TY - JOUR
T1 - Nrf2 regulates ROS production by mitochondria and NADPH oxidase
AU - Kovac, Stjepana
AU - Angelova, Plamena R.
AU - Holmström, Kira M.
AU - Zhang, Ying
AU - Dinkova-Kostova, Albena T.
AU - Abramov, Andrey Y.
PY - 2015
Y1 - 2015
N2 - Background Nuclear factor (erythroid-derived 2) factor 2 (Nrf2) is a crucial transcription factor mediating protection against oxidants. Nrf2 is negatively regulated by cytoplasmic Kelch-like ECH associated protein 1 (Keap1) thereby providing inducible antioxidant defence. Antioxidant properties of Nrf2 are thought to be mainly exerted by stimulating transcription of antioxidant proteins, whereas its effects on ROS production within the cell are uncertain. Methods Live cell imaging and qPCR in brain hippocampal glio-neuronal cultures and explants slice cultures with graded expression of Nrf2, i.e. Nrf2-knockout (Nrf2-KO), wild-type (WT), and Keap1-knockdown (Keap1-KD). Results We here show that ROS production in Nrf2-KO cells and tissues is increased compared to their WT counterparts. Mitochondrial ROS production is regulated by the Keap1-Nrf2 pathway by controlling mitochondrial bioenergetics. Surprisingly, Keap1-KD cells and tissues also showed higher rates of ROS production when compared to WT, although with a smaller magnitude. Analysis of the mRNA expression levels of the two NOX isoforms implicated in brain pathology showed, that NOX2 is dramatically upregulated under conditions of Nrf2 deficiency, whereas NOX4 is upregulated when Nrf2 is constitutively activated (Keap1-KD) to a degree which paralleled the increases in ROS production. Conclusions These observations suggest that the Keap1-Nrf2 pathway regulates both mitochondrial and cytosolic ROS production through NADPH oxidase. General significance Findings supports a key role of the Keap1-Nrf2 pathway in redox homeostasis within the cell.
AB - Background Nuclear factor (erythroid-derived 2) factor 2 (Nrf2) is a crucial transcription factor mediating protection against oxidants. Nrf2 is negatively regulated by cytoplasmic Kelch-like ECH associated protein 1 (Keap1) thereby providing inducible antioxidant defence. Antioxidant properties of Nrf2 are thought to be mainly exerted by stimulating transcription of antioxidant proteins, whereas its effects on ROS production within the cell are uncertain. Methods Live cell imaging and qPCR in brain hippocampal glio-neuronal cultures and explants slice cultures with graded expression of Nrf2, i.e. Nrf2-knockout (Nrf2-KO), wild-type (WT), and Keap1-knockdown (Keap1-KD). Results We here show that ROS production in Nrf2-KO cells and tissues is increased compared to their WT counterparts. Mitochondrial ROS production is regulated by the Keap1-Nrf2 pathway by controlling mitochondrial bioenergetics. Surprisingly, Keap1-KD cells and tissues also showed higher rates of ROS production when compared to WT, although with a smaller magnitude. Analysis of the mRNA expression levels of the two NOX isoforms implicated in brain pathology showed, that NOX2 is dramatically upregulated under conditions of Nrf2 deficiency, whereas NOX4 is upregulated when Nrf2 is constitutively activated (Keap1-KD) to a degree which paralleled the increases in ROS production. Conclusions These observations suggest that the Keap1-Nrf2 pathway regulates both mitochondrial and cytosolic ROS production through NADPH oxidase. General significance Findings supports a key role of the Keap1-Nrf2 pathway in redox homeostasis within the cell.
KW - Keap1
KW - NADPH oxidase
KW - NOX
KW - Nrf2
KW - ROS
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U2 - 10.1016/j.bbagen.2014.11.021
DO - 10.1016/j.bbagen.2014.11.021
M3 - Article
C2 - 25484314
AN - SCOPUS:84921814081
SN - 0304-4165
VL - 1850
SP - 794
EP - 801
JO - Biochimica et Biophysica Acta - General Subjects
JF - Biochimica et Biophysica Acta - General Subjects
IS - 4
ER -