title: Indirubin-3'-monoxime exerts a dual mode of inhibition towards leukotriene-mediated vascular smooth muscle cell migration.
abstract: OBJECTIVE
  The small molecule indirubin-3'-monoxime (I3MO) has been shown to inhibit vascular smooth muscle cell (VSMC) proliferation and neointima formation in vivo. The influence of I3MO on VSMC migration and vascular inflammation, two additional key players during the onset of atherosclerosis and restenosis, should be investigated.
  
  
  RESULTS
  We examined the influence of I3MO on VSMC migration, with focus on monocyte-derived leukotrienes (LTs) and platelet-derived growth factors (PDGFs) as elicitors. Exogenous LTB4 and cysteinyl leukotrienes as well as LT-enriched conditioned medium of activated primary human monocytes induced VSMC migration, which was inhibited by I3MO. I3MO also blunted migration of VSMC stimulated with the PDGF, the strongest motogen tested in this study. Induction of haem oxygenase 1 accounted for this anti-migratory activity of I3MO in VSMC. Notably, I3MO not only interfered with the migratory response in VSMC, but also suppressed the production of pro-migratory LT in monocytes. Conditioned media from monocytes that were activated in the presence of I3MO failed to induce VSMC migration. In cell-based and cell-free assays, I3MO selectively inhibited 5-lipoxygenase (5-LO), the key enzyme in LT biosynthesis, with an IC50 in the low micromolar range.
  
  
  CONCLUSIONS
  Our study reveals a novel dual inhibitory mode of I3MO on LT-mediated VSMC migration: (i) I3MO interferes with pro-migratory signalling in VSMC and (ii) I3MO suppresses LT biosynthesis in monocytes by direct inhibition of 5-LO. These inhibitory actions on both migratory stimulus and response complement the previously demonstrated anti-proliferative properties of I3MO and may further promote I3MO as promising vasoprotective compound.
authors.affiliation: Department of Pharmacognosy, University of Vienna, Althanstrasse 14, Vienna A-1090, Austria.
authors.forename: Tina
authors.initials: T
authors.lastname: Blazevic
authors.forename: Anja M
authors.initials: AM
authors.lastname: Schaible
authors.forename: Katharina
authors.initials: K
authors.lastname: Weinhäupl
authors.forename: Daniel
authors.initials: D
authors.lastname: Schachner
authors.forename: Felix
authors.initials: F
authors.lastname: Nikels
authors.forename: Christina
authors.initials: C
authors.lastname: Weinigel
authors.forename: Dagmar
authors.initials: D
authors.lastname: Barz
authors.forename: Atanas G
authors.initials: AG
authors.lastname: Atanasov
authors.forename: Carlo
authors.initials: C
authors.lastname: Pergola
authors.forename: Oliver
authors.initials: O
authors.lastname: Werz
authors.forename: Verena M
authors.initials: VM
authors.lastname: Dirsch
authors.forename: Elke H
authors.initials: EH
authors.lastname: Heiss
mesh_terms: D001094:Arachidonate 5-Lipoxygenase / Q000378:metabolism; D002465:Cell Movement / Q000187:drug effects* / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003545:Cysteine / Q000378:metabolism*; D005260:Female; D006801:Humans; D007211:Indoles / Q000494:pharmacology*; D015289:Leukotrienes / Q000378:metabolism*; D008297:Male; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D058426:Neointima / Q000188:drug therapy; D010091:Oximes / Q000494:pharmacology*; D010982:Platelet-Derived Growth Factor / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects*
chemical_list: D007211:Indoles; D015289:Leukotrienes; D010091:Oximes; D010982:Platelet-Derived Growth Factor; C112381:cysteinyl-leukotriene; C474021:indirubin-3'-monoxime; D001094:Arachidonate 5-Lipoxygenase; D003545:Cysteine
keywords: 5-Lipoxygenase; Indirubin-3′-monoxime; Leukotrienes; Migration; Vascular smooth muscle cells