title: Tenascin C upregulates interleukin-6 expression in human cardiac myofibroblasts via toll-like receptor 4.
abstract: OBJECTIVE
  To investigate the effect of Tenascin C (TNC) on the expression of pro-inflammatory cytokines and matrix metalloproteinases in human cardiac myofibroblasts (CMF).
  
  
  METHODS
  CMF were isolated and cultured from patients undergoing coronary artery bypass grafting. Cultured cells were treated with either TNC (0.1 μmol/L, 24 h) or a recombinant protein corresponding to different domains of the TNC protein; fibrinogen-like globe (FBG) and fibronectin type III-like repeats (TNIII 5-7) (both 1 μmol/L, 24 h). The expression of the pro-inflammatory cytokines; interleukin (IL)-6, IL-1β, TNFα and the matrix metalloproteinases; MMPs (MMP1, 2, 3, 9, 10, MT1-MMP) was assessed using real time RT-PCR and western blot analysis.
  
  
  RESULTS
  TNC increased both IL-6 and MMP3 (P < 0.01) mRNA levels in cultured human CMF but had no significant effect on the other markers studied. The increase in IL-6 mRNA expression was mirrored by an increase in protein secretion as assessed by enzyme-linked immunosorbant assay (P < 0.01). Treating CMF with the recombinant protein FBG increased IL-6 mRNA and protein (P < 0.01) whereas the recombinant protein TNIII 5-7 had no effect. Neither FBG nor TNIII 5-7 had any significant effect on MMP3 expression. The expression of toll-like receptor 4 (TLR4) in human CMF was confirmed by real time RT-PCR, western blot and immunohistochemistry. Pre-incubation of cells with TLR4 neutralising antisera attenuated the effect of both TNC and FBG on IL-6 mRNA and protein expression.
  
  
  CONCLUSIONS
  TNC up-regulates IL-6 expression in human CMF, an effect mediated through the FBG domain of TNC and via the TLR4 receptor.
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Azhar
authors.initials: A
authors.lastname: Maqbool
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Emma J
authors.initials: EJ
authors.lastname: Spary
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Iain W
authors.initials: IW
authors.lastname: Manfield
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Michaela
authors.initials: M
authors.lastname: Ruhmann
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Lorena
authors.initials: L
authors.lastname: Zuliani-Alvarez
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Filomena O
authors.initials: FO
authors.lastname: Gamboa-Esteves
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Karen E
authors.initials: KE
authors.lastname: Porter
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Mark J
authors.initials: MJ
authors.lastname: Drinkhill
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Kim S
authors.initials: KS
authors.lastname: Midwood
authors.affiliation: Azhar Maqbool, Emma J Spary, Karen E Porter, Mark J Drinkhill, Neil A Turner, Division of Cardiovascular and Diabetes Research, Leeds Institute of Cardiovascular and Metabolic Medicine, School of Medicine, University of Leeds, Leeds LS2 9JT, United Kingdom.
authors.forename: Neil A
authors.initials: NA
authors.lastname: Turner
keywords: Cardiac fibroblasts; Interleukin-6; Matrix metalloproteinase; Tenascin C; Toll-like receptor