title: EGFR participates downstream of ERα in estradiol-17β-D-glucuronide-induced impairment of Abcc2 function in isolated rat hepatocyte couplets.
abstract: Estradiol-17β-D-glucuronide (E17G) induces acute endocytic internalization of canalicular transporters, including multidrug resistance-associated protein 2 (Abcc2) in rat, generating cholestasis. Several proteins organized in at least two different signaling pathways are involved in E17G cholestasis: one pathway involves estrogen receptor alpha (ERα), Ca(2+)-dependent protein kinase C and p38-mitogen activated protein kinase, and the other pathway involves GPR30, PKA, phosphoinositide 3-kinase/AKT and extracellular signal-related kinase 1/2. EGF receptor (EGFR) can potentially participate in both pathways since it interacts with GPR30 and ERα. Hence, the aim of this study was to analyze the potential role of this receptor and its downstream effectors, members of the Src family kinases in E17G-induced cholestasis. In vitro, EGFR inhibition by Tyrphostin (Tyr), Cl-387785 or its knockdown with siRNA strongly prevented E17G-induced impairment of Abcc2 function and localization. Activation of EGFR was necessary but not sufficient to impair the canalicular transporter function, whereas the simultaneous activation of EGFR and GPR30 could impair Abcc2 transport. The protection of Tyr was not additive to that produced by the ERα inhibitor ICI neither with that produced by Src kinase inhibitors, suggesting that EGFR shared the signaling pathway of ERα and Src. Further analysis of ERα, EGFR and Src activations induced by E17G, demonstrated that ERα activation precedes that of EGFR and EGFR activation precedes that of Src. In conclusion, activation of EGFR is a key factor in the alteration of canalicular transporter function and localization induced by E17G and it occurs before that of Src and after that of ERα.
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Ismael R
authors: IR
authors: Barosso
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Andrés E
authors: AE
authors: Zucchetti
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Gisel S
authors: GS
authors: Miszczuk
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Andrea C
authors: AC
authors: Boaglio
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Diego R
authors: DR
authors: Taborda
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Marcelo G
authors: MG
authors: Roma
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina.
authors: Fernando A
authors: FA
authors: Crocenzi
authors: Instituto de Fisiología Experimental (IFISE), Facultad de Ciencias Bioquímicas y Farmacéuticas (CONICET - U.N.R.), Suipacha 570, S2002LRL, Rosario, Argentina. esanchez@unr.edu.ar.
authors: Enrique J
authors: EJ
authors: Sánchez Pozzi
mesh_terms: D018528:ATP-Binding Cassette Transporters / Q000378:metabolism*; D000818:Animals; D001648:Bile Canaliculi / Q000187:drug effects / Q000378:metabolism / Q000503:physiopathology; D002478:Cells, Cultured; D002779:Cholestasis / Q000139:chemically induced / Q000378:metabolism; D066246:ErbB Receptors / Q000235:genetics / Q000378:metabolism*; D004958:Estradiol / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D065171:Estrogen Receptor Antagonists / Q000494:pharmacology; D047628:Estrogen Receptor alpha / Q000378:metabolism*; D005260:Female; D000077267:Fulvestrant; D055785:Gene Knockdown Techniques; D022781:Hepatocytes / Q000187:drug effects / Q000378:metabolism*; D011799:Quinazolines / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D020032:Tyrphostins / Q000494:pharmacology; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D018528:ATP-Binding Cassette Transporters; C423013:Abcc2 protein, rat; D065171:Estrogen Receptor Antagonists; D047628:Estrogen Receptor alpha; D011799:Quinazolines; D020032:Tyrphostins; C101044:RTKI cpd; C025483:estradiol-17 beta-glucuronide; D000077267:Fulvestrant; D004958:Estradiol; C483803:Egfr protein, rat; D066246:ErbB Receptors; D019061:src-Family Kinases
keywords: ABC transporters; Cholestasis; Mrp2; Src kinase