G protein-coupled receptor30/adenylyl cyclase/protein kinase A pathway is involved in estradiol 17ß-D-glucuronide-induced cholestasis

ZUCCHETTI, AE; BAROSSO, IR; BOAGLIO, AC; BASIGLIO, CL; MISCZUK, GS; LAROCCA, MC; RUIZ, ML; DAVIO, CA; ROMA, MG; CROCENZI, FA; SÁNCHEZ POZZI, EJ

HEPATOLOGY (BALTIMORE, MD.)

JOHN WILEY & SONS INC

Lugar: New York; Año: 2014 vol. 59 p. 1016 - 1029

0270-9139

Estradiol-17ß-D-glucuronide (E17G) activates different signaling pathways (such ascPKC, PI3K-Akt, MAP kinases p38 and ERK1/2 and estrogen receptor α) that lead toacute cholestasis in rat liver with retrieval of the canalicular transporters bile salt exportpump (Abcb11) and multidrug resistance-associated protein 2 (Abcc2). E17G shares withnon-conjugated estradiol the capacity to activate these pathways. The G protein-coupledreceptor 30 (GPR30) is a receptor implicated in non-genomic effects of estradiol and theaim of this study was to analyze the potential role of this receptor and its down-streameffectors in E17G-induced cholestasis. In vitro, GPR30 inhibition by G15 or its knockdown with siRNA strongly prevented E17G-induced impairment of canaliculartransporters function and localization. E17G increased cAMP levels and this increase wasblocked by G15, linking GPR30 to adenylyl cyclase (AC). Moreover, AC inhibition totallyprevented E17G insult. E17G also increased PKA activity, which was blocked by G15 andAC inhibitors, connecting the links of the pathway GPR30-AC-PKA. PKA inhibitionprevented E17G-induced cholestasis, whereas Epac/MEK, another cAMP downstreameffector, was not implicated in cAMP cholestatic action. In the perfused rat liver model,inhibition of GPR30-AC-PKA pathway totally prevented E17G-induced alteration inAbcb11 and Abcc2 function and localization. In conclusion, activation of GPR30-AC-PKAis a key factor in the alteration of canalicular transporters function and localization inducedby E17G. The interaction of E17G with GPR30 may be the first event in the cascade ofsignaling activation.