title: TRAF5 deficiency accelerates atherogenesis in mice by increasing inflammatory cell recruitment and foam cell formation.
abstract: BACKGROUND
  Tumor necrosis factor receptor-associated factors (TRAFs) are cytoplasmic adaptor proteins for the TNF/interleukin-1/Toll-like receptor superfamily. Ligands of this family comprise multiple important cytokines such as TNFα, CD40L, and interleukin-1β that promote chronic inflammatory diseases such as atherosclerosis. We recently reported overexpression of TRAF5 in murine and human atheromata and that TRAF5 promotes inflammatory functions of cultured endothelial cells and macrophages.
  
  
  OBJECTIVE
  This study tested the hypothesis that TRAF5 modulates atherogenesis in vivo.
  
  
  RESULTS
  Surprisingly, TRAF5(-/-)/LDLR(-/-) mice consuming a high-cholesterol diet for 18 weeks developed significantly larger atherosclerotic lesions than did TRAF5(+/+)/LDLR(-/-) controls. Plaques of TRAF5-deficient animals contained more lipids and macrophages, whereas smooth muscle cells and collagen remained unchanged. Deficiency of TRAF5 in endothelial cells or in leukocytes enhanced adhesion of inflammatory cells to the endothelium in dynamic adhesion assays in vitro and in murine vessels imaged by intravital microscopy in vivo. TRAF5 deficiency also increased expression of adhesion molecules and chemokines and potentiated macrophage lipid uptake and foam cell formation. These findings coincided with increased activation of JNK and appeared to be independent of TRAF2. Finally, patients with stable or acute coronary heart disease had significantly lower amounts of TRAF5 mRNA in blood compared with healthy controls.
  
  
  CONCLUSIONS
  Unexpectedly, TRAF5 deficiency accelerates atherogenesis in mice, an effect likely mediated by increased inflammatory cell recruitment to the vessel wall and enhanced foam cell formation.
authors.affiliation: Department of Cardiology, University of Freiburg, Germany.
authors.forename: Anna
authors.initials: A
authors.lastname: Missiou
authors.forename: Philipp
authors.initials: P
authors.lastname: Rudolf
authors.forename: Peter
authors.initials: P
authors.lastname: Stachon
authors.forename: Dennis
authors.initials: D
authors.lastname: Wolf
authors.forename: Nerea
authors.initials: N
authors.lastname: Varo
authors.forename: Peter
authors.initials: P
authors.lastname: Aichele
authors.forename: Christian
authors.initials: C
authors.lastname: Colberg
authors.forename: Natalie
authors.initials: N
authors.lastname: Hoppe
authors.forename: Sandra
authors.initials: S
authors.lastname: Ernst
authors.forename: Christian
authors.initials: C
authors.lastname: Münkel
authors.forename: Carina
authors.initials: C
authors.lastname: Walter
authors.forename: Benjamin
authors.initials: B
authors.lastname: Sommer
authors.forename: Ingo
authors.initials: I
authors.lastname: Hilgendorf
authors.forename: Hiroyasu
authors.initials: H
authors.lastname: Nakano
authors.forename: Christoph
authors.initials: C
authors.lastname: Bode
authors.forename: Andreas
authors.initials: A
authors.lastname: Zirlik
mesh_terms: D000368:Aged; D000818:Animals; D050197:Atherosclerosis / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D002454:Cell Differentiation / Q000235:genetics; D002465:Cell Movement / Q000235:genetics; D002478:Cells, Cultured; D003327:Coronary Disease / Q000276:immunology / Q000378:metabolism; D005260:Female; D005487:Foam Cells / Q000378:metabolism / Q000473:pathology*; D005500:Follow-Up Studies; D006801:Humans; D007249:Inflammation / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D008264:Macrophages / Q000473:pathology*; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008875:Middle Aged; D011247:Pregnancy; D048015:TNF Receptor-Associated Factor 5 / Q000172:deficiency* / Q000235:genetics
chemical_list: D048015:TNF Receptor-Associated Factor 5