title: Role of AMP-activated protein kinase α1 in 17α-ethinylestradiol-induced cholestasis in rats.
abstract: Estrogen-induced cholestasis occurs in many women who are susceptible due to pregnancy or hormone replacement therapy for postmenopausal syndrome. 17α-Ethinylestradiol (EE), as a synthetic estrogen, has been widely used to study the underlying mechanisms of estrogen-induced cholestasis. Recent studies have also reported that liver kinase B1 (LKB1)-mediated activation of AMP-activated protein kinase (AMPK) plays a critical role in the regulation of canalicular network formation. However, the role of AMPK in EE-induced cholestasis remains to be determined. In this study, the effects of EE (1-100 µM) on AMPK activation and the expression of farnesoid X receptor (FXR) and hepatic bile acid transporters were examined in in vitro using 3D-cultured rat primary hepatocytes and in in vivo using rat cholestasis models. We also used specific chemical agonist and antagonist of AMPK, AMPK subunit-specific antibodies and lentiviral shRNAs for AMPKα1 and AMPKα2 to delineate the role of AMPK in EE-induced cholestasis and potential cellular mechanisms. We found that EE-induced phosphorylation of AMPKα1 via extracellular signal-regulated kinases-LKB1-mediated signaling pathways and subsequent nuclear translocation accounted for the down-regulation of FXR and bile acid transporters and disruption of bile acid homeostasis. Inhibition of AMPK activation using an AMPK antagonist Compound C (2 µM) or down-regulation of AMPKα1 using gene-specific shRNA attenuated EE-induced cholestasis both in in vitro and in in vivo. In conclusion, these results revealed that activation of cAMP-ERK-LKB1-AMPKα1 signaling pathway plays a critical role in EE-mediated dysregulation of the expression of FXR and bile acid transporters. AMPKα1 may represent an important therapeutic target for estrogen-induced cholestasis.
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.|Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Xiaojiaoyang
authors.initials: X
authors.lastname: Li
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.|Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, 23298, USA.
authors.forename: Runping
authors.initials: R
authors.lastname: Liu
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Lan
authors.initials: L
authors.lastname: Luo
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Linxi
authors.initials: L
authors.lastname: Yu
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Xin
authors.initials: X
authors.lastname: Chen
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Lixin
authors.initials: L
authors.lastname: Sun
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.|Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Wang
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, 23298, USA.|McGuire Veterans Affairs Medical Center, Richmond, VA, 23249, USA.
authors.forename: Phillip B
authors.initials: PB
authors.lastname: Hylemon
authors.affiliation: Department of Microbiology and Immunology, Virginia Commonwealth University, Richmond, VA, 23298, USA. Huiping.Zhou@vcuhealth.org.|McGuire Veterans Affairs Medical Center, Richmond, VA, 23249, USA. Huiping.Zhou@vcuhealth.org.
authors.forename: Huiping
authors.initials: H
authors.lastname: Zhou
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. beaglejiang@cpu.edu.cn.|Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. beaglejiang@cpu.edu.cn.
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Jiang
authors.affiliation: Jiangsu Key Laboratory of Drug Screening, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. lyzhang@cpu.edu.cn.|Jiangsu Center for Pharmacodynamics Research and Evaluation, China Pharmaceutical University, Nanjing, 210009, Jiangsu, China. lyzhang@cpu.edu.cn.
authors.forename: Luyong
authors.initials: L
authors.lastname: Zhang
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D021581:Active Transport, Cell Nucleus / Q000187:drug effects; D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism; D002478:Cells, Cultured; D002779:Cholestasis / Q000139:chemically induced* / Q000201:enzymology / Q000473:pathology / Q000517:prevention & control; D000242:Cyclic AMP / Q000378:metabolism; D004195:Disease Models, Animal; D004789:Enzyme Activation / Q000187:drug effects; D004967:Estrogens / Q000009:adverse effects* / Q000737:chemistry; D004997:Ethinyl Estradiol / Q000009:adverse effects* / Q000037:antagonists & inhibitors; D022781:Hepatocytes / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D008297:Male; D010766:Phosphorylation / Q000187:drug effects; D047428:Protein Kinase Inhibitors / Q000494:pharmacology / Q000627:therapeutic use; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D034622:RNA Interference; D011897:Random Allocation; D017207:Rats, Sprague-Dawley; D018160:Receptors, Cytoplasmic and Nuclear / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism; D015290:Second Messenger Systems / Q000187:drug effects; D000099150:Receptor, Farnesoid X-Activated
chemical_list: D055372:AMP-Activated Protein Kinases; D000074020:ATP Binding Cassette Transporter, Subfamily B, Member 11; D018528:ATP-Binding Cassette Transporters; D001647:Bile Acids and Salts; D000242:Cyclic AMP; D004967:Estrogens; D004997:Ethinyl Estradiol; D047428:Protein Kinase Inhibitors; D018160:Receptors, Cytoplasmic and Nuclear; D000099150:Receptor, Farnesoid X-Activated; C490548:Abcb11 protein, rat; C568305:Prkaa1 protein, rat
keywords: AMPKα1; Bile acid transporters; Cholestasis; Estrogen; FXR