcoma, non-Hodgkin’s lymphoma, and cervical cancer. This aberrant splicing leads to abnormal production of protein and is caused by mutations in cis-acting elements or trans-acting factors in angiogenesis-related genes. Restoring the normal regulation of alternative splicing of angiogenic genes would alter the expression of protein isoforms and may confer normal cell physiology in patients with these cancers. This review highlights the abnormalities in alternative splicing of angiogenesis-related genes and their implication in HIV/AIDS-related cancers. This allows us to gain an insight into the pathogenesis of HIV/AIDS-related cancer and in turn elucidate the therapeutic potential of alternatively spliced genes in HIV/AIDS-related malignancies. Keywords: vascular endothelial growth factor, oncogenic viruses, hypoxia induced factor 1, Kaposi’s sarcoma, non-Hodgkin’s lymphoma, therapies targeting alternative splicing

  11. Ablation of cholesterol biosynthesis in neural stem cells increases their VEGF expression and angiogenesis but causes neuron apoptosis.

    Science.gov (United States)

    Saito, Kanako; Dubreuil, Veronique; Arai, Yoko; Wilsch-Bräuninger, Michaela; Schwudke, Dominik; Saher, Gesine; Miyata, Takaki; Breier, Georg; Thiele, Christoph; Shevchenko, Andrej; Nave, Klaus-Armin; Huttner, Wieland B

    2009-05-19

    Although sufficient cholesterol supply is known to be crucial for neurons in the developing mammalian brain, the cholesterol requirement of neural stem and progenitor cells in the embryonic central nervous system has not been addressed. Here we have conditionally ablated the activity of squalene synthase (SQS), a key enzyme for endogenous cholesterol production, in the neural stem and progenitor cells of the ventricular zone (VZ) of the embryonic mouse brain. Mutant embryos exhibited a reduced brain size due to the atrophy of the neuronal layers, and died at birth. Analyses of the E11.5-E15.5 dorsal telencephalon and diencephalon revealed that this atrophy was due to massive apoptosis of newborn neurons, implying that this progeny of the SQS-ablated neural stem and progenitor cells was dependent on endogenous cholesterol biosynthesis for survival. Interestingly, the neural stem and progenitor cells of the VZ, the primary target of SQS inactivation, did not undergo significant apoptosis. Instead, vascular endothelial growth factor (VEGF) expression in these cells was strongly upregulated via a hypoxia-inducible factor-1-independent pathway, and angiogenesis in the VZ was increased. Consistent with an increased supply of lipoproteins to these cells, the level of lipid droplets containing triacylglycerides with unsaturated fatty acyl chains was found to be elevated. Our study establishes a direct link between intracellular cholesterol levels, VEGF expression, and angiogenesis. Moreover, our data reveal a hitherto unknown compensatory process by which the neural stem and progenitor cells of the developing mammalian brain evade the detrimental consequences of impaired endogenous cholesterol biosynthesis.

  12. Angiogenesis dysregulation in term asphyxiated newborns treated with hypothermia.

    Directory of Open Access Journals (Sweden)

    Henna Shaikh

    Full Text Available Neonatal encephalopathy following birth asphyxia is a major predictor of long-term neurological impairment. Therapeutic hypothermia is currently the standard of care to prevent brain injury in asphyxiated newborns but is not protective in all cases. More robust and versatile treatment options are needed. Angiogenesis is a demonstrated therapeutic target in adult stroke. However, no systematic study examines the expression of angiogenesis-related markers following birth asphyxia in human newborns.This study aimed to evaluate the expression of angiogenesis-related protein markers in asphyxiated newborns developing and not developing brain injury compared to healthy control newborns.Twelve asphyxiated newborns treated with hypothermia were prospectively enrolled; six developed eventual brain injury and six did not. Four healthy control newborns were also included. We used Rules-Based Medicine multi-analyte profiling and protein array technologies to study the plasma concentration of 49 angiogenesis-related proteins. Mean protein concentrations were compared between each group of newborns.Compared to healthy newborns, asphyxiated newborns not developing brain injury showed up-regulation of pro-angiogenic proteins, including fatty acid binding protein-4, glucose-6-phosphate isomerase, neuropilin-1, and receptor tyrosine-protein kinase erbB-3; this up-regulation was not evident in asphyxiated newborns eventually developing brain injury. Also, asphyxiated newborns developing brain injury showed a decreased expression of anti-angiogenic proteins, including insulin-growth factor binding proteins -1, -4, and -6, compared to healthy newborns.These findings suggest that angiogenesis pathways are dysregulated following birth asphyxia and are putatively involved in brain injury pathology and recovery.

  13. Angiogenesis Dysregulation in Term Asphyxiated Newborns Treated with Hypothermia

    Science.gov (United States)

    Shaikh, Henna; Boudes, Elodie; Khoja, Zehra; Shevell, Michael; Wintermark, Pia

    2015-01-01

    Background Neonatal encephalopathy following birth asphyxia is a major predictor of long-term neurological impairment. Therapeutic hypothermia is currently the standard of care to prevent brain injury in asphyxiated newborns but is not protective in all cases. More robust and versatile treatment options are needed. Angiogenesis is a demonstrated therapeutic target in adult stroke. However, no systematic study examines the expression of angiogenesis-related markers following birth asphyxia in human newborns. Objective This study aimed to evaluate the expression of angiogenesis-related protein markers in asphyxiated newborns developing and not developing brain injury compared to healthy control newborns. Design/Methods Twelve asphyxiated newborns treated with hypothermia were prospectively enrolled; six developed eventual brain injury and six did not. Four healthy control newborns were also included. We used Rules-Based Medicine multi-analyte profiling and protein array technologies to study the plasma concentration of 49 angiogenesis-related proteins. Mean protein concentrations were compared between each group of newborns. Results Compared to healthy newborns, asphyxiated newborns not developing brain injury showed up-regulation of pro-angiogenic proteins, including fatty acid binding protein-4, glucose-6-phosphate isomerase, neuropilin-1, and receptor tyrosine-protein kinase erbB-3; this up-regulation was not evident in asphyxiated newborns eventually developing brain injury. Also, asphyxiated newborns developing brain injury showed a decreased expression of anti-angiogenic proteins, including insulin-growth factor binding proteins -1, -4, and -6, compared to healthy newborns. Conclusions These findings suggest that angiogenesis pathways are dysregulated following birth asphyxia and are putatively involved in brain injury pathology and recovery. PMID:25996847

  14. Development of an in silico stochastic 4D model of tumor growth with angiogenesis.

    Science.gov (United States)

    Forster, Jake C; Douglass, Michael J J; Harriss-Phillips, Wendy M; Bezak, Eva

    2017-04-01

    A stochastic computer model of tumour growth with spatial and temporal components that includes tumour angiogenesis was developed. In the current work it was used to simulate head and neck tumour growth. The model also provides the foundation for a 4D cellular radiotherapy simulation tool. The model, developed in Matlab, contains cell positions randomised in 3D space without overlap. Blood vessels are represented by strings of blood vessel units which branch outwards to achieve the desired tumour relative vascular volume. Hypoxic cells have an increased cell cycle time and become quiescent at oxygen tensions less than 1 mmHg. Necrotic cells are resorbed. A hierarchy of stem cells, transit cells and differentiated cells is considered along with differentiated cell loss. Model parameters include the relative vascular volume (2-10%), blood oxygenation (20-100 mmHg), distance from vessels to the onset of necrosis (80-300 μm) and probability for stem cells to undergo symmetric division (2%). Simulations were performed to observe the effects of hypoxia on tumour growth rate for head and neck cancers. Simulations were run on a supercomputer with eligible parts running in parallel on 12 cores. Using biologically plausible model parameters for head and neck cancers, the tumour volume doubling time varied from 45 ± 5 days (n = 3) for well oxygenated tumours to 87 ± 5 days (n = 3) for severely hypoxic tumours. The main achievements of the current model were randomised cell positions and the connected vasculature structure between the cells. These developments will also be beneficial when irradiating the simulated tumours using Monte Carlo track structure methods. © 2017 American Association of Physicists in Medicine.

  15. Intra-laboratory validation of a human cell based in vitro angiogenesis assay for testing angiogenesis modulators

    Directory of Open Access Journals (Sweden)

    Jertta-Riina Sarkanen

    2011-01-01

    Full Text Available The developed standardized human cell based in vitro angiogenesis assay was intra-laboratory validated to verify that the method is reliable and relevant for routine testing of modulators of angiogenesis e.g. pharmaceuticals and industrial chemicals. This assay is based on the earlier published method but it was improved and shown to be more sensitive and rapid than the previous assay. The performance of the assay was assessed by using 6 reference chemicals, which are widely used pharmaceuticals that inhibit angiogenesis: acetyl salicylic acid, erlotinib, 2-methoxyestradiol, levamisole, thalidomide, and anti-vascular endothelial growth factor. In the intra-laboratory validation, the sensitivity of the assay (upper and lower limits of detection and linearity of response in tubule formation, batch to batch variation in tubule formation between different Master cell bank batches, and precision as well as the reliability of the assay (reproducibility and repeatability were tested. The pre-set acceptance criteria for the intra-laboratory validation study were met. The relevance of the assay in man was investigated by comparing the effects of reference chemicals and their concentrations to the published human data. The comparison showed a good concordance, which indicates that this human cell based angiogenesis model predicts well the effects in man and has the potential to be used to supplement and/or replace of animal tests.

  16. Inhibition of calcium uptake during hypoxia in developing zebrafish is mediated by hypoxia-inducible factor.

    Science.gov (United States)

    Kwong, Raymond W M; Kumai, Yusuke; Tzaneva, Velislava; Azzi, Estelle; Hochhold, Nina; Robertson, Cayleih; Pelster, Bernd; Perry, Steve F

    2016-12-15

    The present study investigated the potential role of hypoxia-inducible factor (HIF) in calcium homeostasis in developing zebrafish (Danio rerio). It was demonstrated that zebrafish raised in hypoxic water (30 mmHg; control, 155 mmHg P O 2 ) until 4 days post-fertilization exhibited a substantial reduction in whole-body Ca 2+ levels and Ca 2+ uptake. Ca 2+ uptake in hypoxia-treated fish did not return to pre-hypoxia (control) levels within 2 h of transfer back to normoxic water. Results from real-time PCR showed that hypoxia decreased the whole-body mRNA expression levels of the epithelial Ca 2+ channel (ecac), but not plasma membrane Ca 2+ -ATPase (pmca2) or Na + /Ca 2+ -exchanger (ncx1b). Whole-mount in situ hybridization revealed that the number of ecac-expressing ionocytes was reduced in fish raised in hypoxic water. These findings suggested that hypoxic treatment suppressed the expression of ecac, thereby reducing Ca 2+ influx. To further evaluate the potential mechanisms for the effects of hypoxia on Ca 2+ regulation, a functional gene knockdown approach was employed to prevent the expression of HIF-1αb during hypoxic treatment. Consistent with a role for HIF-1αb in regulating Ca 2+ balance during hypoxia, the results demonstrated that the reduction of Ca 2+ uptake associated with hypoxic exposure was not observed in fish experiencing HIF-1αb knockdown. Additionally, the effects of hypoxia on reducing the number of ecac-expressing ionocytes was less pronounced in HIF-1αb-deficient fish. Overall, the current study revealed that hypoxic exposure inhibited Ca 2+ uptake in developing zebrafish, probably owing to HIF-1αb-mediated suppression of ecac expression. © 2016. Published by The Company of Biologists Ltd.

  17. Sphingosine-1-Phosphate as a Regulator of Hypoxia-Induced Factor-1α in Thyroid Follicular Carcinoma Cells.

    Directory of Open Access Journals (Sweden)

    Veronica Kalhori

    Full Text Available Sphingosine-1-phosphate (S1P is a bioactive lipid, which regulates several cancer-related processes including migration and angiogenesis. We have previously shown S1P to induce migration of follicular ML-1 thyroid cancer cells. Hypoxia-induced factor-1 (HIF-1 is an oxygen-sensitive transcription factor, which adapts cells to hypoxic conditions through increased survival, motility and angiogenesis. Due to these properties and its increased expression in response to intratumoral hypoxia, HIF-1 is considered a significant regulator of tumor biology. We found S1P to increase expression of the regulatory HIF-1α subunit in normoxic ML-1 cells. S1P also increased HIF-1 activity and expression of HIF-1 target genes. Importantly, inhibition or knockdown of HIF-1α attenuated the S1P-induced migration of ML-1 cells. S1P-induced HIF-1α expression was mediated by S1P receptor 3 (S1P3, Gi proteins and their downstream effectors MEK, PI3K, mTOR and PKCβI. Half-life measurements with cycloheximide indicated that S1P treatment stabilized the HIF-1α protein. On the other hand, S1P activated translational regulators eIF-4E and p70S6K, which are known to control HIF-1α synthesis. In conclusion, we have identified S1P as a non-hypoxic regulator of HIF-1 activity in thyroid cancer cells, studied the signaling involved in S1P-induced HIF-1α expression and shown S1P-induced migration to be mediated by HIF-1.

  18. Protective effects of intermittent hypoxia on brain and memory in a mouse model of apnea of prematurity.

    Science.gov (United States)

    Bouslama, Myriam; Adla-Biassette, Homa; Ramanantsoa, Nelina; Bourgeois, Thomas; Bollen, Bieke; Brissaud, Olivier; Matrot, Boris; Gressens, Pierre; Gallego, Jorge

    2015-01-01

    Apnea of prematurity (AOP) is considered a risk factor for neurodevelopmental disorders in children based on epidemiological studies. This idea is supported by studies in newborn rodents in which exposure to intermittent hypoxia (IH) as a model of AOP significantly impairs development. However, the severe IH used in these studies may not fully reflect the broad spectrum of AOP severity. Considering that hypoxia appears neuroprotective under various conditions, we hypothesized that moderate IH would protect the neonatal mouse brain against behavioral stressors and brain damage. On P6, each pup in each litter was randomly assigned to one of three groups: a group exposed to IH while separated from the mother (IH group), a control group exposed to normoxia while separated from the mother (AIR group), and a group of untreated unmanipulated pups left continuously with their mother until weaning (UNT group). Exposure to moderate IH (8% O2) consisted of 20 hypoxic events/hour, 6 h per day from postnatal day 6 (P6) to P10. The stress generated by maternal separation in newborn rodents is known to impair brain development, and we expected this effect to be smaller in the IH group compared to the AIR group. In a separate experiment, we combined maternal separation with excitotoxic brain lesions mimicking those seen in preterm infants. We analyzed memory, angiogenesis, neurogenesis and brain lesion size. In non-lesioned mice, IH stimulated hippocampal angiogenesis and neurogenesis and improved short-term memory indices. In brain-lesioned mice, IH decreased lesion size and prevented memory impairments. Contrary to common perception, IH mimicking moderate apnea may offer neuroprotection, at least in part, against brain lesions and cognitive dysfunctions related to prematurity. AOP may therefore have beneficial effects in some preterm infants. These results support the need for stratification based on AOP severity in clinical trials of treatments for AOP, to determine whether in

  19. Protective effects of intermittent hypoxia on brain and memory in a mouse model of apnea of prematurity

    Directory of Open Access Journals (Sweden)

    Myriam eBouslama

    2015-11-01

    Full Text Available Apnea of prematurity (AOP is considered a risk factor for neurodevelopmental disorders in children based on epidemiological studies. This idea is supported by studies in newborn rodents in which exposure to intermittent hypoxia (IH as a model of AOP significantly impairs development. However, the severe IH used in these studies may not fully reflect the broad spectrum of AOP severity. Considering that hypoxia appears neuroprotective under various conditions, we hypothesized that moderate IH would protect the neonatal mouse brain against behavioral stressors and brain damage. On P6, each pup in each litter was randomly assigned to one of three groups: a group exposed to IH while separated from the mother (IH group, a control group exposed to normoxia while separated from the mother (AIR group, and a group of untreated unmanipulated pups left continuously with their mother until weaning (UNT group. Exposure to moderate IH consisted of 20 hypoxic events/hour, 6 hours per day from postnatal day 6 (P6 to P10. The stress generated by maternal separation in newborn rodents is known to impair brain development, and we expected this effect to be smaller in the IH group compared to the AIR group. In a separate experiment, we combined maternal separation with excitotoxic brain lesions mimicking those seen in preterm infants. We analyzed memory, angiogenesis, neurogenesis and brain lesion size. In non-lesioned mice, IH stimulated hippocampal angiogenesis and neurogenesis and improved short-term memory indices. In brain-lesioned mice, IH decreased lesion size and prevented memory impairments. Contrary to common perception, IH mimicking moderate apnea may offer neuroprotection, at least in part, against brain lesions and cognitive dysfunctions related to prematurity. AOP may therefore have beneficial effects in some preterm infants. These results support the need for stratification based on AOP severity in clinical trials of treatments for AOP, to determine

  20. Sphingosine-1-Phosphate as a Regulator of Hypoxia-Induced Factor-1α in Thyroid Follicular Carcinoma Cells

    Science.gov (United States)

    Asghar, Muhammad Yasir; Bergelin, Nina; Jaakkola, Panu; Törnquist, Kid

    2013-01-01

    Sphingosine-1-phosphate (S1P) is a bioactive lipid, which regulates several cancer-related processes including migration and angiogenesis. We have previously shown S1P to induce migration of follicular ML-1 thyroid cancer cells. Hypoxia-induced factor-1 (HIF-1) is an oxygen-sensitive transcription factor, which adapts cells to hypoxic conditions through increased survival, motility and angiogenesis. Due to these properties and its increased expression in response to intratumoral hypoxia, HIF-1 is considered a significant regulator of tumor biology. We found S1P to increase expression of the regulatory HIF-1α subunit in normoxic ML-1 cells. S1P also increased HIF-1 activity and expression of HIF-1 target genes. Importantly, inhibition or knockdown of HIF-1α attenuated the S1P-induced migration of ML-1 cells. S1P-induced HIF-1α expression was mediated by S1P receptor 3 (S1P3), Gi proteins and their downstream effectors MEK, PI3K, mTOR and PKCβI. Half-life measurements with cycloheximide indicated that S1P treatment stabilized the HIF-1α protein. On the other hand, S1P activated translational regulators eIF-4E and p70S6K, which are known to control HIF-1α synthesis. In conclusion, we have identified S1P as a non-hypoxic regulator of HIF-1 activity in thyroid cancer cells, studied the signaling involved in S1P-induced HIF-1α expression and shown S1P-induced migration to be mediated by HIF-1. PMID:23824493

  1. Hypoxia induces adipogenic differentitation of myoblastic cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Itoigawa, Yoshiaki [Tohoku University School of Medicine, Sendai (Japan); Juntendo University School of Medicine, Tokyo (Japan); Kishimoto, Koshi N., E-mail: kishimoto@med.tohoku.ac.jp [Tohoku University School of Medicine, Sendai (Japan); Okuno, Hiroshi; Sano, Hirotaka [Tohoku University School of Medicine, Sendai (Japan); Kaneko, Kazuo [Juntendo University School of Medicine, Tokyo (Japan); Itoi, Eiji [Tohoku University School of Medicine, Sendai (Japan)

    2010-09-03

    Research highlights: {yields} C2C12 and G8 myogenic cell lines treated by hypoxia differentiate into adipocytes. {yields} The expression of C/EBP{beta}, {alpha} and PPAR{gamma} were increased under hypoxia. {yields} Myogenic differentiation of C2C12 was inhibited under hypoxia. -- Abstract: Muscle atrophy usually accompanies fat accumulation in the muscle. In such atrophic conditions as back muscles of kyphotic spine and the rotator cuff muscles with torn tendons, blood flow might be diminished. It is known that hypoxia causes trans-differentiation of mesenchymal stem cells derived from bone marrow into adipocytes. However, it has not been elucidated yet if hypoxia turned myoblasts into adipocytes. We investigated adipogenesis in C2C12 and G8 murine myogenic cell line treated by hypoxia. Cells were also treated with the cocktail of insulin, dexamethasone and IBMX (MDI), which has been known to inhibit Wnt signaling and promote adipogenesis. Adipogenic differentiation was seen in both hypoxia and MDI. Adipogenic marker gene expression was assessed in C2C12. CCAAT/enhancer-binding protein (C/EBP) {beta}, {alpha} and peroxisome proliferator activating receptor (PPAR) {gamma} were increased by both hypoxia and MDI. The expression profile of Wnt10b was different between hypoxia and MDI. The mechanism for adipogenesis of myoblasts in hypoxia might be regulated by different mechanism than the modification of Wnt signaling.

  2. The controversial origin of pericytes during angiogenesis - Implications for cell-based therapeutic angiogenesis and cell-based therapies.

    Science.gov (United States)

    Blocki, Anna; Beyer, Sebastian; Jung, Friedrich; Raghunath, Michael

    2018-01-01

    Pericytes reside within the basement membrane of small vessels and are often in direct cellular contact with endothelial cells, fulfilling important functions during blood vessel formation and homeostasis. Recently, these pericytes have been also identified as mesenchymal stem cells. Mesenchymal stem cells, and especially their specialized subpopulation of pericytes, represent promising candidates for therapeutic angiogenesis applications, and have already been widely applied in pre-clinical and clinical trials. However, cell-based therapies of ischemic diseases (especially of myocardial infarction) have not resulted in significant long-term improvement. Interestingly, pericytes from a hematopoietic origin were observed in embryonic skin and a pericyte sub-population expressing leukocyte and monocyte markers was described during adult angiogenesis in vivo. Since mesenchymal stem cells do not express hematopoietic markers, the latter cell type might represent an alternative pericyte population relevant to angiogenesis. Therefore, we sourced blood-derived angiogenic cells (BDACs) from monocytes that closely resembled hematopoietic pericytes, which had only been observed in vivo thus far. BDACs displayed many pericytic features and exhibited enhanced revascularization and functional tissue regeneration in a pre-clinical model of critical limb ischemia. Comparison between BDACs and mesenchymal pericytes indicated that BDACs (while resembling hematopoietic pericytes) enhanced early stages of angiogenesis, such as endothelial cell sprouting. In contrast, mesenchymal pericytes were responsible for blood vessel maturation and homeostasis, while reducing endothelial sprouting.Since the formation of new blood vessels is crucial during therapeutic angiogenesis or during integration of implants into the host tissue, hematopoietic pericytes (and therefore BDACs) might offer an advantageous addition or even an alternative for cell-based therapies.

  3. Hypoxia induced VEGF synthesis in visceral adipose depots of obese diabetic patients.

    Science.gov (United States)

    Fusaru, Ana Marina; Pisoschi, Cătălina Gabriela; Bold, Adriana; Taisescu, C; Stănescu, R; Hîncu, Mihaela; Crăiţoiu, Stefania; Baniţă, Ileana Monica

    2012-01-01

    VEGF is one the pro-inflammatory adipokines synthesized by the "adipose secretoma" of obese subjects as a response to hypoxic conditions; but the main function of VEGF is angiogenesis, being recognized as the most important factor increasing blood capillaries in the adipose tissue by stimulating endothelial cell growth. In this paper, we propose a comparative study of the vascular response to VEGF synthesis in the subcutaneous and central-peritoneal adipose depots in lean, obese and obese diabetic patients. We used CD31 to label the endothelial cells in order to evaluate the response of the vascular network to VEGF synthesis. Our results showed an increase of VEGF protein synthesis in obese and obese-diabetic patients compared to lean subjects where the protein was absent. The positivity for VEGF in obese diabetic samples was observed in numerous structures from the adipose depots, both in the stromal vascular fraction--blood vessels and stromal cells--as well as in the cytoplasm of adipocytes. Positivity in the vascular wall was observed more frequently in areas of perivascular and intralobular fibrosis. Obese and diabetic patients showed similar incidence of CD31 immunoreactivity with lean subjects in both subcutaneous and peritoneal depots. In conclusion, human adipose depots show a different incidence of VEGF positive cells in relation with their disposal and the metabolic status. VEGF synthesis in visceral adipose tissue is inefficient being not followed by angiogenesis to counterbalance tissue hypoxia. We suggest that may be a pathogenic link between the degrees of intralobular fibrosis in adipose depots and VEGF expression.

  4. Hypoxia and hypoxia mimetics decrease aquaporin 5 (AQP5 expression through both hypoxia inducible factor-1α and proteasome-mediated pathways.

    Directory of Open Access Journals (Sweden)

    Jitesh D Kawedia

    Full Text Available The alveolar epithelium plays a central role in gas exchange and fluid transport, and is therefore critical for normal lung function. Since the bulk of water flux across this epithelium depends on the membrane water channel Aquaporin 5 (AQP5, we asked whether hypoxia had any effect on AQP5 expression. We show that hypoxia causes a significant (70% decrease in AQP5 expression in the lungs of mice exposed to hypoxia. Hypoxia and the hypoxia mimetic, cobalt, also caused similar decreases in AQP5 mRNA and protein expression in the mouse lung epithelial cell line MLE-12. The action of hypoxia and cobalt on AQP5 transcription was demonstrated by directly quantifying heternonuclear RNA by real-time PCR. Dominant negative mutants of Hypoxia Inducible Factor (HIF-1α and HIF-1α siRNA blocked the action of cobalt, showing that HIF-1α is a key component in this mechanism. The proteasome inhibitors, lactacystin or proteasome inhibitor-III completely abolished the effect of hypoxia and cobalt both at the protein and mRNA level indicating that the proteasome pathway is probably involved not only for the stability of HIF-1α protein, but for the stability of unidentified transcription factors that regulate AQP5 transcription. These studies reveal a potentially important physiological mechanism linking hypoxic stress and membrane water channels.

  5. Hypoxia and Hypoxia Mimetics Decrease Aquaporin 5 (AQP5) Expression through Both Hypoxia Inducible Factor-1α and Proteasome-Mediated Pathways

    Science.gov (United States)

    Kawedia, Jitesh D.; Yang, Fan; Sartor, Maureen A.; Gozal, David; Czyzyk-Krzeska, Maria; Menon, Anil G.

    2013-01-01

    The alveolar epithelium plays a central role in gas exchange and fluid transport, and is therefore critical for normal lung function. Since the bulk of water flux across this epithelium depends on the membrane water channel Aquaporin 5 (AQP5), we asked whether hypoxia had any effect on AQP5 expression. We show that hypoxia causes a significant (70%) decrease in AQP5 expression in the lungs of mice exposed to hypoxia. Hypoxia and the hypoxia mimetic, cobalt, also caused similar decreases in AQP5 mRNA and protein expression in the mouse lung epithelial cell line MLE-12. The action of hypoxia and cobalt on AQP5 transcription was demonstrated by directly quantifying heternonuclear RNA by real-time PCR. Dominant negative mutants of Hypoxia Inducible Factor (HIF-1α) and HIF-1α siRNA blocked the action of cobalt, showing that HIF-1α is a key component in this mechanism. The proteasome inhibitors, lactacystin or proteasome inhibitor-III completely abolished the effect of hypoxia and cobalt both at the protein and mRNA level indicating that the proteasome pathway is probably involved not only for the stability of HIF-1α protein, but for the stability of unidentified transcription factors that regulate AQP5 transcription. These studies reveal a potentially important physiological mechanism linking hypoxic stress and membrane water channels. PMID:23469202

  6. Psychomotor skills learning under chronic hypoxia.

    Science.gov (United States)

    Bouquet, C A; Gardette, B; Gortan, C; Abraini, J H

    1999-09-29

    Psychomotor deficits are a prominent feature in subjects exposed to hypoxia. Eight subjects exposed to chronic hypoxia during a simulated climb to 8848 m (Everest-Comex 97) were investigated using both a simple psychomotor task (Purdue pegboard) and two complex psychomotor tasks including a recognition task of either a color stimulus (high semantic level) or an abstract sign (low semantic level). Exposure to hypoxic stress mainly produced psychomotor skills learning deficits compared to control study, with greater deficits in the complex psychomotor task. The pattern of results suggests disruptions of motor strategic process. Our data further suggest that the relative strength of implicit or automatic memory processes associated with semantic information processing may increase when disturbances occur in brain functions.

  7. Ocular Adverse Effects of Intravitreal Bevacizumab Are Potentiated by Intermittent Hypoxia in a Rat Model of Oxygen-Induced Retinopathy

    Directory of Open Access Journals (Sweden)

    Jeffrey J. Tan

    2017-01-01

    Full Text Available Intravitreal bevacizumab (Avastin use in preterm infants with retinopathy of prematurity is associated with severe neurological disabilities, suggesting vascular leakage. We examined the hypothesis that intermittent hypoxia (IH potentiates intravitreal Avastin leakage. Neonatal rats at birth were exposed to IH from birth (P0–P14. At P14, the time of eye opening in rats, a single dose of Avastin (0.125 mg was injected intravitreally into the left eye. Animals were placed in room air (RA until P23 or P45 for recovery (IHR. Hyperoxia-exposed and RA littermates served as oxygen controls, and equivalent volume saline served as the placebo controls. At P23 and P45 ocular angiogenesis, retinal pathology and ocular and systemic biomarkers of angiogenesis were examined. Retinal flatmounts showed poor peripheral vascularization in Avastin-treated and fellow eyes at P23, with numerous punctate hemorrhages and dilated, tortuous vessels with anastomoses at P45 in the rats exposed to IH. These adverse effects were associated with robust increases in systemic VEGF and in both treated and untreated fellow eyes. Histological analysis showed severe damage in the inner plexiform and inner nuclear layers. Exposure of IH/IHR-induced injured retinal microvasculature to anti-VEGF substances can result in vascular leakage and adverse effects in the developing neonate.

  8. Increased Brain Perfusion Persists over the First Month of Life in Term Asphyxiated Newborns Treated with Hypothermia: Does it Reflect Activated Angiogenesis?

    Science.gov (United States)

    Shaikh, Henna; Lechpammer, Mirna; Jensen, Frances E; Warfield, Simon K; Hansen, Anne H; Kosaras, Bela; Shevell, Michael; Wintermark, Pia

    2015-06-01

    Many asphyxiated newborns still develop brain injury despite hypothermia therapy. The development of brain injury in these newborns has been related partly to brain perfusion abnormalities. The purposes of this study were to assess brain hyperperfusion over the first month of life in term asphyxiated newborns and to search for some histopathological clues indicating whether this hyperperfusion may be related to activated angiogenesis following asphyxia. In this prospective cohort study, regional cerebral blood flow was measured in term asphyxiated newborns treated with hypothermia around day 10 of life and around 1 month of life using magnetic resonance imaging (MRI) and arterial spin labeling. A total of 32 MRI scans were obtained from 24 term newborns. Asphyxiated newborns treated with hypothermia displayed an increased cerebral blood flow in the injured brain areas around day 10 of life and up to 1 month of life. In addition, we looked at the histopathological clues in a human asphyxiated newborn and in a rat model of neonatal encephalopathy. Vascular endothelial growth factor (VEGF) was expressed in the injured brain of an asphyxiated newborn treated with hypothermia in the first days of life and of rat pups 24-48 h after the hypoxic-ischemic event, and the endothelial cell count increased in the injured cortex of the pups 7 and 11 days after hypoxia-ischemia. Our data showed that the hyperperfusion measured by imaging persisted in the injured areas up to 1 month of life and that angiogenesis was activated in the injured brain of asphyxiated newborns.

  9. Hypoxia: Exposure Time Until Significant Performance Effects

    Science.gov (United States)

    2016-03-07

    three alcoholic beverages per day (on average), or were taking any prescription medication (besides oral contraceptives). Likewise, those who were...or tested positively for pregnancy were disqualified from the study, as the risks of hypoxia to a human fetus are currently unknown. Also, those...that could impact inclusion in the study. After the questionnaire, all female participants provided a urine sample for pregnancy testing. Participants

  10. NASA Gulf of Mexico Initiative Hypoxia Research

    Science.gov (United States)

    Armstrong, Curtis D.

    2012-01-01

    The Applied Science & Technology Project Office at Stennis Space Center (SSC) manages NASA's Gulf of Mexico Initiative (GOMI). Addressing short-term crises and long-term issues, GOMI participants seek to understand the environment using remote sensing, in-situ observations, laboratory analyses, field observations and computational models. New capabilities are transferred to end-users to help them make informed decisions. Some GOMI activities of interest to the hypoxia research community are highlighted.

  11. Optical imaging of tumor hypoxia dynamics

    Science.gov (United States)

    Palmer, Gregory M.; Fontanella, Andrew N.; Zhang, Guoqing; Hanna, Gabi; Fraser, Cassandra L.; Dewhirst, Mark W.

    2010-11-01

    The influence of the tumor microenvironment and hypoxia plays a significant role in determining cancer progression, treatment response, and treatment resistance. That the tumor microenvironment is highly heterogeneous with significant intratumor and intertumor variability presents a significant challenge in developing effective cancer therapies. Critical to understanding the role of the tumor microenvironment is the ability to dynamically quantify oxygen levels in the vasculature and tissue in order to elucidate the roles of oxygen supply and consumption, spatially and temporally. To this end, we describe the use of hyperspectral imaging to characterize hemoglobin absorption to quantify hemoglobin content and oxygen saturation, as well as dual emissive fluorescent/phosphorescent boron nanoparticles, which serve as ratiometric indicators of tissue oxygen tension. Applying these techniques to a window-chamber tumor model illustrates the role of fluctuations in hemoglobin saturation in driving changes in tissue oxygenation, the two being significantly correlated (r = 0.77). Finally, a green-fluorescence-protein reporter for hypoxia inducible factor-1 (HIF-1) provides an endpoint for hypoxic stress in the tumor, which is used to demonstrate a significant association between tumor hypoxia dynamics and HIF-1 activity in an in vivo demonstration of the technique.

  12. Hypoxia in the changing marine environment

    International Nuclear Information System (INIS)

    Zhang, J; Cowie, G; Naqvi, S W A

    2013-01-01

    The predicted future of the global marine environment, as a combined result of forcing due to climate change (e.g. warming and acidification) and other anthropogenic perturbation (e.g. eutrophication), presents a challenge to the sustainability of ecosystems from tropics to high latitudes. Among the various associated phenomena of ecosystem deterioration, hypoxia can cause serious problems in coastal areas as well as oxygen minimum zones in the open ocean (Diaz and Rosenberg 2008 Science 321 926–9, Stramma et al 2008 Science 320 655–8). The negative impacts of hypoxia include changes in populations of marine organisms, such as large-scale mortality and behavioral responses, as well as variations of species distributions, biodiversity, physiological stress, and other sub-lethal effects (e.g. growth and reproduction). Social and economic activities that are related to services provided by the marine ecosystems, such as tourism and fisheries, can be negatively affected by the aesthetic outcomes as well as perceived or real impacts on seafood quality (STAP 2011 (Washington, DC: Global Environment Facility) p 88). Moreover, low oxygen concentration in marine waters can have considerable feedbacks to other compartments of the Earth system, like the emission of greenhouse gases to the atmosphere, and can affect the global biogeochemical cycles of nutrients and trace elements. It is of critical importance to prediction and adaptation strategies that the key processes of hypoxia in marine environments be precisely determined and understood (cf Zhang et al 2010 Biogeosciences 7 1–24). (synthesis and review)

  13. Hypoxia in the changing marine environment

    Science.gov (United States)

    Zhang, J.; Cowie, G.; Naqvi, S. W. A.

    2013-03-01

    The predicted future of the global marine environment, as a combined result of forcing due to climate change (e.g. warming and acidification) and other anthropogenic perturbation (e.g. eutrophication), presents a challenge to the sustainability of ecosystems from tropics to high latitudes. Among the various associated phenomena of ecosystem deterioration, hypoxia can cause serious problems in coastal areas as well as oxygen minimum zones in the open ocean (Diaz and Rosenberg 2008 Science 321 926-9, Stramma et al 2008 Science 320 655-8). The negative impacts of hypoxia include changes in populations of marine organisms, such as large-scale mortality and behavioral responses, as well as variations of species distributions, biodiversity, physiological stress, and other sub-lethal effects (e.g. growth and reproduction). Social and economic activities that are related to services provided by the marine ecosystems, such as tourism and fisheries, can be negatively affected by the aesthetic outcomes as well as perceived or real impacts on seafood quality (STAP 2011 (Washington, DC: Global Environment Facility) p 88). Moreover, low oxygen concentration in marine waters can have considerable feedbacks to other compartments of the Earth system, like the emission of greenhouse gases to the atmosphere, and can affect the global biogeochemical cycles of nutrients and trace elements. It is of critical importance to prediction and adaptation strategies that the key processes of hypoxia in marine environments be precisely determined and understood (cf Zhang et al 2010 Biogeosciences 7 1-24).

  14. Intrauterine hypoxia: clinical consequences and therapeutic perspectives

    Directory of Open Access Journals (Sweden)

    Thompson LP

    2015-09-01

    Full Text Available Loren P Thompson,1 Sarah Crimmins,1 Bhanu P Telugu,2 Shifa Turan1 1Department of Obstetrics, Gynecology and Reproductive Sciences, University of Maryland School of Medicine, Baltimore, MD, USA; 2Department of Animal Sciences, University of Maryland, College Park, MD, USA Abstract: Intrauterine hypoxia is a significant clinical challenge in obstetrics that affects both the pregnant mother and fetus. Intrauterine hypoxia can occur in pregnant women living at high altitude and/or with cardiovascular disease. In addition, placental hypoxia can be generated by altered placental development and spiral artery remodeling leading to placental insufficiency and dysfunction. Both conditions can impact normal maternal cardiovascular homeostasis leading to preeclampsia and/or impair transfer of O2/nutrient supply resulting in fetal growth restriction. This review discusses the mechanisms underlying altered placental vessel remodeling, maternal and fetal consequences, patient management, and potential future therapies for improving these conditions. Keywords: fetal growth restriction, oxidative stress, extravillous trophoblast invasion, Doppler ultrasound, pulsatility index, preeclampsia 

  15. Loss of Mel-18 induces tumor angiogenesis through enhancing the activity and expression of HIF-1α mediated by the PTEN/PI3K/Akt pathway.

    Science.gov (United States)

    Park, J H; Lee, J Y; Shin, D H; Jang, K S; Kim, H J; Kong, Gu

    2011-11-10

    Mel-18 has been implicated in several processes in tumor progression, in which the Akt pathway is involved as an important key molecular event. However, the function of Mel-18 in human cancers has not been fully established yet. Here, we examined the effect of Mel-18 on tumor angiogenesis in human breast cancer, and found that Mel-18 was a novel regulator of HIF-1α. Mel-18 negatively regulated the HIF-1α expression and its target gene VEGF transcription during both normoxia and hypoxia. We demonstrated that Mel-18 regulated the HIF-1α expression and activity via the PI3K/Akt pathway. Loss of Mel-18 downregulated Phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression, consequently activating the PI3K/Akt/MDM2 pathway, and leading to an increase of HIF-1α protein level. Mel-18 modulated the HIF-1α transcriptional activity via regulating the cytoplasmic retention of FOXO3a, a downstream effector of Akt, and recruitment of HIF-1α/CBP complex to the VEGF promoter. Furthermore, our data shows that Mel-18 blocked tumor angiogenesis both in vitro and in vivo. Mel-18 overexpression inhibited in vitro tube formation in human umbilical endothelial cells (HUVECs). Xenografts in NOD/SCID mice derived from stably Mel-18 knocked down MCF7 human breast cancer cells showed increased tumor volume, microvessel density, and phospho-Akt and HIF-1α expression levels. In conclusion, our findings provide that Mel-18 is a novel regulator of tumor angiogenesis through regulating HIF-1α and its target VEGF expressions mediated by the PTEN/PI3K/Akt pathway, suggesting a new tumor-suppressive role of Mel-18 in human breast cancer.

  16. Hypoxia induces a phase transition within a kinase signaling network in cancer cells.

    Science.gov (United States)

    Wei, Wei; Shi, Qihui; Remacle, Francoise; Qin, Lidong; Shackelford, David B; Shin, Young Shik; Mischel, Paul S; Levine, R D; Heath, James R

    2013-04-09

    Hypoxia is a near-universal feature of cancer, promoting glycolysis, cellular proliferation, and angiogenesis. The molecular mechanisms of hypoxic signaling have been intensively studied, but the impact of changes in oxygen partial pressure (pO2) on the state of signaling networks is less clear. In a glioblastoma multiforme (GBM) cancer cell model, we examined the response of signaling networks to targeted pathway inhibition between 21% and 1% pO2. We used a microchip technology that facilitates quantification of a panel of functional proteins from statistical numbers of single cells. We find that near 1.5% pO2, the signaling network associated with mammalian target of rapamycin (mTOR) complex 1 (mTORC1)--a critical component of hypoxic signaling and a compelling cancer drug target--is deregulated in a manner such that it will be unresponsive to mTOR kinase inhibitors near 1.5% pO2, but will respond at higher or lower pO2 values. These predictions were validated through experiments on bulk GBM cell line cultures and on neurosphere cultures of a human-origin GBM xenograft tumor. We attempt to understand this behavior through the use of a quantitative version of Le Chatelier's principle, as well as through a steady-state kinetic model of protein interactions, both of which indicate that hypoxia can influence mTORC1 signaling as a switch. The Le Chatelier approach also indicates that this switch may be thought of as a type of phase transition. Our analysis indicates that certain biologically complex cell behaviors may be understood using fundamental, thermodynamics-motivated principles.

  17. Hypoxia induces a phase transition within a kinase signaling network in cancer cells

    Science.gov (United States)

    Wei, Wei; Shi, Qihui; Remacle, Francoise; Qin, Lidong; Shackelford, David B.; Shin, Young Shik; Mischel, Paul S.; Levine, R. D.; Heath, James R.

    2013-01-01

    Hypoxia is a near-universal feature of cancer, promoting glycolysis, cellular proliferation, and angiogenesis. The molecular mechanisms of hypoxic signaling have been intensively studied, but the impact of changes in oxygen partial pressure (pO2) on the state of signaling networks is less clear. In a glioblastoma multiforme (GBM) cancer cell model, we examined the response of signaling networks to targeted pathway inhibition between 21% and 1% pO2. We used a microchip technology that facilitates quantification of a panel of functional proteins from statistical numbers of single cells. We find that near 1.5% pO2, the signaling network associated with mammalian target of rapamycin (mTOR) complex 1 (mTORC1)—a critical component of hypoxic signaling and a compelling cancer drug target—is deregulated in a manner such that it will be unresponsive to mTOR kinase inhibitors near 1.5% pO2, but will respond at higher or lower pO2 values. These predictions were validated through experiments on bulk GBM cell line cultures and on neurosphere cultures of a human-origin GBM xenograft tumor. We attempt to understand this behavior through the use of a quantitative version of Le Chatelier’s principle, as well as through a steady-state kinetic model of protein interactions, both of which indicate that hypoxia can influence mTORC1 signaling as a switch. The Le Chatelier approach also indicates that this switch may be thought of as a type of phase transition. Our analysis indicates that certain biologically complex cell behaviors may be understood using fundamental, thermodynamics-motivated principles. PMID:23530221

  18. Hypoxia symptoms during altitude training in professional Iranian fighter pilots.

    Science.gov (United States)

    Alagha, Babak; AhmadBeygi, Shervin; Ahmadbeigy, Shervin; Moosavi, Seyed Ali Javad; Jalali, Seyed Mahmood

    2012-01-01

    Susceptibility to hypoxia is influenced by a multitude of factors, including fatigue, physical activity, illnesses, ambient temperature, rate of ascent, destination altitude, medications, and alcohol. Anecdotally, several reports have been made regarding changes in the form of hypoxia presentation in Iranian fighter pilots in the absence of these factors. This study focused specifically on the effect of pilot age on susceptibility to hypoxia and its initial presentation. We assumed that a pilot's age may increase his susceptibility to hypoxia and consequently reduce the amount of time it takes for hypoxia to present. Because our literature review did not reveal any previous study addressing the possible relationship between age and susceptibility to hypoxia, the purpose of this study is to address and clarify this relationship. In this retrospective study, we collected information from Iranian fighter pilots (n = 30) through an anonymous questionnaire in 2000. The form of hypoxia presentation of each subject was evaluated during five altitude chamber training (ACT) sessions that were conducted routinely from 1972 to 1984. To enhance the accuracy of the study's results, confounding factors such as prior hypoxia experience in an ACT session have been taken into consideration. The results revealed a statistically significant relationship between age and a change in the form of hypoxia presentation in our subjects. Increased age reduced the amount of time before the first individual hypoxia symptom appeared (P < .000002). Although having previous hypoxia experience may help pilots to recognize their symptoms earlier, its effect was not statistically significant (P < .18). A few changes in the nature of individual symptoms were observed; however, we did not find a meaningful statistical correlation between pilot age and change in the nature of symptoms. Susceptibility ot hypoxia increases with pilot age. Copyright © 2012 Air Medical Journal Associates. Published by

  19. Endogenous markers of tumor hypoxia. Predictors of clinical radiation resistance?

    International Nuclear Information System (INIS)

    Vordermark, D.; Brown, J.M.

    2003-01-01

    Background: Eppendorf electrode measurements of tumor oxygenation have defined an adverse effect of tumor hypoxia on prognosis after radiotherapy and other treatment modalities, in particular in head and neck and cervix carcinomas as well as soft tissue sarcomas. Recently, the immunohistochemical detection of proteins involved in the ''hypoxic response'' of tumor cells has been discussed as a method to estimate hypoxia in clinical tumor specimens. Material and Methods: This review focuses on clinical and experimental data, regarding prognostic impact and comparability with other methods of hypoxia detection, for three proteins suggested as endogenous markers of tumor hypoxia: hypoxia-inducible factor-1α (HIF-1α), carbonic anhydrase 9 (CA 9), and glucose transporter 1 (GLUT1). Results: None of the three potential hypoxia markers is exclusively hypoxia-specific, and in each case protein can be detected under normoxic conditions in vitro. HIF-1α responds rapidly to hypoxia but also to reoxygenation, making this marker quite unstable in the context of clinical sample collection. The perinecrotic labeling pattern typical of chronic hypoxia and a reasonable agreement with injectable hypoxia markers such as pimonidazole have most consistently been described for CA 9. All three markers showed correlation with Eppendorf electrode measurements of tumor oxygenation in carcinoma of the cervix. In nine of 13 reports, among them all three that refer to curative radiotherapy for head and neck cancer, HIF-1α overexpression was associated with poor outcome. CA 9 was an adverse prognostic factor in cervix, head and neck and lung cancer, but not in two other head and neck cancer reports. GLUT1 predicted for poor survival in colorectal, cervix and lung cancer. Conclusion: Endogenous markers have the potential to indicate therapeutically relevant levels of hypoxia within tumors. Clinical trials assessing a marker's ability to predict a benefit from specific hypoxia

  20. Tissue hypoxia during ischemic stroke: adaptive clues from hypoxia-tolerant animal models.

    Science.gov (United States)

    Nathaniel, Thomas I; Williams-Hernandez, Ashley; Hunter, Anan L; Liddy, Caroline; Peffley, Dennis M; Umesiri, Francis E; Imeh-Nathaniel, Adebobola

    2015-05-01

    The treatment and prevention of hypoxic/ischemic brain injury in stroke patients remain a severe and global medical issue. Numerous clinical studies have resulted in a failure to develop chemical neuroprotection for acute, ischemic stroke. Over 150 estimated clinical trials of ischemic stroke treatments have been done, and more than 200 drugs and combinations of drugs for ischemic and hemorrhagic strokes have been developed. Billions of dollars have been invested for new scientific breakthroughs with only limited success. The revascularization of occluded cerebral arteries such as anti-clot treatments of thrombolysis has proven effective, but it can only be used in a 3-4.5h time frame after the onset of a stroke, and not for every patient. This review is about novel insights on how to resist tissue hypoxia from unconventional animal models. Ability to resist tissue hypoxia is an extraordinary ability that is not common in many laboratory animals such as rat and mouse models. For example, we can learn from a naked mole-rat, Chrysemys picta, how to actively regulate brain metabolic activity to defend the brain against fluctuating oxygen tension and acute bouts of oxidative stress following the onset of a stroke. Additionally, a euthermic arctic ground squirrel can teach us how the brain of a stroke patient can remain well oxygenated during tissue hypoxia with no evidence of cellular stress. In this review, we discuss how these animals provide us with a system to gain insight into the possible mechanisms of tissue hypoxia/ischemia. This issue is of clinical significance to stroke patients. We describe specific physiological and molecular adaptations employed by different animals' models of hypoxia tolerance in aquatic and terrestrial environments. We highlight how these adaptations might provide potential clues on strategies to adapt for the clinical management of tissue hypoxia during conditions such as stroke where oxygen demand fails to match the supply. Copyright

  1. Lung cancer and angiogenesis imaging using synchrotron radiation

    International Nuclear Information System (INIS)

    Liu Xiaoxia; Zhao Jun; Xu, Lisa X; Sun Jianqi; Gu Xiang; Liu Ping; Xiao Tiqiao

    2010-01-01

    Early detection of lung cancer is the key to a cure, but a difficult task using conventional x-ray imaging. In the present study, synchrotron radiation in-line phase-contrast imaging was used to study lung cancer. Lewis lung cancer and 4T1 breast tumor metastasis in the lung were imaged, and the differences were clearly shown in comparison to normal lung tissue. The effect of the object-detector distance and the energy level on the phase-contrast difference was investigated and found to be in good agreement with the theory of in-line phase-contrast imaging. Moreover, 3D image reconstruction of lung tumor angiogenesis was obtained for the first time using a contrast agent, demonstrating the feasibility of micro-angiography with synchrotron radiation for imaging tumor angiogenesis deep inside the body.

  2. THE ROLE OF AUTOPHAGY AND ANGIOGENESIS IN COLORECTAL CANCER

    Directory of Open Access Journals (Sweden)

    K. V. Rachkovsky

    2017-01-01

    Full Text Available The purpose of the study was a review of available data on the role of autophagy and angiogenesis in the development, progression and prognosis of colorectal cancer. Material and methods. Databases searched were Medline, Cochrane Library and Elibrary. Of 340 studies, 48 were used to write a systematic review. Results. To date, there is a variety of prognostic markers used in the study of pathogenesis, diagnosis and treatment of colorectal cancer. The review describes the molecular mechanisms of the participation of various proteins of autophagy and angiogenesis in the pathogenesis and progression of colorectal cancer, and the potential importance of their use in clinical practice is presented. Conclusion. Many of the existing markers can be used not only in assessing the prognosis, but also sensitivity to chemotherapy. However, the contradictory results of studies with respect to certain proteins require further study, validation, and subsequent introduction into practice. 

  3. Regulation of Angiogenesis by Aminoacyl-tRNA Synthetases

    Directory of Open Access Journals (Sweden)

    Adam C. Mirando

    2014-12-01

    Full Text Available In addition to their canonical roles in translation the aminoacyl-tRNA synthetases (ARSs have developed secondary functions over the course of evolution. Many of these activities are associated with cellular survival and nutritional stress responses essential for homeostatic processes in higher eukaryotes. In particular, six ARSs and one associated factor have documented functions in angiogenesis. However, despite their connection to this process, the ARSs are mechanistically distinct and exhibit a range of positive or negative effects on aspects of endothelial cell migration, proliferation, and survival. This variability is achieved through the appearance of appended domains and interplay with inflammatory pathways not found in prokaryotic systems. Complete knowledge of the non-canonical functions of ARSs is necessary to understand the mechanisms underlying the physiological regulation of angiogenesis.

  4. Cognitive responses to hypobaric hypoxia: implications for aviation training

    Directory of Open Access Journals (Sweden)

    Neuhaus C

    2014-11-01

    Full Text Available Christopher Neuhaus,1,2 Jochen Hinkelbein2,31Department of Anesthesiology, Heidelberg University Hospital, Ruprecht Karls University of Heidelberg, Heidelberg, 2Emergency Medicine and Air Rescue Working Group, German Society of Aviation and Space Medicine (DGLRM, Munich, 3Department of Anesthesiology and Intensive Care Medicine, University Hospital of Cologne, Cologne, GermanyAbstract: The aim of this narrative review is to provide an overview on cognitive responses to hypobaric hypoxia and to show relevant implications for aviation training. A principal element of hypoxia-awareness training is the intentional evocation of hypoxia symptoms during specific training sessions within a safe and controlled environment. Repetitive training should enable pilots to learn and recognize their personal hypoxia symptoms. A time span of 3–6 years is generally considered suitable to refresh knowledge of the more subtle and early symptoms especially. Currently, there are two different technical approaches available to induce hypoxia during training: hypobaric chamber training and reduced-oxygen breathing devices. Hypoxia training for aircrew is extremely important and effective, and the hypoxia symptoms should be emphasized clearly to aircrews. The use of tight-fitting masks, leak checks, and equipment checks should be taught to all aircrew and reinforced regularly. It is noteworthy that there are major differences in the required quality and quantity of hypoxia training for both military and civilian pilots.Keywords: cognitive response, aviation training, pilot, hypoxia, oxygen, loss of consciousness

  5. Yak response to high-altitude hypoxic stress by altering mRNA expression and DNA methylation of hypoxia-inducible factors.

    Science.gov (United States)

    Xiong, Xianrong; Fu, Mei; Lan, Daoliang; Li, Jian; Zi, Xiangdong; Zhong, Jincheng

    2015-01-01

    Hypoxia-inducible factors (HIFs) are oxygen-dependent transcriptional activators, which play crucial roles in tumor angiogenesis and mammalian development, and regulate the transcription of genes involved in oxygen homeostasis in response to hypoxia. However, information on HIF-1α and HIF-2α in yak (Bos grunniens) is scarce. The complete coding region of yak HIF-2α was cloned, its mRNA expression in several tissues were determined, and the expression levels were compared with those of closely related low-altitude cattle (Bos taurus), and the methylation status of promoter regions were analyzed to better understand the roles of HIF-1α and HIF-2α in domesticated yak. The yak HIF-2α cDNA was cloned and sequenced in the present work reveals the evolutionary conservation through multiple sequence alignment, although 15 bases changed, resulting in 8 amino acid substitutions in the translated proteins in cattle. The tissue-specific expression results showed that HIF-1α is ubiquitously expressed, whereas HIF-2α expression is limited to endothelial tissues (kidney, heart, lung, spleen, and liver) and blood in yak. Both HIF-1α and HIF-2α expressions were higher in yak tissues than in cattle. The HIF-1α expression level is much higher in yak than cattle in these organs, except for the lung (P hypoxic stress response mechanism and may assist current medical research to understand hypoxia-related diseases.

  6. Angiogenesis in the degeneration of the lumbar intervertebral disc

    OpenAIRE

    David, Gh; Ciurea, AV; Iencean, SM; Mohan, A

    2010-01-01

    The goal of the study is to show the histological and biochemical changes that indicate the angiogenesis of the intervertebral disc in lumbar intervertebral disc hernia and the existence of epidemiological correlations between these changes and the risk factors of lumbar intervertebral disc hernia, as well as the patient's quality of life (QOL). We have studied 50 patients aged between 18 and 73 years old, who have undergone lumbar intervertebral disc hernia surgery, making fibroblast growth ...

  7. Mechanisms of lumen formation during sprouting angiogenesis in vivo

    OpenAIRE

    Gebala, V. M.

    2016-01-01

    During development, vascular networks expand following a process known as sprouting angiogenesis. New vascular branches arise from pre-existing vessels through the coordinated migration and proliferation of endothelial cells, and eventually connect to form new vascular loops. The functionality of these new vessel segments is dependent on the opening of a central lumen to allow perfusion. While mechanisms of lumen formation during the establishment of the primary vasculature by vasculogenesis ...

  8. Examining cerebral angiogenesis in response to physical exercise.

    Science.gov (United States)

    Berggren, Kiersten L; Kay, Jacob J M; Swain, Rodney A

    2014-01-01

    Capillary growth and expansion (angiogenesis) is a prerequisite for many forms of neural and behavioral plasticity. It is commonly observed in both brain and muscle of aerobically exercising animals. As such, several histological methods have been used to quantify capillary density, including perfusion with India ink, various Nissl stains, and immunohistochemistry. In this chapter, we will describe these histological procedures and describe the stereological analysis used to quantify vessel growth in response to aerobic exercise.

  9. An IP-10 (CXCL10)-Derived Peptide Inhibits Angiogenesis

    Science.gov (United States)

    Yates-Binder, Cecelia C.; Rodgers, Margaret; Jaynes, Jesse; Wells, Alan; Bodnar, Richard J.; Turner, Timothy

    2012-01-01

    Angiogenesis plays a critical role in processes such as organ development, wound healing, and tumor growth. It requires well-orchestrated integration of soluble and matrix factors and timely recognition of such signals to regulate this process. Previous work has shown that newly forming vessels express the chemokine receptor CXC receptor 3 (CXCR3) and, activation by its ligand IP-10 (CXCL10), both inhibits development of new vasculature and causes regression of newly formed vessels. To identify and develop new therapeutic agents to limit or reverse pathological angiogenesis, we identified a 21 amino acid fragment of IP-10, spanning the α-helical domain residues 77–98, that mimic the actions of the whole IP-10 molecule on endothelial cells. Treatment of the endothelial cells with the 22 amino acid fragment referred to as IP-10p significantly inhibited VEGF-induced endothelial motility and tube formation in vitro, properties critical for angiogenesis. Using a Matrigel plug assay in vivo, we demonstrate that IP-10p both prevented vessel formation and induced involution of nascent vessels. CXCR3 neutralizing antibody was able to block the inhibitory effects of the IP-10p, demonstrating specificity of the peptide. Inhibition of endothelial function by IP-10p was similar to that described for IP-10, secondary to CXCR3-mediated increase in cAMP production, activation of PKA inhibiting cell migration, and inhibition of VEGF-mediated m-calpain activation. IP-10p provides a novel therapeutic agent that inhibits endothelial cell function thus, allowing for the modulation of angiogenesis. PMID:22815829

  10. Standardization of a method to study angiogenesis in a mouse model

    Directory of Open Access Journals (Sweden)

    DAVID FEDER

    2013-01-01

    Full Text Available In the adult organism, angiogenesis is restricted to a few physiological conditions. On the other hand, uncontrolled angiogenesis have often been associated to angiogenesis-dependent pathologies. A variety of animal models have been described to provide more quantitative analysis of in vivo angiogenesis and to characterize pro- and antiangiogenic molecules. However, it is still necessary to establish a quantitative, reproducible and specific method for studies of angiogenesis factors and inhibitors. This work aimed to standardize a method for the study of angiogenesis and to investigate the effects of thalidomide on angiogenesis. Sponges of 0.5 x 0.5 x 0.5 cm were implanted in the back of mice groups, control and experimental (thalidomide 200 mg/K/day by gavage. After seven days, the sponges were removed. The dosage of hemoglobin in sponge and in circulation was performed and the ratio between the values was tested using nonparametric Mann-Whitney test. Results have shown that sponge-induced angiogenesis quantitated by ratio between hemoglobin content in serum and in sponge is a helpful model for in vivo studies on angiogenesis. Moreover, it was observed that sponge-induced angiogenesis can be suppressed by thalidomide, corroborating to the validity of the standardized method.

  11. Photoacoustic imaging of angiogenesis in subdermal islet transplant sites

    Science.gov (United States)

    Shi, Wei; Pawlick, Rena; Bruni, Antonio; Rafiei, Yasmin; Pepper, Andrew R.; Gala-Lopez, Boris; Choi, Min; Malcolm, Andrew; Zemp, Roger J.; Shapiro, A. M. James

    2016-03-01

    Exogenous insulin administration is the mainstay treatment therapy for patients with Type-1 diabetes mellitus (T1DM). However, for select patients, clinical islet transplantation is an alternative therapeutic treatment. In this procedure, islets are transplanted into the hepatic portal vein, and despite improved success within the last decade, obstacles are still associated with this approach. It has been discovered that the subcutaneous space may be an effective alternative site for islet transplantation, and may provide advantages of easy access and potential for simple monitoring. The ability to monitor islet viability and the transplant microenvironment may be key to future success in islet transplantation. A subcutaneous device-less technique has been developed to facilitate angiogenesis in the islet transplant site, however, a method for monitoring the potential engraftment site have yet to be explored fully. Here we demonstrate the ability to track angiogenesis in mice with 1, 2, 3 and 4 weeks post-catheter implant on both sides of the abdomen using a FujiFilm VisualSonics Vevo-LAZR system. Quantitative analysis on vessel densities exhibited gradual vessel growth successfully induced by catheter implantation. Our study demonstrates the ability of employing photoacoustic and micro-ultrasound imaging to track angiogenesis around the catheter site prior to islet transplantation.

  12. Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

    Energy Technology Data Exchange (ETDEWEB)

    Aoyagi, Tomoyoshi; Shuto, Kiyohiko; Okazumi, Shinichi; Hayano, Kohichi; Satoh, Asami; Saitoh, Hiroshige; Shimada, Hideaki; Nabeya, Yoshihiro; Matsubara, Hisahiro [Chiba University, Department of Frontier Surgery, Graduate School of Medicine, Chiba (Japan); Kazama, Toshiki [Chiba University, Department of Radiology, Graduate School of Medicine, Chiba (Japan)

    2012-06-15

    Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. circle Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen circle There is also negative correlation between ADCs and vascular endothelial growth factor circle ADC values may contribute to the treatment of oesophageal cancer. (orig.)

  13. Dendritic cells regulate angiogenesis associated with liver fibrogenesis.

    Science.gov (United States)

    Blois, Sandra M; Piccioni, Flavia; Freitag, Nancy; Tirado-González, Irene; Moschansky, Petra; Lloyd, Rodrigo; Hensel-Wiegel, Karin; Rose, Matthias; Garcia, Mariana G; Alaniz, Laura D; Mazzolini, Guillermo

    2014-01-01

    During liver fibrogenesis the immune response and angiogenesis process are fine-tuned resulting in activation of hepatic stellate cells that produce an excess of extracellular matrix proteins. Dendritic cells (DC) play a central role modulating the liver immunity and have recently been implicated to favour fibrosis regression; although their ability to influence the development of fibrogenesis is unknown. Therefore, we explored whether the depletion of DC during early stages of liver injury has an impact in the development of fibrogenesis. Using the CD11c.DTR transgenic mice, DC were depleted in two experimental models of fibrosis in vivo. The effect of anti-angiogenic therapy was tested during early stages of liver fibrogenesis. DC depletion accelerates the development of fibrosis and as a consequence, the angiogenesis process is boosted. We observed up-regulation of pro-angiogenic factors together with an enhanced vascular endothelial growth factor (VEGF) bioavailability, mainly evidenced by the decrease of anti-angiogenic VEGF receptor 1 (also known as sFlt-1) levels. Interestingly, fibrogenesis process enhanced the expression of Flt-1 on hepatic DC and administration of sFlt-1 was sufficient to abrogate the acceleration of fibrogenesis upon DC depletion. Thus, DC emerge as novel players during the development of liver fibrosis regulating the angiogenesis process and thereby influencing fibrogenesis.

  14. Digital Microscopy Assessment of Angiogenesis in Different Breast Cancer Compartments

    Directory of Open Access Journals (Sweden)

    Anca Haisan

    2013-01-01

    Full Text Available Background/Aim. Tumour angiogenesis defined by microvessel density (MVD is generally accepted as a prognostic factor in breast cancer. However, due to variability of measurement systems and cutoffs, it is questionable to date whether it contributes to predictive outline. Our study aims to grade vascular heterogeneity by comparing clear-cut compartments: tumour associated stroma (TAS, tumour parenchyma, and tumour invasive front. Material and Methods. Computerized vessel area measurement was performed using a tissue cytometry system (TissueFAXS on slides originated from 50 patients with breast cancer. Vessels were marked using immunohistochemistry with CD34. Regions of interest were manually defined for each tumour compartment. Results. Tumour invasive front vascular endothelia area was 2.15 times higher than that in tumour parenchyma and 4.61 times higher than that in TAS (P<0.002. Worth to mention that the lymph node negative subgroup of patients show a slight but constant increase of vessel index in all examined compartments of breast tumour. Conclusion. Whole slide digital examination and region of interest (ROI analysis are a valuable tool in scoring angiogenesis markers and disclosing their prognostic capacity. Our study reveals compartments’ variability of vessel density inside the tumour and highlights the propensity of invasive front to associate an active process of angiogenesis with potential implications in adjuvant therapy.

  15. Apparent diffusion coefficient correlation with oesophageal tumour stroma and angiogenesis

    International Nuclear Information System (INIS)

    Aoyagi, Tomoyoshi; Shuto, Kiyohiko; Okazumi, Shinichi; Hayano, Kohichi; Satoh, Asami; Saitoh, Hiroshige; Shimada, Hideaki; Nabeya, Yoshihiro; Matsubara, Hisahiro; Kazama, Toshiki

    2012-01-01

    Because diffusion-weighted imaging (DWI) can predict the prognosis of patients with oesophageal squamous cell carcinoma (ESCC), we hypothesised that apparent diffusion coefficient (ADC) values might be correlated with the collagen content and tumour angiogenesis. The purpose of this study was to determine the correlation between ADC values of ESCC before treatment and oesophageal tumour stroma and angiogenesis. Seventeen patients with ESCC were enrolled. The ADC values were calculated from the DWI score. Seventeen patients who had undergone oesophagectomy were analysed for tumour stroma, vascular endothelial growth factor (VEGF) and CD34. Tissue collagen was stained with azocarmine and aniline blue to quantitatively analyse the extracellular matrix in cancer stroma. Tissues were stained with VEGF and CD34 to analyse the angiogenesis. The ADC values decreased with stromal collagen growth. We found a negative correlation between the tumour ADC and the amount of stromal collagen (r = -0.729, P = 0.001), i.e. the ADC values decreased with growth of VEGF. We also found a negative correlation between the ADC of the tumours and the amount of VEGF (r = 0.538, P = 0.026). Our results indicated that the ADC value may be a novel prognostic factor and contribute to the treatment of oesophageal cancer. circle Magnetic resonance apparent diffusion coefficient values inversely indicate tumour stromal collagen circle There is also negative correlation between ADCs and vascular endothelial growth factor circle ADC values may contribute to the treatment of oesophageal cancer. (orig.)

  16. Developmental Hypoxia Has Negligible Effects on Long-Term Hypoxia Tolerance and Aerobic Metabolism of Atlantic Salmon (Salmo salar).

    Science.gov (United States)

    Wood, Andrew T; Clark, Timothy D; Andrewartha, Sarah J; Elliott, Nicholas G; Frappell, Peter B

    Exposure to developmental hypoxia can have long-term impacts on the physiological performance of fish because of irreversible plasticity. Wild and captive-reared Atlantic salmon (Salmo salar) can be exposed to hypoxic conditions during development and continue to experience fluctuating oxygen levels as juveniles and adults. Here, we examine whether developmental hypoxia impacts subsequent hypoxia tolerance and aerobic performance of Atlantic salmon. Individuals at 8°C were exposed to 50% (hypoxia) or 100% (normoxia) dissolved oxygen (DO) saturation (as percent of air saturation) from fertilization for ∼100 d (800 degree days) and then raised in normoxic conditions for a further 15 mo. At 18 mo after fertilization, aerobic scope was calculated in normoxia (100% DO) and acute (18 h) hypoxia (50% DO) from the difference between the minimum and maximum oxygen consumption rates ([Formula: see text] and [Formula: see text], respectively) at 10°C. Hypoxia tolerance was determined as the DO at which loss of equilibrium (LOE) occurred in a constantly decreasing DO environment. There was no difference in [Formula: see text], [Formula: see text], or aerobic scope between fish raised in hypoxia or normoxia. There was some evidence that hypoxia tolerance was lower (higher DO at LOE) in hypoxia-raised fish compared with those raised in normoxia, but the magnitude of the effect was small (12.52% DO vs. 11.73% DO at LOE). Acute hypoxia significantly reduced aerobic scope by reducing [Formula: see text], while [Formula: see text] remained unchanged. Interestingly, acute hypoxia uncovered individual-level relationships between DO at LOE and [Formula: see text], [Formula: see text], and aerobic scope. We discuss our findings in the context of developmental trajectories and the role of aerobic performance in hypoxia tolerance.

  17. Mesenchymal stromal cells reverse hypoxia-mediated suppression of α-smooth muscle actin expression in human dermal fibroblasts

    International Nuclear Information System (INIS)

    Faulknor, Renea A.; Olekson, Melissa A.; Nativ, Nir I.; Ghodbane, Mehdi; Gray, Andrea J.; Berthiaume, François

    2015-01-01

    During wound healing, fibroblasts deposit extracellular matrix that guides angiogenesis and supports the migration and proliferation of cells that eventually form the scar. They also promote wound closure via differentiation into α-smooth muscle actin (SMA)-expressing myofibroblasts, which cause wound contraction. Low oxygen tension typical of chronic nonhealing wounds inhibits fibroblast collagen production and differentiation. It has been suggested that hypoxic mesenchymal stromal cells (MSCs) secrete factors that promote wound healing in animal models; however, it is unclear whether these factors are equally effective on the target cells in a hypoxic wound environment. Here we investigated the impact of MSC-derived soluble factors on the function of fibroblasts cultured in hypoxic fibroblast-populated collagen lattices (FPCLs). Hypoxia alone significantly decreased FPCL contraction and α-SMA expression. MSC-conditioned medium restored hypoxic FPCL contraction and α-SMA expression to levels similar to normoxic FPCLs. (SB431542), an inhibitor of transforming growth factor-β 1 (TGF-β 1 )-mediated signaling, blocked most of the MSC effect on FPCL contraction, while exogenous TGF-β 1 at levels similar to that secreted by MSCs reproduced the MSC effect. These results suggest that TGF-β 1 is a major paracrine signal secreted by MSCs that can restore fibroblast functions relevant to the wound healing process and that are impaired in hypoxia. - Highlights: • Fibroblasts were cultured in collagen lattices (FPCLs) as model contracting wounds. • Hypoxia decreased FPCL contraction and fibroblast α-smooth muscle actin expression. • Mesenchymal stromal cells (MSCs) restored function of hypoxic fibroblasts. • MSCs regulate fibroblast function mainly via secreted transforming growth factor-β 1

  18. Mesenchymal stromal cells reverse hypoxia-mediated suppression of α-smooth muscle actin expression in human dermal fibroblasts

    Energy Technology Data Exchange (ETDEWEB)

    Faulknor, Renea A.; Olekson, Melissa A.; Nativ, Nir I.; Ghodbane, Mehdi; Gray, Andrea J.; Berthiaume, François, E-mail: fberthia@rci.rutgers.edu

    2015-02-27

    During wound healing, fibroblasts deposit extracellular matrix that guides angiogenesis and supports the migration and proliferation of cells that eventually form the scar. They also promote wound closure via differentiation into α-smooth muscle actin (SMA)-expressing myofibroblasts, which cause wound contraction. Low oxygen tension typical of chronic nonhealing wounds inhibits fibroblast collagen production and differentiation. It has been suggested that hypoxic mesenchymal stromal cells (MSCs) secrete factors that promote wound healing in animal models; however, it is unclear whether these factors are equally effective on the target cells in a hypoxic wound environment. Here we investigated the impact of MSC-derived soluble factors on the function of fibroblasts cultured in hypoxic fibroblast-populated collagen lattices (FPCLs). Hypoxia alone significantly decreased FPCL contraction and α-SMA expression. MSC-conditioned medium restored hypoxic FPCL contraction and α-SMA expression to levels similar to normoxic FPCLs. (SB431542), an inhibitor of transforming growth factor-β{sub 1} (TGF-β{sub 1})-mediated signaling, blocked most of the MSC effect on FPCL contraction, while exogenous TGF-β{sub 1} at levels similar to that secreted by MSCs reproduced the MSC effect. These results suggest that TGF-β{sub 1} is a major paracrine signal secreted by MSCs that can restore fibroblast functions relevant to the wound healing process and that are impaired in hypoxia. - Highlights: • Fibroblasts were cultured in collagen lattices (FPCLs) as model contracting wounds. • Hypoxia decreased FPCL contraction and fibroblast α-smooth muscle actin expression. • Mesenchymal stromal cells (MSCs) restored function of hypoxic fibroblasts. • MSCs regulate fibroblast function mainly via secreted transforming growth factor-β{sub 1}.

  19. Chronic hydrocephalus-induced hypoxia: increased expression of VEGFR-2+ and blood vessel density in hippocampus.

    Science.gov (United States)

    Dombrowski, S M; Deshpande, A; Dingwall, C; Leichliter, A; Leibson, Z; Luciano, M G

    2008-03-18

    Chronic hydrocephalus (CH) is a neurological disease characterized by increased cerebrospinal fluid volume and pressure that is often associated with impaired cognitive function. By and large, CH is a complex and heterogeneous cerebrospinal fluid (CSF) disorder where the exact site of brain insult is uncertain. Several mechanisms including neural compression, fiber stretch, and local or global hypoxia have been implicated in the underlying pathophysiology of CH. Specifically, the hippocampus, which plays a significant role in memory processing and is in direct contact with expanding CSF ventricles, may be involved. Using our model of chronic hydrocephalus, we quantified the density of vascular endothelial growth factor receptor 2 (VEGFR-2(+)) neurons, glial, endothelial cells, and blood vessels in hippocampal regions CA1, CA2-3, dentate gyrus and hilus using immunohistochemical and stereological methods. Density and %VEGFR-2(+) cell populations were estimated for CH animals (2-3 weeks vs. 12-16 weeks) and surgical controls (SC). Overall, we found approximately six- to eightfold increase in the cellular density of VEGFR-2(+) and more than double blood vessel density (BVd) in the hippocampus of CH compared with SC. There were no significant regional differences in VEGFR-2(+) cellular and BVd expression in the CH group. VEGFR-2(+) and BVds were significantly related to changes in CSF volume (Phypoxia conditions as previously described. These findings suggest that VEGFR-2 may play an adaptive role in angiogenesis after CH

  20. Hypoxia positron emission tomography imaging: combining information on perfusion and tracer retention to improve hypoxia specificity

    DEFF Research Database (Denmark)

    Busk, Morten; Munk, Ole L; Jakobsen, Steen S

    2017-01-01

    BACKGROUND: Static positron emission tomography (PET) allows mapping of tumor hypoxia, but low resolution and slow tracer retention/clearance results in poor image contrast and the risk of missing areas where hypoxic cells and necrosis are intermixed. Fully dynamic PET may improve accuracy but scan...

  1. Human erythropoietin response to hypocapnic hypoxia, normocapnic hypoxia, and hypocapnic normoxia

    DEFF Research Database (Denmark)

    Klausen, T; Christensen, H; Hansen, J M

    1996-01-01

    This study investigated the human erythropoietin (EPO) response to short-term hypocapnic hypoxia, its relationship to a normoxic or hypoxic increase of the haemoglobin oxygen affinity, and its suppression by the addition of CO2 to the hypoxic gas. On separate days, eight healthy male subjects were...

  2. Hypoxia and hypoxia-inducible factors as regulators of T cell development, differentiation, and function

    Science.gov (United States)

    McNamee, Eóin N.; Johnson, Darlynn Korns; Homann, Dirk

    2014-01-01

    Oxygen is a molecule that is central to cellular respiration and viability, yet there are multiple physiologic and pathological contexts in which cells experience conditions of insufficient oxygen availability, a state known as hypoxia. Given the metabolic challenges of a low oxygen environment, hypoxia elicits a range of adaptive responses at the cellular, tissue, and systemic level to promote continued survival and function. Within this context, T lymphocytes are a highly migratory cell type of the adaptive immune system that frequently encounters a wide range of oxygen tensions in both health and disease. It is now clear that oxygen availability regulates T cell differentiation and function, a response orchestrated in large part by the hypoxia-inducible factor transcription factors. Here, we discuss the physiologic scope of hypoxia and hypoxic signaling, the contribution of these pathways in regulating T cell biology, and current gaps in our understanding. Finally, we discuss how emerging therapies that modulate the hypoxic response may offer new modalities to alter T cell function and the outcome of acute and chronic pathologies. PMID:22961658

  3. Imaging tumor hypoxia: Blood-borne delivery of imaging agents is fundamentally different in hypoxia subtypes

    Directory of Open Access Journals (Sweden)

    Peter Vaupel

    2014-03-01

    Full Text Available Hypoxic tissue subvolumes are a hallmark feature of solid malignant tumors, relevant for cancer therapy and patient outcome because they increase both the intrinsic aggressiveness of tumor cells and their resistance to several commonly used anticancer strategies. Pathogenetic mechanisms leading to hypoxia are diverse, may coexist within the same tumor and are commonly grouped according to the duration of their effects. Chronic hypoxia is mainly caused by diffusion limitations resulting from enlarged intercapillary distances and adverse diffusion geometries and — to a lesser extent — by hypoxemia, compromised perfusion or long-lasting microregional flow stops. Conversely, acute hypoxia preferentially results from transient disruptions in perfusion. While each of these features of the tumor microenvironment can contribute to a critical reduction of oxygen availability, the delivery of imaging agents (as well as nutrients and anticancer agents may be compromised or remain unaffected. Thus, a critical appraisal of the effects of the various mechanisms leading to hypoxia with regard to the blood-borne delivery of imaging agents is necessary to judge their ability to correctly represent the hypoxic phenotype of solid malignancies.

  4. Intermittent hypoxia training in prediabetes patients: Beneficial effects on glucose homeostasis, hypoxia tolerance and gene expression.

    Science.gov (United States)

    Serebrovska, Tetiana V; Portnychenko, Alla G; Drevytska, Tetiana I; Portnichenko, Vladimir I; Xi, Lei; Egorov, Egor; Gavalko, Anna V; Naskalova, Svitlana; Chizhova, Valentina; Shatylo, Valeriy B

    2017-09-01

    The present study aimed at examining beneficial effects of intermittent hypoxia training (IHT) under prediabetic conditions. We investigate the effects of three-week IHT on blood glucose level, tolerance to acute hypoxia, and leukocyte mRNA expression of hypoxia inducible factor 1α (HIF-1α) and its target genes, i.e. insulin receptor, facilitated glucose transporter-solute carrier family-2, and potassium voltage-gated channel subfamily J. Seven healthy and 11 prediabetic men and women (44-70 years of age) were examined before, next day and one month after three-week IHT (3 sessions per week, each session consisting 4 cycles of 5-min 12% O 2 and 5-min room air breathing). We found that IHT afforded beneficial effects on glucose homeostasis in patients with prediabetes reducing fasting glucose and during standard oral glucose tolerance test. The most pronounced positive effects were observed at one month after IHT termination. IHT also significantly increased the tolerance to acute hypoxia (i.e. SaO 2 level at 20th min of breathing with 12% O 2 ) and improved functional parameters of respiratory and cardiovascular systems. IHT stimulated HIF-1α mRNA expression in blood leukocytes in healthy and prediabetic subjects, but in prediabetes patients the maximum increase was lagged. The greatest changes in mRNA expression of HIF-1α target genes occurred a month after IHT and coincided with the largest decrease in blood glucose levels. The higher expression of HIF-1α was positively associated with higher tolerance to hypoxia and better glucose homeostasis. In conclusion, our results suggest that IHT may be useful for preventing the development of type 2 diabetes. Impact statement The present study investigated the beneficial effects of intermittent hypoxia training (IHT) in humans under prediabetic conditions. We found that three-week moderate IHT induced higher HIF-1α mRNA expressions as well as its target genes, which were positively correlated with higher tolerance

  5. Radiolabeled Probes Targeting Hypoxia-Inducible Factor-1-Active Tumor Microenvironments

    Directory of Open Access Journals (Sweden)

    Masashi Ueda

    2014-01-01

    Full Text Available Because tumor cells grow rapidly and randomly, hypoxic regions arise from the lack of oxygen supply in solid tumors. Hypoxic regions in tumors are known to be resistant to chemotherapy and radiotherapy. Hypoxia-inducible factor-1 (HIF-1 expressed in hypoxic regions regulates the expression of genes related to tumor growth, angiogenesis, metastasis, and therapy resistance. Thus, imaging of HIF-1-active regions in tumors is of great interest. HIF-1 activity is regulated by the expression and degradation of its α subunit (HIF-1α, which is degraded in the proteasome under normoxic conditions, but escapes degradation under hypoxic conditions, allowing it to activate transcription of HIF-1-target genes. Therefore, to image HIF-1-active regions, HIF-1-dependent reporter systems and injectable probes that are degraded in a manner similar to HIF-1α have been recently developed and used in preclinical studies. However, no probe currently used in clinical practice directly assesses HIF-1 activity. Whether the accumulation of 18F-FDG or 18F-FMISO can be utilized as an index of HIF-1 activity has been investigated in clinical studies. In this review, the current status of HIF-1 imaging in preclinical and clinical studies is discussed.

  6. Intermittent hypoxia increases kidney tumor vascularization in a murine model of sleep apnea.

    Science.gov (United States)

    Vilaseca, Antoni; Campillo, Noelia; Torres, Marta; Musquera, Mireia; Gozal, David; Montserrat, Josep M; Alcaraz, Antonio; Touijer, Karim A; Farré, Ramon; Almendros, Isaac

    2017-01-01

    We investigate the effects of intermittent hypoxia (IH), a characteristic feature of obstructive sleep apnea (OSA), on renal cancer progression in an animal and cell model. An in vivo mouse model (Balb/c, n = 50) of kidney cancer was used to assess the effect of IH on tumor growth, metastatic capacity, angiogenesis and tumor immune response. An in vitro model tested the effect of IH on RENCA cells, macrophages and endothelial cells. Tumor growth, metastatic capacity, circulating vascular endothelial growth factor (VEGF) and content of endothelial cells, tumor associated macrophages and their phenotype were assessed in the tumor. In vitro, VEGF cell expression was quantified.Although IH did not boost tumor growth, it significantly increased endothelial cells (p = 0.001) and circulating VEGF (p<0.001) in the in vivo model. Macrophages exposed to IH in vitro increased VEGF expression, whereas RENCA cells and endothelial cells did not. These findings are in keeping with previous clinical data suggesting that OSA has no effect on kidney cancer size and that the association observed between OSA and higher Fuhrman grade of renal cell carcinoma may be mediated though a proangiogenic process, with a key role of macrophages.

  7. Intermittent hypoxia increases kidney tumor vascularization in a murine model of sleep apnea.

    Directory of Open Access Journals (Sweden)

    Antoni Vilaseca

    Full Text Available We investigate the effects of intermittent hypoxia (IH, a characteristic feature of obstructive sleep apnea (OSA, on renal cancer progression in an animal and cell model. An in vivo mouse model (Balb/c, n = 50 of kidney cancer was used to assess the effect of IH on tumor growth, metastatic capacity, angiogenesis and tumor immune response. An in vitro model tested the effect of IH on RENCA cells, macrophages and endothelial cells. Tumor growth, metastatic capacity, circulating vascular endothelial growth factor (VEGF and content of endothelial cells, tumor associated macrophages and their phenotype were assessed in the tumor. In vitro, VEGF cell expression was quantified.Although IH did not boost tumor growth, it significantly increased endothelial cells (p = 0.001 and circulating VEGF (p<0.001 in the in vivo model. Macrophages exposed to IH in vitro increased VEGF expression, whereas RENCA cells and endothelial cells did not. These findings are in keeping with previous clinical data suggesting that OSA has no effect on kidney cancer size and that the association observed between OSA and higher Fuhrman grade of renal cell carcinoma may be mediated though a proangiogenic process, with a key role of macrophages.

  8. Hypoxia-targeting antitumor prodrugs and photosensitizers

    International Nuclear Information System (INIS)

    Zhang Zhouen; Nishimoto, S.I.

    2006-01-01

    Tumor hypoxia has been identified as a key subject for tumor therapy, since hypoxic tumor cells show resistance to treatment of tumor tissues by radiotherapy, chemotherapy and phototherapy. For improvement of tumor radiotherapy, we have proposed a series of radiation-activated prodrugs that could selectively release antitumor agent 5-fluorouracil or 5-fluorodeoxyuridine under hypoxic conditions. Recently, we attempted to develop two families of novel hypoxia-targeting antitumor agents, considering that tumor-hypoxic environment is favorable to biological and photochemical reductions. The first family of prodrugs was derived from camptothecin as a potent topoisomerase I inhibitor and several bioreductive motifs. These prodrugs could be activated by NADPH-cytochrome P450 reductase or DT-diaphorase to release free camptothecin, and thereby showed hypoxia-selective cytotoxictiy towards tumor cells. These prodrugs were also applicable to the real-time monitoring of activation and antitumor effect by fluorometry. Furthermore, the camptothecin-bioreductive motif conjugates was confirmed to show an oxygen-independent DAN photocleaving activity, which could overcome a drawback of back electron transfer occurring in the photosensitized one-electron oxidation of DNA. Thus, these camptothecin derivatives could be useful to both chemotherapy and phototherapy for hypoxic tumor cells. The second family of prodrugs harnessed UV light for cancer therapy, incorporating the antitumor agent 5-fluorourcil and the photolabile 2-nitrobenzyl chromophores. The attachment of a tumor-homing cyclic peptide CNGRC was also employed to construct the prototype of tumor-targeting photoactiaved antitumor prodrug. These novel prodrugs released high yield of 5-fluorourcil upon UV irradiation at λ ex =365 nm, while being quite stable in the dark. The photoactivation mechanism was also clarified by means of nanosecond laser flash photolysis. (authors)

  9. Evaluation of Notch and Hypoxia Signaling Pathways in Chemically ...

    African Journals Online (AJOL)

    Hepatocellular carcinoma (HCC) is a common worldwide malignancy. Notch signaling pathway contributes to the genesis of diverse cancers, however, its role in HCC is unclear. Hypoxia is a common feature of HCC. Signal integration between Notch and hypoxia may be involved in HCC. The aim of this study was to ...

  10. Comparative aspects of hypoxia tolerance of the ectothermic vertebrate heart

    DEFF Research Database (Denmark)

    Gesser, Hans; Overgaard, Johannes

    2009-01-01

    This chapter reviews cardiac contractile performance and its regulation during hypoxia/anoxia with regard to cellular metabolism and energy state, in particular hypoxia-tolerant ectothermic vertebrates. Overall the contractile performance of the hypoxic isolated heart muscle varies in a way...

  11. Role of hypoxia-inducible factor in diabetic myocardial hypertrophy ...

    African Journals Online (AJOL)

    Purpose: This study was carried out to investigate the role of hypoxia-inducible factor (HIF) in diabetic cardiomyopathy in vitro. Methods: Hypoxia was induced chemically in H9C2 cells (cardiac hypertrophy model), and the cells were treated with phenylephrine (PE), deferoxamine (DFO), PE + DFO, and HIF-1α siRNA under ...

  12. Hypoxic hypoxia as a means of modifying radiosensibility

    International Nuclear Information System (INIS)

    Neumeister, K.; Niemiec, C.; Bolck, M.; Jahns, J.; Kamprad, F.; Arnold, P.; Johannsen, U.; Koch, F.; Mehlhorn, G.

    1977-01-01

    Following an overview of the various possibilities of creating hypoxia in mammals, the problem of reducing radioresistance of hypoxic tumor cells is treated. Furthermore, the results of irradiation experiments with mice, rats and pigs breathing hypoxic mixtures of O 2 and N 2 are given and discussed with a view to applying hypoxic hypoxia in the radiotherapy of human tumors. (author)

  13. Hypoxia-induced dysfunction of rat diaphragm: role of peroxynitrite.

    NARCIS (Netherlands)

    Zhu, X.; Heunks, L.M.A.; Versteeg, E.M.M.; Heijden, E. van der; Ennen, L.; Kuppevelt, A.H.M.S.M. van; Vina, J.; Dekhuijzen, P.N.R.

    2005-01-01

    Oxidants may play a role in hypoxia-induced respiratory muscle dysfunction. In the present study we hypothesized that hypoxia-induced impairment in diaphragm contractility is associated with elevated peroxynitrite generation. In addition, we hypothesized that strenuous contractility of the diaphragm

  14. Effects of hypoxia and hypercapnia on geniohyoid contractility and endurance.

    Science.gov (United States)

    Salmone, R J; Van Lunteren, E

    1991-08-01

    Sleep apnea and other respiratory diseases produce hypoxemia and hypercapnia, factors that adversely affect skeletal muscle performance. To examine the effects of these chemical alterations on force production by an upper airway dilator muscle, the contractile and endurance characteristics of the geniohyoid muscle were examined in situ during severe hypoxia (arterial PO2 less than 40 Torr), mild hypoxia (PO2 45-65 Torr), and hypercapnia (PCO2 55-80 Torr) and compared with hyperoxic-normocapnic conditions in anesthetized cats. Muscles were studied at optimal length, and contractile force was assessed in response to supramaximal electrical stimulation of the hypoglossal nerve (n = 7 cats) or geniohyoid muscle (n = 2 cats). There were no significant changes in the twitch kinetics or force-frequency curve of the geniohyoid muscle during hypoxia or hypercapnia. However, the endurance of the geniohyoid, as reflected in the fatigue index (ratio of force at 2 min to initial force in response to 40-Hz stimulation at a duty cycle 0.33), was significantly reduced by severe hypoxia but not by hypercapnia or mild hypoxia. In addition, the downward shift in the force-frequency curve after the repetitive stimulation protocol was greater during hypoxia than hyperoxia, especially at higher frequencies. In conclusion, the ability of the geniohyoid muscle to maintain force output during high levels of activation is adversely affected by severe hypoxia but not mild hypoxia or hypercapnia. However, none of these chemical perturbations affected muscle contractility acutely.

  15. Brain adaptation to hypoxia and hyperoxia in mice

    Directory of Open Access Journals (Sweden)

    Laura Terraneo

    2017-04-01

    Conclusion: Prolonged mild hyperoxia leads to persistent cerebral damage, comparable to that inferred by prolonged mild hypoxia. The underlying mechanism appears related to a model whereby the imbalance between ROS generation and anti-ROS defense is similar, but occurs at higher levels in hypoxia than in hyperoxia.

  16. The infectious hypoxia: occurrence and causes during Shigella infection.

    Science.gov (United States)

    Arena, Ellen T; Tinevez, Jean-Yves; Nigro, Giulia; Sansonetti, Philippe J; Marteyn, Benoit S

    2017-03-01

    Hypoxia is defined as a tissue oxygenation status below physiological needs. During Shigella infection, an infectious hypoxia is induced within foci of infection. In this review, we discuss how Shigella physiology and virulence are modulated and how the main recruited immune cells, the neutrophils, adapt to this environment. Copyright © 2016 Institut Pasteur. Published by Elsevier Masson SAS. All rights reserved.

  17. Mitochondrial Reactive Oxygen Species Trigger Hypoxia-Induced Transcription

    Science.gov (United States)

    Chandel, N. S.; Maltepe, E.; Goldwasser, E.; Mathieu, C. E.; Simon, M. C.; Schumacker, P. T.

    1998-09-01

    Transcriptional activation of erythropoietin, glycolytic enzymes, and vascular endothelial growth factor occurs during hypoxia or in response to cobalt chloride (CoCl2) in Hep3B cells. However, neither the mechanism of cellular O2 sensing nor that of cobalt is fully understood. We tested whether mitochondria act as O2 sensors during hypoxia and whether hypoxia and cobalt activate transcription by increasing generation of reactive oxygen species (ROS). Results show (i) wild-type Hep3B cells increase ROS generation during hypoxia (1.5% O2) or CoCl2 incubation, (ii) Hep3B cells depleted of mitochondrial DNA (ρ 0 cells) fail to respire, fail to activate mRNA for erythropoietin, glycolytic enzymes, or vascular endothelial growth factor during hypoxia, and fail to increase ROS generation during hypoxia; (iii) ρ 0 cells increase ROS generation in response to CoCl2 and retain the ability to induce expression of these genes; and (iv) the antioxidants pyrrolidine dithiocarbamate and ebselen abolish transcriptional activation of these genes during hypoxia or CoCl2 in wild-type cells, and abolish the response to CoCl2 in ρ 0 cells. Thus, hypoxia activates transcription via a mitochondria-dependent signaling process involving increased ROS, whereas CoCl2 activates transcription by stimulating ROS generation via a mitochondria-independent mechanism.

  18. Effect of acute exposure to moderate altitude on muscle power: hypobaric hypoxia vs. normobaric hypoxia.

    Directory of Open Access Journals (Sweden)

    Belén Feriche

    Full Text Available When ascending to a higher altitude, changes in air density and oxygen levels affect the way in which explosive actions are executed. This study was designed to compare the effects of acute exposure to real or simulated moderate hypoxia on the dynamics of the force-velocity relationship observed in bench press exercise. Twenty-eight combat sports athletes were assigned to two groups and assessed on two separate occasions: G1 (n = 17 in conditions of normoxia (N1 and hypobaric hypoxia (HH and G2 (n = 11 in conditions of normoxia (N2 and normobaric hypoxia (NH. Individual and complete force-velocity relationships in bench press were determined on each assessment day. For each exercise repetition, we obtained the mean and peak velocity and power shown by the athletes. Maximum power (Pmax was recorded as the highest P(mean obtained across the complete force-velocity curve. Our findings indicate a significantly higher absolute load linked to P(max (∼ 3% and maximal strength (1 RM (∼ 6% in G1 attributable to the climb to altitude (P<0.05. We also observed a stimulating effect of natural hypoxia on P(mean and P(peak in the middle-high part of the curve (≥ 60 kg; P<0.01 and a 7.8% mean increase in barbell displacement velocity (P<0.001. No changes in any of the variables examined were observed in G2. According to these data, we can state that acute exposure to natural moderate altitude as opposed to simulated normobaric hypoxia leads to gains in 1 RM, movement velocity and power during the execution of a force-velocity curve in bench press.

  19. Hypoxia Aggravates Inactivity-Related Muscle Wasting

    Directory of Open Access Journals (Sweden)

    Tadej Debevec

    2018-05-01

    Full Text Available Poor musculoskeletal state is commonly observed in numerous clinical populations such as chronic obstructive pulmonary disease (COPD and heart failure patients. It, however, remains unresolved whether systemic hypoxemia, typically associated with such clinical conditions, directly contributes to muscle deterioration. We aimed to experimentally elucidate the effects of systemic environmental hypoxia upon inactivity-related muscle wasting. For this purpose, fourteen healthy, male participants underwent three 21-day long interventions in a randomized, cross-over designed manner: (i bed rest in normoxia (NBR; PiO2 = 133.1 ± 0.3 mmHg, (ii bed rest in normobaric hypoxia (HBR; PiO2 = 90.0 ± 0.4 mmHg and ambulatory confinement in normobaric hypoxia (HAmb; PiO2 = 90.0 ± 0.4 mmHg. Peripheral quantitative computed tomography and vastus lateralis muscle biopsies were performed before and after the interventions to obtain thigh and calf muscle cross-sectional areas and muscle fiber phenotype changes, respectively. A significant reduction of thigh muscle size following NBR (-6.9%, SE 0.8%; P < 0.001 was further aggravated following HBR (-9.7%, SE 1.2%; P = 0.027. Bed rest-induced muscle wasting in the calf was, by contrast, not exacerbated by hypoxic conditions (P = 0.47. Reductions in both thigh (-2.7%, SE 1.1%, P = 0.017 and calf (-3.3%, SE 0.7%, P < 0.001 muscle size were noted following HAmb. A significant and comparable increase in type 2× fiber percentage of the vastus lateralis muscle was noted following both bed rest interventions (NBR = +3.1%, SE 2.6%, HBR = +3.9%, SE 2.7%, P < 0.05. Collectively, these data indicate that hypoxia can exacerbate inactivity-related muscle wasting in healthy active participants and moreover suggest that the combination of both, hypoxemia and lack of activity, as seen in COPD patients, might be particularly harmful for muscle tissue.

  20. 2013 Gulf of Mexico Hypoxia Forecast

    Science.gov (United States)

    Scavia, Donald; Evans, Mary Anne; Obenour, Dan

    2013-01-01

    The Gulf of Mexico annual summer hypoxia forecasts are based on average May total nitrogen loads from the Mississippi River basin for that year. The load estimate, recently released by USGS, is 7,316 metric tons per day. Based on that estimate, we predict the area of this summer’s hypoxic zone to be 18,900 square kilometers (95% credible interval, 13,400 to 24,200), the 7th largest reported and about the size of New Jersey. Our forecast hypoxic volume is 74.5 km3 (95% credible interval, 51.5 to 97.0), also the 7th largest on record.

  1. 2014 Gulf of Mexico Hypoxia Forecast

    Science.gov (United States)

    Scavia, Donald; Evans, Mary Anne; Obenour, Dan

    2014-01-01

    The Gulf of Mexico annual summer hypoxia forecasts are based on average May total nitrogen loads from the Mississippi River basin for that year. The load estimate, recently released by USGS, is 4,761 metric tons per day. Based on that estimate, we predict the area of this summer’s hypoxic zone to be 14,000 square kilometers (95% credible interval, 8,000 to 20,000) – an “average year”. Our forecast hypoxic volume is 50 km3 (95% credible interval, 20 to 77).

  2. Diversity of radioprobes targeted to tumor angiogenesis on molecular functional imaging

    International Nuclear Information System (INIS)

    Lu Xia; Zhang Huabei

    2013-01-01

    Molecular functional imaging could visualize, characterize, and measure the bio- logical processes including tumor angiogenesis at the molecular and cellular levels in humans and other living systems. The molecular probes labeled by a variety of radionuclide used in the field of the nuclear medicine play pivotal roles in molecular imaging of tumor angiogenesis. However, the regulatory role of different probes in tumor angiogenesis has not been systematically illustrated. The current status of tumor angiogenesis imaging with radiolabeled probes of peptide, monoclonal antibody as well as its fragment, especially nanoparticle-based probes to gain insights into the robust tumor angiogenesis development were summarized. It was recognized that only the probes such as nanoparticle-based probes, which truly target the tumor vasculature rather than tumor cells because of poor extravasation, are really tumor angiogenesis imaging agent. The research of molecular probe targeted to angiogenesis would meet its flourish just after the outstanding improvements in the in vivo stability and biocompatibility, tumor-targeting efficacy, and pharmacokinetics of tumor angiogenesis imaging probes are made. Translation to clinical applications will also be critical for the maximize benefits of these novel agents. The future of tumor angiogenesis imaging lies in liable imaging probes and multiple imaging modalities, imaging of protein-protein interactions, and quantitative molecular imaging. (authors)

  3. Modulation of Radioprotective Effects of Respiratory Hypoxia by Changing the Duration of Hypoxia before Irradiation and by Combining Hypoxia and Administration of Hemopoiesis-Stimulating Agents

    Czech Academy of Sciences Publication Activity Database

    Vacek, Antonín; Tačev, T.; Hofer, Michal

    2001-01-01

    Roč. 177, č. 9 (2001), s. 474-481 ISSN 0179-7158 Institutional research plan: CEZ:AV0Z5004920 Keywords : radioprotection * mice * hypoxia Subject RIV: BO - Biophysics Impact factor: 3.005, year: 2001

  4. Development of a novel fluorescent imaging probe for tumor hypoxia by use of a fusion protein with oxygen-dependent degradation domain of HIF-1α

    Science.gov (United States)

    Tanaka, Shotaro; Kizaka-Kondoh, Shinae; Harada, Hiroshi; Hiraoka, Masahiro

    2007-02-01

    More malignant tumors contain more hypoxic regions. In hypoxic tumor cells, expression of a series of hypoxiaresponsive genes related to malignant phenotype such as angiogenesis and metastasis are induced. Hypoxia-inducible factor-1 (HIF-1) is a master transcriptional activator of such genes, and thus imaging of hypoxic tumor cells where HIF-1 is active, is important in cancer therapy. We have been developing PTD-ODD fusion proteins, which contain protein transduction domain (PTD) and the VHL-mediated protein destruction motif in oxygen-dependent degradation (ODD) domain of HIF-1 alpha subunit (HIF-1α). Thus PTD-ODD fusion proteins can be delivered to any tissue in vivo through PTD function and specifically stabilized in hypoxic cells through ODD function. To investigate if PTD-ODD fusion protein can be applied to construct hypoxia-specific imaging probes, we first constructed a fluorescent probe because optical imaging enable us to evaluate a probe easily, quickly and economically in a small animal. We first construct a model fusion porein PTD-ODD-EGFP-Cy5.5 named POEC, which is PTD-ODD protein fused with EGFP for in vitro imaging and stabilization of fusion protein, and conjugated with a near-infrared dye Cy5.5. This probe is designed to be degraded in normoxic cells through the function of ODD domain and followed by quick clearance of free fluorescent dye. On the other hand, this prove is stabilized in hypoxic tumor cells and thus the dye is stayed in the cells. Between normoxic and hypoxic conditions, the difference in the clearance rate of the dye will reveals suited contrast for tumor-hypoxia imaging. The optical imaging probe has not been optimized yet but the results presented here exhibit a potential of PTD-ODD fusion protein as a hypoxia-specific imaging probe.

  5. Angiogenesis concept in odontogenic keratocyst: A comparative study

    Directory of Open Access Journals (Sweden)

    Donia Sadri

    2017-01-01

    Full Text Available Context: Recent reports have indicated that angiogenesis possibly affects the biologic behavior of the lesions. Aim: Given the different clinical behaviors of odontogenic keratocyst (OKC, the present study was undertaken to evaluate the concept of angiogenesis in pathogenesis and clinical behavior of OKC. Setting and Design: This experimental study was carried out on 22 and 24 samples of OKCs and dentigerous cysts (DCs, respectively. Methods: Immunohistochemical staining was approached using CD34 and vascular endothelial growth factor (VEGF antibodies. The expression of VEGF was first reported by determining the counts of stained cells, including epithelial cells, fibroblasts, and endothelial cells, followed by the percentage of stained cells in each sample based on a 0–2 scoring system. The counts of CD34+ cells were reported in each group in the form of means ± standard deviations. In addition, the patterns of blood vessels in the samples prepared from the walls of both cysts were evaluated. Statistical Analysis Used: Mann–Whitney U-test, Chi-squared test, and t-test were used for analysis of data, and statistical significance was defined at p < 0.05. Results: The expression percentage and scores of VEGF and the mean expression rate of CD34 were significantly higher in OKCs than DCs (p = 0.045, 0.000, and < 0.001. No significant difference was detected in the vascular patterns of these lesions (p = 0.58. Finally, there was a strong correlation between the expressions of the two markers in the samples (Correlation coefficient = 0.766. Conclusion: The present results indicate the angiogenesis may play an important role in the pathogenesis and the unique clinical behavior of OKC.

  6. Osteogenesis and angiogenesis: The potential for engineering bone

    Directory of Open Access Journals (Sweden)

    JM Kanczler

    2008-05-01

    Full Text Available The repair of large bone defects remains a major clinical orthopaedic challenge. Bone is a highly vascularised tissue reliant on the close spatial and temporal connection between blood vessels and bone cells to maintain skeletal integrity. Angiogenesis thus plays a pivotal role in skeletal development and bone fracture repair. Current procedures to repair bone defects and to provide structural and mechanical support include the use of grafts (autologous, allogeneic or implants (polymeric or metallic. These approaches face significant limitations due to insufficient supply, potential disease transmission, rejection, cost and the inability to integrate with the surrounding host tissue.The engineering of bone tissue offers new therapeutic strategies to aid musculoskeletal healing. Various scaffold constructs have been employed in the development of tissue-engineered bone; however, an active blood vessel network is an essential pre-requisite for these to survive and integrate with existing host tissue. Combination therapies of stem cells and polymeric growth factor release scaffolds tailored to promote angiogenesis and osteogenesis are under evaluation and development actively to stimulate bone regeneration. An understanding of the cellular and molecular interactions of blood vessels and bone cells will enhance and aid the successful development of future vascularised bone scaffold constructs, enabling survival and integration of bioengineered bone with the host tissue. The role of angiogenic and osteogenic factors in the adaptive response and interaction of osteoblasts and endothelial cells during the multi step process of bone development and repair will be highlighted in this review, with consideration of how some of these key mechanisms can be combined with new developments in tissue engineering to enable repair and growth of skeletal fractures. Elucidation of the processes of angiogenesis, osteogenesis and tissue engineering strategies offer

  7. Ets2 in tumor fibroblasts promotes angiogenesis in breast cancer.

    Directory of Open Access Journals (Sweden)

    Julie A Wallace

    Full Text Available Tumor fibroblasts are active partners in tumor progression, but the genes and pathways that mediate this collaboration are ill-defined. Previous work demonstrates that Ets2 function in stromal cells significantly contributes to breast tumor progression. Conditional mouse models were used to study the function of Ets2 in both mammary stromal fibroblasts and epithelial cells. Conditional inactivation of Ets2 in stromal fibroblasts in PyMT and ErbB2 driven tumors significantly reduced tumor growth, however deletion of Ets2 in epithelial cells in the PyMT model had no significant effect. Analysis of gene expression in fibroblasts revealed a tumor- and Ets2-dependent gene signature that was enriched in genes important for ECM remodeling, cell migration, and angiogenesis in both PyMT and ErbB2 driven-tumors. Consistent with these results, PyMT and ErbB2 tumors lacking Ets2 in fibroblasts had fewer functional blood vessels, and Ets2 in fibroblasts elicited changes in gene expression in tumor endothelial cells consistent with this phenotype. An in vivo angiogenesis assay revealed the ability of Ets2 in fibroblasts to promote blood vessel formation in the absence of tumor cells. Importantly, the Ets2-dependent gene expression signatures from both mouse models were able to distinguish human breast tumor stroma from normal stroma, and correlated with patient outcomes in two whole tumor breast cancer data sets. The data reveals a key function for Ets2 in tumor fibroblasts in signaling to endothelial cells to promote tumor angiogenesis. The results highlight the collaborative networks that orchestrate communication between stromal cells and tumor cells, and suggest that targeting tumor fibroblasts may be an effective strategy for developing novel anti-angiogenic therapies.

  8. The usability of a 15-gene hypoxia classifier as a universal hypoxia profile in various cancer cell types

    DEFF Research Database (Denmark)

    Sørensen, Brita Singers; Knudsen, Anders Bisgård; Wittrup, Catja Foged

    2015-01-01

    genes, with BNIP3 not being upregulated at hypoxic conditions in 3 out of 6 colon cancer cell lines, and ALDOA in OE21 and FAM162A and SLC2A1 in SW116 only showing limited hypoxia induction. Furthermore, in the esophagus cell lines, the normoxic and hypoxic expression levels of LOX and BNIP3 were below...... the tissue type dependency of hypoxia induced genes included in a 15-gene hypoxic profile in carcinoma cell lines from prostate, colon, and esophagus cancer, and demonstrated that in vitro, with minor fluctuations, the genes in the hypoxic profile are hypoxia inducible, and the hypoxia profile may......BACKGROUND AND PURPOSE: A 15-gene hypoxia profile has previously demonstrated to have both prognostic and predictive impact for hypoxic modification in squamous cell carcinoma of the head and neck. This gene expression profile may also have a prognostic value in other histological cancer types...

  9. 3D Multiscale Modelling of Angiogenesis and Vascular Tumour Growth

    KAUST Repository

    Perfahl, H.

    2012-11-01

    We present a three-dimensional, multiscale model of vascular tumour growth, which couples nutrient/growth factor transport, blood flow, angiogenesis, vascular remodelling, movement of and interactions between normal and tumour cells, and nutrient-dependent cell cycle dynamics within each cell. We present computational simulations which show how a vascular network may evolve and interact with tumour and healthy cells. We also demonstrate how our model may be combined with experimental data, to predict the spatio-temporal evolution of a vascular tumour.

  10. Brassinosteroids inhibit in vitro angiogenesis in human endothelial cells

    Czech Academy of Sciences Publication Activity Database

    Rárová, L.; Zahler, S.; Liebl, J.; Kryštof, Vladimír; Sedlák, David; Bartůněk, Petr; Kohout, Ladislav; Strnad, Miroslav

    2012-01-01

    Roč. 77, č. 13 (2012), s. 1502-1509 ISSN 0039-128X R&D Projects: GA MŠk(CZ) LC06077 Grant - others:GA MŠk(CZ) ED0007/01/01 Program:ED Institutional research plan: CEZ:AV0Z50380511; CEZ:AV0Z50520514; CEZ:AV0Z40550506 Keywords : Angiogenesis * Human umbilical vein endothelial cells * Migration Subject RIV: EB - Genetics ; Molecular Biology Impact factor: 2.803, year: 2012

  11. 3D Multiscale Modelling of Angiogenesis and Vascular Tumour Growth

    KAUST Repository

    Perfahl, H.; Byrne, H. M.; Chen, T.; Estrella, V.; Alarcó n, T.; Lapin, A.; Gatenby, R. A.; Gillies, R. J.; Lloyd, M. C.; Maini, P. K.; Reuss, M.; Owen, M. R.

    2012-01-01

    We present a three-dimensional, multiscale model of vascular tumour growth, which couples nutrient/growth factor transport, blood flow, angiogenesis, vascular remodelling, movement of and interactions between normal and tumour cells, and nutrient-dependent cell cycle dynamics within each cell. We present computational simulations which show how a vascular network may evolve and interact with tumour and healthy cells. We also demonstrate how our model may be combined with experimental data, to predict the spatio-temporal evolution of a vascular tumour.

  12. Toxicity management of angiogenesis inhibitors: resolution of expert panel

    Directory of Open Access Journals (Sweden)

    Pavel O. Rumiantsev

    2017-12-01

    Full Text Available On 22 June 2017 in St. Petersburg the expert panel was held on the topic “Management of toxicity of angiogenesis inhibitors”, which discussed current issues of systemic therapy of advanced differentiated thyroid cancer resistant to radioactive iodine therapy, advanced kidney cancer and questions of efficacy and safety of new target drugs in the treatment of these diseases. The reports and discussions of experts raised the following questions: 1. Own experience of using lenvatinib in patients with differentiated thyroid cancer refractory to therapy with radioactive iodine and kidney cancer. 2. Profile of efficacy and safety of modern targeted therapy with multikinase inhibitors. 3. Prophylaxis and management of predictable toxicity.

  13. Understanding and exploiting the genomic response to hypoxia

    International Nuclear Information System (INIS)

    Giaccia, A.J.

    2003-01-01

    The tumor microenvironment influences both therapeutic outcome and malignant progression. Of the many factors that may be altered in the tumor microenvironment, changes in tumor oxygenation have been strongly associated with a lower probability of local tumor control and survival. In vitro studies indicate that cells exposed to a low oxygen environment exhibit multiple phenotypes, including cell-cycle arrest, increased expression of pro-angiogenic genes, increased invasive capacity, increased apoptosis, increased anaerobic metabolism and altered differentiation programs. While the mechanistic basis of hypoxia as an impediment to radiotherapy and chemotherapy is well understood, it is unclear what changes in the cellular phenotype are important in understanding how hypoxia modifies malignant progression. One insight into how hypoxia modulates malignant progression comes from understanding the critical transcriptional regulators of gene expression under hypoxic conditions such as hypoxia inducible factor 1 (HIF-1) as well as changes in gene expression in untransformed and transformed cells. Overall, about 1.5% of the genome is found to be transcriptionally responsive to changes in oxygenation. Most importantly, the coordinated changes in gene expression under hypoxic conditions underscore the physiologic basis for altering gene expression in response to a low oxygen environment. In addition, some hypoxia-induced genes exhibit increased expression after reoxygenation, suggesting that they are regulated both by hypoxia and oxidative stress. Analysis of the genomic response to hypoxia has several therapeutic uses. First, it allows one to ask the question of what the cellular consequences are to inhibition of the transcriptional response to hypoxia such as by targeting the HIF-1 transcription factor. While the effect of loss of HIF-1 in tumors leads to inhibition of tumor growth, it does not eliminate tumors. In fact, studies indicate that inhibition of HIF-1 leads to a

  14. Bone marrow-derived cells are differentially involved in pathological and physiological retinal angiogenesis in mice

    Energy Technology Data Exchange (ETDEWEB)

    Zou, He [Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Otani, Atsushi, E-mail: otan@kuhp.kyoto-u.ac.jp [Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan); Oishi, Akio; Yodoi, Yuko; Kameda, Takanori; Kojima, Hiroshi; Yoshimura, Nagahisa [Department of Ophthalmology and Visual Sciences, Kyoto University Graduate School of Medicine, Kyoto 606-8507 (Japan)

    2010-01-08

    Purpose: Bone marrow-derived cells have been shown to play roles in angiogenesis. Although these cells have been shown to promote angiogenesis, it is not yet clear whether these cells affect all types of angiogenesis. This study investigated the involvement of bone marrow-derived cells in pathological and physiological angiogenesis in the murine retina. Materials and methods: The oxygen-induced retinopathy (OIR) model was used as a retinal angiogenesis model in newborn mice. To block the influence of bone marrow-derived cells, the mice were irradiated with a 4-Gy dose of radiation from a {sup 137}Cs source. Irradiation was performed in four different conditions with radio dense 2-cm thick lead disks; (1) H group, the head were covered with these discs to protect the eyes from radiation; (2) A group, all of the body was covered with these discs; (3) N group, mice were completely unshielded; (4) C group, mice were put in the irradiator but were not irradiated. On P17, the retinal areas showing pathological and physiological retinal angiogenesis were measured and compared to the retinas of nonirradiated mice. Results: Although irradiation induced leukocyte depletion, it did not affect the number of other cell types or body weight. Retinal nonperfusion areas were significantly larger in irradiated mice than in control mice (P < 0.05), indicating that physiological angiogenesis was impaired. However, the formation of tuft-like angiogenesis processes was more prominent in the irradiated mice (P < 0.05), indicating that pathological angiogenesis was intact. Conclusions: Bone marrow-derived cells seem to be differentially involved in the formation of physiological and pathological retinal vessels. Pathological angiogenesis in the murine retina does not require functional bone marrow-derived cells, but these cells are important for the formation of physiological vessels. Our results add a new insight into the pathology of retinal angiogenesis and bolster the hypothesis that

  15. Bone marrow-derived cells are differentially involved in pathological and physiological retinal angiogenesis in mice

    International Nuclear Information System (INIS)

    Zou, He; Otani, Atsushi; Oishi, Akio; Yodoi, Yuko; Kameda, Takanori; Kojima, Hiroshi; Yoshimura, Nagahisa

    2010-01-01

    Purpose: Bone marrow-derived cells have been shown to play roles in angiogenesis. Although these cells have been shown to promote angiogenesis, it is not yet clear whether these cells affect all types of angiogenesis. This study investigated the involvement of bone marrow-derived cells in pathological and physiological angiogenesis in the murine retina. Materials and methods: The oxygen-induced retinopathy (OIR) model was used as a retinal angiogenesis model in newborn mice. To block the influence of bone marrow-derived cells, the mice were irradiated with a 4-Gy dose of radiation from a 137 Cs source. Irradiation was performed in four different conditions with radio dense 2-cm thick lead disks; (1) H group, the head were covered with these discs to protect the eyes from radiation; (2) A group, all of the body was covered with these discs; (3) N group, mice were completely unshielded; (4) C group, mice were put in the irradiator but were not irradiated. On P17, the retinal areas showing pathological and physiological retinal angiogenesis were measured and compared to the retinas of nonirradiated mice. Results: Although irradiation induced leukocyte depletion, it did not affect the number of other cell types or body weight. Retinal nonperfusion areas were significantly larger in irradiated mice than in control mice (P < 0.05), indicating that physiological angiogenesis was impaired. However, the formation of tuft-like angiogenesis processes was more prominent in the irradiated mice (P < 0.05), indicating that pathological angiogenesis was intact. Conclusions: Bone marrow-derived cells seem to be differentially involved in the formation of physiological and pathological retinal vessels. Pathological angiogenesis in the murine retina does not require functional bone marrow-derived cells, but these cells are important for the formation of physiological vessels. Our results add a new insight into the pathology of retinal angiogenesis and bolster the hypothesis that bone

  16. Identification of Hypoxia-Regulated Proteins Using MALDI-Mass Spectrometry Imaging Combined with Quantitative Proteomics

    DEFF Research Database (Denmark)

    Djidja, Marie-Claude; Chang, Joan; Hadjiprocopis, Andreas

    2014-01-01

    Hypoxia is present in most solid tumors and is clinically correlated with increased metastasis and poor patient survival. While studies have demonstrated the role of hypoxia and hypoxia-regulated proteins in cancer progression, no attempts have been made to identify hypoxia-regulated proteins using...

  17. Tumor hypoxia and reoxygenation: the yin and yang for radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Hong, Beom Ju; Kim, Jong Woo; Jeong, Hoi Bin; Bok, Seo Yeon; Kim, Young Eun; Ahn, G One [Division of Integrative Biosciences and Biotechnology, Pohang University of Science and Technology, Pohang (Korea, Republic of)

    2016-12-15

    Tumor hypoxia, a common feature occurring in nearly all human solid tumors is a major contributing factor for failures of anticancer therapies. Because ionizing radiation depends heavily on the presence of molecular oxygen to produce cytotoxic effect, the negative impact of tumor hypoxia had long been recognized. In this review, we will highlight some of the past attempts to overcome tumor hypoxia including hypoxic radiosensitizers and hypoxia-selective cytotoxin. Although they were (still are) a very clever idea, they lacked clinical efficacy largely because of ‘reoxygenation’ phenomenon occurring in the conventional low dose hyperfractionation radiotherapy prevented proper activation of these compounds. Recent meta-analysis and imaging studies do however indicate that there may be a significant clinical benefit in lowering the locoregional failures by using these compounds. Latest technological advancement in radiotherapy has allowed to deliver high doses of radiation conformally to the tumor volume. Although this technology has brought superb clinical responses for many types of cancer, recent modeling studies have predicted that tumor hypoxia is even more serious because ‘reoxygenation’ is low thereby leaving a large portion of hypoxic tumor cells behind. Wouldn’t it be then reasonable to combine hypoxic radiosensitizers and/or hypoxia-selective cytotoxin with the latest radiotherapy? We will provide some preclinical and clinical evidence to support this idea hoping to revamp an enthusiasm for hypoxic radiosensitizers or hypoxia-selective cytotoxins as an adjunct therapy for radiotherapy.

  18. Radiation, hypoxia and genetic stimulation: implications for future therapies

    International Nuclear Information System (INIS)

    Adams, Gerald E.; Hasan, Na'il M.; Joiner, Michael C.

    1997-01-01

    The cellular stress response, whereby very low doses of cytotoxic agents induce resistance to much higher doses, is an evolutionary defence mechanism and is stimulated following challenges by numerous chemical, biological and physical agents including particularly radiation, drugs, heat and hypoxia. There is much homology in the effects of these agents which are manifest through the up-regulation of various genetic pathways. Low-dose radiation stress influences processes involved in cell-cycle control, signal transduction pathways, radiation sensitivity, changes in cell adhesion and cell growth. There is also homology between radiation and other cellular stress agents, particularly hypoxia. Whereas traditionally, hypoxia was regarded mainly as an agent conferring resistance to radiation, there is now much evidence illustrating the cytokine-like properties of hypoxia as well as radiation. Stress phenomena are likely to be important in risks arising from low doses of radiation. Conversely, exploitation of the stress response in settings appropriate to therapy can be particularly beneficial not only in regard to radiation alone but in combinations of radiation and drugs. Similarly, tissue hypoxia can be exploited in novel ways of enhancing therapeutic efficacy. Bioreductive drugs, which are cytotoxically activated in hypoxic regions of tissue, can be rendered even more effective by hypoxia-induced increased expression of enzyme reductases. Nitric oxide pathways are influenced by hypoxia thereby offering possibilities for novel vascular based therapies. Other approaches are discussed

  19. Intermittent hypoxia increases insulin resistance in genetically obese mice.

    Science.gov (United States)

    Polotsky, Vsevolod Y; Li, Jianguo; Punjabi, Naresh M; Rubin, Arnon E; Smith, Philip L; Schwartz, Alan R; O'Donnell, Christopher P

    2003-10-01

    Obstructive sleep apnoea, a syndrome that leads to recurrent intermittent hypoxia, is associated with insulin resistance in obese individuals, but the mechanisms underlying this association remain unknown. We utilized a mouse model to examine the effects of intermittent hypoxia on insulin resistance in lean C57BL/6J mice and leptin-deficient obese (C57BL/6J-Lepob) mice. In lean mice, exposure to intermittent hypoxia for 5 days (short term) resulted in a decrease in fasting blood glucose levels (from 173 +/- 11 mg dl-1 on day 0 to 138 +/- 10 mg dl-1 on day 5, P obese mice, short-term intermittent hypoxia led to a decrease in blood glucose levels accompanied by a 607 +/- 136 % (P intermittent hypoxia was completely abolished by prior leptin infusion. Obese mice exposed to intermittent hypoxia for 12 weeks (long term) developed a time-dependent increase in fasting serum insulin levels (from 3.6 +/- 1.1 ng ml-1 at baseline to 9.8 +/- 1.8 ng ml-1 at week 12, P intermittent hypoxia is dependent on the disruption of leptin pathways.

  20. Angiogenesis in calcium phosphate scaffolds by inorganic copper ion release.

    Science.gov (United States)

    Barralet, Jake; Gbureck, Uwe; Habibovic, Pamela; Vorndran, Elke; Gerard, Catherine; Doillon, Charles J

    2009-07-01

    Angiogenesis in a tissue-engineered device may be induced by incorporating growth factors (e.g., vascular endothelial growth factor [VEGF]), genetically modified cells, and=or vascular cells. It represents an important process during the formation and repair of tissue and is essential for nourishment and supply of reparative and immunological cells. Inorganic angiogenic factors, such as copper ions, are therefore of interest in the fields of regenerative medicine and tissue engineering due to their low cost, higher stability, and potentially greater safety compared with recombinant proteins or genetic engineering approaches. The purpose of this study was to compare tissue responses to 3D printed macroporous bioceramic scaffolds implanted in mice that had been loaded with either VEGF or copper sulfate. These factors were spatially localized at the end of a single macropore some 7 mm from the surface of the scaffold. Controls without angiogenic factors exhibited only poor tissue growth within the blocks; in contrast, low doses of copper sulfate led to the formation of microvessels oriented along the macropore axis. Further, wound tissue ingrowth was particularly sensitive to the quantity of copper sulfate and was enhanced at specific concentrations or in combination with VEGF. The potential to accelerate and guide angiogenesis and wound healing by copper ion release without the expense of inductive protein(s) is highly attractive in the area of tissue-engineered bone and offers significant future potential in the field of regenerative biomaterials.

  1. MicroRNA-9 Couples Brain Neurogenesis and Angiogenesis

    Directory of Open Access Journals (Sweden)

    Romain Madelaine

    2017-08-01

    Full Text Available In the developing brain, neurons expressing VEGF-A and blood vessels grow in close apposition, but many of the molecular pathways regulating neuronal VEGF-A and neurovascular system development remain to be deciphered. Here, we show that miR-9 links neurogenesis and angiogenesis through the formation of neurons expressing VEGF-A. We found that miR-9 directly targets the transcription factors TLX and ONECUTs to regulate VEGF-A expression. miR-9 inhibition leads to increased TLX and ONECUT expression, resulting in VEGF-A overexpression. This untimely increase of neuronal VEGF-A signal leads to the thickening of blood vessels at the expense of the normal formation of the neurovascular network in the brain and retina. Thus, this conserved transcriptional cascade is critical for proper brain development in vertebrates. Because of this dual role on neural stem cell proliferation and angiogenesis, miR-9 and its downstream targets are promising factors for cellular regenerative therapy following stroke and for brain tumor treatment.

  2. ANGIOGENESIS INHIBITORS FOR THE TREATMENT OF HEPATOCELLULAR CARCINOMA

    Directory of Open Access Journals (Sweden)

    Massimiliano Berretta

    2016-11-01

    Full Text Available Background: Angiogenesis inhibitors have become an important therapeutic approach in the treatment of hepatocellular carcinoma (HCC patients. The achievement of Sorafenib in prolonging overall survival of patients with HCC makes therapeutic inhibition of angiogenesis a fundamental element of the treatment of HCC. Considering the heterogeneous aspects of HCC and to enhance therapeutic efficacy, overcome drug resistance and reduce toxicity, the combination of antiangiogenic drugs with antiblastic chemotherapy (AC, radiotherapy or other targeted drugs have been evaluated. The issue is further complicated by the combination of antiangiogenesis with other AC or biologic drugs. To date, there is no planned approach to determine which patients are more responsive to a given type of antiangiogenic treatment. Conclusion: Large investments in the clinical research are essential to improve treatment response and minimize toxicities for patients with HCC. Future investigations will need to focus on utilizing patterns of genetic information to classify HCC into groups that display similar prognosis and treatment sensitivity, and combining targeted therapies with AC producing enhanced anti-tumor effect. In this review the current panel of available antiangiogenic therapies for the treatment of HCC have been analyzed. In addition current clinical trials are also reported herein.

  3. WNT Signaling Is Required for Peritoneal Membrane Angiogenesis.

    Science.gov (United States)

    Padwal, Manreet Kaur; Cheng, Genyang; Liu, Limin; Boivin, Felix J; Gangji, Azim; Brimble, Kenneth Scott; Bridgewater, Darren; Margetts, Peter J

    2018-01-24

    The WNT signaling pathway is involved in wound healing and fibrosis. We evaluated the WNT signaling pathway in peritoneal membrane injury. We assessed WNT1 protein expression in the peritoneal effluents of 54 stable peritoneal dialysis (PD) patients and WNT-related gene expression in ex vivo mesothelial cell cultures from 21 PD patients. In a transforming growth factor beta (TGFB) mediated animal model of peritoneal fibrosis, we evaluated regulation of the WNT pathway and the effect of WNT inhibition on peritoneal fibrosis and angiogenesis. WNT1 and WNT2 gene expression were positively correlated with peritoneal membrane solute transport in PD patients. In the mouse peritoneum, TGFΒ-induced peritoneal fibrosis was associated with increased expression of WNT2 and WNT4. Peritoneal b-catenin protein was significantly upregulated after infection with AdTGFB along with elements of the WNT signaling pathway. Treatment with a b-catenin inhibitor (ICG-001) in mice with AdTGFB-induced peritoneal fibrosis resulted in attenuation of peritoneal angiogenesis and reduced vascular endothelial growth factor. Similar results were also observed with the WNT antagonist Dickkopf related protein (DKK) 1. In addition to this, DKK-1 blocked epithelial to mesenchymal transition and increased levels of the cell adhesion protein E-cadherin. We provide evidence that WNT signaling is active in the setting of experimental peritoneal fibrosis and WNT1 correlates with patient peritoneal membrane solute transport in PD patients. Intervention in this pathway is a possible therapy for peritoneal membrane injury.

  4. Abnormalities in the Regulators of Angiogenesis in Patients with Scleroderma

    Science.gov (United States)

    HUMMERS, LAURA K.; HALL, AMY; WIGLEY, FREDRICK M.; SIMONS, MICHAEL

    2014-01-01

    Objective To determine plasma levels of regulators of angiogenesis in patients with scleroderma and to correlate those levels with manifestations of scleroderma-related vascular disease. Methods Plasma levels of vascular endothelial growth factor (VEGF), platelet-derived growth factor (PDGF), fibroblast growth factor-2 (FGF-2), matrix metalloproteinase-9 (MMP-9), endostatin, pro-MMP-1, hepatocyte growth factor (HGF), placental growth factor (PlGF), and FGF-4 were examined by ELISA in a cross-sectional study of 113 patients with scleroderma and 27 healthy controls. Simple and multivariate regression models were used to look for associations between factor levels and clinical disease characteristics. Results There were marked differences in the levels of pro-angiogenic growth factors between patients with scleroderma and controls, with significant elevations of VEGF, PDGF, FGF-2, and PlGF among patients with scleroderma (p scleroderma patients compared to controls (MMP-9 and pro-MMP-1) (p scleroderma, but had a positive correlation with right ventricular systolic pressure (RVSP) as measured by echocardiogram (p scleroderma (p scleroderma. The levels of some factors correlate with measures of vascular disease among patients with scleroderma. Dysregulated angiogenesis may play a role in the development of scleroderma vascular disease. PMID:19228661

  5. Uncaria rhynchophylla induces angiogenesis in vitro and in vivo.

    Science.gov (United States)

    Choi, Do-Young; Huh, Jeong-Eun; Lee, Jae-Dong; Cho, Eun-Mi; Baek, Yong-Hyeon; Yang, Ha-Ru; Cho, Yoon-Je; Kim, Kang-Il; Kim, Deog-Yoon; Park, Dong-Suk

    2005-12-01

    Angiogenesis consists of the proliferation, migration, and differentiation of endothelial cells, and angiogenic factors and matrix protein interactions modulate this process. The aim of this study was to determine the angiogenic properties of Uncaria rhynchophylla. Uncaria rhynchophylla significantly enhanced human umbilical vein endothelial cells (HUVECs) proliferation in a dose-dependent manner. Neutralization of vascular endothelial growth factor (VEGF) or basic fibroblast growth factor (bFGF) by monoclonal antibody suppressed the Uncaria rhynchophylla stimulatory effect on proliferation. In addition, Uncaria rhynchophylla significantly increased chemotactic-migration on gelatin and tubular structures on Matrigel of HUVECs in a dose-dependent manner. Interestingly, Uncaria rhynchophylla dose-dependently increased VEGF, and bFGF gene expression and protein secretion of HUVEC. The angiogenic activity of Uncaria rhynchophylla was confirmed using an in vivo Matrigel angiogenesis model, showing promotion of blood vessel formation. These results suggest that Uncaria rhynchophylla could potentially used to accelerate vascular wound healing or to promote the growth of collateral blood vessel in ischemic tissues.

  6. BAG3 controls angiogenesis through regulation of ERK phosphorylation.

    Science.gov (United States)

    Falco, A; Festa, M; Basile, A; Rosati, A; Pascale, M; Florenzano, F; Nori, S L; Nicolin, V; Di Benedetto, M; Vecchione, M L; Arra, C; Barbieri, A; De Laurenzi, V; Turco, M C

    2012-12-13

    BAG3 is a co-chaperone of the heat shock protein (Hsp) 70, is expressed in many cell types upon cell stress, however, its expression is constitutive in many tumours. We and others have previously shown that in neoplastic cells BAG3 exerts an anti-apoptotic function thus favoring tumour progression. As a consequence we have proposed BAG3 as a target of antineoplastic therapies. Here we identify a novel role for BAG3 in regulation of neo-angiogenesis and show that its downregulation results in reduced angiogenesis therefore expanding the role of BAG3 as a therapeutical target. In brief we show that BAG3 is expressed in endothelial cells and is essential for the interaction between ERK and its phosphatase DUSP6, as a consequence its removal results in reduced binding of DUSP6 to ERK and sustained ERK phosphorylation that in turn determines increased levels of p21 and p15 and cell-cycle arrest in the G1 phase.

  7. The radiation response of cells recovering after chronic hypoxia

    International Nuclear Information System (INIS)

    Kwok, T.T.; Sutherland, R.M.

    1989-01-01

    Experiments were performed to study the influence of hypoxic pretreatment on the radiation response of A431 human squamous carcinoma cells. Reaeration for 10 min after chronic hypoxia (greater than 2 h) was found to enhance the radiosensitivity of A431 cells, and the maximal effect was seen for those cells reaerated after 12 h of hypoxia. The radiosensitivity enhancement for reaerated cells after 12 h of hypoxia was maximized by 5 min after the return to aerobic conditions and reached the control level by 12 h of reaeration. This enhanced radiosensitive state was characterized by a reduced shoulder region and increased slope of the radiation dose-response curve for cells in both the exponential and plateau phases of growth. There was a slight increase in the number of G1 and decrease in the number of S and G2 + M cells for both exponential- and plateau-phase cultures following 12 h hypoxic treatment. Although growth inhibition induced by 12 h of hypoxia was seen for cells in the exponential phase, there was no cell number change in the plateau-phase culture after hypoxia. Plating efficiency (PE) of cells in both growth phases was reduced by 30% after hypoxia. Furthermore, in the exponential-phase culture, the extent of reduction in PE after hypoxia was similar among cells in different phases of the cell cycle. Although S-phase cells in exponentially growing cultures were relatively more resistant to radiation than G1 and G2 + M cells, the cell age-response pattern was the same whether the cells had been aerobic or hypoxic before reaeration and irradiation. Furthermore, the enhancement ratio associated with reaeration after 12 h of hypoxia for these three subpopulations of cells was 1.3. Our results indicate that the increase in radiosensitivity due to reaeration after chronic hypoxia is unlikely to be related to the changes of cell cycle stage and growth phase during hypoxic treatment

  8. Serum inter-alpha-trypsin inhibitor and matrix hyaluronan promote angiogenesis in fibrotic lung injury.

    Science.gov (United States)

    Garantziotis, Stavros; Zudaire, Enrique; Trempus, Carol S; Hollingsworth, John W; Jiang, Dianhua; Lancaster, Lisa H; Richardson, Elizabeth; Zhuo, Lisheng; Cuttitta, Frank; Brown, Kevin K; Noble, Paul W; Kimata, Koji; Schwartz, David A

    2008-11-01

    The etiology and pathogenesis of angiogenesis in idiopathic pulmonary fibrosis (IPF) is poorly understood. Inter-alpha-trypsin inhibitor (IaI) is a serum protein that can bind to hyaluronan (HA) and may contribute to the angiogenic response to tissue injury. To determine whether IaI promotes HA-mediated angiogenesis in tissue injury. An examination was undertaken of angiogenesis in IaI-sufficient and -deficient mice in the bleomycin model of pulmonary fibrosis and in angiogenesis assays in vivo and in vitro. IaI and HA in patients with IPF were examined. IaI significantly enhances the angiogenic response to short-fragment HA in vivo and in vitro. lal deficiency Ieads to decreased angiogenesis in the matrigel model, and decreases lung angiogenesis after bleomycin exposure in mice. IaI is found in fibroblastic foci in IPF, where it colocalizes with HA. The colocalization is particularly strong in vascular areas around fibroblastic foci. Serum levels of IaI and HA are significantly elevated in patients with IPF compared with control subjects. High serum IaI and HA levels are associated with decreased lung diffusing capacity, but not FVC. Our findings indicate that serum IaI interacts with HA, and promotes angiogenesis in lung injury. IaI appears to contribute to the vascular response to lung injury and may lead to aberrant angiogenesis. Clinical trial registered with www.clinicaltrials.gov (NCT00016627).

  9. Serum Inter–α-Trypsin Inhibitor and Matrix Hyaluronan Promote Angiogenesis in Fibrotic Lung Injury

    Science.gov (United States)

    Garantziotis, Stavros; Zudaire, Enrique; Trempus, Carol S.; Hollingsworth, John W.; Jiang, Dianhua; Lancaster, Lisa H.; Richardson, Elizabeth; Zhuo, Lisheng; Cuttitta, Frank; Brown, Kevin K.; Noble, Paul W.; Kimata, Koji; Schwartz, David A.

    2008-01-01

    Rationale: The etiology and pathogenesis of angiogenesis in idiopathic pulmonary fibrosis (IPF) is poorly understood. Inter-α-trypsin inhibitor (IaI) is a serum protein that can bind to hyaluronan (HA) and may contribute to the angiogenic response to tissue injury. Objectives: To determine whether IaI promotes HA-mediated angiogenesis in tissue injury. Methods: An examination was undertaken of angiogenesis in IaI-sufficient and -deficient mice in the bleomycin model of pulmonary fibrosis and in angiogenesis assays in vivo and in vitro. IaI and HA in patients with IPF were examined. Measurements and Main Results: IaI significantly enhances the angiogenic response to short-fragment HA in vivo and in vitro. lal deficiency Ieads to decreased angiogenesis in the matrigel model, and decreases lung angiogenesis after bleomycin exposure in mice. IaI is found in fibroblastic foci in IPF, where it colocalizes with HA. The colocalization is particularly strong in vascular areas around fibroblastic foci. Serum levels of IaI and HA are significantly elevated in patients with IPF compared with control subjects. High serum IaI and HA levels are associated with decreased lung diffusing capacity, but not FVC. Conclusions: Our findings indicate that serum IaI interacts with HA, and promotes angiogenesis in lung injury. IaI appears to contribute to the vascular response to lung injury and may lead to aberrant angiogenesis. Clinical trial registered with www.clinicaltrials.gov (NCT00016627). PMID:18703791

  10. Angiogenesis in Balb/c mice under beta-carotene supplementation in diet

    NARCIS (Netherlands)

    Razny, U.; Polus, P.; Kiec-wilk, B.; Wator, L.; Hartwich, J.; Keijer, J.

    2010-01-01

    Angiogenesis is a process of new blood vessel formation from pre-existing ones. The most important steps in angiogenesis include detachment, proliferation, migration, homing and differentiation of vascular wall cells, which are mainly endothelial cells and their progenitors. The study focused on the

  11. Human IgG1 antibodies suppress angiogenesis in a target-independent manner

    NARCIS (Netherlands)

    Bogdanovich, Sasha; Kim, Younghee; Mizutani, Takeshi; Yasuma, Reo; Tudisco, Laura; Cicatiello, Valeria; Bastos-Carvalho, Ana; Kerur, Nagaraj; Hirano, Yoshio; Baffi, Judit Z; Tarallo, Valeria; Li, Shengjian; Yasuma, Tetsuhiro; Arpitha, Parthasarathy; Fowler, Benjamin J; Wright, Charles B; Apicella, Ivana; Greco, Adelaide; Brunetti, Arturo; Ruvo, Menotti; Sandomenico, Annamaria; Nozaki, Miho; Ijima, Ryo; Kaneko, Hiroki; Ogura, Yuichiro; Terasaki, Hiroko; Ambati, Balamurali K; Leusen, Jeanette HW; Langdon, Wallace Y; Clark, Michael R; Armour, Kathryn L; Bruhns, Pierre; Verbeek, J Sjef; Gelfand, Bradley D; De Falco, Sandro; Ambati, Jayakrishna

    2016-01-01

    Aberrant angiogenesis is implicated in diseases affecting nearly 10% of the world's population. The most widely used anti-angiogenic drug is bevacizumab, a humanized IgG1 monoclonal antibody that targets human VEGFA. Although bevacizumab does not recognize mouse Vegfa, it inhibits angiogenesis in

  12. Effects of amelogenins on angiogenesis-associated processes of endothelial cells

    DEFF Research Database (Denmark)

    Almqvist, S; Kleinman, H K; Werthén, M

    2011-01-01

    To study the effects of an amelogenin mixture on integrin-dependent adhesion, DNA synthesis and apoptosis of cultured human dermal microvascular endothelial cells and angiogenesis in an organotypic assay.......To study the effects of an amelogenin mixture on integrin-dependent adhesion, DNA synthesis and apoptosis of cultured human dermal microvascular endothelial cells and angiogenesis in an organotypic assay....

  13. Endothelial-Rac1 is not required for tumor angiogenesis unless alphavbeta3-integrin is absent.

    Directory of Open Access Journals (Sweden)

    Gabriela D'Amico

    2010-03-01

    Full Text Available Endothelial cell migration is an essential aspect of tumor angiogenesis. Rac1 activity is needed for cell migration in vitro implying a requirement for this molecule in angiogenesis in vivo. However, a precise role for Rac1 in tumor angiogenesis has never been addressed. Here we show that depletion of endothelial Rac1 expression in adult mice, unexpectedly, has no effect on tumor growth or tumor angiogenesis. In addition, repression of Rac1 expression does not inhibit VEGF-mediated angiogenesis in vivo or ex vivo, nor does it affect chemotactic migratory responses to VEGF in 3-dimensions. In contrast, the requirement for Rac1 in tumor growth and angiogenesis becomes important when endothelial beta3-integrin levels are reduced or absent: the enhanced tumor growth, tumor angiogenesis and VEGF-mediated responses in beta3-null mice are all Rac1-dependent. These data indicate that in the presence of alphavbeta3-integrin Rac1 is not required for tumor angiogenesis.

  14. Canonical hedgehog signaling augments tumor angiogenesis by induction of VEGF-A in stromal perivascular cells

    Science.gov (United States)

    Chen, Weiwei; Tang, Tracy; Eastham-Anderson, Jeff; Dunlap, Debra; Alicke, Bruno; Nannini, Michelle; Gould, Stephen; Yauch, Robert; Modrusan, Zora; DuPree, Kelly J.; Darbonne, Walter C.; Plowman, Greg; de Sauvage, Frederic J.; Callahan, Christopher A.

    2011-01-01

    Hedgehog (Hh) signaling is critical to the patterning and development of a variety of organ systems, and both ligand-dependent and ligand-independent Hh pathway activation are known to promote tumorigenesis. Recent studies have shown that in tumors promoted by Hh ligands, activation occurs within the stromal microenvironment. Testing whether ligand-driven Hh signaling promotes tumor angiogenesis, we found that Hh antagonism reduced the vascular density of Hh-producing LS180 and SW480 xenografts. In addition, ectopic expression of sonic hedgehog in low-Hh–expressing DLD-1 xenografts increased tumor vascular density, augmented angiogenesis, and was associated with canonical Hh signaling within perivascular tumor stromal cells. To better understand the molecular mechanisms underlying Hh-mediated tumor angiogenesis, we established an Hh-sensitive angiogenesis coculture assay and found that fibroblast cell lines derived from a variety of human tissues were Hh responsive and promoted angiogenesis in vitro through a secreted paracrine signal(s). Affymetrix array analyses of cultured fibroblasts identified VEGF-A, hepatocyte growth factor, and PDGF-C as candidate secreted proangiogenic factors induced by Hh stimulation. Expression studies of xenografts and angiogenesis assays using combinations of Hh and VEGF-A inhibitors showed that it is primarily Hh-induced VEGF-A that promotes angiogenesis in vitro and augments tumor-derived VEGF to promote angiogenesis in vivo. PMID:21597001

  15. Angiogenesis is not impaired in connective tissue growth factor (CTGF) knock-out mice

    NARCIS (Netherlands)

    Kuiper, Esther J.; Roestenberg, Peggy; Ehlken, Christoph; Lambert, Vincent; van Treslong-de Groot, Henny Bloys; Lyons, Karen M.; Agostini, Hans-Jürgen T.; Rakic, Jean-Marie; Klaassen, Ingeborg; van Noorden, Cornelis J. F.; Goldschmeding, Roel; Schlingemann, Reinier O.

    2007-01-01

    Connective tissue growth factor (CTGF) is a member of the CCN family of growth factors. CTGF is important in scarring, wound healing, and fibrosis. It has also been implicated to play a role in angiogenesis, in addition to vascular endothelial growth factor (VEGF). In the eye, angiogenesis and

  16. The effect of altitude hypoxia on glucose homeostasis in men

    DEFF Research Database (Denmark)

    Larsen, J J; Hansen, J M; Olsen, Niels Vidiendal

    1997-01-01

    1. Exposure to altitude hypoxia elicits changes in glucose homeostasis with increases in glucose and insulin concentrations within the first few days at altitude. Both increased and unchanged hepatic glucose production (HGP) have previously been reported in response to acute altitude hypoxia...... (noradrenaline and adrenaline) and day 7 (adrenaline), but not at sea level. 4. In conclusion, insulin action decreases markedly in response to two days of altitude hypoxia, but improves with more prolonged exposure. HGP is always unchanged. The changes in insulin action may in part be explained by the changes...

  17. Endogenous markers of tumor hypoxia. Predictors of clinical radiation resistance?

    Energy Technology Data Exchange (ETDEWEB)

    Vordermark, D. [Dept. of Radiation Oncology, Univ. of Wuerzburg (Germany); Dept. of Radiation Oncology, Stanford Univ. School of Medicine, Stanford, CA (United States); Brown, J.M. [Dept. of Radiation Oncology, Stanford Univ. School of Medicine, Stanford, CA (United States)

    2003-12-01

    Background: Eppendorf electrode measurements of tumor oxygenation have defined an adverse effect of tumor hypoxia on prognosis after radiotherapy and other treatment modalities, in particular in head and neck and cervix carcinomas as well as soft tissue sarcomas. Recently, the immunohistochemical detection of proteins involved in the ''hypoxic response'' of tumor cells has been discussed as a method to estimate hypoxia in clinical tumor specimens. Material and Methods: This review focuses on clinical and experimental data, regarding prognostic impact and comparability with other methods of hypoxia detection, for three proteins suggested as endogenous markers of tumor hypoxia: hypoxia-inducible factor-1{alpha} (HIF-1{alpha}), carbonic anhydrase 9 (CA 9), and glucose transporter 1 (GLUT1). Results: None of the three potential hypoxia markers is exclusively hypoxia-specific, and in each case protein can be detected under normoxic conditions in vitro. HIF-1{alpha} responds rapidly to hypoxia but also to reoxygenation, making this marker quite unstable in the context of clinical sample collection. The perinecrotic labeling pattern typical of chronic hypoxia and a reasonable agreement with injectable hypoxia markers such as pimonidazole have most consistently been described for CA 9. All three markers showed correlation with Eppendorf electrode measurements of tumor oxygenation in carcinoma of the cervix. In nine of 13 reports, among them all three that refer to curative radiotherapy for head and neck cancer, HIF-1{alpha} overexpression was associated with poor outcome. CA 9 was an adverse prognostic factor in cervix, head and neck and lung cancer, but not in two other head and neck cancer reports. GLUT1 predicted for poor survival in colorectal, cervix and lung cancer. Conclusion: Endogenous markers have the potential to indicate therapeutically relevant levels of hypoxia within tumors. Clinical trials assessing a marker's ability to predict a

  18. Culture media from hypoxia conditioned endothelial cells protect human intestinal cells from hypoxia/reoxygenation injury.

    Science.gov (United States)

    Hummitzsch, Lars; Zitta, Karina; Bein, Berthold; Steinfath, Markus; Albrecht, Martin

    2014-03-10

    Remote ischemic preconditioning (RIPC) is a phenomenon, whereby short episodes of non-lethal ischemia to an organ or tissue exert protection against ischemia/reperfusion injury in a distant organ. However, there is still an apparent lack of knowledge concerning the RIPC-mediated mechanisms within the target organ and the released factors. Here we established a human cell culture model to investigate cellular and molecular effects of RIPC and to identify factors responsible for RIPC-mediated intestinal protection. Human umbilical vein cells (HUVEC) were exposed to repeated episodes of hypoxia (3 × 15 min) and conditioned culture media (CM) were collected after 24h. Human intestinal cells (CaCo-2) were cultured with or without CM and subjected to 90 min of hypoxia/reoxygenation injury. Reverse transcription-polymerase chain reaction, Western blotting, gelatin zymography, hydrogen peroxide measurements and lactate dehydrogenase (LDH) assays were performed. In HUVEC cultures hypoxic conditioning did not influence the profile of secreted proteins but led to an increased gelatinase activity (Pcultures 90 min of hypoxia/reoxygenation resulted in morphological signs of cell damage, increased LDH levels (Pculture model may help to unravel RIPC-mediated cellular events and to identify molecules released by RIPC. Copyright © 2014 Elsevier Inc. All rights reserved.

  19. Celecoxib ameliorates portal hypertension of the cirrhotic rats through the dual inhibitory effects on the intrahepatic fibrosis and angiogenesis.

    Directory of Open Access Journals (Sweden)

    Jin-Hang Gao

    Full Text Available BACKGROUND: Increased intra-hepatic resistance to portal blood flow is the primary factor leading to portal hypertension in cirrhosis. Up-regulated expression of cyclooxygenase-2 (COX-2 in the cirrhotic liver might be a potential target to ameliorate portal hypertension. OBJECTIVE: To verify the effect of celecoxib, a selective inhibitor of COX-2, on portal hypertension and the mechanisms behind it. METHODS: Cirrhotic liver model of rat was established by peritoneal injection of thiacetamide (TAA. 36 rats were randomly assigned to control, TAA and TAA+celecoxib groups. Portal pressures were measured by introduction of catheters into portal vein. Hepatic fibrosis was assessed by the visible hepatic fibrotic areas and mRNAs for collagen III and α-SMA. The neovasculature was determined by hepatic vascular areas, vascular casts and CD31 expression. Expressions of COX-2, vascular endothelial growth factor (VEGF, VEGF receptor-2 (VEGFR-2 and related signal molecules were quantitated. RESULTS: Compared with TAA group, the portal pressure in TAA+celecoxib group was significantly decreased by 17.8%, p<0.01. Celecoxib treatment greatly reduced the tortuous hepatic portal venules. The data of fibrotic areas, CD31expression, mRNA levels of α-SMA and collagen III in TAA+celecoxib group were much lower than those in TAA group, p<0.01. Furthermore, the up-regulation of hepatic mRNA and protein levels of VEGF, VEGFR-2 and COX-2 induced by TAA was significantly inhibited after celecoxib treatment. The expressions of prostaglandin E2 (PGE2, phosphorylated extracellular signal-regulated kinase (p-ERK, hypoxia-inducible factor-1α (HIF-1α, and c-fos were also down-regulated after celecoxib treatment. CONCLUSIONS: Long term administration of celecoxib can efficiently ameliorate portal hypertension in TAA rat model by its dual inhibitory effects on the intrahepatic fibrosis and angiogenesis. The anti-angiogenesis effect afforded by celecoxib may attribute to its

  20. Evaluation of Functionalized Porous Titanium Implants for Enhancing Angiogenesis in Vitro

    Directory of Open Access Journals (Sweden)

    Laura Roland

    2016-04-01

    Full Text Available Implant constructs supporting angiogenesis are favorable for treating critically-sized bone defects, as ingrowth of capillaries towards the center of large defects is often insufficient. Consequently, the insufficient nutritional supply of these regions leads to impaired bone healing. Implants with specially designed angiogenic supporting geometry and functionalized with proangiogenic cytokines can enhance angiogenesis. In this study, Vascular Endothelial Growth Factor (VEGF and High Mobility Group Box 1 (HMGB1 were used for incorporation into poly-ε-caprolactone (PCL-coated porous titanium implants. Bioactivity of released factors and influence on angiogenesis of functionalized implants were evaluated using a migration assay and angiogenesis assays. Both implants released angiogenic factors, inducing migration of endothelial cells. Also, VEGF-functionalized PCL-coated titanium implants enhanced angiogenesis in vitro. Both factors were rapidly released in high doses from the implant coating during the first 72 h.

  1. Hypoxia-Inducible Factor 3 Is an Oxygen-Dependent Transcription Activator and Regulates a Distinct Transcriptional Response to Hypoxia

    Directory of Open Access Journals (Sweden)

    Peng Zhang

    2014-03-01

    Full Text Available Hypoxia-inducible factors (HIFs play key roles in the cellular response to hypoxia. It is widely accepted that whereas HIF-1 and HIF-2 function as transcriptional activators, HIF-3 inhibits HIF-1/2α action. Contrary to this idea, we show that zebrafish Hif-3α has strong transactivation activity. Hif-3α is degraded under normoxia. Mutation of P393, P493, and L503 inhibits this oxygen-dependent degradation. Transcriptomics and chromatin immunoprecipitation analyses identify genes that are regulated by Hif-3α, Hif-1α, or both. Under hypoxia or when overexpressed, Hif-3α binds to its target gene promoters and upregulates their expression. Dominant-negative inhibition and knockdown of Hif-3α abolish hypoxia-induced Hif-3α-promoter binding and gene expression. Hif-3α not only mediates hypoxia-induced growth and developmental retardation but also possesses hypoxia-independent activities. Importantly, transactivation activity is conserved and human HIF-3α upregulates similar genes in human cells. These findings suggest that Hif-3 is an oxygen-dependent transcription factor and activates a distinct transcriptional response to hypoxia.

  2. A preclinical model for noninvasive imaging of hypoxia-induced gene expression; comparison with an exogenous marker of tumor hypoxia

    Energy Technology Data Exchange (ETDEWEB)

    Wen Bixiu; Burgman, Paul; Zanzonico, Pat; O' Donoghue, Joseph; Li, Gloria C.; Ling, C. Clifton [Memorial Sloan-Kettering Cancer Center, Department of Medical Physics, New York (United States); Cai Shangde; Finn, Ron [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York (United States); Serganova, Inna [Memorial Sloan-Kettering Cancer Center, Department of Neurology, New York (United States); Blasberg, Ronald; Gelovani, Juri [Memorial Sloan-Kettering Cancer Center, Department of Radiology, New York (United States); Memorial Sloan-Kettering Cancer Center, Department of Neurology, New York (United States)

    2004-11-01

    Hypoxia is associated with tumor aggressiveness and is an important cause of resistance to radiation therapy and chemotherapy. Assays of tumor hypoxia could provide selection tools for hypoxia-modifying treatments. The purpose of this study was to develop and characterize a rodent tumor model with a reporter gene construct that would be transactivated by the hypoxia-inducible molecular switch, i.e., the upregulation of HIF-1. The reporter gene construct is the herpes simplex virus 1-thymidine kinase (HSV1-tk) fused with the enhanced green fluorescent protein (eGFP) under the regulation of an artificial hypoxia-responsive enhancer/promoter. In this model, tumor hypoxia would up-regulate HIF-1, and through the hypoxia-responsive promoter transactivate the HSV1-tkeGFPfusion gene. The expression of this reporter gene can be assessed with the {sup 124}I-labeled reporter substrate 2'-fluoro-2'-deoxy-1-{beta}-d-arabinofuranosyl-5-iodouracil ({sup 124}I-FIAU), which is phosphorylated by the HSV1-tk enzyme and trapped in the hypoxic cells. Animal positron emission tomography (microPET) and phosphor plate imaging (PPI) were used in this study to visualize the trapped {sup 124}I-FIAU, providing a distribution of the hypoxia-induced molecular events. The distribution of {sup 124}I-FIAU was also compared with that of an exogenous hypoxic cell marker, {sup 18}F-fluoromisonidazole (FMISO). Our results showed that {sup 124}I-FIAU microPET imaging of the hypoxia-induced reporter gene expression is feasible, and that the intratumoral distributions of {sup 124}I-FIAU and {sup 18}F-FMISO are similar. In tumor sections, detailed radioactivity distributions were obtained with PPI which also showed similarity between {sup 124}I-FIAU and {sup 18}F-FMISO. This reporter system is sufficiently sensitive to detect hypoxia-induced transcriptional activation by noninvasive imaging and might provide a valuable tool in studying tumor hypoxia and in validating existing and future

  3. Chronic mild hypoxia promotes profound vascular remodeling in spinal cord blood vessels, preferentially in white matter, via an α5β1 integrin-mediated mechanism.

    Science.gov (United States)

    Halder, Sebok K; Kant, Ravi; Milner, Richard

    2018-05-01

    Spinal cord injury (SCI) leads to rapid destruction of neuronal tissue, resulting in devastating motor and sensory deficits. This is exacerbated by damage to spinal cord blood vessels and loss of vascular integrity. Thus, approaches that protect existing blood vessels or stimulate the growth of new blood vessels might present a novel approach to minimize loss or promote regeneration of spinal cord tissue following SCI. In light of the remarkable power of chronic mild hypoxia (CMH) to stimulate vascular remodeling in the brain, the goal of this study was to examine how CMH (8% O 2 for up to 7 days) affects blood vessel remodeling in the spinal cord. We found that CMH promoted the following: (1) endothelial proliferation and increased vascularity as a result of angiogenesis and arteriogenesis, (2) increased vascular expression of the angiogenic extracellular matrix protein fibronectin as well as concomitant increases in endothelial expression of the fibronectin receptor α5β1 integrin, (3) strongly upregulated endothelial expression of the tight junction proteins claudin-5, ZO-1 and occludin and (4) astrocyte activation. Of note, the vascular remodeling changes induced by CMH were more extensive in white matter. Interestingly, hypoxic-induced vascular remodeling in spinal cord blood vessels was markedly attenuated in mice lacking endothelial α5 integrin expression (α5-EC-KO mice). Taken together, these studies demonstrate the considerable remodeling potential of spinal cord blood vessels and highlight an important angiogenic role for the α5β1 integrin in promoting endothelial proliferation. They also imply that stimulation of the α5β1 integrin or controlled use of mild hypoxia might provide new approaches for promoting angiogenesis and improving vascular integrity in spinal cord blood vessels.

  4. HIF-2α mediates a marked increase in migration and stemness characteristics in a subset of glioma cells under hypoxia by activating an Oct-4/Sox-2-Mena (INV) axis.

    Science.gov (United States)

    Bhagat, Mohita; Palanichamy, Jayanth Kumar; Ramalingam, Pradeep; Mudassir, Madeeha; Irshad, Khushboo; Chosdol, Kunzang; Sarkar, Chitra; Seth, Pankaj; Goswami, Sumanta; Sinha, Subrata; Chattopadhyay, Parthaprasad

    2016-05-01

    Hypoxia is a salient feature of most solid tumors and plays a central role in tumor progression owing to its multiple contributions to therapeutic resistance, metastasis, angiogenesis and stemness properties. Reports exist in literature about hypoxia increasing stemness characteristics and invasiveness potential of malignant cells. In order to delineate molecular crosstalk among factors driving glioma progression, we used knockdown and overexpression strategies. We have demonstrated that U87MG and A172 glioma cells inherently have a subset of cells with high migratory potential due to migration-inducing Mena transcripts. These cells also have elevated stemness markers (Sox-2 and Oct-4). There was a significant increase of number in this subset of migratory cells on exposure to hypoxia with corresponding elevation (over 1000 fold) in migration-inducing Mena transcripts. We were able to demonstrate that a HIF-2α-Sox-2/Oct-4-Mena (INV) axis that is strongly activated in hypoxia and markedly increases the migratory potential of the cells. Such cells also formed tumor spheres with greater efficiency. We have correlated our in-vitro results with human glioblastoma samples and found that hypoxia, invasiveness and stemness markers correlated well in native tumor samples. This study identifies a novel signaling mechanism mediated by HIF-2α in regulating invasiveness and stemness characteristics, suggesting that under hypoxic conditions, some tumor cells acquire more migratory potential by increased Pan Mena and Mena INV expression as a consequence of this HIF-2α mediated increase in Oct-4 and Sox-2. These properties would help the cells to form a new nidus after local invasion or metastasis. Copyright © 2016 Elsevier Ltd. All rights reserved.

  5. Targeting angiogenesis-dependent calcified neoplasms using combined polymer therapeutics.

    Directory of Open Access Journals (Sweden)

    Ehud Segal

    Full Text Available There is an immense clinical need for novel therapeutics for the treatment of angiogenesis-dependent calcified neoplasms such as osteosarcomas and bone metastases. We developed a new therapeutic strategy to target bone metastases and calcified neoplasms using combined polymer-bound angiogenesis inhibitors. Using an advanced "living polymerization" technique, the reversible addition-fragmentation chain transfer (RAFT, we conjugated the aminobisphosphonate alendronate (ALN, and the potent anti-angiogenic agent TNP-470 with N-(2-hydroxypropylmethacrylamide (HPMA copolymer through a Glycine-Glycine-Proline-Norleucine linker, cleaved by cathepsin K, a cysteine protease overexpressed at resorption sites in bone tissues. In this approach, dual targeting is achieved. Passive accumulation is possible due to the increase in molecular weight following polymer conjugation of the drugs, thus extravasating from the tumor leaky vessels and not from normal healthy vessels. Active targeting to the calcified tissues is achieved by ALN's affinity to bone mineral.The anti-angiogenic and antitumor potency of HPMA copolymer-ALN-TNP-470 conjugate was evaluated both in vitro and in vivo. We show that free and conjugated ALN-TNP-470 have synergistic anti-angiogenic and antitumor activity by inhibiting proliferation, migration and capillary-like tube formation of endothelial and human osteosarcoma cells in vitro. Evaluation of anti-angiogenic, antitumor activity and body distribution of HPMA copolymer-ALN-TNP-470 conjugate was performed on severe combined immunodeficiency (SCID male mice inoculated with mCherry-labeled MG-63-Ras human osteosarcoma and by modified Miles permeability assay. Our targeted bi-specific conjugate reduced VEGF-induced vascular hyperpermeability by 92% and remarkably inhibited osteosarcoma growth in mice by 96%.This is the first report to describe a new concept of a narrowly-dispersed combined polymer therapeutic designed to target both tumor and

  6. 2011 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  7. 2008 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  8. Radioprotective effect of exogenic hypoxia in fractionated irradiation

    International Nuclear Information System (INIS)

    Kazymbetov, P.; Yarmonenko, S.P.; Vajnson, A.A.

    1988-01-01

    During the experiments with mice it is established, that exogenic hypoxia protective effect (8%O 2 ), evaluated according to survival rate, decreases at the change from single to fractionated irradiation. Dose change factor (DCF) is equal to 1.55 and 1.22-1.31, respectively. Skin protection using exogenic hypoxia at the local fractionated irradiation is expressed more, than at the fractionated one. DCF is equal to 1.56 and 1.28, respectively. Exogenic hypoxia protection effect in the tumor is expressed rather weakly. DCF at single and fractionated irradiation constitutes 1.03 and 1.07-1.13, respectively. Due to skin preferential protection the therapeutic gain factor at irradiation under the exogenic hypoxia conditions constitutes 1.24 and 1.38-1.46, respectively, at single and fractionated irradiation

  9. 2013 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  10. Exercise performed at hypoxia influences mood state and anxiety symptoms

    Directory of Open Access Journals (Sweden)

    Jorge Fernando Tavares de Souza

    2015-06-01

    Full Text Available During hypoxia conditions, psychological states can be worsened. However, little information is available regarding the effect of physical exercise performed in hypoxia conditions on mood state and anxiety symptoms. The aim of the present study was to elucidate the acute effect of moderate physical exercise performed at hypoxia on mood states and anxiety symptoms in healthy young subjects. Ten volunteers were subjected to the following conditions: a normoxic condition (NC and a hypoxic condition (HC. They performed 45 min of physical exercise. Their anxiety symptoms and mood states were evaluated at the initial time point as well as immediately following and 30 and 60 min after the exercise session. Our results showed a significant increase in post-exercise anxiety symptoms and a significant decrease in mood scores immediately after and 30 min after exercise performed in the HC. Moderate physical activity performed at hypoxia condition increased post-exercise anxiety and worsened mood state.

  11. Elevation of hypoxia resistance with the use of gutimine

    Energy Technology Data Exchange (ETDEWEB)

    Vinogradov, V.M.; Pastushenkov, L.V.; Sumina, E.N.

    Experimental data demonstrating the protection from the adverse effects of hypoxia offered by the antioxidant gutimine and its analogs are presented. The experiments included preliminary studies of hypoxia resistance and recovery under simulated altitude, studies of circulatory hypoxia in the brain and in intrauterine fetuses, studies of myocardial ischemia during acute and chronic experiments and studies where cardiac, kidney and limb circulation is cut off. The compound was also found to be effective in cases of hemorrhagic hypotension, complex hypoxia in peritonitis, meningococcal meningitis, and the weakening of uterine muscle contractility during prolonged deliveries, and in cranial-cerebral trauma. Mechanisms of the antihypoxic action of gutimine and its analogs have been found to include the reduction of oxygen utilization, the activation of aerobic and anaerobic metabolism, the acceleration of lactate utilization, the inhibition of lipolysis in fat tissue, and stabilization of cell membranes. Clinical observations also support the experimental data.

  12. Qidantongmai Protects Endothelial Cells Against Hypoxia-Induced ...

    African Journals Online (AJOL)

    induced damage. The ability of QDTM to modulate the serum VEGF-A level may play an important role in its effects on endothelial cells. Key words: Traditional Chinese Medicine, human umbilical vein endothelial cells, hypoxia, VEGF ...

  13. 2015 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  14. 2012 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  15. 2009 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  16. Short-term hypoxia/reoxygenation activates the angiogenic pathway ...

    Indian Academy of Sciences (India)

    2013-04-20

    Apr 20, 2013 ... angiogenic pathway in the rat caudate putamen as a neuroprotective mechanism to hypoxia .... (1:3 w/v) with a homogenator (Pellet Pestle Motor Cordless, ..... showing that the capillary density in the rat cerebral cortex was.

  17. 2010 Summer Hypoxia Watch Bottom CTD Station Locations

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — The NOAA Hypoxia Watch project provides near-real-time, web-based maps of dissolved oxygen near the sea floor over the Texas-Louisiana continental shelf during a...

  18. Management of renal dysfunction following term perinatal hypoxia-ischaemia.

    LENUS (Irish Health Repository)

    Sweetman, Deirdre U

    2013-03-01

    Acute kidney injury frequently develops following the term perinatal hypoxia-ischaemia. Quantifying the degree of acute kidney injury is difficult, however, as the methods currently in use are suboptimal. Acute kidney injury management is largely supportive with little evidence basis for many interventions. This review discusses management strategies and novel biomarkers that may improve diagnosis and management of renal injury following perinatal hypoxia-ischaemia.

  19. Hypoxia as a biomarker for radioresistant cancer stem cells.

    Science.gov (United States)

    Peitzsch, Claudia; Perrin, Rosalind; Hill, Richard P; Dubrovska, Anna; Kurth, Ina

    2014-08-01

    Tumor initiation, growth and relapse after therapy are thought to be driven by a population of cells with stem cell characteristics, named cancer stem cells (CSC). The regulation of their radiation resistance and their maintenance is poorly understood. CSC are believed to reside preferentially in special microenvironmental niches located within tumor tissues. The features of these niches are of crucial importance for CSC self-renewal, metastatic potential and therapy resistance. One of the characteristics of solid tumors is occurrence of less oxygenated (hypoxic regions), which are believed to serve as so-called hypoxic niches for CSC. The purpose of this review was the critical discussion of the supportive role of hypoxia and hypoxia-related pathways during cancer progression and radiotherapy resistance and the relevance for therapeutic implications in the clinic. It is generally known since decades that hypoxia inside solid tumors impedes chemo- and radiotherapy. However, there is limited evidence to date that targeting hypoxic regions during conventional therapy is effective. Nonetheless improved hypoxia-imaging technologies and image guided individualized hypoxia targeted therapy in conjunction with the development of novel molecular targets may be able to challenge the protective effect on the tumor provided by hypoxia.

  20. Macrophage-mediated response to hypoxia in disease

    Directory of Open Access Journals (Sweden)

    Tazzyman S

    2014-11-01

    Full Text Available Simon Tazzyman,1 Craig Murdoch,2 James Yeomans,1 Jack Harrison,1 Munitta Muthana3 1Department of Oncology, 2School of Clinical Dentistry, 3Department of Infection and Immunity, University of Sheffield, Sheffield, UK Abstract: Hypoxia plays a critical role in the pathobiology of various inflamed, diseased tissues, including malignant tumors, atherosclerotic plaques, myocardial infarcts, the synovia of rheumatoid arthritic joints, healing wounds, and sites of bacterial infection. These areas of hypoxia form when the blood supply is occluded and/or the oxygen supply is unable to keep pace with cell growth and/or infiltration of inflammatory cells. Macrophages are ubiquitous in all tissues of the body and exhibit great plasticity, allowing them to perform divergent functions, including, among others, patrolling tissue, combating invading pathogens and tumor cells, orchestrating wound healing, and restoring homeostasis after an inflammatory response. The number of tissue macrophages increases markedly with the onset and progression of many pathological states, with many macrophages accumulating in avascular and necrotic areas, where they are exposed to hypoxia. Recent studies show that these highly versatile cells then respond rapidly to the hypoxia present by altering their expression of a wide array of genes. Here we review the evidence for hypoxia-driven macrophage inflammatory responses in various disease states, and how this influences disease progression and treatment. Keywords: macrophage, hypoxia, inflammation, cytokine

  1. Hypoxia tolerance in coral-reef triggerfishes (Balistidae)

    Science.gov (United States)

    Wong, Corrie C.; Drazen, Jeffrey C.; Callan, Chatham K.; Korsmeyer, Keith E.

    2018-03-01

    Despite high rates of photosynthetic oxygen production during the day, the warm waters of coral reefs are susceptible to hypoxia at night due to elevated respiration rates at higher temperatures that also reduce the solubility of oxygen. Hypoxia may be a challenge for coral-reef fish that hide in the reef to avoid predators at night. Triggerfishes (Balistidae) are found in a variety of reef habitats, but they also are known to find refuge in reef crevices and holes at night, which may expose them to hypoxic conditions. The critical oxygen tension ( P crit) was determined as the point below which oxygen uptake could not be maintained to support standard metabolic rate (SMR) for five species of triggerfish. The triggerfishes exhibited similar levels of hypoxia tolerance as other coral-reef and coastal marine fishes that encounter low oxygen levels in their environment. Two species, Rhinecanthus rectangulus and R. aculeatus, had the lowest P crit ( 3.0 kPa O2), comparable to the most hypoxia-tolerant obligate coral-dwelling gobies, while Odonus niger and Sufflamen bursa were moderately tolerant to hypoxia ( P crit 4.5 kPa), and Xanthichthys auromarginatus was intermediate ( P crit 3.7 kPa). These differences in P crit were not due to differences in oxygen demand, as all the species had a similar SMR once mass differences were taken into account. The results suggest that triggerfish species are adapted for different levels of hypoxia exposure during nocturnal sheltering within the reef.

  2. Hypoxia inhibits colonic ion transport via activation of AMP kinase.

    LENUS (Irish Health Repository)

    Collins, Danielle

    2012-02-01

    BACKGROUND AND AIMS: Mucosal hypoxia is a common endpoint for many pathological processes including ischemic colitis, colonic obstruction and anastomotic failure. Previous studies suggest that hypoxia modulates colonic mucosal function through inhibition of chloride secretion. However, the molecular mechanisms underlying this observation are poorly understood. AMP-activated protein kinase (AMPK) is a metabolic energy regulator found in a wide variety of cells and has been linked to cystic fibrosis transmembrane conductance regulator (CFTR) mediated chloride secretion in several different tissues. We hypothesized that AMPK mediates many of the acute effects of hypoxia on human and rat colonic electrolyte transport. METHODS: The fluorescent chloride indicator dye N-(ethoxycarbonylmethyl)-6-methoxyquinolinium bromide was used to measure changes in intracellular chloride concentrations in isolated single rat colonic crypts. Ussing chamber experiments in human colonic mucosa were conducted to evaluate net epithelial ion transport. RESULTS: This study demonstrates that acute hypoxia inhibits electrogenic chloride secretion via AMPK mediated inhibition of CFTR. Pre-treatment of tissues with the AMPK inhibitor 6-[4-(2-piperidin-1-yl-ethoxy)-phenyl)]-3-pyridin-4-yl-pyyrazolo [1,5-a] pyrimidine (compound C) in part reversed the effects of acute hypoxia on chloride secretion. CONCLUSION: We therefore suggest that AMPK is a key component of the adaptive cellular response to mucosal hypoxia in the colon. Furthermore, AMPK may represent a potential therapeutic target in diseased states or in prevention of ischemic intestinal injury.

  3. Radiation-induced hypoxia may perpetuate late normal tissue injury

    International Nuclear Information System (INIS)

    Vujaskovic, Zeljko; Anscher, Mitchell S.; Feng, Q.-F.; Rabbani, Zahid N.; Amin, Khalid; Samulski, Thaddeus S.; Dewhirst, Mark W.; Haroon, Zishan A.

    2001-01-01

    Purpose: The purpose of this study was to determine whether or not hypoxia develops in rat lung tissue after radiation. Methods and Materials: Fisher-344 rats were irradiated to the right hemithorax using a single dose of 28 Gy. Pulmonary function was assessed by measuring the changes in respiratory rate every 2 weeks, for 6 months after irradiation. The hypoxia marker was administered 3 h before euthanasia. The tissues were harvested at 6 weeks and 6 months after irradiation and processed for immunohistochemistry. Results: A moderate hypoxia was detected in the rat lungs at 6 weeks after irradiation, before the onset of functional or histopathologic changes. The more severe hypoxia, that developed at the later time points (6 months) after irradiation, was associated with a significant increase in macrophage activity, collagen deposition, lung fibrosis, and elevation in the respiratory rate. Immunohistochemistry studies revealed an increase in TGF-β, VEGF, and CD-31 endothelial cell marker, suggesting a hypoxia-mediated activation of the profibrinogenic and proangiogenic pathways. Conclusion: A new paradigm of radiation-induced lung injury should consider postradiation hypoxia to be an important contributing factor mediating a continuous production of a number of inflammatory and fibrogenic cytokines

  4. HRGFish: A database of hypoxia responsive genes in fishes

    Science.gov (United States)

    Rashid, Iliyas; Nagpure, Naresh Sahebrao; Srivastava, Prachi; Kumar, Ravindra; Pathak, Ajey Kumar; Singh, Mahender; Kushwaha, Basdeo

    2017-02-01

    Several studies have highlighted the changes in the gene expression due to the hypoxia response in fishes, but the systematic organization of the information and the analytical platform for such genes are lacking. In the present study, an attempt was made to develop a database of hypoxia responsive genes in fishes (HRGFish), integrated with analytical tools, using LAMPP technology. Genes reported in hypoxia response for fishes were compiled through literature survey and the database presently covers 818 gene sequences and 35 gene types from 38 fishes. The upstream fragments (3,000 bp), covered in this database, enables to compute CG dinucleotides frequencies, motif finding of the hypoxia response element, identification of CpG island and mapping with the reference promoter of zebrafish. The database also includes functional annotation of genes and provides tools for analyzing sequences and designing primers for selected gene fragments. This may be the first database on the hypoxia response genes in fishes that provides a workbench to the scientific community involved in studying the evolution and ecological adaptation of the fish species in relation to hypoxia.

  5. Curcumin and turmeric attenuate arsenic-induced angiogenesis in ovo.

    Science.gov (United States)

    Pantazis, Panayotis; Varman, Aarthi; Simpson-Durand, Cindy; Thorpe, Jessica; Ramalingam, Satish; Subramaniam, Dharmalingam; Houchen, Courtney; Ihnat, Michael; Anant, Shrikant; Ramanujam, Rama P

    2010-01-01

    Trivalent arsenic [As(III)] is currently approved by the FDA for the treatment of chronic and acute leukemias. However, As(III) has also demonstrated damaging effects on human health, including development of cardiovascular disease, diabetes, and cancer. Further, As(III) is a potent angiogenic agent. In this context, curcumin, an active ingredient in the dietary agent turmeric, has demonstrated potent antiproliferative, antiinflammatory, and antiangiogenic properties. In this report, we have shown that both curcumin and turmeric inhibit expression of vascular endothelial growth factor in HCT-116 human colon cancer cells exposed to As(III). Further, in the chicken chorioallantoic membrane assay model, treatment with low As(III) concentrations results in extensive increase in blood vessel density, which, however, is reduced in the presence of curcumin or turmeric. Collectively, the findings reported here strongly suggest that turmeric and curcumin can dramatically attenuate the process of angiogenesis induced by low As(III) concentrations.

  6. Coupling growth-factor engineering with nanotechnology for therapeutic angiogenesis.

    Science.gov (United States)

    Sinha Roy, Rituparna; Soni, Shivani; Harfouche, Rania; Vasudevan, Pooja R; Holmes, Oliver; de Jonge, Hugo; Rowe, Arthur; Paraskar, Abhimanyu; Hentschel, Dirk M; Chirgadze, Dimitri; Blundell, Tom L; Gherardi, Ermanno; Mashelkar, Raghunath A; Sengupta, Shiladitya

    2010-08-03

    Therapeutic angiogenesis is an emerging paradigm for the management of ischemic pathologies. Proangiogenic T