Tumor necrosis factor-alpha increases alkaline phosphatase expression in vascular smooth muscle cells via MSX2 induction

Biochem Biophys Res Commun. 2010 Jan 1;391(1):1087-92. doi: 10.1016/j.bbrc.2009.12.027. Epub 2009 Dec 14.


Vascular calcification is implicated in many diseases including atherosclerosis and diabetes. Tumor necrosis factor-alpha (TNF-alpha) has been shown to promote vascular calcification both in vitro and in vivo. However, the molecular mechanism of TNF-alpha-mediated vascular calcification has not yet been fully defined. Therefore, in this study, we aimed to investigate whether MSX2 acts as a crucial regulator in TNF-alpha-induced vascular calcification and to define the regulatory mechanism of MSX2 induction in human vascular smooth muscle cells (VSMCs). TNF-alpha increased the expression of osteogenic marker genes including RUNX2, osterix, alkaline phosphatase (ALP), and bone sialoprotein, and it also promoted matrix mineralization in VSMCs. In addition, TNF-alpha enhanced MSX2 expression in a dose- and time-dependent manner. MSX2 over-expression alone induced ALP expression, whereas knockdown of MSX2 with small interfering RNA completely blocked TNF-alpha-induced ALP expression. New protein synthesis was dispensable for MSX2 induction by TNF-alpha, and the inhibition of NF-kappaB by BAY-11-7082 or by dominant negative IkappaBalpha abolished the TNF-alpha-directed induction of MSX2 expression. However, inhibition of NADPH oxidase did not affect MSX2 expression. In conclusion, our study suggests that TNF-alpha directly induces MSX2 expression through the NF-kappaB pathway, which in turn induces expression of ALP, a key molecule in mineralization, in VSMCs.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Alkaline Phosphatase / biosynthesis*
  • Calcinosis / metabolism*
  • Cells, Cultured
  • Homeodomain Proteins / metabolism*
  • Humans
  • Muscle, Smooth, Vascular / drug effects
  • Muscle, Smooth, Vascular / enzymology*
  • Myocytes, Smooth Muscle / drug effects
  • Myocytes, Smooth Muscle / enzymology
  • NF-kappa B / metabolism
  • Osteogenesis
  • Tumor Necrosis Factor-alpha / metabolism*
  • Tumor Necrosis Factor-alpha / pharmacology


  • Homeodomain Proteins
  • MSX2 protein
  • NF-kappa B
  • Tumor Necrosis Factor-alpha
  • Alkaline Phosphatase