PDGF-AA promotes osteogenic differentiation and migration of mesenchymal stem cell by down-regulating PDGFRα and derepressing BMP-Smad1/5/8 signaling

PLoS One. 2014 Dec 3;9(12):e113785. doi: 10.1371/journal.pone.0113785. eCollection 2014.

Abstract

Platelet-derived growth factors (PDGFs) play important roles in skeletal development and bone fracture healing, yet how PDGFs execute their functions remains incompletely understood. Here we show that PDGF-AA, but not -AB or -BB, could activate the BMP-Smad1/5/8 pathway in mesenchymal stem cells (MSCs), which requires BMPRIA as well as PDGFRα. PDGF-AA promotes MSC osteogenic differentiation through the BMP-Smad1/5/8-Runx2/Osx axis and MSC migration via the BMP-Smad1/5/8-Twist1/Atf4 axis. Mechanistic studies show that PDGF-AA activates BMP-Smad1/5/8 signaling by feedback down-regulating PDGFRα, which frees BMPRI and allows for BMPRI-BMPRII complex formation to activate smad1/5/8, using BMP molecules in the microenvironment. This study unravels a physical and functional interaction between PDGFRα and BMPRI, which plays an important role in MSC differentiation and migration, and establishes a link between PDGF-AA and BMPs pathways, two essential regulators of embryonic development and tissue homeostasis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Blotting, Western
  • Bone Morphogenetic Protein 2 / metabolism*
  • Bone Morphogenetic Protein Receptors, Type I / deficiency
  • Bone Morphogenetic Protein Receptors, Type I / genetics
  • Cell Differentiation / drug effects*
  • Cell Movement / drug effects*
  • Cells, Cultured
  • Down-Regulation / drug effects
  • Mesenchymal Stem Cells / drug effects*
  • Mesenchymal Stem Cells / metabolism
  • Mice, Inbred C57BL
  • Mice, Knockout
  • Osteogenesis / genetics
  • Platelet-Derived Growth Factor / pharmacology*
  • Protein Binding
  • RNA Interference
  • Receptor, Platelet-Derived Growth Factor alpha / genetics
  • Receptor, Platelet-Derived Growth Factor alpha / metabolism*
  • Signal Transduction / drug effects
  • Smad Proteins / metabolism*
  • Smad1 Protein / metabolism
  • Smad5 Protein / metabolism
  • Smad8 Protein / metabolism

Substances

  • Bmp2 protein, mouse
  • Bone Morphogenetic Protein 2
  • Platelet-Derived Growth Factor
  • Smad Proteins
  • Smad1 Protein
  • Smad5 Protein
  • Smad8 Protein
  • platelet-derived growth factor A
  • Receptor, Platelet-Derived Growth Factor alpha
  • Bmpr1a protein, mouse
  • Bone Morphogenetic Protein Receptors, Type I

Grants and funding

The work was supported by grants from the Ministry of Science and Technology of China (The National Key Scientific Program (2012CB966901, to BL))(http://www.most.gov.cn/) and the National Natural Science Foundation of China (81130039, 31071229, and 81121001(http://www.nsfc.gov.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.