Figure 8.

Schematic of the regulation of catabolic and anti-anabolic actions of FGF2 in intervertebral disc cells. Fibroblast growth factor 2 (FGF2) activates the mitogen-activated protein kinase (MAPK) and NF-κB pathways, which upregulate both MMP-13 and noggin gene expression. The upregulation of the noggin gene inhibits the anabolic transforming growth factor beta/bone morphogenetic protein signaling pathway, leading to decreased proteoglycan (PG) production.