title: Red blood cells stimulate fibroblast-mediated contraction of three dimensional collagen gels in co-culture.
abstract: OBJECTIVE
  Following injury, red blood cells (RBC) may interact with extracellular matrix (ECM). In the present study we hypothesised that RBC, and soluble factors from RBC, might mediate remodelling of ECM by affecting fibroblast-mediated contraction of three dimensional collagen gels.
  
  
  METHODS
  Human lung fibroblasts (HFL-1), were cultured together with isolated RBC, conditioned medium from RBC (RBC-CM) and hemolysed RBC in type I collagen gels. Gel contraction was determined by an image analyser.
  
  
  RESULTS
  Both RBC, RBC-CM and hemolysed RBC stimulated gel contraction by fibroblasts (P < 0.001), compared to fibroblasts alone. The RBC-CM stimulated (P < 0.01) gel contraction in a time and concentration dependent manner. A similar effect was observed when supernatant from hemolysed RBC was tested. The production of fibronectin was increased (P < 0.01) in the co-culture system, compared to fibroblasts cultured alone.
  
  
  CONCLUSIONS
  The present study shows that RBC can interact with mesenchymal cells in vitro. The ability of RBC to modulate fibroblast-mediated contraction in vitro, might therefore be an important mechanism regulating repair processes after injury.
authors.affiliation: Department of Medicine, Karolinska Hospital, Stockholm, Sweden. karin.fredriksson@ks.se
authors.forename: K
authors.initials: K
authors.lastname: Fredriksson
authors.forename: J
authors.initials: J
authors.lastname: Lundahl
authors.forename: E
authors.initials: E
authors.lastname: Fernvik
authors.forename: X D
authors.initials: XD
authors.lastname: Liu
authors.forename: S I
authors.initials: SI
authors.lastname: Rennard
authors.forename: C M
authors.initials: CM
authors.lastname: Sköld
mesh_terms: D000818:Animals; D018920:Coculture Techniques; D003094:Collagen / Q000737:chemistry*; D017077:Culture Media, Conditioned; D004247:DNA / Q000737:chemistry / Q000235:genetics; D004797:Enzyme-Linked Immunosorbent Assay; D004912:Erythrocytes / Q000502:physiology*; D005109:Extracellular Matrix / Q000502:physiology; D005347:Fibroblasts / Q000502:physiology; D005353:Fibronectins / Q000737:chemistry; D005782:Gels; D006461:Hemolysis; D006801:Humans; D010206:Papain / Q000494:pharmacology; D051381:Rats
chemical_list: D017077:Culture Media, Conditioned; D005353:Fibronectins; D005782:Gels; D003094:Collagen; D004247:DNA; D010206:Papain