Bach1 differentially regulates distinct Nrf2-dependent genes in human venous and coronary artery endothelial cells adapted to physiological oxygen levels

TY - JOUR

T1 - Bach1 differentially regulates distinct Nrf2-dependent genes in human venous and coronary artery endothelial cells adapted to physiological oxygen levels

AU - Chapple, Sarah J.

AU - Keeley, Thomas P.

AU - Mastronicola, Daniela

AU - Arno, Matthew

AU - Vizcay-Barrena, Gema

AU - Fleck, Roland

AU - Siow, Richard

AU - Mann, Giovanni

PY - 2016/3/1

Y1 - 2016/3/1

N2 - The effects of physiological oxygen tension on Nuclear Factor-E2-Related Factor 2 (Nrf2)-regulated redox signaling remain poorly understood. We report the first study of Nrf2-regulated signaling in human primary endothelial cells (EC) adapted long-term to physiological O2 (5%). Adaptation of EC to 5% O2 had minimal effects on cell ultrastructure, viability, basal redox status or HIF1-α expression. Affymetrix array profiling and subsequent qPCR/protein validation revealed that induction of select Nrf2 target genes, HO-1 and NQO1, was significantly attenuated in cells adapted to 5% O2, despite nuclear accumulation and DNA binding of Nrf2. Diminished HO-1 induction under 5% O2 was stimulus independent and reversible upon re-adaptation to air or silencing of the Nrf2 repressor Bach1, notably elevated under 5% O2. Induction of GSH-related genes xCT and GCLM were oxygen and Bach1-insensitive during long-term culture under 5% O2, providing the first evidence that genes related to GSH synthesis mediate protection afforded by Nrf2-Keap1 defense pathway in cells adapted to physiological O2 levels encountered in vivo.

AB - The effects of physiological oxygen tension on Nuclear Factor-E2-Related Factor 2 (Nrf2)-regulated redox signaling remain poorly understood. We report the first study of Nrf2-regulated signaling in human primary endothelial cells (EC) adapted long-term to physiological O2 (5%). Adaptation of EC to 5% O2 had minimal effects on cell ultrastructure, viability, basal redox status or HIF1-α expression. Affymetrix array profiling and subsequent qPCR/protein validation revealed that induction of select Nrf2 target genes, HO-1 and NQO1, was significantly attenuated in cells adapted to 5% O2, despite nuclear accumulation and DNA binding of Nrf2. Diminished HO-1 induction under 5% O2 was stimulus independent and reversible upon re-adaptation to air or silencing of the Nrf2 repressor Bach1, notably elevated under 5% O2. Induction of GSH-related genes xCT and GCLM were oxygen and Bach1-insensitive during long-term culture under 5% O2, providing the first evidence that genes related to GSH synthesis mediate protection afforded by Nrf2-Keap1 defense pathway in cells adapted to physiological O2 levels encountered in vivo.

KW - Bach1

KW - Coronary artery

KW - Endothelial cells

KW - GCL

KW - Glutathione

KW - Glutathione reductase GR

KW - HO-1

KW - Mitochondria

KW - Normoxia

KW - NQO1

KW - NuclearFactor-E2-RelatedFactor2,Nrf2

KW - Physiologicaloxygentension

KW - Redoxsignaling

KW - Sequestosome-1

KW - Solute CarrierFamily7-anionicaminoacid

KW - Thioredoxinreductase-1

KW - transporterlightchainxCT

U2 - 10.1016/j.freeradbiomed.2015.12.013

DO - 10.1016/j.freeradbiomed.2015.12.013

M3 - Article

AN - SCOPUS:84958768283

SN - 0891-5849

VL - 92

SP - 152

EP - 162

JO - Free Radical Biology and Medicine

JF - Free Radical Biology and Medicine

IS - 0

ER -