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Excessive N-acetyl-p-benzoquinone imine(NAPQI)formation is a starting event that triggers oxidative stress and subsequent hepatocyte necrosis in acetaminophen(APAP)overdose caused acute liver failure(ALF).S-glutathionylation is a reversible redox post-translational modification and a prospective mechanism of APAP hepatotoxicity.Glutaredoxin-1(Glrx1),a glutathione-specific thioltransferase,is a primary enzyme to catalyze deglutathionylation.The objective of this study was to explored whether and how Glrx1 is associated with the development of ALF induced by APAP.The Glrx1 knockout mice(Glrx1-/-)and liver-specific overexpression of Glrx1(AAV8-Glrx1)mice were produced and underwent APAP-induced ALF.Pirfenidone(PFD),a potential inducer of Glrx1,was administrated preceding APAP to assess its protective effects.Our results revealed that the hepatic total protein S-glutathionylation(PSSG)increased and the Glrx1 level reduced in mice after APAP toxicity.Glrx1-/- mice were more sensitive to APAP overdose,with higher oxidative stress and more toxic metabolites of APAP.This was attributed to Glrx1 deficiency increasing the total hepatic PSSG and the S-glutathionylation of cytochrome p450 3a 11(Cyp3a11),which likely increased the activity of Cyp3a11.Conversely,AAV8-Glrx1 mice were defended against liver damage caused by APAP overdose by inhibiting the S-glutathionylation and activity of Cyp3a11,which reduced the toxic metabolites of APAP and oxidative stress.PFD precede administration upregulated Glrx1 expression and alleviated APAP-induced ALF by decreasing oxidative stress.We have identified the function of Glrx1 mediated PSSG in liver injury caused by APAP overdose.Increasing Glrx1 expression may be investigated for the medical treatment of APAP-caused hepatic injury.
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ObjectiveTo explore the effect of Gelsemium elegans combined with Mussaenda pubescens on efflux transporter breast cancer resistance protein （BCRP） and cytochrome P450 3A11 （CYP3A11） and their attenuation mechanism， and to investigate whether the nuclear receptors were involved in such regulation by intervening it with nuclear receptor activators. MethodC57BL/6 mice were divided into the blank group， G. elegans （GE， 0.25 g·kg-1）group， GE + M. pubescens （MP） （0.25 g·kg-1+10 g·kg-1） group， GE + pregnane X receptor （PXR） activator （rifampicin）（GE + Rif，0.25 g·kg-1+50 mg·kg-1） group， GE + MP + Rif （0.25 g·kg-1+10 g·kg-1+50 mg·kg-1） group， GE + constitutive androstane receptor （CAR） activator （1，4-Bis ［2-（3，5-Dichloropyridyloxy）］ benzene， TCPOBOP）（GE + TCP， 0.25 g·kg-1+0.5 mg·kg-1） group， and GE + MP + TCP （0.25 g·kg-1+10 g·kg-1+0.5 mg·kg-1） group. The medication lasted for 14 successive days. One hour after the last administration， the mice were sacrificed by cervical dislocation and the liver tissue was harvested. The left liver tissue was stained with hematoxylin- eosin （HE） for observing the pathological changes. The right liver tissue was used for BCRP and CYP3A11 mRNA and protein expression detection by real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. ResultThe survival rates of mice in the GE + Rif group， GE group， and GE + MP group were 25% （the lowest）， 40%， and 80%， respectively， and no death was observed in the other groups. Compared with the obvious lesions in the liver cells of the GE group， the pathological changes in liver cells of the GE + MP group were alleviated， while those in the GE + Rif group were worsened. Compared with the GE + Rif group， the GE + MP + Rif group exhibited relieved pathological changes in liver cells. Both the GE + TCP group and the GE + MP + TCP group showed mild liver lesions. The comparison with the GE + MP group revealed that the pathological changes in the GE + MP + TCP group were slightly relieved. Compared with the blank group， the expression of BCRP protein and mRNA in GE group were significantly decreased （P<0.05，P<0.01）.The expression of CYP3A11 protein in GE group were significantly decreased （P<0.01）. Compared with the GE group， the GE + MP group displayed remarkably up-regulated BCRP protein and mRNA expression （P<0.05，P<0.01） and CYP3A11 protein expression （P<0.05）， but slightly up-regulated CYP3A11 mRNA expression. Compared with the GE group， the GE + Rif group exhibited down-regulated BCRP protein expression （P < 0.05）. The protein and mRNA expression levels of BCRP were lower in the GE + MP + Rif group than in the GE + MP group （P<0.05，P<0.01）. The PXR activator rifampicin regulated BCRP before and after the combination of G. elegans with M. pubescens. The CYP3A11 protein and mRNA expression levels in the GE + TCP group were higher than those in the GE group （P<0.05，P<0.01）. Compared with the GE + MP group， the GE + MP + TCP group showed up-regulated CYP3A11 protein and mRNA expression （P<0.05，P<0.01）. CAR activator TCPOBOP also had a regulatory effect on CYP3A11 before and after the compatibility of G. elegans with M. pubescens. ConclusionThe attenuated toxin after the combination of G. elegans with M. pubescens is closely related to the efflux transporter BCRP and the drug-metabolizing enzyme CYP3A11.
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Objective To explore the effect of a herbalcompound Gehua Jiejue Dizhi Decoction (GJDD) on the liver fat deposition and the expression of PXR, and the mRNA and protein expression of its target genes CYP3A11 and CYP3A25in the liver tissues of mouse models of alcoholic fatty liver.Methods Twenty-nine healthy male C57BL/6J mice were randomly divided into control group (n=5), model group (n=8), high dose GJDD group (n=8)and low dose GJDD group (n=8).The mouse model of alcoholic fatty liver was prepared according to the National Institute on Alcohol Abuse and Alcoholism (NIAAA) method.Then, the mice were treated with the high dose and low dose GJDD for 9 days.Serum glutamic-pyruvic transaminase (AST) and aspartate aminotransferase (AST) were detected by enzyme-linked immunosorbent assay (ELISA).Liver fat deposition was detected by oil red O staining.Real-time RT-PCR and immunohistochemistry were performed to examine the expressions of PXR, CYP3A11 and CYP3A25.Results Compared with the model group, the liver fat deposition in the intervention groups was significantly reduced in a dose-dependent manner, with a significant increase of the expression of PXR and CYP3A25 (P < 0.01).The serum ALT level was significantly reduced in the model group (P < 0.01), while the transcriptional levels of CYP3A11 mRNA in the groups were similar (P ≥ 0.05).Conclusions Gehua Jiejue Dizhi Decoction has obvious therapeutic effect on the AFLD in mice, which may be related to the activation of PXR and its target genes CYP3A25.