Figure 1. ZIP4 expression changes in NP cells after treatment with IL-1β or H2O2. (A, B) NP cells were treated with IL-1β (5, 10, 20, 50 ng/ml) for 24 hours. RT-PCR and western blotting were used to check ZIP4, MMP3, MMP13, collagen II, and aggrecan mRNA and protein profiles in NP cells. (C, D) NP cells were treated with H2O2 (10, 25, 50, and 100 μM) for 24 hours. RT-PCR and western blotting were used to determine ZIP4, MMP3, MMP13, collagen II, and aggrecan mRNA and protein profiles in NP cells. N=3. *P<0.05, **P<0.01, ***P<0.001 (vs. CON).