Fig. 6

Regulation of the CCN2 gene and protein by Wnt–β-catenin signaling via the mitogen-activated protein kinase (MAPK) pathway. a Western blot analysis of the CCN2 protein in nucleus pulposus (NP) cells after treatment with 6-bromoindirubin-3′-oxime (BIO) with the extracellular signal-related protein kinase (ERK) inhibitor PD98059 (PD) (25 μM) or the p38–MAPK inhibitor SB202190 (SB) (10 μM) in rat NP cells. β-actin was used as a loading control. Data are the mean and 95% CI. One-way analysis of variance with the Tukey-Kramer post-hoc test was used. Immunoblots shown are representative of experiments with similar results (n = 8 for each group). b Real-time RT-PCR analysis of CCN2 mRNA expression after treatment with BIO with the ERK inhibitor PD98059 (25 μM) or the p38–MAPK inhibitor SB202190 (10 μM) in rat NP cells. Data are the mean and 95% CI expressed as the fold change relative to the control (n = ≥ 7 for each group). c Densitometric analysis as shown (A) confirms that BIO treatment significantly decreased the activity of the CCN2 protein and this activity was suppressed by the MAPK inhibitors treatment. One-way ANOVA with the Tukey-Kramer post-hoc test was used