Now showing 1 - 3 of 3
  • Publication
    Phenotype-based Discovery of 2-[(E)-2-(Quinolin-2-yl)vinyl]phenol as a Novel Regulator of Ocular Angiogenesis
    Retinal angiogenesis is tightly regulated to meet oxygenation and nutritional requirements. In diseases such as proliferative diabetic retinopathy and neovascular age-related macular degeneration, uncontrolled angiogenesis can lead to blindness. Our goal is to better understand the molecular processes controlling retinal angiogenesis and discover novel drugs that inhibit retinal neovascularization. Phenotype-based chemical screens were performed using the ChemBridge DiversetTM library and inhibition of hyaloid vessel angiogenesis in Tg(fli1:EGFP) zebrafish. 2-[(E)-2-(Quinolin-2-yl)vinyl]phenol, (quininib) robustly inhibits developmental angiogenesis at 4–10 μm in zebrafish and significantly inhibits angiogenic tubule formation in HMEC-1 cells, angiogenic sprouting in aortic ring explants, and retinal revascularization in oxygen-induced retinopathy mice. Quininib is well tolerated in zebrafish, human cell lines, and murine eyes. Profiling screens of 153 angiogenic and inflammatory targets revealed that quininib does not directly target VEGF receptors but antagonizes cysteinyl leukotriene receptors 1 and 2 (CysLT1–2) at micromolar IC50 values. In summary, quininib is a novel anti-angiogenic small-molecule CysLT receptor antagonist. Quininib inhibits angiogenesis in a range of cell and tissue systems, revealing novel physiological roles for CysLT signaling. Quininib has potential as a novel therapeutic agent to treat ocular neovascular pathologies and may complement current anti-VEGF biological agents.
      515Scopus© Citations 32
  • Publication
    BMP7-induced-Pten inhibits Akt and prevents renal fibrosis
    Bone morphogenetic protein-7 (BMP-7) counteracts pro-fibrotic effects of TGFβ1 in cultured renal cells and protects from fibrosis in acute and chronic renal injury models. Using the unilateral ureteral obstruction (UUO) model of chronic renal fibrosis, we investigated the effect of exogenous-rhBMP-7 on pro-fibrotic signaling pathways mediated by TGFβ1 and hypoxia. Mice undergoing UUO were treated with vehicle or rhBMP-7 (300 μg/kg i.p.) every other day for eight days and kidneys analysed for markers of fibrosis and SMAD, MAPK, and PI3K signaling. In the kidney, collecting duct and tubular epithelial cells respond to BMP-7 via activation of SMAD1/5/8. Phosphorylation of SMAD1/5/8 was reduced in UUO kidneys from vehicle-treated animals yet maintained in UUO kidneys from BMP-7-treated animals, confirming renal bioactivity of exogenous rhBMP-7. BMP-7 inhibited Collagen Iα1 and Collagen IIIα1 gene expression and Collagen I protein accumulation, while increasing expression of Collagen IVα1 in UUO kidneys. Activation of SMAD2, SMAD3, ERK, p38 and PI3K/Akt signaling occurred during fibrogenesis and BMP-7 significantly attenuated SMAD3 and Akt signaling in vivo. Analysis of renal collecting duct (mIMCD) and tubular epithelial (HK-2) cells stimulated with TGFβ1 or hypoxia (1% oxygen) to activate Akt provided further evidence that BMP-7 specifically inhibited PI3K/Akt signaling. PTEN is a negative regulator of PI3K and BMP-7 increased PTEN expression in vivo and in vitro. These data demonstrate an important mechanism by which BMP-7 orchestrates renal protection through Akt inhibition and highlights Akt inhibitors as anti-fibrotic therapeutics
      592Scopus© Citations 54
  • Publication
    ELM--the database of eukaryotic linear motifs
    Linear motifs are short, evolutionarily plastic components of regulatory proteins and provide low-affinity interaction interfaces. These compact modules play central roles in mediating every aspect of the regulatory functionality of the cell. They are particularly prominent in mediating cell signaling, controlling protein turnover and directing protein localization. Given their importance, our understanding of motifs is surprisingly limited, largely as a result of the difficulty of discovery, both experimentally and computationally. The Eukaryotic Linear Motif (ELM) resource at http://elm.eu.org provides the biological community with a comprehensive database of known experimentally validated motifs, and an exploratory tool to discover putative linear motifs in user-submitted protein sequences. The current update of the ELM database comprises 1800 annotated motif instances representing 170 distinct functional classes, including approximately 500 novel instances and 24 novel classes. Several older motif class entries have been also revisited, improving annotation and adding novel instances. Furthermore, addition of full-text search capabilities, an enhanced interface and simplified batch download has improved the overall accessibility of the ELM data. The motif discovery portion of the ELM resource has added conservation, and structural attributes have been incorporated to aid users to discriminate biologically relevant motifs from stochastically occurring non-functional instances.
      407Scopus© Citations 261