Fibroblast growth factor 10 regulates Meckel's cartilage formation during early mandibular morphogenesis in rats.

Fibroblast growth factors (FGF) are pluripotent growth factors that play pivotal roles in the development of various organs. During mandibular organogenesis, Meckel's cartilage, teeth, and mandibular bone differentiate under the control of various FGF. In the present study, we evaluated the role of FGF10 in rat mandibular chondrogenesis and morphogenesis using mandibular organ culture and mandibular cell micromass culture systems. The overexpression of Fgf10 induced by the electroporation of an FGF10 expression vector not only altered the size and shape of Meckel's cartilage, but also upregulated the expression of the cartilage characteristic genes Col2a1 and Sox9 in a mandibular organ culture system. Meckel's cartilage was deformed, and its size was increased when Fgf10 was overexpressed in the lateral area of the mandible. Meanwhile, no effect was found when Fgf10 was overexpressed in the medial portion. In the mandibular cell micromass culture, recombinant FGF10 treatment enhanced chondrogenic differentiation and endogenous ERK (extracellular signal-regulated kinase) phosphorylation in cells derived from the lateral area of the mandible. On the other hand, FGF10 did not have significant effects on mandibular cell proliferation. These results indicate that FGF10 regulates Meckel's cartilage formation during early mandibular morphogenesis by controlling the cell differentiation in the lateral area of the mandibular process in rats.