title: Clones of interstitial cells from bovine aortic valve exhibit different calcifying potential when exposed to endotoxin and phosphate.
abstract: OBJECTIVE
  Our purpose was to study in vitro whether phenotypically-distinct interstitial cell clones from bovine aortic valve (BVIC) possess different calcifying potential in response to endotoxin (lipopolysaccharide [LPS]) and phosphate (Pi).
  
  
  RESULTS
  Among various clones of BVIC obtained by limited dilution technique we selected 4 clones displaying different growth patterns and immunophenotypes. Uncloned and cloned cells were treated with combinations of LPS (100 ng/mL) and Pi (2.4 mmol/L). Uncloned BVIC showed increased alkaline phosphatase activity (ALP) after treatment with LPS, which resulted in calcification after addition of Pi. Among BVIC clones, only Clone 1 (fibroblast-like phenotype) showed a relevant increase in ALP after LPS treatment in parallel with prevention of smooth muscle (SM) alpha-actin accumulation. No effect was observed in clonal cells harboring a more stable SM cell-like profile (Clone 4). None of the isolated clones calcified but mineralization was induced in the presence of LPS plus Pi when Clone 1 was cocultured with Clone 4 or after seeding on type I collagen sponges.
  
  
  CONCLUSIONS
  Endotoxin and phosphate can act as valve calcification promoters by targeting specific fibroblast-like interstitial valve cells that possess a unique procalcific potential.
authors.affiliation: Dipartimento di Medicina Clinica e Sperimentale, Università degli Studi di Padova, Treviso, Italy. marcello.rattazzi@unipd.it
authors.forename: Marcello
authors.initials: M
authors.lastname: Rattazzi
authors.forename: Laura
authors.initials: L
authors.lastname: Iop
authors.forename: Elisabetta
authors.initials: E
authors.lastname: Faggin
authors.forename: Elisa
authors.initials: E
authors.lastname: Bertacco
authors.forename: Giacomo
authors.initials: G
authors.lastname: Zoppellaro
authors.forename: Ilenia
authors.initials: I
authors.lastname: Baesso
authors.forename: Massimo
authors.initials: M
authors.lastname: Puato
authors.forename: Gianluca
authors.initials: G
authors.lastname: Torregrossa
authors.forename: Gian Paolo
authors.initials: GP
authors.lastname: Fadini
authors.forename: Carlo
authors.initials: C
authors.lastname: Agostini
authors.forename: Gino
authors.initials: G
authors.lastname: Gerosa
authors.forename: Saverio
authors.initials: S
authors.lastname: Sartore
authors.forename: Paolo
authors.initials: P
authors.lastname: Pauletto
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D000818:Animals; D001021:Aortic Valve / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology*; D002114:Calcinosis / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D002118:Calcium / Q000378:metabolism; D002417:Cattle; D002999:Clone Cells; D018920:Coculture Techniques; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D006349:Heart Valve Diseases / Q000209:etiology* / Q000378:metabolism / Q000473:pathology; D008070:Lipopolysaccharides / Q000633:toxicity*; D032389:Myocytes, Smooth Muscle / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D010641:Phenotype; D010710:Phosphates / Q000633:toxicity*
chemical_list: D008070:Lipopolysaccharides; D010710:Phosphates; D000469:Alkaline Phosphatase; D002118:Calcium