Pre-treatment twice with liposomal clodronate protects against acetaminophen hepatotoxicity through a pre-conditioning effect  

作　　者：Melissa M.Clemens Joel H.Vazquez Stefanie Kennon-McGill Sandra S.McCullough Laura P.James Mitchell R.McGill 

机构地区：[1]Department of Pharmacology and Toxicology,College of Medicine,University of Arkansas for Medical Sciences,Little Rock,AR,USA [2]Interdisciplinary Graduate Program in Biomedical Sciences,Graduate School,University of Arkansas for Medical Sciences,Little Rock,AR,USA [3]Department of Environmental and Occupational Health,Fay W.Boozman College of Public Health,University of Arkansas for Medical Sciences,Little Rock,AR,USA [4]Department of Pediatrics,College of Medicine,University of Arkansas for Medical Sciences,Little Rock,AR,USA [5]Center for Dietary Supplement Research,University of Arkansas for Medical Sciences,Little Rock,AR,USA

出　　处：《Liver Research》2020年第3期145-152,共8页肝脏研究（英文）

基　　金：This work was supported by the American Association for the Study of Liver Diseases Foundation,Alexandria,VA,USA(2018 Pinnacle Research Award);by the United States National Institutes of Health(grant numbers T32 GM106999,UL1 TR003107,R42 DK079387 and KL2 TR003108).

摘　　要：Background and aim:Acetaminophen(APAP)overdose is a major cause of acute liver injury,but the role of macrophages in the propagation of the hepatotoxicity is controversial.Early research revealed that macrophage inhibitors protect against APAP injury.However,later work demonstrated that macrophage ablation by acute pre-treatment with liposomal clodronate(LC)exacerbates the toxicity.To our surprise,during other studies,we observed that pre-treatment twice with LC seemed to protect against APAP hepatotoxicity,in contrast to acute pre-treatment.The aim of this study was to confirm that observation and to explore the mechanisms.Methods:We treated mice with empty liposomes(LE)or LC twice per week for 1 week before APAP overdose and collected blood and liver tissue at 0,2,and 6 h post-APAP.We then measured liver injury(serum alanine aminotransferase activity,histology),APAP bioactivation(total glutathione,APAP-protein adducts),oxidative stress(oxidized glutathione(GSSG)),glutamate-cysteine ligase subunit c(Gclc)mRNA,and nuclear factor erythroid 2-related factor(Nrf2)immunofluorescence.We also confirmed the ablation of macrophages by F4/80 immunohistochemistry.Results:Pre-treatment twice with LC dramatically reduced F4/80 staining,protected against liver injury,and reduced oxidative stress at 6 h post-APAP,without affecting APAP bioactivation.Importantly,Gclc mRNA was higher in the LC group at 0 h and total glutathione was higher at 2 h,indicating accelerated glutathione re-synthesis after APAP overdose due to greater basal glutamate-cysteine ligase.Oxidative stress was lower in the LC groups at both time points.Finally,total Nrf2 immunofluorescence was higher in the LC group.Conclusions:We conclude that multiple pre-treatments with LC protect against APAP by accelerating glutathione re-synthesis through glutamate-cysteine ligase.Investigators using twice or possibly more LC pre-treatments to deplete macrophages,including peritoneal macrophages,should be aware of this possible confounder.

关 键 词：Acetaminophen(APAP) Acute liver failure(ALF) Damage-associated molecular patterns(DAMPs) Drug-induced liver injury Liposomal clodronate(LC) Kupffer cells Nuclear factor erythroid 2-related factor(Nrf2) Sterile inflammation Stress response 

分 类 号：R96[医药卫生—药理学]