Extracellular matrix in intervertebral disc: basic and translational implications.

Intervertebral disc (IVD) degeneration (IVDD) is the most common spinal disorder, which can lead to the symptoms of neck pain or low back pain. In healthy mature IVD tissues, extracellular matrix (ECM) complex possesses favorable biochemical and biomechanical properties, withstanding compression and torsion forces. IVD cells and ECM associate with each other to form a coordinated functional system. IVD cells are the main producers of ECM components, while ECM could modulate the viability and phenotype of IVD cells via direct interactions or indirect regulations. However, with the process of IVDD and ageing, ECM of IVD undergoes content loss and structure degeneration. Moreover, the accumulation of catabolic products may further deteriorate the IVD microenvironment. A better understanding of the physiology and the pathology of ECM within the IVD provides new insight into potential IVD regeneration strategies. Natural ECM components, functional motifs, or mimetic peptides are widely used in IVD repair by not only restoring structural support but also regulating cell fate and tissue microenvironment. Herein, we reviewed recent advances in the involvement of ECM in IVD health and disease, with an emphasis on ECM composition and organization, cell-matrix interactions, pathological ECM degradation, and promising matrix-based biomaterials for IVD regeneration.