Molecular factors in intervertebral disc degeneration

The aim of this paper is to review the literature on molecular protein and messenger ribonucleic acid (mRNA) factors involved in intervertebral disc degeneration (IVDD). These elements were categorized basing on the changes in i) cell viability or number, ii) extracellular matrix (ECM) and iii) inflammation. Factors found to influence cell number and viability in IVDD included Fas/FasL, tumor necrosis factor related apoptosis-inducing ligand, death receptor-4/-5, bcl2-like 11, p53 inducible nuclear protein 1, p53/p21 factors, basic fibroblast growth factor and transforming growth factor-β. Factors found to affect IVD ECM included a range of matrix metalloproteinase, metalloproteinases with thrombospondin motifs, tissue inhibitors of metalloproteinases and disintegrins. Several proinflammatory factors have been identified in IVDD including interleukin-1β and TNF-α. The advent of protein and mRNA detection techniques has increased the understanding of IVDD from a molecular perspective. Further study of molecular protein and mRNA factors has the potential to identify and optimize therapeutic targets in the future.