Figure 4.

ROS induces NUPR1 and antioxidants do not prevent NUPR1 induction by nickel (Ni). (A) Acute exposure to H₂O₂ induced NUPR1 expression. Total RNA was extracted from unexposed BEAS-2B cells and BEAS-2B cells exposed to 0.1 mM H₂O₂ for 6 h. (B) EGCG does not prevent NUPR1 induction by Ni. Total RNA was extracted from unexposed BEAS-2B cells, BEAS-2B cells exposed to 1.0 mM Ni for 6 h, BEAS-2B cells exposed to 0.025 mM EGCG for 6 h, and BEAS-2B cells co-treated with 0.025 mM EGCG and 1.0 mM Ni for 6 h. (C) Ascorbate (Asc) does not prevent NUPR1 induction by Ni. Total RNA was extracted from unexposed BEAS-2B cells, BEAS-2B cells exposed to 1.0 mM Ni for 6 h, BEAS-2B cells exposed to 100 µM ascorbate for 6 h, and BEAS-2B cells pre-treated with 100 µM ascorbate for 2 h and then exposed to 1.0 mM Ni for 6 h. (D) Vitamin E (Vit. E) was unable to significantly reduce NUPR1 induction by Ni. Total RNA was extracted from unexposed BEAS-2B cells, BEAS-2B cells exposed to 1.0 mM Ni for 6 h, BEAS-2B cells exposed to 100 µM vit. E for 6 h, and BEAS-2B cells pre-treated with 100 µM vit. E for 2 h and then exposed to 1.0 mM Ni for 6 h. NUPR1 mRNA levels were measured by RT-qPCR. Gene expression levels were normalized to actin, and are presented as fold change relative to the control group. All data shown are the mean ± SD from qPCRs performed in triplicate. **P<0.01; ns, not significant. ROS, reactive oxygen species; NUPR1, nuclear protein 1; EGCG, (−)-epigallocatechin gallate.