Effects of Interferons α/β on the Proliferation of Human Micro- and Macrovascular Endothelial Cells

Department of Surgery, Erasmus MC, Rotterdam, The Netherlands.
Journal of interferon & cytokine research: the official journal of the International Society for Interferon and Cytokine Research (Impact Factor: 3.9). 03/2011; 31(5):451-8. DOI: 10.1089/jir.2009.0103
Source: PubMed

ABSTRACT Synthetic interferons (IFNs) are used in the treatment of several types of cancer. In addition to an antitumor effect, IFNs show antiangiogenic activity. The aim of this study was to investigate the effects of IFN-α and IFN-β on human micro- and macrovascular endothelial cells in vitro [human micro vascular lung endothelial cells (HMVEC-L) and human umbilical cord endothelial cells (HUVEC)]. By immunohistochemical staining and quantitative reverse transcriptase (RT)-polymerase chain reaction, we studied expression of type I IFN receptors. We evaluated the effects of IFN-α and IFN-β on the proliferation (DNA content), apoptosis (DNA fragmentation by enzyme-linked immunosorbent assay), and cell cycle distribution (flow-cytometric analysis) of endothelial cells. HUVEC and HMVEC-L cells show comparable expression level of the distinct IFN receptor subtypes. Proliferation of HMVEC-L and HUVEC was inhibited by IFN-β (the half maximal inhibitory concentration [IC(50)] = 60 and 90 IU/mL, respectively), but not by IFN-α at a dose up to 1,000 IU/mL. An interesting and unexpected observation was an inhibition of apoptosis by IFN-β. After 72 h of treatment with IFN-β. Cell cycle inhibition occurs in late S-phase in both cell lines. In conclusion, only IFN-β, not IFN-α (10-1,000 IU/mL), has an inhibitory activity on endothelial cell proliferation. Surprisingly, apoptosis was decreased by IFN treatment, whereas inhibition of proliferation is caused by cell cycle arrest in late S-phase.

Download full-text


Available from: Ed Croze, Apr 14, 2014
  • [Show abstract] [Hide abstract]
    ABSTRACT: Interferon-beta (IFN-beta) is biologically unstable under physiologic conditions in vitro and is cleared rapidly from the bloodstream on administration in vivo. In the present study, we demonstrate that a soluble recombinant form of the type I IFN receptor subunit, sIFNAR-2, can neutralize the bioactivity of type I IFNs at high concentrations and, at lower concentrations, causes an enhancement of IFN-beta-mediated antiviral activity. The in vitro enhancement is due to the specific interaction of IFN-beta with sIFNAR-2, followed by dissociation of IFN-beta from the complex over time in culture. In vivo, the serum half-life of IFN-beta is extended from minutes to hours when administered intravenously in mice as a sIFNAR-2-associated complex. Moreover, the antitumor effect of IFN-beta is increased by between 9-fold and 27-fold when injected as an sIFNAR-2-associated complex, as demonstrated by an increase in the mean survival time of immunodeficient mice challenged with human Burkitt lymphoma cell (Daudi) xenografts (sIFNAR-2-complexed vs. free IFN-beta treatment). These results show that on association with sIFNAR-2, IFN-beta is more stable in vitro and exhibits increased efficacy when administered in vivo. Administration as a complex with sIFNAR-2 may, therefore, provide a method of enhancing the delivery and effectiveness of type I IFNs.
    Journal of Interferon & Cytokine Research 03/2004; 24(2):119-29. DOI:10.1089/107999004322813363 · 3.90 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: Chemokine (CC motif) receptor-like 2 (CCRL2) binds leukocyte chemoattractant chemerin and can regulate local levels of the attractant, but does not itself support cell migration. In this study, we show that CCRL2 and VCAM-1 are upregulated on cultured human and mouse vascular endothelial cells (EC) and cell lines by proinflammatory stimuli. CCRL2 induction is dependent on NF-κB and JAK/STAT signaling pathways, and activated endothelial cells specifically bind chemerin. In vivo, CCRL2 is constitutively expressed at high levels by lung endothelial cells and at lower levels by liver endothelium; and liver but not lung EC respond to systemic LPS injection by further upregulation of the receptor. Plasma levels of total chemerin are elevated in CCRL2(-/-) mice and are significantly enhanced after systemic LPS treatment in CCRL2(-/-) mice compared with wild-type mice. Following acute LPS-induced pulmonary inflammation in vivo, chemokine-like receptor 1 (CMKLR1)(+) NK cell recruitment to the airways is significantly impaired in CCRL2(-/-) mice compared with wild-type mice. In vitro, chemerin binding to CCRL2 on endothelial cells triggers robust adhesion of CMKLR1(+) lymphoid cells through an α(4)β(1) integrin/VCAM-1-dependent mechanism. In conclusion, CCRL2 is expressed by EC in a tissue- and activation-dependent fashion, regulates circulating chemerin levels and its bioactivity, and enhances chemerin- and CMKLR1-dependent lymphocyte/EC adhesion in vitro and recruitment to inflamed airways in vivo. Its expression and/or induction on EC by proinflammatory stimuli provide a novel and specific mechanism for the local enrichment of chemerin at inflammatory sites, regulating the recruitment of CMKLR1(+) cells.
    The Journal of Immunology 06/2012; 189(2):956-67. DOI:10.4049/jimmunol.1102871 · 5.36 Impact Factor
  • [Show abstract] [Hide abstract]
    ABSTRACT: PKR (protein kinase, RNA activated) is an interferon (IFN)-induced serine-threonine protein kinase and is one of the key mediators in IFN's cellular actions. Although double-stranded (ds) RNA is the most relevant PKR activator during viral infections, PACT acts as a stress-modulated activator of PKR and is an important regulator of PKR dependent signaling pathways in the absence of viral infections. Stress-induced phosphorylation of PACT is essential for PACT's association with PKR leading to PKR activation. PKR activation by PACT leads to phosphorylation of translation initiation factor eIF2α, inhibition of protein synthesis, and apoptosis. In the present study, we have investigated the functional significance of PACT-PACT interaction in mediating PKR activation in response to cellular stress. Our results suggest that enhanced interaction between PACT molecules when PACT is phosphorylated in response to stress signals on serines 246 and 287 is essential for efficient PKR activation. Using a point mutant of PACT that is deficient in PACT-PACT interaction, we demonstrate that PACT-PACT interaction is essential for efficient PKR activation.
    Journal of Cellular Biochemistry 08/2012; 113(8):2754-64. DOI:10.1002/jcb.24152 · 3.37 Impact Factor
Show more