OXIDATIVE STRESS IS INVOLVED IN THE IMPAIR MENT OF MRP2 ACTIVITY INDUCED BY ESTRADIOL 17ß-D-GLUCURONIDE IN RAT HEPATOCYTES.

SCHUCK, VIRGINIA SOLEDAD; CIRIACI, NADIA; ROMA, MARCELO GABRIEL; SALAS, GIMENA; MISZCZUK, GISEL SABRINA; RAZORI, MARÍA VALERIA; CROCENZI, FERNANDO ARIEL; MEDEOT, ANABELA CAROLINA; ANDERMATTEN, ROMINA BELÉN; SÁNCHEZ POZZI, ENRIQUE JUAN

Virtual

Congreso; Reunión de Sociedades de Biociencias 2020; 2020

SAIC/SAFIS/SAI

Estradiol 17β-D-glucuronide (E17G) is an endogenous metabolite of estradiol which mediates the intrahepatic cholestasis of pregnancy. E17G impairs canalicular secretion via several kinase-mediated signaling pathways which leads to endocytosis and intracellular retention of canalicular transporters, contributing the MEK-ERK1/2 pathway to the second process. Oxidative stress has also been shown to trigger these effects on canalicular transporters. We studied the possible role of oxidative stress in E17G-induced impairment of Mrp2 function by assessing the canalicular vacuolar accumulation (cVA) of glutathione-S-methylfluorescein (GS-MF) in rat hepatocyte couplets (RHC). The possible E17G-induced increase in intracellu- lar reactive oxygen species (ROS) was assessed fluorometrically in primary cultured rat hepatocytes (PCH) by the 2´,7´-dichloro- fluorescin-diacetate (DCFH-DA) assay. A probable role of ROS in E17G-induced Mrp2 function impairment was evaluated by preincu- bating RHC for 15 min with the antioxidants vitamin C (VitC), mannitol (Man), N,N?-diphenyl-p-phenylenediamine (DPPD), and also with apocynin (Apo), a specific inhibitor of the ROS-producing enzyme NADPH oxidase (NOX), prior to a 20-min exposure to E17G; a potential role of MEK-ERK1/2 pathway was assessed by its inhibition with the MEK inhibitor PD98059 (PD). E17G increased intracellular ROS by 43±9 % [p