CCN4/WISP-1 positively regulates chondrogenesis by controlling TGF-β3 function

Bone. 2016 Feb:83:162-170. doi: 10.1016/j.bone.2015.11.007. Epub 2015 Nov 10.

Abstract

The CCN family of proteins plays important roles in development and homeostasis of bone and cartilage. To understand the role of CCN4 in chondrogenesis, human bone marrow stromal cells (hBMSCs) were transduced with CCN4 adenovirus (adCCN4) or siRNA to CCN4 (siCCN4) in the presence or absence of transforming growth factor-β3 (TGF-β3). Overexpression of CCN4 enhanced TGF-β3-induced SMAD2/3 phosphorylation and chondrogenesis of hBMSCs in an in vitro assay using a micromass culture model. On the other hand, knockdown of CCN4 inhibited the TGF-β3-induced SMAD2/3 phosphorylation and synthesis of cartilage matrix in micromass cultures of hBMSCs. Immunoprecipitation-western blot analysis revealed that CCN4 bound to TGF-β3 and regulated the ability of TGF-β3 to bind to hBMSCs. In vivo analysis confirmed there was a significant decrease in the gene expression levels of chondrocyte markers in cartilage samples from Ccn4-knock out (KO) mice, compared to those from wild type (WT) control. In order to investigate the regenerative properties of the articular cartilage in Ccn4-KO mice, articular cartilage defects were surgically performed in the knee joints of young mice, and the results showed that the cartilage was partially repaired in WT mice, but not in Ccn4-KO mice. In conclusion, these results show, for the first time, that CCN4 has a positive influence on chondrogenic differentiation by modulating the effects of TGF-β3.

Keywords: Articular cartilage; Bone marrow stromal cell (BMSC); CCN4/WISP-1; Chondrogenesis; TGF-β3.

Publication types

  • Research Support, N.I.H., Intramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Biomarkers / metabolism
  • CCN Intercellular Signaling Proteins / genetics
  • CCN Intercellular Signaling Proteins / metabolism*
  • Cartilage, Articular / pathology
  • Cell Differentiation
  • Cells, Cultured
  • Chondrogenesis* / genetics
  • Gene Expression Regulation
  • Humans
  • Mesenchymal Stem Cells / cytology
  • Mice, Knockout
  • Phosphorylation
  • Protein Binding
  • Proto-Oncogene Proteins / genetics
  • Proto-Oncogene Proteins / metabolism*
  • Real-Time Polymerase Chain Reaction
  • Regeneration
  • Signal Transduction / genetics
  • Smad Proteins / metabolism
  • Transforming Growth Factor beta3 / metabolism*
  • Wound Healing

Substances

  • Biomarkers
  • CCN Intercellular Signaling Proteins
  • CCN4 protein, human
  • CCN4 protein, mouse
  • Proto-Oncogene Proteins
  • Smad Proteins
  • Transforming Growth Factor beta3