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Hu S, Feng J, Wang M, Wufuer R, Liu K, Zhang Z, Zhang Y. Nrf1 is an indispensable redox-determining factor for mitochondrial homeostasis by integrating multi-hierarchical regulatory networks. Redox Biol 2022; 57:102470. [PMID: 36174386 PMCID: PMC9520269 DOI: 10.1016/j.redox.2022.102470] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/04/2022] [Accepted: 09/07/2022] [Indexed: 11/24/2022] Open
Abstract
To defend against a vast variety of challenges in oxygenated environments, all life forms have evolutionally established a set of antioxidants, detoxification, and cytoprotective systems during natural selection and adaptive survival, to maintain cell redox homeostasis and organ integrity in the healthy development and growth. Such antioxidant defense systems are predominantly regulated by two key transcription factors Nrf1 and Nrf2, but the underlying mechanism(s) for their coordinated redox control remains elusive. Here, we found that loss of full-length Nrf1 led to a dramatic increase in reactive oxygen species (ROS) and oxidative damages in Nrf1α-∕- cells, and this increase was not eliminated by drastic elevation of Nrf2, even though the antioxidant systems were also substantially enhanced by hyperactive Nrf2. Further studies revealed that the increased ROS production in Nrf1α-∕- resulted from a striking impairment in the mitochondrial oxidative respiratory chain and its gene expression regulated by nuclear respiratory factors, called αPalNRF1 and GABPNRF2. In addition to the antioxidant capacity of cells, glycolysis was greatly augmented by aberrantly-elevated Nrf2, so to partially relieve the cellular energy demands, but aggravate its mitochondrial stress. The generation of ROS was also differentially regulated by Nrf1 and Nrf2 through miR-195 and/or mIR-497-mediated UCP2 pathway. Consequently, the epithelial-mesenchymal transformation (EMT) of Nrf1α-∕- cells was activated by putative ROS-stimulated signaling via MAPK, HIF1α, NF-ƙB, PI3K and AKT, all players involved in cancer development and progression. Taken together, it is inferable that Nrf1 acts as a potent integrator of redox regulation by multi-hierarchical networks.
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Affiliation(s)
- Shaofan Hu
- Bioengineering College and Graduate School, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China; Chongqing University Jiangjin Hospital, School of Medicine, Chongqing University, No. 725 Jiangzhou Avenue, Dingshan Street, Jiangjin District, Chongqing, 402260, China; The Laboratory of Cell Biochemistry and Topogenetic Regulation, College of Bioengineering & Faculty of Medical Sciences, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China
| | - Jing Feng
- Bioengineering College and Graduate School, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China; Chongqing University Jiangjin Hospital, School of Medicine, Chongqing University, No. 725 Jiangzhou Avenue, Dingshan Street, Jiangjin District, Chongqing, 402260, China; The Laboratory of Cell Biochemistry and Topogenetic Regulation, College of Bioengineering & Faculty of Medical Sciences, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China
| | - Meng Wang
- Bioengineering College and Graduate School, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China; The Laboratory of Cell Biochemistry and Topogenetic Regulation, College of Bioengineering & Faculty of Medical Sciences, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China
| | - Reziyamu Wufuer
- Bioengineering College and Graduate School, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China; Chongqing University Jiangjin Hospital, School of Medicine, Chongqing University, No. 725 Jiangzhou Avenue, Dingshan Street, Jiangjin District, Chongqing, 402260, China; The Laboratory of Cell Biochemistry and Topogenetic Regulation, College of Bioengineering & Faculty of Medical Sciences, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China
| | - Keli Liu
- Bioengineering College and Graduate School, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China; Chongqing University Jiangjin Hospital, School of Medicine, Chongqing University, No. 725 Jiangzhou Avenue, Dingshan Street, Jiangjin District, Chongqing, 402260, China; The Laboratory of Cell Biochemistry and Topogenetic Regulation, College of Bioengineering & Faculty of Medical Sciences, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China
| | - Zhengwen Zhang
- Laboratory of Neuroscience, Institute of Cognitive Neuroscience and School of Pharmacy, University College London, 29-39 Brunswick Square, London, WC1N 1AX, England, United Kingdom
| | - Yiguo Zhang
- Chongqing University Jiangjin Hospital, School of Medicine, Chongqing University, No. 725 Jiangzhou Avenue, Dingshan Street, Jiangjin District, Chongqing, 402260, China; The Laboratory of Cell Biochemistry and Topogenetic Regulation, College of Bioengineering & Faculty of Medical Sciences, Chongqing University, No. 174 Shazheng Street, Shapingba District, Chongqing, 400044, China.
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Synergism and Antagonism of Two Distinct, but Confused, Nrf1 Factors in Integral Regulation of the Nuclear-to-Mitochondrial Respiratory and Antioxidant Transcription Networks. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2020; 2020:5097109. [PMID: 33376579 PMCID: PMC7744186 DOI: 10.1155/2020/5097109] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 08/09/2020] [Accepted: 10/16/2020] [Indexed: 12/30/2022]
Abstract
There is hitherto no literature available for explaining two distinct, but confused, Nrf1 transcription factors, because they shared the same abbreviations from nuclear factor erythroid 2-related factor 1 (also called Nfe2l1) and nuclear respiratory factor (originally designated α-Pal). Thus, we have here identified that Nfe2l1Nrf1 and α-PalNRF1 exert synergistic and antagonistic roles in integrative regulation of the nuclear-to-mitochondrial respiratory and antioxidant transcription profiles. In mouse embryonic fibroblasts (MEFs), knockout of Nfe2l1−/− leads to substantial decreases in expression levels of α-PalNRF1 and Nfe2l2, together with TFAM (mitochondrial transcription factor A) and other target genes. Similar inhibitory results were determined in Nfe2l2−/− MEFs but with an exception that both GSTa1 and Aldh1a1 were distinguishably upregulated in Nfe2l1−/− MEFs. Such synergistic contributions of Nfe2l1 and Nfe2l2 to the positive regulation of α-PalNRF1 and TFAM were validated in Keap1−/− MEFs. However, human α-PalNRF1 expression was unaltered by hNfe2l1α−/−, hNfe2l2-/-ΔTA, or even hNfe2l1α−/−+siNrf2, albeit TFAM was activated by Nfe2l1 but inhibited by Nfe2l2; such an antagonism occurred in HepG2 cells. Conversely, almost all of mouse Nfe2l1, Nfe2l2, and cotarget genes were downexpressed in α-PalNRF1+/- MEFs. On the contrary, upregulation of human Nfe2l1, Nfe2l2, and relevant reporter genes took place after silencing of α-PalNRF1, but their downregulation occurred upon ectopic expression of α-PalNRF1. Furtherly, Pitx2 (pituitary homeobox 2) was also identified as a direct upstream regulator of Nfe2l1 and TFAM, besides α-PalNRF1. Overall, these across-talks amongst Nfe2l1, Nfe2l2, and α-PalNRF1, along with Pitx2, are integrated from the endoplasmic reticulum towards the nuclear-to-mitochondrial communication for targeting TFAM, in order to finely tune the robust balance of distinct cellular oxidative respiratory and antioxidant gene transcription networks, albeit they differ between the mouse and the human. In addition, it is of crucial importance to note that, in view of such mutual interregulation of these transcription factors, much cautions should be severely taken for us to interpret those relevant experimental results obtained from knockout of Nfe2l1, Nfe2l2, α-Pal or Pitx2, or their gain-of-functional mutants.
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