Fig 2: PARP2 PARylates NRF2 and traps it in the nucleus.

Fig 3: The silecing of PARP2 does not interfere with the expression of the elements of the NRF2 system. (A,B) 200 000 cells from scPARP2 and shPARP2 C2C12 cells were seeded into a 6-well plate and the expression of PARP2 was determined by (A) RT-qPCR (n = 3) and (B) Western blotting (n = 3). (C,D) 200 000 cells from scPARP2 and shPARP2 C2C12 cells were seeded into a 6-well plate and the expression of NRF2 was determined by (C) RT-qPCR (n = 6) and (D) Western blotting (n = 3) using the antibodies indicated. (E,F) 200 000 cells from scPARP2 and shPARP2 C2C12 cells were seeded into a 6-well plate and the expression of (E) KEAP1 and (F) the indicated MAF genes was determined by RT-qPCR (n = 3). Numerical values are presented as the average ± SD. Statistical significance was determined using paired, two-tailed Student’s t-test. ***Represent statistically significant differences between the scPARP2 and shPARP2 C2C12 cells at p < 0.001. n.s.—not significant.

Fig 4: Silencing of PARP2 reduces the nuclear fraction of NRF2. 70 000 cells from scPARP2 and shPARP2 C2C12 cells were seeded into a 24-well plate on glass coverslips. The cells were stained with NRF2 specific antibody and nuclei were visualized using DAPI (n = 3). Images were analyzed using ImageJ software (50/50 cells were measured). For each biological replicate an average was generated that is depicted on the graph. Representative immunofluorescence images are presented in the figure. Numerical values are presented as the average ± SD. Statistical significance was determined using paired, two-tailed Student’s t-test. *Or **statistically significant differences between the scPARP2 and shPARP2 C2C12 cells at p < 0.05 or p < 0.01, respectively.

Fig 5: Silencing of PARP2 reorganizes the expression of antioxidant genes. (A,B) The expression of genes involved in antioxidant defense were assessed by the reanalysis of microarrays assessing (A) scPARP2 and shPARP2 C2C12 and (B) scPARP2 and shPARP2 HepG2 cells. (C) The differentially expressed redox genes identified upon the reanalysis of the microarrays were grouped as a function of the expression changes and were depicted in Venn-diagrams. In black, the NRF2-independent genes, in red the NRF2-dependent genes with similar changes between the microarray experiments. In blue, the NRF2-dependent genes with different expression between the microarray experiments.