tx9b00399_si_001.pdf (879.79 kB)
Induction of the Antioxidant Response by the Transcription Factor NRF2 Increases Bioactivation of the Mutagenic Air Pollutant 3‑Nitrobenzanthrone in Human Lung Cells
journal contribution
posted on 2019-11-20, 12:39 authored by Jessica
R. Murray, Laureano de la Vega, John D. Hayes, Ling Duan, Trevor M. Penning3-Nitrobenzanthrone (3-NBA) is a suspected human carcinogen
present
in diesel exhaust. It requires metabolic activation via nitroreduction
in order to form DNA adducts and promote mutagenesis. We have determined
that human aldo-keto reductases (AKR1C1–1C3) and NAD(P)H:quinone
oxidoreductase 1 (NQO1) contribute equally to the nitroreduction of
3-NBA in lung epithelial cell lines and collectively represent 50%
of the nitroreductase activity. The genes encoding these enzymes are
induced by the transcription factor NF-E2 p45-related factor 2 (NRF2),
which raises the possibility that NRF2 activation exacerbates 3-NBA
toxification. Since A549 cells possess constitutively active NRF2,
we examined the effect of heterozygous (NRF2-Het) and homozygous NRF2
knockout (NRF2-KO) by CRISPR-Cas9 gene editing on the activation of
3-NBA. To evaluate whether NRF2-mediated gene induction increases
3-NBA activation, we examined the effects of NRF2 activators in immortalized
human bronchial epithelial cells (HBEC3-KT). Changes in AKR1C1–1C3
and NQO1 expression by NRF2 knockout or use of NRF2 activators were
confirmed by qPCR, immunoblots, and enzyme activity assays. We observed
decreases in 3-NBA activation in the A549 NRF2 KO cell lines (53%
reduction in A549 NRF2-Het cells and 82% reduction in A549 NRF2-KO
cells) and 40–60% increases in 3-NBA bioactivation due to NRF2
activators in HBEC3-KT cells. Together, our data suggest that activation
of the transcription factor NRF2 exacerbates carcinogen metabolism
following exposure to diesel exhaust which may lead to an increase
in 3-NBA-derived DNA adducts.
History
Usage metrics
Categories
Keywords
NADenzyme activity assaysAKR 1Cform DNA adductstranscription factor NF-E 2 p 45-related factor 2diesel exhaustNRF 2-mediated gene induction increases 3- NBA activation3- NBA toxification549 NRF 2-Het cellsNQO 1 expressionNRF 2 activatorsHBEC 3-KT Changes3- NBA activationNRF 2 knockout3- NBA bioactivationTranscription Factor NRF 2 Increases Bioactivationlung epithelial cell linestranscription factor NRF 23- NBA3- NBA-derived DNA adductsCRISPR-Cas 9 gene editingHBEC 3-KT cellsNRF 2 activation549 NRF 2-KO cells
Licence
Exports
RefWorks
BibTeX
Ref. manager
Endnote
DataCite
NLM
DC