Actively synthesised proteins in human intervertebral disc

The intervertebral disc (IVD) is a joint in the spine that facilitates daily movement, comprising of the central nucleus pulposus (NP), surrounded by the annulus fibrosus (AF) and sandwiched between two cartilage endplates that function together as a unit. Changes to the IVD occur with aging, most drastically in the NP where it experiences dehydration and loss of cellularity, directly impacting on the integrity of the biomechanical functions of the IVD. Whilst the static proteome reflects the long-term accumulation of proteins and their turnover over the lifetime of the IVD, this information may not reflect immediate cellular changes that may alter during the course of time. To gain a better understanding of cellular function and protein turnover in disc homeostasis (health) versus aging, we analysed the actively synthesized proteins using the SILAC approach. Clinical specimens from spine surgeries for scoliosis (young samples; NP n=2, AF n=4) or degeneration (aged samples; NP n=1, AF n=1) were used in this study.