A Proteomic Glance at the Bovine Intervertebral Disc.

Trauma- or age-inflicted intervertebral disc (IVD) degeneration (IVDD) is a leading cause of chronic and severe low back pain. Raising interest in regenerative, cell-based therapies depends on a solid understanding of cell identities and their natural habitat, most importantly the extracellular matrix (ECM) composition. We and others previously proposed IVD biomarkers to characterize IVD cells. To complement our transcriptome data, we also investigated the proteome of the annulus fibrosus (AF) and nucleus pulposus (NP) bovine coccygeal tissue via nano liquid chromatography electrospray ionization tandem quadrupole time-of-flight mass spectrometry (nano LC-ESI-qTOF-MS). The mature bovine coccygeal IVD is an accepted animal model to study IVD homeostasis. We performed both qualitative and quantitative analyses, identifying proteins involved with ECM homeostasis and metabolism. We discuss this information in relation to our previously published 2D in vitro transcriptome data and in the context of other significant progress made in the IVD omics field.