Role of NRF2 signaling pathway in trichloroethylene-induced oxidative stress in HepG2 cells
10.11763/j.issn.2095-2619.2020.06.008
- Author:
Hai ZHONG
1
;
Weiquan WU
;
Fei TANG
;
Lu HUANG
;
Zhihui ZOU
1
;
Rian YU
1
Author Information
1. Department of Occupational and Environmental Health, School of Public Health, Guangdong Pharmaceutical University Guangzhou, Guangdong 510310, China
- Publication Type:Journal Article
- Keywords:
Trichloroethylene;
Nuclear factor erythroid-2-related factor 2;
Signaling pathway;
Oxidative stress;
Catalase;
Glutathione peroxidase;
Malondialdehyde
- From:
China Occupational Medicine
2020;47(06):660-665
- CountryChina
- Language:Chinese
-
Abstract:
OBJECTIVE: To investigate the role of nuclear factor erythroid-2-related factor 2(NRF2) signaling pathway in trichloroethylene(TCE) induced oxidative stress in human liver cancer HepG2 cells. METHODS: HepG2 cells in the exponential growth phase were randomly divided into control group and low-, medium-and high-dose groups, and the cells were stimulated with TCE at the final concentrations of 0, 2, 4 or 8 mmol/L respectively for 24 hours. After TCE exposure, the cells were collected. The activity of superoxide dismutase(SOD) was measured by 2-(2-methoxy-4-nitrophenyl)-3-(4-nitrophenyl)-5-(2,4-disulphenyl)-2 h-tetrazole monosodium salt method.The activities of catalase(CAT) and glutathione peroxidase(GSH-Px) were detected by enzymatic method. The level of malondialdehyde(MDA) was detected by thiobarbituric acid method. The level of 8-hydroxydeoxyguanosine(8-OHDG) was detected by enzyme-linked immunosorbent assay. The mRNA expression of NRF2, heme oxygenase(HO1), glutamate-cysteine ligase catalytic subunit(GCLC), NAD(P) quinone oxidoreductase 1(NQO1) were detected by real-time polymerase chain reaction and the protein expression of NRF2, HO1, GCLC, NQO1 were detected by Western blotting. RESULTS: The activity of CAT in HepG2 cells decreased in the 3 doses drug exposure groups(all P<0.05). The activity of GSH-Px increased(all P<0.05), while the level of MDA in HepG2 cells decreased in low-dose group compared with the control group(P<0.05). There was no statistical significance in SOD activity and 8-OHDG level of HepG2 cells among these 4 groups(all P>0.05). The mRNA and protein relative expression of NRF2 and GCLC in HepG2 cells decreased in the low-and medium-dose groups(all P<0.05) compared with the control group. The mRNA relative expression of HO1 decreased(all P<0.05). The HO1 protein relative expression of HepG2 cells increased in low-dose group compared with the control group(P<0.05). The mRNA and protein relative expression of NQO1 in low-dose group increased(both P<0.05). The protein relative expression of HO1 in HepG2 cells in medium-dose group was lower than that in control group(P<0.05).The mRNA and protein relative expression levels of NRF2 and NQO1 increased in HepG2 cells of high-dose group(all P<0.05) and the mRNA relative expression of HO1 increased in HepG2 cells of high-dose group(all P<0.05) compared with the other 3 groups. CONCLUSION: The low and medium dose TCE stimulation can cause oxidative stress in HepG2 cells and decrease the antioxidant enzyme activity. The high dose TCE stimulation to HepG2 cells can activate NRF2 signaling pathway, thus upregulating the expression of downstream antioxidant enzymes HO1, GCLC and NQO1, and relieving the oxidative damage caused by TCE.
