title: Magnesium reduces calcification in bovine vascular smooth muscle cells in a dose-dependent manner.
abstract: BACKGROUND
  Vascular calcification (VC), mainly due to elevated phosphate levels, is one major problem in patients suffering from chronic kidney disease. In clinical studies, an inverse relationship between serum magnesium and VC has been reported. However, there is only few information about the influence of magnesium on calcification on a cellular level available. Therefore, we investigated the effect of magnesium on calcification induced by β-glycerophosphate (BGP) in bovine vascular smooth muscle cells (BVSMCs).
  
  
  METHODS
  BVSMCs were incubated with calcification media for 14 days while simultaneously increasing the magnesium concentration. Calcium deposition, transdifferentiation of cells and apoptosis were measured applying quantification of calcium, von Kossa and Alizarin red staining, real-time reverse transcription-polymerase chain reaction and annexin V staining, respectively.
  
  
  RESULTS
  Calcium deposition in the cells dramatically increased with addition of BGP and could be mostly prevented by co-incubation with magnesium. Higher magnesium levels led to inhibition of BGP-induced alkaline phosphatase activity as well as to a decreased expression of genes associated with the process of transdifferentiation of BVSMCs into osteoblast-like cells. Furthermore, estimated calcium entry into the cells decreased with increasing magnesium concentrations in the media. In addition, higher magnesium concentrations prevented cell damage (apoptosis) induced by BGP as well as progression of already established calcification.
  
  
  CONCLUSIONS
  Higher magnesium levels prevented BVSMC calcification, inhibited expression of osteogenic proteins, apoptosis and further progression of already established calcification. Thus, magnesium is influencing molecular processes associated with VC and may have the potential to play a role for VC also in clinical situations.
authors.affiliation: Division of Nephrology, Ege University School of Medicine, Izmir, Turkey. fatihkircelli@yahoo.com
authors.forename: Fatih
authors.initials: F
authors.lastname: Kircelli
authors.forename: Mirjam E
authors.initials: ME
authors.lastname: Peter
authors.forename: Ebru
authors.initials: E
authors.lastname: Sevinc Ok
authors.forename: Fatma Gul
authors.initials: FG
authors.lastname: Celenk
authors.forename: Mumtaz
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Sonja
authors.initials: S
authors.lastname: Steppan
authors.forename: Gulay
authors.initials: G
authors.lastname: Asci
authors.forename: Ercan
authors.initials: E
authors.lastname: Ok
authors.forename: Jutta
authors.initials: J
authors.lastname: Passlick-Deetjen
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000187:drug effects* / Q000502:physiology; D015153:Blotting, Western; D002417:Cattle; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured / Q000187:drug effects / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004797:Enzyme-Linked Immunosorbent Assay; D008274:Magnesium / Q000378:metabolism / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology* / Q000187:drug effects*; D060888:Real-Time Polymerase Chain Reaction / Q000379:methods; D061205:Vascular Calcification / Q000188:drug therapy* / Q000517:prevention & control
chemical_list: D008274:Magnesium