Stromal cell-derived factor-1 and vascular endothelial growth factor may play an important role in the process of neovascularization of herniated intervertebral discs.

Increased levels of stromal cell-derived factor (SDF)-1 occur in certain pathological situations, however the relationship between SDF-1alpha expression and human intervertebral disc herniation is unknown. Vascular endothelial growth factor (VEGF) plays an essential role in the formation of new blood vessels. The present study used immunohistochemistry to measure the expression of SDF-1alpha and VEGF in surgical specimens of human intervertebral discs to evaluate their role in neovascularization. The frequency of expression of SDF-1alpha and VEGF was found to be significantly higher in extruded and sequestrated herniated intervertebral discs compared with bulging, protruding and prolapsed herniated discs and control discs and there was high correlation between SDF-1alpha and VEGF expressions. It is concluded that SDF-1alpha and VEGF are expressed in human intervertebral discs and their interaction may be important in accumulating endothelial progenitor cells during the neovascularization processes in herniated intervertebral discs.