tert-Butylhydroquinone (tBHQ) protects hepatocytes against lipotoxicity via inducing autophagy independently of Nrf2 activation

© 2013..

Saturated fatty acids (SFAs) induce hepatocyte cell death, wherein oxidative stress is mechanistically involved. Nuclear factor (erythroid-derived 2)-like 2 (Nrf2) is a master transcriptional regulator of cellular antioxidant defense enzymes. Therefore, Nrf2 activation is regarded as an effective strategy against oxidative stress-triggered cellular damage. In this study, tert-butylhydroquinone (tBHQ), a widely used Nrf2 activator, was initially employed to investigate the potential protective role of Nrf2 activation in SFA-induced hepatoxicity. As expected, SFA-induced hepatocyte cell death was prevented by tBHQ in both AML-12 mouse hepatocytes and HepG2 human hepatoma cells. However, the protective effect of tBHQ is Nrf2-independent, because the siRNA-mediated Nrf2 silencing did not abrogate tBHQ-conferred protection. Alternatively, our results revealed that autophagy activation was critically involved in the protective effect of tBHQ on lipotoxicity. tBHQ induced autophagy activation and autophagy inhibitors abolished tBHQ's protection. The induction of autophagy by tBHQ exposure was demonstrated by the increased accumulation of LC3 puncta, LC3-II conversion, and autophagic flux (LC3-II conversion in the presence of proteolysis inhibitors). Subsequent mechanistic investigation discovered that tBHQ exposure activated AMP-activated protein kinase (AMPK) and siRNA-mediated AMPK gene silencing abolished tBHQ-induced autophagy activation, indicating that AMPK is critically involved in tBHQ-triggered autophagy induction. Furthermore, our study provided evidence that tBHQ-induced autophagy activation is required for its Nrf2-activating property. Collectively, our data uncover a novel mechanism for tBHQ in protecting hepatocytes against SFA-induced lipotoxicity. tBHQ-triggered autophagy induction contributes not only to its hepatoprotective effect, but also to its Nrf2-activating property.

Medienart:

E-Artikel

Erscheinungsjahr:

2014

Erschienen:

2014

Enthalten in:

Zur Gesamtaufnahme - volume:1841

Enthalten in:

Biochimica et biophysica acta - 1841(2014), 1 vom: 01. Jan., Seite 22-33

Sprache:

Englisch

Beteiligte Personen:

Li, Songtao [VerfasserIn]
Li, Jiaxin [VerfasserIn]
Shen, Chen [VerfasserIn]
Zhang, Ximei [VerfasserIn]
Sun, Shan [VerfasserIn]
Cho, Michael [VerfasserIn]
Sun, Changhao [VerfasserIn]
Song, Zhenyuan [VerfasserIn]

Links:

Volltext

Themen:

2-tert-butylhydroquinone
AMP-Activated Protein Kinases
AMPK
ARE
Adenosine monophosphate-activated protein kinase
Amino acid and serum depletion medium
Antioxidant response element
Antioxidants
Autophagy
BSA
Baf
Bafilomycin A1
Bovine serum albumin
C-Jun N-terminal kinase
C12674942B
CQ
CaMKK2
Calcium/calmodulin-dependent protein kinase kinase 2
Chloroquine
EBSS
EC 2.7.11.31
ER
ERK
Endoplasmic reticulum
Extracellular signal-regulated kinases
FFAs
Fatty Acids
Free fatty acids
HO-1
Heme oxygenase 1
Hydroquinones
JNK
Journal Article
Keap1
Kelch-like ECH-associated protein 1
LC3
LC3 protein, rat
LKB1
Lipotoxicity
Liver kinase B1
MAP1LC3A protein, human
MTOR
Mammalian target of rapamycin
Microtubule associated protein 1 (MAP1) light chain 3
Microtubule-Associated Proteins
NAFLD
NF-E2-Related Factor 2
NFE2L2 protein, human
Nfe2l2 protein, rat
Non-alcohol fatty liver diseases
Nrf2
Nuclear factor (erythroid-derived 2)-like 2
PP2A
Protein phosphatase 2A
ROS
Reactive oxygen species
Research Support, N.I.H., Extramural
Research Support, Non-U.S. Gov't
SFAs
Saturated fatty acids
TBHQ
Tert-Butylhydroquinone
Tert-butylhydroquinone

Anmerkungen:

Date Completed 21.02.2014

Date Revised 10.04.2022

published: Print-Electronic

Citation Status MEDLINE

doi:

10.1016/j.bbalip.2013.09.004

funding:

Förderinstitution / Projekttitel:

PPN (Katalog-ID):

NLM231060432