title: Toll-like receptor 4 is involved in human and mouse vein graft remodeling, and local gene silencing reduces vein graft disease in hypercholesterolemic APOE*3Leiden mice.
abstract: OBJECTIVE
  The goal of this study was to explore the role of Toll-like receptor 4 (TLR4) in vein graft remodeling and disease.
  
  
  RESULTS
  First, expression of TLR4 was analyzed in freshly isolated human saphenous veins (huSV), in freshly isolated huSV ex vivo perfused in an extracorporeal circulation, or in huSV used as coronary vein grafts. Marked induction of focal TLR4 expression was observed in perfused fresh huSV. Moreover, TLR4 was abundantly present in lesions in fresh huSV or in intimal hyperplasia in coronary vein grafts. Second, mouse venous bypass grafting was performed. In grafts of hypercholesterolemic APOE*3Leiden mice, increased TLR4 mRNA and protein was detected over time by reverse transcription-polymerase chain reaction and immunohistochemistry. Furthermore, the local presence of the endogenous TLR4 ligands heat shock protein 60, high-mobility group box 1, tenascin-C, and biglycan in the grafts was demonstrated. TLR4 deficiency in C3H-Tlr4LPS-d (LPS indicates lipopolysaccharide) mice resulted in 48±12% less vein graft wall thickening (P=0.04) than in Balb/c controls. Moreover, local TLR4 gene silencing in hypercholesterolemic APOE*3Leiden mice using lentiviral short hairpin RNA against TLR4 administered perivascularly around vein grafts led to a 44±13% reduction of vessel wall thickening compared with controls (P=0.0059).
  
  
  CONCLUSIONS
  These results indicate that TLR4 is involved in vein graft remodeling and can be used as a local therapeutic target against vein graft disease.
authors.affiliation: Department of Vascular Surgery, Leiden University Medical Center, PO Box 9600, 2300 RC Leiden, the Netherlands.
authors.forename: Jacco C
authors.initials: JC
authors.lastname: Karper
authors.forename: Margreet R
authors.initials: MR
authors.lastname: de Vries
authors.forename: Ben T
authors.initials: BT
authors.lastname: van den Brand
authors.forename: Imo E
authors.initials: IE
authors.lastname: Hoefer
authors.forename: Jens W
authors.initials: JW
authors.lastname: Fischer
authors.forename: J Wouter
authors.initials: JW
authors.lastname: Jukema
authors.forename: Hans W M
authors.initials: HW
authors.lastname: Niessen
authors.forename: Paul H A
authors.initials: PH
authors.lastname: Quax
mesh_terms: D000818:Animals; D053318:Apolipoprotein E3 / Q000235:genetics / Q000378:metabolism*; D058578:Biglycan / Q000378:metabolism; D016466:CHO Cells; D018834:Chaperonin 60 / Q000378:metabolism; D001026:Coronary Artery Bypass / Q000009:adverse effects; D006224:Cricetinae; D003412:Cricetulus; D004195:Disease Models, Animal; D006083:Graft Occlusion, Vascular / Q000235:genetics / Q000378:metabolism / Q000473:pathology / Q000517:prevention & control*; D024243:HMGB1 Protein / Q000378:metabolism; D006801:Humans; D006937:Hypercholesterolemia / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D007150:Immunohistochemistry; D008024:Ligands; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D024101:Mitochondrial Proteins / Q000378:metabolism; D034622:RNA Interference; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012501:Saphenous Vein / Q000378:metabolism / Q000473:pathology / Q000637:transplantation*; D019063:Tenascin / Q000378:metabolism; D013997:Time Factors; D051197:Toll-Like Receptor 4 / Q000235:genetics / Q000378:metabolism*; D014162:Transfection; D014684:Venae Cavae / Q000378:metabolism / Q000473:pathology / Q000637:transplantation*
chemical_list: D053318:Apolipoprotein E3; C546885:Bgn protein, mouse; D058578:Biglycan; D018834:Chaperonin 60; D024243:HMGB1 Protein; C557066:Hspd1 protein, mouse; D008024:Ligands; D024101:Mitochondrial Proteins; D012333:RNA, Messenger; C495345:TLR4 protein, human; D019063:Tenascin; C493487:Tlr4 protein, mouse; D051197:Toll-Like Receptor 4; C052720:apolipoprotein E3 (Leidein)