Stromal cell-derived factor-1α promotes recruitment and differentiation of nucleus pulposus-derived stem cells

Figure 2 Expression of stromal cell-derived factor-1α and the condition of the degenerative disc. A and B: The mRNA (A) and protein (B) levels of stromal cell-derived factor-1α (SDF-1α) expressed in nucleus pulposus cells with pro-inflammatory cytokines were markedly increased compared with those in normal condition, based on real-time reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay; C: Immunohistochemical analysis showing the significant upregulation of SDF-1α in the degenerative disc. Data are expressed as the mean ± SD, n = 3, ^aP < 0.05. SDF-1α: Stromal cell-derived factor-1α; NP: Nucleus pulposus; IOD: Integrated optical density; TNF-α: Tumor necrosis factor-α; IL: Interleukin.