Expression And Significance Of Stromal Cell-derived Factor-lalpha And Vascular Endothelial Growth Factor In Degenerated Intervertebral Disc

IntroductionNormally,few blood vessels exist in the mature human intervertebral disc.With aging the small blood vessels appear gradually in the human intervertebral disc tissue. Increased stromal cell-derived factor(SDF)-1 level is seen in some pathological situations.However,the association between SDF-1αexpression and pathologic conditions of the human intervertebral disc is unknown.VEGF plays an essential role in the formation of new blood vessels.Here,Surgical specimens of SDF-1αhuman intervertebral disc were collected for the study of and vascular endothelial growth factor(VEGF) using immunohistochemical staining to study the expression of SDF-1αand VEGF in human intervertebral discs,and to evaluate the role of SDF-1αand VEGF in the neovascularization of herniated discs.Materials and MethodsTwenty-seven specimens of human lumbar intervertebral disc were collected from 25 patients following surgical discectomy in the treatment of various pathologic conditions.There were 14 men and 11 women,and their ages were 17-69 years (average 43.8).the specimens of herniated intervertebral disc were divided into general group(n=11,bulging,protrusion,prolapsed) and serious group(n=9,extruded, sequestrated).For the control group,the intervertebral disc specimens came from patients with spine burst fractures(n=7).Surgical specimens of human intervertebral disc were collected for the study of stromal cell-derived factor(SDF)-lalpha and vascular endothelial growth factor(VEGF) using immunohistochemical staining to study the expression of SDF-1αand VEGF in human intervertebral discs,The total number of cells and number of positive cells was randomly counted in 10 fields in high-power field(×100),and the proportion of the immunoreactive cells among the immunoreactive cells among the total cells was presented as a percentage.The nonparametric Mann-Whitney U Test was used to determine the differences among each group.The Spearman Rank coefficient was used to determine correlation between SDF-1αand VEGF.In this study,P＜=0.05 was considered as significant difference.ResultsThis study has demonstrated the presence of SDF-1αand VEGF in human intervertebral discs using immunohistochemical staining,and both of their expression are highest in the serious group of herniated nucleus pulposus.The difference of expression was statistically significant(P＜0.001).A high correlation was presemed in the expression of SDF-1αand VEGF(r_s = 0.74,P＜0.01).ConclusionSDF-1αand VEGF are expressed in the human intervertebral discs.Based on the biological functions of SDF-1 and VEGF,our findings suggest that the interaction between SDF-1αand VEGF may play a important role in the process for the neovascularization of herniated intervertebral disc tissue.