Glycogen Synthase Kinase 3 ß (GSK3ß) participates in estradiol-17ß-D-glucuronide (E17G) induced impairment of Mrp2 Function in isolated rat hepatocyte couplets (IRHC).

BAROSSO, IR; ANDERMATTEN, ROMINA B.; SCHUCK, VIRGINIA S.; CIRIACI, NADIA; TABORDA, DIEGO; CROCENZI, FERNANDO A.; SANCHEZ POZZI, ENRIQUE J.

Mar del Plata

Congreso; Reunión Anual de la SAIC; 2019

Sociedad Argentina de Investigación Clínica

Abstract/Resumen: E17G induces acute cholestasis in rat with endocytic internalization of the canalicular transporter Mrp2, activating two different pathways, each one involving an estrogen receptor: ERalpha or GPR30. cPKC activation precedes that of ERalpha. cPKC probably uses intermediaries to phosphorylate ERalpha. Several kinases can be phosphorylated by cPKC and are able to phosphorylate the ERalpha, among them we find GSK3ß. The aim of this study was to evaluate the role of GSK3ß in the E17G-induced alteration of Mrp2 activity. IRHC were treated with GSK3ß inhibitors Li (3 mM) or BIO (1 μM) and then exposed to E17G (100 μM). To investigate in which pathway GSK3ß participates, IRHC were exposed to BIO and inhibitors of ERalpha (ICI182,780, ICI, 1 μM), cPKC (Gö6976, Gö, 1 μM) or PI3K (Wortmannin, W, 100 nM) before exposure to E17G. All preparations were incubated with CMFDA (intracellularly converted in gluthation-methylfluorescein [GMF], substrate of Mrp2). IHRC accumulating GMF in their canalicular vacuoles (cVA) were counted and compared to control IHRC. Results (% Control): GSK3ß inhibition (Li+E17G: 71 ± 7b; BIO+E17G: 70 ± 5b) partially prevented the effect of E17G (48 ± 4a) on cVA of GMF. The preventive effects of W (W+E17G: 75 ± 5b) and BIO on the decrease in cVA induced by E17G were additive (BIO+W+E17G: 91 ± 1a,c). Contrarily, the preventive effects of ICI (ICI+E17G: 69 ± 3b) or Gö (Gö+E17G: 77 ± 3b) did not modified BIO protective effects (BIO+ICI+E17G: 72 ± 2b) and (BIO+Gö+E17G: 77 ± 10b). a: significantly different from Control; b: significantly different from E17G and Control; c: significantly different from E17G+BIO and E17G+W. BIO, Li, W, Gö, and ICI did not affect % cVA. (p