Platelet-derived growth factor enhances proliferation and matrix synthesis of temporomandibular joint disc-derived cells.

Platelet-derived growth factor (PDGF) is an essential signaling molecule for wound healing and tissue repair. This study was aimed at evaluating the effect of PDGF on the proliferation of temporomandibular joint (TMJ) disc-derived cells and extracellular matrix synthesis. The number of cultured cells were counted by COULTER Z1. The assay for collagen synthesis was performed using a sircol soluble collagen assay. Hyaluronic acid (HA) synthesis was analyzed by a high performance liquid chromatography. The expression of collagens, matrix metalloproteinases (MMPs), and the tissue inhibitors of metalloproteinases (TIMPs) were examined using SYBR Green in terms of the RNA levels. PDGF treatment significantly (P < .01) increased the proliferation rate of the disc-derived cells as compared with the controls when the dose was 5 ng/ mL or greater. Treatment with more than 5 ng/mL PDGF resulted in an amount of collagen synthesis significantly (P < .01) higher than the controls. HA synthesis was maximal with 5 ng/mL PDGF treatment. Quantitative real-time polymerase chain reaction analyses showed that treatment with 5 ng/mL of PDGF-BB upregulated the mitochondrial RNA levels of type I and II collagens, MMPs, and TIMPs within 6 hours. It is concluded that PDGF, if its concentration is optimal, enhanced proliferation and matrix synthesis of TMJ disc-derived cells, indicating that PDGF may be effective for use in tissue engineering of the TMJ disc.