Synergism and Antagonism of Two Distinct, but Confused, Nrf1 Factors in Integral Regulation of the Nuclear-to-Mitochondrial Respiratory and Antioxidant Transcription Networks

Figure 1

Distinct effects of Nfe2l1^-/-and Nfe2l2^-/- on the basal expression of mouse α-Pal^NRF1, TFAM, and relevant genes in MEFs. (a) The mRNA levels of Nfe2l1 and Nfe2l2, as well as indicated antioxidant genes, were determined by real-time qPCR of Nfe2l1^-/- and Nfe2l1^+/+ MEFs. The data are shown as () with significant decreases (, ) or increases ($, ; $$, ). (b) Distinct Nfe2l1 isoforms, along with a loading control β-actin, were also examined by Western blotting of Nfe2l1^-/- and Nfe2l1^+/+ MEFs. (c) Changes in basal protein levels of Nfe2l2 and antioxidant enzymes HO-1, GCLM, SOD1, and Aldh1a1 between Nfe2l1^-/- and Nfe2l1^+/+ MEFs were also observed. (d) Alterations in the basal mRNA expression levels of α-pal^NRF1, COX5a, TFAM, Ndufv1, Ndufb6, and SOD1 were unraveled by real-time qPCR of Nfe2l1^-/- and Nfe2l1^+/+ MEFs. The results are shown as () with significant decreases (, ). (e) Altered proteins of α-Pal^NRF1, TFAM, and SOD1 between Nfe2l1^-/- and Nfe2l1^+/+ MEFs were visualized by Western blotting. (f) A model is proposed to present possible effects of Nfe2l1^-/- on the basal expression of Nfe2l2, α-Pal^NRF1, TFAM, and relevant genes in MEFs. (g) Basal mRNA levels of Nfe2l1 and Nfe2l2, as well as indicated antioxidant genes, in between Nfe2l2^-/- and Nfe2l2^+/+ MEFs were also comparatively analyzed. The results are shown as () with significant decreases (, ) or ND (no statistical difference). (h) Distinct abundances of Nfe2l2 and antioxidant enzymes in between Nfe2l2^-/- and Nfe2l2^+/+ MEFs were determined by Western blotting. (i) Altered abundances of distinct Nfe2l1 isoforms in Nfe2l2^-/- from Nfe2l2^+/+ MEFs were found. (j) The mRNA expression levels of α-Pal^NRF1, COX5a, TFAM, Ndufv1, Ndufb6, and SOD1 were analyzed by comparing real-time qPCR data from Nfe2l2^-/- and Nfe2l2^+/+ MEFs. The results are shown as () with significant decreases (, ) or ND (no statistical difference). (k) Abundances of α-Pal^NRF1, TFAM, and SOD1 were compared by immunoblotting of Nfe2l2^-/- with Nfe2l2^+/+ MEFs. (l) Another model is proposed to present potential influence of Nfe2l2^-/- on Nfe2l1, α-Pal^NRF1, TFAM, and relevant genes (and their proteins) in MEFs.

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