CST protected against IVD degeneration through regulating the NF-κB signalling pathway. (A) Relative mRNA expression of NF-κB1 in IVD tissues from 6-month-old WT and CST-/- mice, as measured by real-time PCR. Normalized values were calibrated against the wild-type (WT) group and given a value of 1 (n=5). (B) Immunohistochemistry to detect pIκBα in IVD tissues from 6-month-old WT and CST-/- mice (n=5). Scale bar, 150 µm. (C) Nuclear translocation of p65 in NP tissue was enhanced in CST-/- mice, as detected by immunofluorescence (n=5). Scale bar, 100 µm. (D) Representative immunofluorescence images for p65 in the cultured human NP cells of each indicated group (n=5). Nuclei were stained with DAPI. Scale bar, 100 µm. (E) Exogenous CST antagonized the nuclear translocation of NF-κB p65 in human NP cells, as assayed by Western blot analysis. Tubulin and Lamin A are shown as loading controls (n=5). **p<0.01 vs. the indicated control group. Data are presented as the mean ± SD.