ABSTRACT
@#Objective To evaluate the protective effect of the activator of silent information regulator 2-related enzymes 1(SIRT1),SRT1720,on liver injury induced by acetaminophen(APAP)in mice and explore its mechanism. Methods Forty male C57BL/6J mice were randomly divided into normal control group,SRT1720 treatment group,APAP treatment group,and APAP + SRT1720 treatment group,with 10 mice in each group. Mice in SRT1720 and APAP + SRT1720 groups were given SRT1720(30 mg/kg body mass)by intragastric administration,while normal saline of equal volume was given by intragastric administration in control and APAP groups,once a day for 5 days;On the 6th day,mice in APAP and APAP + SRT1720 groups were injected i. p. with APAP(325 mg/kg body mass),while those in control and SRT1720 groups with equal volume of normal saline. After 24 hours,the peripheral blood was taken and the serum was separated,which were detected for the levels of alanine aminotransferase(ALT)and aspartate aminotransferase(AST)by the corresponding kits;The liver tissue of mice was taken aseptically,observed for the pathological changes by HE staining,detected for the mRNA transcription levels of GRP78,PERK,eIF2 α,ATF4 and CHOP genes related to PERK-eIF2α-CHOP signaling pathway by RT-qPCR and detected for the relative expression levels of these corresponding proteins and Caspase12 protein by Western blot. Results Compared with normal control group,the serum ALT and AST levels of mice in APAP group significantly increased(t = 55. 21 and34. 29 respectively,each P < 0. 01);significant necrosis of hepatocytes was observed in liver tissue,the structure of hepatic lobules changed significantly,and the swelling and deformation of hepatocytes in some areas were serious;the mRNA transcription and relative protein expression levels of GRP78,PERK,eIFα,ATF4 and CHOP genes increased significantly(t = 9. 85～33. 89,each P < 0. 05)and the relative expression level of Caspase12 protein increased significantly(t = 11. 78,P < 0. 01). Compared with APAP group,the serum ALT and AST levels of mice in APAP + SRT1720 group decreased significantly(t = 42. 92 and 18. 02 respectively,each P < 0. 01);the degree of hepatocyte injury was obviously reduced and the number of swollen and deformed cells also significantly decreased;the mRNA transcription and relative protein expression levels of GRP78,PERK,eIF2α,ATF4 and CHOP decreased significantly(t = 6. 19～22. 43,each P < 0. 05)and the expression level of Caspase12 protein showed no significant decrease(t = 0. 34,P > 0. 05). Conclusion SRT1720improved APAP-induced liver injury in mice,possibly by inhibiting PERK-eIF2α-CHOP signaling pathway in endoplasmic reticulum stress(ERS).
ABSTRACT
Chemicals possessing reactive electrophiles can denature innate proteins leading to undesired toxicity, and the overdose-induced liver injury by drugs containing electrophiles has been one of the major causes of non-approval and withdraw by the US Food and Drug Administration (FDA). Elucidating the associated proteins could guide the future development of therapeutics to circumvent these drugs' toxicities, but was largely limited by the current probing tools due to the steric hindrance of chemical tags including the common "click chemistry" labels. Taking the widely used non-steroidal anti-inflammatory drug acetaminophen (APAP) as an example, we hereby designed and synthesized an APAP analogue using fluorine as a steric-free label. Cell toxicity studies indicated our analogue has similar activity to the parent drug. This analogue was applied to the mouse hepatocellular proteome together with the corresponding desthiobiotin-SH probe for subsequent fluorine-thiol displacement reactions (FTDRs). This set of probes has enabled the labeling and pull-down of hepatocellular target proteins of the APAP metabolite as validated by Western blotting. Our preliminary validation results supported the interaction of APAP with the thioredoxin protein, which is an important redox protein for normal liver function. These results demonstrated that our probes confer minimal steric perturbation and mimic the compounds of interest, allowing for global profiling of interacting proteins. The fluorine-thiol displacement probing system could emerge as a powerful tool to enable the investigation of drug-protein interactions in complex biological environments.
ABSTRACT
The model of drug-induced liver injury (DILI) induced by acetaminophen (APAP) in mice was established to investigate the anti-oxidation and anti-ferroptosis mechanisms of Fuzheng Yanggan Mixture on DILI. C57BL/6 mice were randomly divided into five groups: control group, model group, positive group, and low and high-dose Fuzheng Yanggan Mixture groups (0.12, 0.24 g·kg⁻¹). Mice were intragastrically administration with Fuzheng Yanggan Mixture (0.12, 0.24 g·kg⁻¹) once per day for 21 consecutive days, and at the same time, mice were weighted every day. The mice were injected intraperitoneally with 600 mg·kg⁻¹ of APAP to establish a mouse model of acute DILI after 16 h from the last administration of Fuzheng Yanggan Mixture. After 6 h from APAP challenge, the experimental animals were weighted and sacrificed to collect blood and liver tissue samples. And then, the effect of Fuzheng Yanggan Mixture on liver weight and the liver weight ratio of mice were examined; the content of alanine aminotransferase (ALT) and aspartate aminotransferase (AST) in the serum and the level of malondialdehyde (MDA), glutathione (GSH) and nicotinamide adenine dinucleotide phosphate (NADPH) in the liver tissue were measured. Prostaglandinendoperoxide synthase 2(ptgs2) mRNA level in liver tissues was detected by Q-PCR, and protein expression levels of SLC7A11 and GPX4 in liver tissues were detected by Western blot. Moreover, HE staining, immunohistochemical assay and TUNEL staining were used to observe pathological changes of the liver tissue sections. It is found that Fuzheng Yanggan Mixture could relieve APAP-induced liver enlargement and inhibit hepatic weight ratio increase. Compared with model group, the mice in Fuzheng Yanggan Mixture groups showed decreases in the content of ALT, AST and MDA, and increases in the content of GSH and NADPH. What is more, Fuzheng Yanggan Mixture could down-regulate ptgs2 mRNA level and up-regulate SLC7A11 and GPX4 protein levels. All of the results lead to a conclusion that Fuzheng Yanggan Mixture plays a protective effect on DILI in mice, which may be associated with the inhibition of ferroptosis.