Article

Investigation of vascular endothelial growth factor effects on pulmonary endothelial monolayer permeability and neutrophil transmigration.

Department of Pharmacology, Conway Institute of Biomolecular and Biomedical Research, University College Dublin, Belfield, Dublin 4, Ireland.
General Pharmacology 10/2000; 35(3):149-57. DOI: 10.1016/S0306-3623(01)00102-1
Source: PubMed

ABSTRACT This study sought to determine whether vascular endothelial growth factor (VEGF)-induced permeabilisation of pulmonary endothelium to macromolecules could be related to a permissive role for neutrophil-derived VEGF in neutrophil transmigration. Treatment of human pulmonary artery endothelial cell (HPAEC) monolayers with 1, 10 or 100 ng/ml VEGF for 15 min or 1, 10 ng/ml for 90 min significantly increased endothelial permeability to trypan blue-labelled albumin (TB-BSA). These increases were correlated with changes in the cellular distribution of F-actin, as visualised by rhodamine-phalloidin staining: increased stress fibre formation, cellular elongation and formation of intercellular gaps after 15 min; at 90 min, there was also evidence of microspike formation and extension of spindle processes from the cell surface. Treatment of human neutrophil suspensions with 200 nM phorbol myristyl acetate (PMA), n-formyl-methionyl leucylphenylalanine (fMLP, 10 nM), interleukin-8 (IL-8, 10 nM) (but not with leukotriene B(4) (LTB(4)) 100 nM), for 30 min caused significant extracellular release of neutrophil VEGF stores. A permissive role for neutrophil-derived VEGF in facilitating migration across HPAEC monolayers was assessed in experiments using a functional blocking antihuman VEGF antibody. In the presence of this antibody (10 microg/ml), neutrophil migration in response to fMLP (10 nM), IL-8 (10 nM) or LTB(4) (100 nM) was not significantly different to that in the absence of antibody. We conclude that neutrophil-derived VEGF does not play a functional role in facilitating neutrophil migration across pulmonary vascular endothelium, despite its ability to induce cytoskeletal changes and enhance endothelial macromolecular permeability.

0 Bookmarks
 · 
40 Views
  • [Show abstract] [Hide abstract]
    ABSTRACT: Both pregnancy and diabetes are thought to predispose to the impairment of oral health. As saliva contributes to oral homeostasis, we have characterised its properties and flow rate in pregnant women with or without diabetes. Unstimulated whole mixed saliva was collected from 63 women in the first trimester of pregnancy and analysed for the concentration of selected antioxidants, cytokines, and growth factors. Pregnant women with diabetes were found to have markedly increased indexes of caries activity, plaque formation, gingival and periodontal status, as well as increased salivary antioxidant capacity and pro-inflammatory cytokine levels. These changes were more pronounced in patients with long-term disease and systemic diabetic complications, but only partly correlated with the level of blood glycated haemoglobin. Of the cytokines examined, salivary VEGF and HGF concentrations in diabetic pregnant women correlated in a positive and negative manner, respectively, with the prevalence of caries. Moreover, VEGF levels in this group correlated inversely with the probing depth and clinical attachment levels. All such associations did not occur in healthy individuals. In contrast, the salivary pH and flow rate correlated inversely with several parameters of caries and plaque formation irrespectively of whether the pregnant women were diabetic or not. Diabetes in pregnant women significantly changes saliva properties, which may contribute to accelerated deterioration of the oral status in this population.
    Archives of oral biology 12/2010; 56(5):428-36. · 1.65 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Angiogenesis in ischemic tissue is a complex and multi-gene event. In the study, we constructed hypoxic response elements (HRE) and the Tet-On advanced double-controlled systems and investigated their effects on the expression of hVEGF165 and angiopoietin-1 (Ang-1) genes in rat cardiomyocytes exposed to hypoxia and pharmacologic induction. We infected neonatal rat cardiomyocytes with recombinant rAAV-rtTA-Rs-M2/rAAV-TRE-Tight-Ang-1 and rAAV-9HRE- hVEGF165. Our results indicated that the viral titer was 1×10(12) vg /mL and the viral purity exceeded 98%. hVEGF 165 expression was induced by hypoxia, but not by normoxia (P < 0.001). Ang-1 expression was evident under doxycycline induction, but undetectable without doxycycline induction (P < 0.001). Immunofluorescence staining showed that positively stained hVEGF165 and Ang-1 protein appeared only under both hypoxia and doxycycline induction. We demonstrate here that HRE and the recombinant Tet-On advanced double gene-controlled systems sensitively regulate the expression of hVEGF165 and Ang-1 genes in an altered oxygen environment and under pharmacological induction in vitro.
    Journal of biomedical research. 05/2011; 25(3):204-12.
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Data from past research is presented showing that neutrophils are active participants in new vessel formation in normal physiology, in proliferating human endometrium, in non-cancer pathologies as in the pannus of rheumatoid arthritis, and in various cancers, among them glioblastoma. These data show that interleukin-8 (IL-8) is a major chemokine attracting neutrophil infiltrates in these states. Since the old anti-Hansen's disease drug dapsone inhibits neutrophil migration along an IL-8 gradient towards increasing concentrations, and is used therapeutically for this attribute to good effect in dermatitis herpetiformis, bullous pemphigoid and rheumatoid arthritis, we suggest dapsone may deprive glioblastoma of neutrophil-mediated growth promoting effects. We review past research showing that vascular endothelial growth factor, VEGF, is carried predominantly intracellularly within neutrophils--only 2% of circulating VEGF is found free in serum. Based on the available evidence summarized by the authors, dapsone has a strong theoretical potential to become a useful anti-VEGF, anti-angiogenic agent in glioblastoma treatment.
    Anti-cancer agents in medicinal chemistry 06/2011; 11(8):756-61.