Potentiated interaction between NF-κB and cbs promoter regions. The specific anti-p65 antibody or CON normal mouse IgG was used for immunoprecipitation. A, B, Products of PCR amplifications for P1 (192 bp) and P2 (258 bp) from the proximal region of the cbs promoter. ChIP assays indicated a significant increase in binding activity of p65 with the first binding site of promoter of cbs gene in diabetic rats (n = 3 sample, 2 rats for each sample) compared with age- and sex-matched CON rats (n = 3 sample, 2 rats for each sample, **p < 0.01 compared with CON, 2-sample t test). C, D, ChIP assays indicated a significant increase in binding activity of p65 with the second binding site of promoter of cbs gene in diabetic rats (n = 3 sample, 2 rats for each sample) compared with age- and sex-matched CON rats (n = 3, each for 2 rats, *p < 0.05 compared with CON, 2-sample t test). E, STZ injection significantly enhanced the expression of p65 in T7–T10 DRGs (CON, n = 5, STZ, n = 4, *p < 0.05 compared with CON, 2-sample t test). F, STZ injection did not significantly alter expression of p65 in T7–T10 DRGs in N-DM rats (n = 4) compared with CON (n = 4) (p > 0.05, 2-sample t test). G, Administration of PDTC at different doses (once daily for consecutive 7 d) dramatically reduced the expression of CBS mRNA (STZ + NS, n = 4; n = 3 for other each group, **p < 0.01 compared with STZ + NS group; Tukey post hoc test after one-way ANOVA). H, Administration of PDTC (50 mg/kg once daily for consecutive 7 d) dramatically reduced CBS expression at the protein level (STZ + NS, n = 4; STZ + PDTC, n = 5, *p < 0.05 compared with NS group, 2-sample t test).