title: Flavopiridol protects against inflammation by attenuating leukocyte-endothelial interaction via inhibition of cyclin-dependent kinase 9.
abstract: OBJECTIVE
  The cyclin-dependent kinase (CDK) inhibitor flavopiridol is currently being tested in clinical trials as anticancer drug. Beyond its cell death-inducing action, we hypothesized that flavopiridol affects inflammatory processes. Therefore, we elucidated the action of flavopiridol on leukocyte-endothelial cell interaction and endothelial activation in vivo and in vitro and studied the underlying molecular mechanisms.
  
  
  RESULTS
  Flavopiridol suppressed concanavalin A-induced hepatitis and neutrophil infiltration into liver tissue. Flavopiridol also inhibited tumor necrosis factor-α-induced leukocyte-endothelial cell interaction in the mouse cremaster muscle. Endothelial cells were found to be the major target of flavopiridol, which blocked the expression of endothelial cell adhesion molecules (intercellular adhesion molecule-1, vascular cell adhesion molecule-1, and E-selectin), as well as NF-κB-dependent transcription. Flavopiridol did not affect inhibitor of κB (IκB) kinase, the degradation and phosphorylation of IκBα, nuclear translocation of p65, or nuclear factor-κB (NF-κB) DNA-binding activity. By performing a cellular kinome array and a kinase activity panel, we found LIM domain kinase-1 (LIMK1), casein kinase 2, c-Jun N-terminal kinase (JNK), protein kinase C (PKC), CDK4, CDK6, CDK8, and CDK9 to be influenced by flavopiridol. Using specific inhibitors, as well as RNA interference (RNAi), we revealed that only CDK9 is responsible for the action of flavopiridol.
  
  
  CONCLUSIONS
  Our study highlights flavopiridol as a promising antiinflammatory compound and inhibition of CDK9 as a novel approach for the treatment of inflammation-associated diseases.
authors.affiliation: Department of Pharmacy, Pharmaceutical Biology, University of Munich, Butenandtstrasse 5-13, Munich, Germany. robert.fuerst@cup.uni-muenchen.de.
authors.forename: Ulrike K
authors.initials: UK
authors.lastname: Schmerwitz
authors.forename: Gabriele
authors.initials: G
authors.lastname: Sass
authors.forename: Alexander G
authors.initials: AG
authors.lastname: Khandoga
authors.forename: Jos
authors.initials: J
authors.lastname: Joore
authors.forename: Bettina A
authors.initials: BA
authors.lastname: Mayer
authors.forename: Nina
authors.initials: N
authors.lastname: Berberich
authors.forename: Frank
authors.initials: F
authors.lastname: Totzke
authors.forename: Fritz
authors.initials: F
authors.lastname: Krombach
authors.forename: Gisa
authors.initials: G
authors.lastname: Tiegs
authors.forename: Stefan
authors.initials: S
authors.lastname: Zahler
authors.forename: Angelika M
authors.initials: AM
authors.lastname: Vollmar
authors.forename: Robert
authors.initials: R
authors.lastname: Fürst
mesh_terms: D000818:Animals; D002448:Cell Adhesion / Q000187:drug effects; D002450:Cell Communication / Q000187:drug effects / Q000502:physiology*; D002465:Cell Movement / Q000187:drug effects; D002478:Cells, Cultured; D056486:Chemical and Drug Induced Liver Injury / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control; D003208:Concanavalin A / Q000009:adverse effects; D042863:Cyclin-Dependent Kinase 9 / Q000037:antagonists & inhibitors* / Q000378:metabolism; D004195:Disease Models, Animal; D019040:E-Selectin / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D005419:Flavonoids / Q000494:pharmacology / Q000627:therapeutic use*; D006801:Humans; D007249:Inflammation / Q000378:metabolism / Q000503:physiopathology / Q000517:prevention & control*; D018799:Intercellular Adhesion Molecule-1 / Q000378:metabolism; D007962:Leukocytes / Q000166:cytology* / Q000187:drug effects; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D016328:NF-kappa B / Q000378:metabolism; D010880:Piperidines / Q000494:pharmacology / Q000627:therapeutic use*; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism
chemical_list: D019040:E-Selectin; D005419:Flavonoids; D016328:NF-kappa B; D010880:Piperidines; D047428:Protein Kinase Inhibitors; D019010:Vascular Cell Adhesion Molecule-1; D003208:Concanavalin A; D018799:Intercellular Adhesion Molecule-1; C077990:alvocidib; C467972:Cdk9 protein, mouse; D042863:Cyclin-Dependent Kinase 9