The cytoprotective effect of N-acetyl-L-cysteine against ROS-induced cytotoxicity is independent of its ability to enhance glutathione synthesis

Fengjiao Zhang, Serrine Lau, Terrence Monks

Research output: Contribution to journalArticle

69 Citations (Scopus)

Abstract

2,3,5-Tris(glutathion-S-yl)-hydroquinone (TGHQ), a metabolite of hydroquinone, is toxic to renal proximal tubule epithelial cells. TGHQ retains the ability to redox cycle and create an oxidative stress. To assist in elucidating the contribution of reactive oxygen species (ROS) to TGHQ-induced toxicity, we determined whether the antioxidant, N-acetyl-L-cysteine (NAC), could protect human kidney proximal tubule epithelial cells (HK-2 cell line) against TGHQ-induced toxicity. NAC provided remarkable protection against TGHQ-induced toxicity to HK-2 cells. NAC almost completely inhibited TGHQ-induced cell death, mitochon-drial membrane potential collapse, as well as ROS production. NAC also attenuated TGHQ-induced DNA damage and the subsequent activation of poly (ADP-ribose) polymerase and ATP depletion. Moreover, NAC significantly attenuated c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase phosphorylation induced by TGHQ. In contrast, NAC itself markedly increased extracellular regulated kinase1/2 (ERK1/2) activation, and the upstream mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor, PD-98059, only partially inhibited this activation, suggesting that NAC can directly activate ERK1/2 activity. However, although NAC is frequently utilized as a glutathione (GSH) precursor, the cytoprotection afforded by NAC in HK-2 cells was not a consequence of increased GSH levels. We speculate that NAC exerts its protective effect in part by directly scavenging ROS and in part via ERK1/2 activation.

Original languageEnglish (US)
Pages (from-to)87-97
Number of pages11
JournalToxicological Sciences
Volume120
Issue number1
DOIs
StatePublished - 2011

Fingerprint

Acetylcysteine
Cytotoxicity
Glutathione
Reactive Oxygen Species
Chemical activation
Toxicity
Proximal Kidney Tubule
Epithelial Cells
Phosphorylation
Oxidative stress
Cytoprotection
Poly(ADP-ribose) Polymerases
JNK Mitogen-Activated Protein Kinases
Poisons
Scavenging
Extracellular Signal-Regulated MAP Kinases
p38 Mitogen-Activated Protein Kinases
Cell death
Metabolites
Mitogens

Keywords

  • 2,3,5-tris(glutathion-S-yl)-hydroquinone
  • Glutathione
  • HK-2 cells
  • Mitogen-activated protein kinase
  • N-acetyl-L-cysteine
  • Reactive oxygen species

ASJC Scopus subject areas

  • Toxicology

Cite this

@article{ba7f5a0184e54d88b90fefc7412d3fbb,
title = "The cytoprotective effect of N-acetyl-L-cysteine against ROS-induced cytotoxicity is independent of its ability to enhance glutathione synthesis",
abstract = "2,3,5-Tris(glutathion-S-yl)-hydroquinone (TGHQ), a metabolite of hydroquinone, is toxic to renal proximal tubule epithelial cells. TGHQ retains the ability to redox cycle and create an oxidative stress. To assist in elucidating the contribution of reactive oxygen species (ROS) to TGHQ-induced toxicity, we determined whether the antioxidant, N-acetyl-L-cysteine (NAC), could protect human kidney proximal tubule epithelial cells (HK-2 cell line) against TGHQ-induced toxicity. NAC provided remarkable protection against TGHQ-induced toxicity to HK-2 cells. NAC almost completely inhibited TGHQ-induced cell death, mitochon-drial membrane potential collapse, as well as ROS production. NAC also attenuated TGHQ-induced DNA damage and the subsequent activation of poly (ADP-ribose) polymerase and ATP depletion. Moreover, NAC significantly attenuated c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase phosphorylation induced by TGHQ. In contrast, NAC itself markedly increased extracellular regulated kinase1/2 (ERK1/2) activation, and the upstream mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor, PD-98059, only partially inhibited this activation, suggesting that NAC can directly activate ERK1/2 activity. However, although NAC is frequently utilized as a glutathione (GSH) precursor, the cytoprotection afforded by NAC in HK-2 cells was not a consequence of increased GSH levels. We speculate that NAC exerts its protective effect in part by directly scavenging ROS and in part via ERK1/2 activation.",
keywords = "2,3,5-tris(glutathion-S-yl)-hydroquinone, Glutathione, HK-2 cells, Mitogen-activated protein kinase, N-acetyl-L-cysteine, Reactive oxygen species",
author = "Fengjiao Zhang and Serrine Lau and Terrence Monks",
year = "2011",
doi = "10.1093/toxsci/kfq364",
language = "English (US)",
volume = "120",
pages = "87--97",
journal = "Toxicological Sciences",
issn = "1096-6080",
publisher = "Oxford University Press",
number = "1",

}

TY - JOUR

T1 - The cytoprotective effect of N-acetyl-L-cysteine against ROS-induced cytotoxicity is independent of its ability to enhance glutathione synthesis

AU - Zhang, Fengjiao

AU - Lau, Serrine

AU - Monks, Terrence

PY - 2011

Y1 - 2011

N2 - 2,3,5-Tris(glutathion-S-yl)-hydroquinone (TGHQ), a metabolite of hydroquinone, is toxic to renal proximal tubule epithelial cells. TGHQ retains the ability to redox cycle and create an oxidative stress. To assist in elucidating the contribution of reactive oxygen species (ROS) to TGHQ-induced toxicity, we determined whether the antioxidant, N-acetyl-L-cysteine (NAC), could protect human kidney proximal tubule epithelial cells (HK-2 cell line) against TGHQ-induced toxicity. NAC provided remarkable protection against TGHQ-induced toxicity to HK-2 cells. NAC almost completely inhibited TGHQ-induced cell death, mitochon-drial membrane potential collapse, as well as ROS production. NAC also attenuated TGHQ-induced DNA damage and the subsequent activation of poly (ADP-ribose) polymerase and ATP depletion. Moreover, NAC significantly attenuated c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase phosphorylation induced by TGHQ. In contrast, NAC itself markedly increased extracellular regulated kinase1/2 (ERK1/2) activation, and the upstream mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor, PD-98059, only partially inhibited this activation, suggesting that NAC can directly activate ERK1/2 activity. However, although NAC is frequently utilized as a glutathione (GSH) precursor, the cytoprotection afforded by NAC in HK-2 cells was not a consequence of increased GSH levels. We speculate that NAC exerts its protective effect in part by directly scavenging ROS and in part via ERK1/2 activation.

AB - 2,3,5-Tris(glutathion-S-yl)-hydroquinone (TGHQ), a metabolite of hydroquinone, is toxic to renal proximal tubule epithelial cells. TGHQ retains the ability to redox cycle and create an oxidative stress. To assist in elucidating the contribution of reactive oxygen species (ROS) to TGHQ-induced toxicity, we determined whether the antioxidant, N-acetyl-L-cysteine (NAC), could protect human kidney proximal tubule epithelial cells (HK-2 cell line) against TGHQ-induced toxicity. NAC provided remarkable protection against TGHQ-induced toxicity to HK-2 cells. NAC almost completely inhibited TGHQ-induced cell death, mitochon-drial membrane potential collapse, as well as ROS production. NAC also attenuated TGHQ-induced DNA damage and the subsequent activation of poly (ADP-ribose) polymerase and ATP depletion. Moreover, NAC significantly attenuated c-Jun NH2-terminal kinase and p38 mitogen-activated protein kinase phosphorylation induced by TGHQ. In contrast, NAC itself markedly increased extracellular regulated kinase1/2 (ERK1/2) activation, and the upstream mitogen-activated protein/extracellular signal-regulated kinase kinase inhibitor, PD-98059, only partially inhibited this activation, suggesting that NAC can directly activate ERK1/2 activity. However, although NAC is frequently utilized as a glutathione (GSH) precursor, the cytoprotection afforded by NAC in HK-2 cells was not a consequence of increased GSH levels. We speculate that NAC exerts its protective effect in part by directly scavenging ROS and in part via ERK1/2 activation.

KW - 2,3,5-tris(glutathion-S-yl)-hydroquinone

KW - Glutathione

KW - HK-2 cells

KW - Mitogen-activated protein kinase

KW - N-acetyl-L-cysteine

KW - Reactive oxygen species

UR - http://www.scopus.com/inward/record.url?scp=79952079462&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=79952079462&partnerID=8YFLogxK

U2 - 10.1093/toxsci/kfq364

DO - 10.1093/toxsci/kfq364

M3 - Article

VL - 120

SP - 87

EP - 97

JO - Toxicological Sciences

JF - Toxicological Sciences

SN - 1096-6080

IS - 1

ER -