FIGURE 5.

Cytokines modulate NOTCH2 expression through NF-κB/MAPK signaling in rat NP cells. A and B, activity of NOTCH2 promoter following IL-1β (A) and TNF-α (B) treatment for 24 h with or without NF-κB inhibitor (SM7368 (SM)) or JNK inhibitor (SP60025 (SP)) or p38 inhibitor (SB203580 (SB)) or ERK inhibitor (PD98059 (PD)). A significant blocking of cytokine-dependent induction in NOTCH2 promoter activity is seen by all inhibitors. C and D, real-time RT-PCR analysis of NOTCH2 expression shows significant blocking of cytokine dependent induction in NOTCH2 mRNA expression by the inhibitors. E and F, Western blot (E) and corresponding densitometric analysis shows that IL-1β-dependent (F) and TNF-α-dependent (G) increase in cleaved NOTCH2 level in NP cells was blocked by signaling inhibitors. Values shown are mean ± S.E. of three independent experiments; *, p < 0.05.