多药耐药蛋白2
沃特曼宁
内化
胆汁淤积
胆盐出口泵
激酶
p38丝裂原活化蛋白激酶
MAPK/ERK通路
细胞生物学
生物
内分泌学
化学
内科学
生物化学
运输机
ATP结合盒运输机
医学
受体
磷脂酰肌醇
基因
作者
Andrea C. Boaglio,Andrés E. Zucchetti,Flavia D. Toledo,Ismael R. Barosso,Enrique J. Sánchez Pozzi,Fernando A. Crocenzi,Marcelo G. Roma
出处
期刊:PLOS ONE
[Public Library of Science]
日期:2012-11-14
卷期号:7 (11): e49255-e49255
被引量:27
标识
DOI:10.1371/journal.pone.0049255
摘要
Objective The endogenous, cholestatic metabolite estradiol 17ß-d-glucuronide (E217G) induces endocytic internalization of the canalicular transporters relevant to bile formation, Bsep and Mrp2. We evaluated here whether MAPKs are involved in this effect. Design ERK1/2, JNK1/2, and p38 MAPK activation was assessed by the increase in their phosphorylation status. Hepatocanalicular function was evaluated in isolated rat hepatocyte couplets (IRHCs) by quantifying the apical secretion of fluorescent Bsep and Mrp2 substrates, and in isolated, perfused rat livers (IPRLs), using taurocholate and 2,4-dinitrophenyl-S-glutathione, respectively. Protein kinase participation in E217G-induced secretory failure was assessed by co-administering selective inhibitors. Internalization of Bsep/Mrp2 was assessed by confocal microscopy and image analysis. Results E217G activated all kinds of MAPKs. The PI3K inhibitor wortmannin prevented ERK1/2 activation, whereas the cPKC inhibitor Gö6976 prevented p38 activation, suggesting that ERK1/2 and p38 are downstream of PI3K and cPKC, respectively. The p38 inhibitor SB203580 and the ERK1/2 inhibitor PD98059, but not the JNK1/2 inhibitor SP600125, partially prevented E217G-induced changes in transporter activity and localization in IRHCs. p38 and ERK1/2 co-inhibition resulted in additive protection, suggesting complementary involvement of these MAPKs. In IPRLs, E217G induced endocytosis of canalicular transporters and a rapid and sustained decrease in bile flow and biliary excretion of Bsep/Mrp2 substrates. p38 inhibition prevented this initial decay, and the internalization of Bsep/Mrp2. Contrarily, ERK1/2 inhibition accelerated the recovery of biliary secretion and the canalicular reinsertion of Bsep/Mrp2. Conclusions cPKC/p38 MAPK and PI3K/ERK1/2 signalling pathways participate complementarily in E217G-induced cholestasis, through internalization and sustained intracellular retention of canalicular transporters, respectively.
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