Oxidative stress is involved in the impairment of Mrp2 activity induced by estradiol 17ß-D-glucuronide in rat hepatocytes

SALAS, G; MEDEOT, AC; SCHUK, VS; MISZCZUK, GC; ANDERMATTEN, RB; CIRIACI, N; RAZORI, MV; SANCHEZ POZZI, EJ; ROMA, MG; BASIGLIO, CL; CROCENZI FA

Modalidad virtual

Congreso; Reunión Anual de Sociedades de Biociencias; 2020

SAIC, SAFIS, SAI

Estradiol 17β-d-glucuronide (E17G) is an endogenous metaboliteof estradiol which mediates the intrahepatic cholestasis of pregnancy.E17G impairs canalicular secretion via several kinase-mediatedsignaling pathways which leads to endocytosis and intracellularretention of canalicular transporters, contributing the MEK-ERK1/2pathway to the second process. Oxidative stress has also beenshown to trigger these effects on canalicular transporters. We studiedthe possible role of oxidative stress in E17G-induced impairmentof Mrp2 function by assessing the canalicular vacuolar accumulation(cVA) of glutathione-S-methylfluorescein (GS-MF) in rat hepatocytecouplets (RHC). The possible E17G-induced increase in intracellularreactive oxygen species (ROS) was assessed fluorometricallyin primary cultured rat hepatocytes (PCH) by the 2?,7?-dichlorofluorescin-diacetate (DCFH-DA) assay. A probable role of ROS inE17G-induced Mrp2 function impairment was evaluated by preincubatingRHC for 15 min with the antioxidants vitamin C (VitC), mannitol(Man), N,N?-diphenyl-p-phenylenediamine (DPPD), and also withapocynin (Apo), a specific inhibitor of the ROS-producing enzymeNADPH oxidase (NOX), prior to a 20-min exposure to E17G; a potentialrole of MEK-ERK1/2 pathway was assessed by its inhibitionwith the MEK inhibitor PD98059 (PD). E17G increased intracellularROS by 43±9 %[p