Platelet-derived growth factor receptor signaling is required for postnatal tendon growth. Mus musculus

Platelet-derived growth factor receptor (PDGFR) signaling plays an important role in the embryonic formation of many different tissues. There is a family of PDGF isoforms which signal through the PDGF receptors α (PDGFRα) and β (PDGFRβ). PDGF regulates many key cellular processes of mesenchymal cell function including proliferation, differentiation, migration and extracellular matrix (ECM) synthesis. While PDGF has been used to enhance flexor tendon healing in vivo, its role in postnatal tendon growth has remained largely unexplored. To determine the importance of PDGFR signaling in postnatal tendon growth, we performed pharmacological blockade of PDGFRα and PDGFRβ, and then induced tendon growth via mechanical overload using the hindlimb synergist ablation model. Our hypothesis was that inhibition of PDGFR signaling will restrict normal growth of tendon tissue in response to mechanical loading. Overall design: 10 pooled samples total. Equal amounts of RNA isolated from four individual tendons were pooled into a single sample for microarray analysis, and two pooled samples from each group were analyzed. RNA was pooled because gene expression from a pooled sample is similar to the average of the individual samples composing the pooled sample.