Figure 5. Genomic Antagonism between VDR and SMAD.
(A) and (B) Plots of VDR and SMAD3 ChIP-Seq signal intensity relative to the center of VDR/SMAD3 co-occupied sites in LX-2 cells (TGFβ1 (1ng/ml) ± calcipotriol (100nM) for 4 hours). (C) Representative ChIP-Seq reads aligned to COL1A1 for VDR and SMAD3 in treated LX-2 cells (Vehicle (DMSO), Calcipotriol (Cal, 100nM), TGFβ1 (1ng/ml), or TGFβ1+calcipotriol). The three co-occupied sites are designated as 1, 2 and 3. (D) and (F) ChIP-qPCR at COL1A1 regulatory region #1 co-bound by VDR and SMAD3 in LX-2 cells treated as above. (E) and (G) ChIP-qPCR at COL1A1 regulatory region #1 of control (siCNTL), VDR-specific (siVDR), or SMAD3-specific (siSMAD3) siRNA transfected LX-2 cells treated as above. Occupancy is expressed relative to input chromatin. Data represents the mean ± SEM of at least three independent experiments performed in triplicate. Asterisks denote statistically significant differences (Student’s t-test, *p < 0.05, **p < 0.01). See also Fig. S6 & S7.