title: Treatment with vitamin k(2) combined with bisphosphonates synergistically inhibits calcification in cultured smooth muscle cells.
abstract: OBJECTIVE
  Vascular calcification is a common feature in patients with advanced atherosclerosis, postmenopausal women and patients with renal failure, which results in reduced elasticity of arteries. Pamidronate, a bisphosphonate, is used as a therapeutic agent for anti-osteoporosity, although there are adverse side effects, such as renal damage and aortic inflamed plaque rupture. In the present study, we demonstrated the effects of vitamin K(2) alone or in combination with pamidronate in an arterial calcification model induced using inorganic phosphate in cultured bovine aortic smooth muscle cells (BASMCs).
  
  
  METHODS
  Calcification was induced by the addition of Pi (3 mM) in BASMCs. Calcium deposition was determined by Calcium C-test Wako and von Kossa staining. mRNA expression was assessed by semi-quantitative reverse transcription-polymerase chain reaction.
  
  
  RESULTS
  Calcium deposition assay and von Kossa staining showed that calcification could be inhibited in a dose-dependent manner by treatment with vitamin K(2) alone, and that its inhibitory effect was enhanced when combined with pamidronate. It was found that the expression of tropoelastin mRNA was synergistically enhanced by combined treatment with vitamin K(2) and pamidronate, and the expression matrix Gla protein mRNA and osteopontin mRNA expression were also enhanced and suppressed, respectively, by treatment with vitamin K(2) or pamidronate. Moreover, our data showed that the suppression of TE expression by siRNA significantly increased Pi-induced vascular calcification.
  
  
  CONCLUSIONS
  Taken together, our study suggests that vitamin K(2) in combination with pamidronate synergistically inhibits arterial calcification via the increased expression of tropoelastin, which would be a useful marker for developing effective therapeutic or prophylactic agents for arterial calcification.
authors.affiliation: Department of Clinical Chemistry, Hoshi University School of Pharmacy and Pharmaceutical Sciences, Japan.
authors.forename: Eiji
authors.initials: E
authors.lastname: Saito
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Wachi
authors.forename: Fumiaki
authors.initials: F
authors.lastname: Sato
authors.forename: Hideki
authors.initials: H
authors.lastname: Sugitani
authors.forename: Yoshiyuki
authors.initials: Y
authors.lastname: Seyama
mesh_terms: D002114:Calcinosis / Q000188:drug therapy* / Q000517:prevention & control; D002478:Cells, Cultured; D004164:Diphosphonates / Q000494:pharmacology* / Q000627:therapeutic use; D004357:Drug Synergism; D004359:Drug Therapy, Combination; D006801:Humans; D009131:Muscle, Smooth, Vascular / Q000166:cytology*; D032389:Myocytes, Smooth Muscle / Q000166:cytology / Q000187:drug effects*; D000077268:Pamidronate; D014333:Tropoelastin / Q000235:genetics; D015854:Up-Regulation / Q000235:genetics; D024482:Vitamin K 2 / Q000494:pharmacology* / Q000627:therapeutic use
chemical_list: D004164:Diphosphonates; D014333:Tropoelastin; D024482:Vitamin K 2; D000077268:Pamidronate