Activation of insulin-like growth factor 1 receptor participates downstream of GPR30 in estradiol-17β-d-glucuronide-induced cholestasis in rats
- 280 Downloads
Estradiol-17β-d-glucuronide (E17G), through the activation of different signaling proteins, induces acute endocytic internalization of canalicular transporters in rat, including multidrug resistance-associated protein 2 (Abcc2) and bile salt export pump (Abcb11), generating cholestasis. Insulin-like growth factor 1 receptor (IGF-1R) is a membrane-bound tyrosine kinase receptor that can potentially interact with proteins activated by E17G. The aim of this study was to analyze the potential role of IGF-1R in the effects of E17G in isolated perfused rat liver (IPRL) and isolated rat hepatocyte couplets. In vitro, IGF-1R inhibition by tyrphostin AG1024 (TYR, 100 nM), or its knock-down with siRNA, strongly prevented E17G-induced impairment of Abcc2 and Abcb11 function and localization. The protection by TYR was not additive to that produced by wortmannin (PI3K inhibitor, 100 nM), and both protections share the same dependency on microtubule integrity, suggesting that IGF-1R shared the signaling pathway of PI3K/Akt. Further analysis of the activation of Akt and IGF-1R induced by E17G indicated a sequence of activation GPR30-IGF-1R-PI3K/Akt. In IPRL, an intraportal injection of E17G triggered endocytosis of Abcc2 and Abcb11, and this was accompanied by a sustained decrease in the bile flow and the biliary excretion of Abcc2 and Abcb11 substrates. TYR did not prevent the initial decay, but it greatly accelerated the recovery to normality of these parameters and the reinsertion of transporters into the canalicular membrane. In conclusion, the activation of IGF-1R is a key factor in the alteration of canalicular transporter function and localization induced by E17G, and its activation follows that of GPR30 and precedes that of PI3K/Akt.
KeywordsAbcb11 Abcc2 IGF-1 receptor Cholestasis ABC transporters
Multidrug resistance-associated protein 2
Bile salt export pump
Epidermal growth factor receptor
Estrogen receptor alpha
G protein-coupled receptor 30
Insulin-like growth factor 1
Protein kinase B
Isolated rat hepatocyte couplets
Sandwich-cultured rat hepatocytes
Canalicular vacuolar accumulation
Isolated perfused rat liver
We thank J. Pellegrino for assistance with confocal microscopy.
Compliance with ethical standards
This work was supported by grants from Agencia Nacional de Promoción Científica y Tecnológica (PICTs 2013 N° 1222 and 2013 N° 0974) and Consejo Nacional de Investigaciones Científicas y Técnicas (PIP 0217 and PUE IFISE 0089).
- García-Regalado A, Guzmán-Hernández ML, Ramírez-Rangel I et al (2008) G protein-coupled receptor-promoted trafficking of Gbeta1gamma2 leads to AKT activation at endosomes via a mechanism mediated by Gbeta1gamma2-Rab11a interaction. Mol Biol Cell 19:4188–4200. doi: 10.1091/mbc.E07-10-1089 CrossRefPubMedPubMedCentralGoogle Scholar
- Garcia-Segura LM, Arévalo M-A, Azcoitia I (2010) Interactions of estradiol and insulin-like growth factor-I signalling in the nervous system. In: Progress in brain research. pp 251–272Google Scholar
- Miyata M (2004) Role of farnesoid X receptor in the enhancement of canalicular bile acid output and excretion of unconjugated bile acids: a mechanism for protection against cholic acid-induced liver toxicity. J Pharmacol Exp Ther 312:759–766. doi: 10.1124/jpet.104.076158 CrossRefPubMedGoogle Scholar
- Song RX-D, Zhang Z, Chen Y et al (2007) Estrogen signaling via a linear pathway involving insulin-like growth factor I receptor, matrix metalloproteinases, and epidermal growth factor receptor to activate mitogen-activated protein kinase in MCF-7 breast cancer cells. Endocrinology 148:4091–4101. doi: 10.1210/en.2007-0240 CrossRefPubMedPubMedCentralGoogle Scholar