C-type natriuretic peptide enhances osteogenic protein-1-induced osteoblastic cell differentiation via smad5 phosphorylation

Lee Chuan C. Yeh, Michelle C. Zavala, John C. Lee

Research output: Contribution to journalArticle

19 Scopus citations

Abstract

In the present study, we examined the hypothesis that the C-type natriuretic peptide (CNP) enhances osteogenic protein-1 (OP-1) action in stimulating osteoblastic cell differentiation in primary cultures of fetal rat calvaria cell (FRC). CNP enhanced synergistically the OP-1-induced Alkaline Phosphatase (AP) activity and mineralized bone nodule formation in a dose- and time-dependent manner. To examine possible mechanism of the synergy between OP-1 and CNP, the expression levels of key BMP receptors and signaling molecules were examined. Western blot analysis showed that BMPR-IB and -II receptor protein expression was not affected by CNP alone, but was stimulated by OP-1 alone. The combination of OP-1 and CNP did not further increase their protein levels. The Runx2 protein expression level was not altered by CNP alone, but was elevated by OP-1 alone, and was slightly reduced by the combination. The Smad5 protein expression level was slightly decreased by CNP alone, but was stimulated by OP-1 alone, and was not further stimulated by the combination. SmadS phosphorylation was not stimulated by CNP alone, but was stimulated significantly by OP-1 alone. The combination of OP-1 and CNP further stimulated the OP-1-induced Smad5 phosphorylation. Thus, one mechanism of the observed synergy between OP-1 and CNP involves enhancement of the Smad5 phosphorylation.

Original languageEnglish (US)
Pages (from-to)494-500
Number of pages7
JournalJournal of Cellular Biochemistry
Volume97
Issue number3
DOIs
StatePublished - Feb 15 2006

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Keywords

  • Bone morphogenetic protein-7
  • C-natriuretic peptide
  • Osteoblast differentiation
  • Osteogenic protein-1
  • Smads
  • Synergy

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Cell Biology

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