An investigation of BMP-7 mediated alterations to BMP signalling components in human tenocyte-like cells

Sci Rep. 2016 Jul 11:6:29703. doi: 10.1038/srep29703.

Abstract

The incidence of tendon re-tears post-surgery is an ever present complication. It is suggested that the application of biological factors, such as bone morphogenetic protein 7 (BMP-7), can reduce complication rates by promoting tenogenic characteristics in in vitro studies. However, there remains a dearth of information in regards to the mechanisms of BMP-7 signalling in tenocytes. Using primary human tenocyte-like cells (hTLCs) from the supraspinatus tendon the BMP-7 signalling pathway was investigated: induction of the BMP associated Smad pathway and non-Smad pathways (AKT, p38, ERK1/2 and JNK); alterations in gene expression of BMP-7 associated receptors, Smad pathway components, Smad target gene (ID1) and tenogenic marker scleraxis. BMP-7 increases the expression of specific BMP associated receptors, BMPR-Ib and BMPR-II, and Smad8. Additionally, BMP-7 activates significantly Smad1/5/8 and slightly p38 pathways as indicated by an increase in phosphorylation and proven by inhibition experiments, where p-ERK1/2 and p-JNK pathways remain mainly unresponsive. Furthermore, BMP-7 increases the expression of the Smad target gene ID1, and the tendon specific transcription factor scleraxis. The study shows that tenocyte-like cells undergo primarily Smad8 and p38 signalling after BMP-7 stimulation. The up-regulation of tendon related marker genes and matrix proteins such as Smad8/9, scleraxis and collagen I might lead to positive effects of BMP-7 treatment for rotator cuff repair, without significant induction of osteogenic and chondrogenic markers.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Antigens, Differentiation / biosynthesis
  • Antigens, Differentiation / genetics
  • Bone Morphogenetic Protein 7 / genetics
  • Bone Morphogenetic Protein 7 / metabolism*
  • Extracellular Matrix Proteins / biosynthesis
  • Extracellular Matrix Proteins / genetics
  • Gene Expression Regulation / physiology*
  • Humans
  • MAP Kinase Signaling System / physiology*
  • Male
  • Middle Aged
  • Signal Transduction / physiology*
  • Tendons / cytology
  • Tendons / metabolism*

Substances

  • Antigens, Differentiation
  • BMP7 protein, human
  • Bone Morphogenetic Protein 7
  • Extracellular Matrix Proteins