Fig. 1.

Disc-matrix metabolism: balance of synthesis and degradation. a In the homeostatic state, the disc undergoes matrix synthesis and degradation in a balanced manner. b As the disc matrix undergoes a turnover during the course of an individual’s lifetime, any small imbalance between synthesis and degradation can lead to significant changes in overall disc-matrix content. c One of the major goals of molecular therapy of the disc involves modulating this metabolic balance to the more favorable anabolic state. This can be accomplished by increasing the synthesis or decreasing the catabolism