简介：AbstractObjective:This study aimed at investigating the expression of nuclear factor kappa B (NF-κB) and mammalian target of rapamycin (mTOR) related signal pathways in liver tissues of intrahepatic cholestasis of pregnancy animal models.Methods:Estrogen (EE)-induced cholestasis and a placental ischemia-reperfusion (IR) model were established in pregnant rats. All pregnant rats were divided into four groups by random number table: EE-IR group (n= 6), EE-sham group (n = 6), control-IR group (n= 6) and control-sham group (n= 6). Liver expression of mTOR, its upstream regulator DNA damage response-1 (REDD1), and downstream factor glucose transporter type-1 (GLUT1), accompanied by NF-κB (p65 is the most important component), its activator toll-like receptor 4 (TLR4), and inhibitor IκBα, were detected by western blot analysis and real-time polymerase chain reaction. The intergroup comparisons were performed with a one-way analysis of variance, the comparisons among groups were analyzed with the nonparametric Kruskal-Wallis test.Results:Giving pregnant rats EE alone reduced the hepatic expression of IκBα (0.72 ± 0.20 vs. 1.01 ± 0.07, P= 0.008). Meanwhile, giving pregnant rats placental IR alone increased liver levels of REDD1 (3.24 ± 0.98 vs. 1.06 ± 0.24, P= 0.025), GLUT1 (2.37 ± 0.82 vs. 1.09 ± 0.10, P= 0.039), TLR4 (2.12 ± 0.29 vs. 1.20 ± 0.28, P= 0.010), and p65 (2.09 ± 0.85 vs. 1.04 ± 0.06, P= 0.023), and decreased hepatic mTOR (0.50 ± 0.07 vs. 1.01 ± 0.03, P= 0.001) and IκBα (0.61 ± 0.08 vs. 1.01 ± 0.07, P= 0.014) expression. Subjecting EE-treated rats to placental IR did not further alter liver levels of GLUT1 (2.02 ± 0.45 vs. 1.79 ± 0.39, P= 0.240), TLR4 (2.10 ± 0.74 vs. 1.60 ± 0.36, P= 0.129), or p65 (2.41 ± 0.83 vs. 1.65 ± 0.46, P= 0.145), whereas it did decrease hepatic mTOR (0.42 ± 0.09 vs. 0.90 ± 0.14, P= 0.008) and IκBα (0.43 ± 0.09 vs. 0.72 ± 0.20, P= 0.004) expression and enhance REDD1 expression (4.46 ± 0.65 vs. 2.05 ± 0.47, P= 0.009). Placental IR stress did impact the hepatic expression of REDD1-mTOR-GLUT1 and TLR4/NF-κB/IκBα in pregnant rats.Conclusion:Placental IR-induced hepatic GLUT1, TLR4, and p65 alternation, which responded efficiently in control rats, were impaired in EE-induced ICP rats.

简介：AbstractObjective:To investigate the possible regulatory mechanism of corticotropin-releasing hormone (CRH), urocortin (UCN), and Wolfram syndrome 1 (WFS1) in 17α-ethynylestradiol (EE)-induced intrahepatic cholestasis pregnant rats and its ischemia reperfusion (IR) model.Methods:Pregnant rats (n=60) were randomly divided into four experimental groups by random number table (Control, EE, IR, and EE-IR groups),and were studied on the 17th, 19th, and 21st gestational days (GD) (n=5 in each group at the indicated time). Growth and development indicators of fetal rats among these four groups were recorded. Enzyme-linked immunosorbent assay was employed to detect CRH, UCN, and WFS1 levels in maternal sera. Western blotting and real-time polymerase chain reaction were used to quantify placental protein and placental mRNA levels of CRH, UCN, and WFS1. Multivariate analysis of variance and least significant difference test were used to establish the group and individual comparisons.Results:A significant difference was found in placenta weight (F=8.10, P<0.05), fetal rat weight (F=40.86, P<0.05), fetal rat length (F=61.61, P<0.05), and fetal rat tail length (F=55.63, P<0.05) among four groups on the 17th ,19th , and 21st GD.What’s more, the overall differences of maternal serum UCN levels among Control, EE, IR, and EE-IR groups were significant (F=2.48, P<0.05). Expression of WFS1 mRNA in the EE-IR group was significantly increased and higher than Control (0.46±0.15 vs. 0.24±0.09, P<0.05), EE (0.46±0.15 vs. 0.17±0.04, P>0.05), and IR (0.46±0.15 vs. 0.22±0.15, P>0.05) groups at 19th GD, indicating that endoplasmic reticulum stress may be activated. However, the expression of CRH (0.42±0.05 vs. 0.58±0.12, P<0.05), UCN (0.43±0.01 vs. 0.47±0.16, P>0.05), and WFS1 (0.57±0.07 vs. 0.74±0.12, P>0.05) protein in the EE-IR group was subsided compared to the IR group at 17th GD.Conclusion:Fetal rat growth restriction was found in the EE-induced intrahepatic cholestasis model. This study revealed that significant changes in the maternal sera level of UCN , placental level of WFS1 mRNA and placental levels of CRH, UCN, and WFS1 protein in chronic versus acute stress in a rat model of pregnancy. This suggests an impaired compensatory vasodilatory effect mediated by these factors at gene transcription and protein translation levels, following acute hypoxia stress in EE-induced intrahepatic cholestasis in pregnant rats.