Since Nrf1 and Nrf2 are essential for regulating the lipid metabolism pathways, their dysregulation was also shown to be critically involved in the non-controllable inflammatory pathology into cancer development. However, it is unknown that the interaction between Nrf1 and Nrf2 in the regulation of lipid metabolism, especially in hepatoma cells. Here, we have further explored the molecular mechanisms underlying their distinct regulation of lipid metabolism, by comparative analysis of changes in those lipid metabolism-related genes in Nrf1α-/- and/or Nrf2-/- cell lines relative to wild-type controls. The results revealed that loss of Nrf1 leads to disordered lipid metabolism; its lipid synthesis pathway was up-regulated by JNK-Nrf2-AP1 signaling, while its lipid decomposition pathway was down-regulated by the nuclear receptor PPAR-PGC1 signaling, resulting in severe accumulation of lipids as deposited in lipid droplets. By contrast, knockout of Nrf2 gave rise to decreases in lipid synthesis and uptake capacity. These demonstrate that Nrf1 and Nrf2 contribute to significant differences in the cellular lipid metabolism regulatory profiles and relevant pathological responses. Further experiments unraveled that lipid deposition in Nrf1α-/- cells was resulted from CD36 upregulation by activating the PI3K-AKT-mTOR pathway, leading to induction of the inflammatory response. Following treatment of Nrf1[alpha]-/- cells with 2-bromopalmitate (2BP), it enabled the yield of lipid droplets to be strikingly alleviated, as companied by substantial abolishment of CD36 and critical inflammatory cytokines. Such Nrf1[alpha]-/--led inflammatory accumulation of lipids and ROS was significantly ameliorated by 2BP. Overall, this study provides a potential strategy for cancer prevention and treatment by precision targeting of Nrf1, Nrf2, or both.

All living organisms have undergone the evolutionary selection under the changing natural environments to survive as diverse life forms. All life processes including normal homeostatic development and growth into organismic bodies with distinct cellular identifications, as well as their adaptive responses to various intracellular and environmental stresses, are tightly controlled by signaling of transcriptional networks towards regulation of cognate genes by many different transcription factors. Amongst them, one of the most conserved is the basic-region leucine zipper (bZIP) family. They play vital roles essential for cell proliferation, differentiation and maintenance in complex multicellular organisms. Notably, an unresolved divergence on the evolution of bZIP proteins is addressed here. By a combination of bioinformatics with genomics and molecular biology, we have demonstrated that two of the most ancestral family members classified into BATF and Jun subgroups are originated from viruses, albeit expansion and diversification of the bZIP superfamily occur in different vertebrates. Interestingly, a specific ancestral subfamily of bZIP proteins is identified and also designated Nach (Nrf and CNC homology) on account of their highly conservativity with NF-E2 p45 subunit-related factors Nrf1/2. Further experimental evidence reveals that Nach1/2 from the marine bacteria exerts distinctive functions from Nrf1/2 in the transcriptional ability to regulate antioxidant response element (ARE)-driven cytoprotective genes. Collectively, an insight into Nach/CNC-bZIP proteins provides a better understanding of distinct biological functions between these factors selected during evolution from the marine bacteria to human. Significance:We identified the novel ancestral subfamily (i.e. Nach) of CNC-bZIP transcription factors with highly conservativity from marine bacteria to human. Combination of bioinformatics with genomics and molecular biology demonstrated that two of the most ancestral family members classified into BATF and Jun subgroups are originated from viruses. The Jun and CNC subfamilies also share a common origin of these bZIP proteins. Further experimental evidence reveals that Nach1/2 from the marine bacteria exerts nuance functions from human Nrf1/2 in the transcriptional ability to regulate antioxidant response element (ARE)-driven genes, responsible for the host cytoprotection against inflammation and cancer. Overall, this study is of multidisciplinary interests to provide a better understanding of distinct biological functions between Nach/CNC-bZIPs selected during evolution. Short title:Nach is a novel ancestral group of CNC-bZIP factors 2 protein-1 (AP-1)-binding site, in order to control the transcriptional expression of cognate genes and display relevant functional performances in many ways (3,4).One of the most conserved TFs is the basic-region leucine zipper (bZIP) superfamily. They are involved in the transcriptional regulation of distinct subsets of target genes by forming diverse functional homodime...