Bile acids evoke placental inflammation by activating Gpbar1/NF-κB pathway in intrahepatic cholestasis of pregnancy

Ursodeoxycholic and chenodeoxycholic bile acids alleviate endotoxininduced acute lung injury in rats by modulating aquaporin expression and pathways associated with apoptosis and inflammation

Introduction

This study aimed to investigate the anti-inflammatory, antioxidant, and anti-apoptotic properties of ursodeoxycholic (UDCA) and chenodeoxycholic (CDCA) bile acids in a rat model of endotoxin (lipopolysaccharide, LPS)-induced acute lung injury (ALI).

Methods

The study included six groups of Wistar rats exposed to different pretreatments. The control and endotoxin groups were pretreated with propylene glycol, a solvent for bile acids, while the other groups received UDCA or CDCA for 10 days. On the 10th day, an endotoxin injection was given to evaluate the impact of these pretreatments. Lung tissue sections were analyzed by immunohistochemistry, targeting the pro-inflammatory marker nuclear factor kappa B (NF-κB), the anti-apoptotic marker B-cell lymphoma 2 (BCL-2), pro-apoptotic markers BCL-2-associated X protein (BAX) and caspase 3, as well as the aquaporins 1 and 5 (AQP1 and AQP5). Oxidative stress was assessed in bronchoalveolar lavage fluid (BALF).

Results and discussion

This study demonstrates that UDCA and CDCA can mitigate endotoxin-induced lung injury in rats. These effects are achieved through modulation of AQP1 and AQP5 expression, reduction of oxidative stress, regulation of apoptotic pathways (BAX, caspase 3, BCL-2), and attenuation of pro-inflammatory activity of NF-κB. Although the results indicate a significant association between the expression of these proteins and histopathological changes, the potential influence of additional factors cannot be excluded. These findings suggest that UDCA and CDCA provide lung protection by acting through complex mechanisms involving inflammatory, oxidative, and apoptotic pathways.

Detection of serum lactate dehydrogenase A and its metabolites on placental function in patients with intrahepatic cholestasis of pregnancy

A specific liver disease during pregnancy is intrahepatic cholestasis of pregnancy (ICP). The current clinical diagnosis mainly depends on the level of serum total bile acid (TBA), which lacks sensitivity and specificity. Lactate dehydrogenase A (LDHA) is a new biomarker highly expressed in the serum of ICP patients, which was screened by data-independent acquisition (DIA) proteomic technology in our previous studies. There is currently a lack of a rapid, quantitative, and sensitive detection method to measure LDHA levels in serum. This study aimed to establish a time-resolved fluorescent nanomicrospheres immunochromatographic test strip to detect LDHA in serum and evaluate its value in clinical diagnosis and treatment of ICP. Subsequently, the mechanism of LDHA in mediating the inflammatory of ICP was explored in vitro. In vitro, taurocholic acid (TCA) at a concentration of 100 μM was used to simulate an ICP environment. The AKT/mTOR/HIF-1α signaling pathway was activated in TCA-treated HTR-8/SVeno cells, leading to an increase in LDHA levels. The lactic acid produced by LDHA-mediated glycolytic metabolism may be related to the regulation of inflammation in placental trophoblast cells. According to these findings, LDHA could be a new target that provide promising ideas for the diagnosis, prediction and treatment of ICP.

Activation of aryl hydrocarbon receptor protein promotes testosterone synthesis to alleviate abnormal spermatogenesis caused by cholestasis

In this study, we have investigated potential roles of cholestasis played in spermatogenesis in the cholestatic animal model generated by giving the mice DDC diet. The data showed that cholestasis jeopardized the testicular structure and function by downregulating the expressions of genes related to the androgen's synthesis. Mechanistically, the cholestasis disturbers the liver's tryptophan metabolism and its metabolites. These tryptophan metabolites including serotonin, 5-Hydroxyindoleacetic acid, 4-(2-Aminophenyl)-2,4-dioxobutanoic acid and Quinoline-4,8-diol were significantly reduced in the cholestatic mice model compared to their controlled counterparts. These tryptophan metabolites are the endogenous ligands of AHR and their levels are positively correlated to the expressions of genes related to the androgen's synthesis and AHR. Notably, supplementation of AHR ligand ITE promoted the expression of genes related to the testosterone synthesis and alleviated abnormal spermatogenesis. In addition, the bacteria that disturbed the tryptophan metabolism in cholestatic mice were identified by 16S rDNA sequencing and Spearman correlation analysis. Briefly, we have identified a cholestasis associated gut microbiota-testis axis. This axis is responsible for the cholestasis induced abnormal spermatogenesis and male reproductive dysfunction. Breaking vicious cycle of this axis may be a suitable strategy to prevent and treat the cholestasis associated male infertility.

Taurocholic acid represents an earlier and more sensitive biomarker and promotes cholestatic hepatotoxicity in ANIT-treated rats

Bile acid homeostasis is crucial for the normal physiological functioning of the liver. Disruptions in bile acid profiles are closely linked to the occurrence of cholestatic liver injury. As part of our diagnostic and therapeutic approach, we aimed to investigate the disturbance in bile acid profiles during cholestasis and its correlation with cholestatic liver injury. Before the occurrence of liver injury, alterations in bile acid profiles were detected in both plasma and liver between 8 and 16 h, persisting up to 96 h. TCA, TCDCA, and TUDCA in the plasma, as well as TCA, TUDCA, TCDCA, TDCA, TLCA, and THDCA in the liver, emerged as early sensitive and potential markers for diagnosing ANIT-induced cholestasis at 8-16 h. The distinguishing features of ANIT-induced liver injury were as follows: T-BAs exceeding G-BAs and serum biochemical indicators surpassing free bile acids. Notably, plasma T-BAs, particularly TCA, exhibited higher sensitivity to cholestatic hepatotoxicity compared with serum enzyme activity and liver histopathology. Further investigation revealed that TCA exacerbated ANIT-induced liver injury by elevating liver function enzyme activity, inflammation, and bile duct proliferation and promoting the migration of bile duct epithelial cell. Nevertheless, no morphological changes or alterations in transaminase activity indicative of liver damage were observed in the rats treated with TCA alone. Additionally, there were no changes in bile acid profiles or inflammatory responses under physiological conditions with maintained bile acid homeostasis. In summary, our findings suggest that taurine-conjugated bile acids in both plasma and liver, particularly TCA, can serve as early and sensitive markers for predicting intrahepatic cholestatic drugs and can act as potent exacerbators of cholestatic liver injury progression. However, exogenous TCA does not induce liver injury under physiological conditions where bile acid homeostasis is maintained.

Impacts of prenatal environmental exposures on fetal-placental-maternal bile acid homeostasis and long-term health in offspring

During pregnancy, the maternal body undergoes a series of adaptative physiological changes, leading to a slight increase in serum bile acid (BA) levels. Although the fetal liver can synthesize BAs since the first trimester through the alternative pathway, the BA metabolic system is immature in the fetus. Compared to adults, the fetus has a distinct composition of BA pool and limited expression of BA synthesis enzymes and transporters. Besides, the "enterohepatic circulation" of BAs is absent in fetus. Thus, fetal BAs need to be transported to the mother through the placenta for further metabolism and excretion, and maternal BAs can also be transported to the fetus. That is what we call the "fetal-placental-maternal BA circulation". Various BA transporters and nuclear receptors are essential for maintaining the balance of this BA circulation to ensure normal fetal development. However, prenatal adverse environments can alter fetal BA metabolism, resulting in intrauterine developmental abnormalities and susceptibility to a variety of adult chronic diseases. This review summarizes the current understanding of the fetal-placental-maternal BA circulation and discusses the effects of prenatal adverse environments on this particular BA circulation, aiming to provide a theoretical basis for exploring early prevention and treatment strategies for BA metabolism-associated adverse pregnancy outcomes and long-term impairments.

Evaluation of alanine aminotransferase/aspartate aminotransferase ratio and high-density lipoprotein for predicting neonatal adverse outcomes associated with intrahepatic cholestasis of pregnancy

Background

To determine the association between lipid metabolism and intrahepatic cholestasis of pregnancy (ICP), and explore the value of maternal alanine aminotransferase/aspartate aminotransferase (ALT/AST) and high-density lipoprotein (HDL) in predicting adverse neonatal outcomes in women with ICP.

Methods

A total of 147 pregnant women with ICP admitted to The Fourth Hospital of Shijiazhuang and 120 normal pregnant women in the same period were selected in this study. The Mann-Whitney U test and Chi-square tests were used to compare the differences in clinical data. Multivariate logistic regression was used to analyze the relationship between ALT/AST and the occurrence of adverse pregnancy outcomes in patients with ICP. The combined predictive value of ALT/AST and HDL was determined by receiver operating characteristic (ROC) curve analysis.

Results

Among 147 women with ICP, 122 women had total bile acid (TBA) levels of 10-39.9 µmol/L, and 25 had TBA ≥ 40 µmol/L. There was significantly lower gestational age in patients with severe ICP than in those with mild and control groups (all p < 0.05), and the weight of newborns in the maternal ICP group was significantly lower than in the control group (p < 0.05). Increasing TBA levels was associated with higher AST, ALT, ALT/AST, and lower HDL level (all p < 0.05). Meanwhile, higher levels of ALT/AST was positively associated with neonatal hyperbilirubinemia [adjusted odds ratio (AOR) = 4.019, 95% CI [1.757-9.194, p = 0.001] and cardiac injury [AOR = 3.500, 95% CI [1.535-7.987], p = 0.003]. HDL was a significant protective factor for neonatal hyperbilirubinemia and cardiac injury [AOR = 0.315, 95% CI [0.126-0.788], p = 0.014; AOR = 0.134 (0.039-0.461), p = 0.001]. The area under the ROC curve (AUC) for prediction of neonatal hyperbilirubinemia by ALT/AST combined with HDL was 0.668 [95% CI [56.3-77.3%], p = 0.002], and the sensitivity and specificity were 47.1% and 84.0%, respectively. To predict neonatal cardiac injury, the AUC value was 0.668 [95% CI [56.4-77.1%], p = 0.002], with sensitivity and specificity were 41.2% and 87.1%, respectively.

Conclusions

The levels of higher ALT/AST and lower HDL were significantly associated with the risk of ICP-related adverse neonatal outcomes. Moreover, ALT/AST combined with HDL has moderate clinical value in predicting the adverse outcomes of neonatal hyperbilirubinemia and cardiac injury.

Proteomic Biomarkers of Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease, which can lead to adverse fetal outcomes, including preterm labor and intrauterine death. The pathogenesis of ICP is still unclear. We hypothesized that pathological index leads to abnormal placenta changes in ICP. Investigation of these differences in protein expression in parallel profiling is essential to understand the comprehensive pathophysiological mechanism underlying ICP. The present study screened differentially expressed proteins (DEPs) as novel diagnostic markers for ICP. Proteomic profiles of placental tissues from 32 ICP patients and 24 healthy volunteers (controls) were analyzed. Our founding was valid by following western blotting and immunohistochemistry staining, respectively. The association of the key protein expression with clinicopathological features of ICP was further analyzed. A total of 178 DEPs were identified between the ICP and control groups. Functional enrichment analysis showed these proteins were significantly enriched in the PPAR singling pathway by KEGG and PPARα/RXRα activation by IPA. Apolipoprotein A2 (APOA2) was the only upregulated protein, which uniquely identified in ICP groups and related to both pathways. Validation of western blotting and immunohistochemical staining analysis showed significantly higher APOA2 expression in the ICP group than in the control group. Furthermore, the expression of APOA2 is associated with clinicopathological features in ICP groups. Receiver operating characteristic (ROC) curve analyses showed that the AUC of APOA2 was 0.8984 (95% confidence interval (CI): 0.772-1.000). This study has identified up-regulated APOA2 associated with PPAR singling pathway and PPARα/RXRα activation in ICP. Thus, APOA2 may be involved in ICP pathogenesis, serving as a novel biomarker for its diagnosis.

Detrimental Role of CXCR3 in α-Naphthylisothiocyanate- and Triptolide-Induced Cholestatic Liver Injury

The chemokine receptor CXCR3 is functionally pleiotropic, not only recruiting immune cells to the inflamed liver but also mediating the pathological process of cholestatic liver injury (CLI). However, the mechanism of its involvement in the CLI remains unclear. Both alpha-naphthylisothiocyanate (ANIT) and triptolide are hepatotoxicants that induce CLI by bile acid (BA) dysregulation, inflammation, and endoplasmic reticulum (ER)/oxidative stress. Through molecular docking, CXCR3 is a potential target of ANIT and triptolide. Therefore, this study aimed to investigate the role of CXCR3 in ANIT- and triptolide-induced CLI and to explore the underlying mechanisms. Wild-type mice and CXCR3-deficient mice were administered with ANIT or triptolide to compare CLI, BA profile, hepatic recruitment of IFN-γ/IL-4/IL-17+CD4+T cells, IFN-γ/IL-4/IL-17+iNKT cells and IFN-γ/IL-4+NK cells, and the expression of ER/oxidative stress pathway. The results showed that CXCR3 deficiency ameliorated ANIT- and triptolide-induced CLI. CXCR3 deficiency alleviated ANIT-induced dysregulated BA metabolism, which decreased the recruitment of IFN-γ+NK cells and IL-4+NK cells to the liver and inhibited ER stress. After triptolide administration, CXCR3 deficiency ameliorated dysregulation of BA metabolism, which reduced the migration of IL-4+iNKT cells and IL-17+iNKT cells and reduced oxidative stress through inhibition of Egr1 expression and AKT phosphorylation. Our findings suggest a detrimental role of CXCR3 in ANIT- and triptolide-induced CLI, providing a promising therapeutic target and introducing novel mechanisms for understanding cholestatic liver diseases.

Gut microbiota-mediated C-sulfonate metabolism impairs the bioavailability and anti-cholestatic efficacy of andrographolide

Cholestatic liver injury results from the accumulation of toxic bile acids in the liver, presenting a therapeutic challenge with no effective treatment available to date. Andrographolide (AP) has exhibited potential as a treatment for cholestatic liver disease. However, its limited oral bioavailability poses a significant obstacle to harnessing its potent therapeutic properties and restricts its clinical utility. This limitation is potentially attributed to the involvement of gut microbiota in AP metabolism. In our study, employing pseudo-germ-free, germ-free and strain colonization animal models, along with 16S rRNA and shotgun metagenomic sequencing analysis, we elucidate the pivotal role played by gut microbiota in the C-sulfonate metabolism of AP, a process profoundly affecting its bioavailability and anti-cholestatic efficacy. Subsequent investigations pinpoint a specific enzyme, adenosine-5'-phosphosulfate (APS) reductase, predominantly produced by Desulfovibrio piger, which catalyzes the reduction of SO42- to HSO3-. HSO3- subsequently interacts with AP, targeting its C=C unsaturated double bond, resulting in the formation of the C-sulfonate metabolite, 14-deoxy-12(R)-sulfo andrographolide (APM). Inhibition of APS reductase leads to a notable enhancement in AP bioavailability and anti-cholestatic efficacy. Furthermore, employing RNA sequencing analysis and farnesoid X receptor (FXR) knockout mice, our findings suggest that AP may exert its anti-cholestatic effects by activating the FXR pathway to promote bile acid efflux. In summary, our study unveils the significant involvement of gut microbiota in the C-sulfonate metabolism of AP and highlights the potential benefits of inhibiting APS reductase to enhance its therapeutic effects. These discoveries provide valuable insights into enhancing the clinical applicability of AP as a promising treatment for cholestatic liver injury.

Therapeutic effect of ouabagenin, a novel liver X receptor agonist, on atherosclerosis in nonalcoholic steatohepatitis in SHRSP5/Dmcr rat model

The liver X receptor (LXR) can enhance cholesterol transporters, which could remove excess cholesterol from foam cells in atheromas. LXR has two subtypes: LXRα, which aggravates hepatic lipid accumulation, and LXRβ, which does not. In 2018, ouabagenin (OBG) was reported as a potential LXRβ-specific agonist. We aimed to examine whether OBG specifically affects LXRβ in nonalcoholic steatohepatitis (NASH); it did not aggravate hepatic steatosis and can suppress the development of atherosclerosis. SHRSP5/Dmcr rats fed a high-fat and high-cholesterol diet were divided into four groups as follows: (I) L-NAME group, (II) L-NAME/OBG group, (III) OBG (-) group, and (IV) OBG (+) group. All groups' rats were intraperitoneally administered L-NAME. The L-NAME/OBG group's rats were intraperitoneally administered OBG and L-NAME simultaneously. After L-NAME administration, the OBG (+) group's rats were administered OBG, while the OBG (-) group's rats were not. Although all rats developed NASH, OBG did not exacerbate steatosis (L-NAME/OBG and OBG (+) groups). In addition, endothelial cells were protected in the L-NAME/OBG group and foam cells in the atheroma were reduced in the OBG (+) group. OBG is an LXRβ-specific agonist and has a potential therapeutic effect on atherosclerosis without developing lipid accumulation in the liver.

Sensitive LC-MS/MS method for the temporal profiling of bile acids, fatty acids and branched-chain alpha-keto acids in maternal plasma during pregnancy and cord blood plasma at delivery

BACKGROUND AND AIMS

There are significant changes to the maternal inflammatory profile across pregnancy. Recent studies suggest that perturbations in maternal gut microbial and dietary-derived plasma metabolites over the course of pregnancy mediate inflammation through a complex interplay of immunomodulatory effects. Despite this body of evidence, there is currently no analytical method that is suitable for the simultaneous profiling of these metabolites within human plasma.

MATERIALS AND METHODS

We developed a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for the high-throughput analysis of these metabolites in human plasma without derivatization. Plasma samples were processed using liquid-liquid extraction method with varying proportions of methyl tert-butyl ether, methanol, and water in a 3:10:2.5 ratio to reduce matrix effects.

RESULTS

LC-MS/MS detection was sufficiently sensitive to quantify these gut microbial and dietary-derived metabolites at physiological concentrations and linear calibration curves with r2 > 0.99 were obtained. Recovery was consistent across concentration levels. Stability experiments confirmed that up to 160 samples could be analyzed within a single batch. The method was validated and applied to analyse maternal plasma during the first and third trimester and cord blood plasma of 5 mothers.

CONCLUSION

This study validated a straightforward and sensitive LC-MS/MS method for the simultaneous quantitation of gut microbial and dietary-derived metabolites in human plasma within 9 minutes without prior sample derivatization.

Resveratrol intervention attenuates chylomicron secretion via repressing intestinal FXR-induced expression of scavenger receptor SR-B1

Two common features of dietary polyphenols have hampered our mechanistic understanding of their beneficial effects for decades: targeting multiple organs and extremely low bioavailability. We show here that resveratrol intervention (REV-I) in high-fat diet (HFD)-challenged male mice inhibits chylomicron secretion, associated with reduced expression of jejunal but not hepatic scavenger receptor class B type 1 (SR-B1). Intestinal mucosa-specific SR-B1-/- mice on HFD-challenge exhibit improved lipid homeostasis but show virtually no further response to REV-I. SR-B1 expression in Caco-2 cells cannot be repressed by pure resveratrol compound while fecal-microbiota transplantation from mice on REV-I suppresses jejunal SR-B1 in recipient mice. REV-I reduces fecal levels of bile acids and activity of fecal bile-salt hydrolase. In Caco-2 cells, chenodeoxycholic acid treatment stimulates both FXR and SR-B1. We conclude that gut microbiome is the primary target of REV-I, and REV-I improves lipid homeostasis at least partially via attenuating FXR-stimulated gut SR-B1 elevation.

Cordyceps militaris polysaccharide alleviates ovalbumin-induced allergic asthma through the Nrf2/HO-1 and NF-κB signaling pathways and regulates the gut microbiota

Polysaccharides, as one of the main types of bioactive components of Cordyceps militaris, have anti-allergic asthma effects. Herein, an ovalbumin-induced allergic asthma mouse model was established to assess the potential mechanisms of the separated and purified Cordyceps militaris polysaccharide (CMP). CMP is an α-pyranose with a molecular weight of 15.94 kDa that consists of Glc, Man, Gal, Xyl, Ara and GlcA in a molar ratio of 81.25:21.96:13.88:3.92:3.58:1.00. CMP improved inflammatory cytokine levels, alleviated the histopathological changes in the lung and intestinal tissues, regulated the expression of mRNA and proteins related to oxidative stress and inflammatory pathways, reversed gut dysbiosis at the phylum and family levels and improved microbiota function in allergic asthma mice. Moreover, it was found that the levels of inflammatory cytokines in lung tissue of mice were significantly correlated with some intestinal microbial communities. Overall, CMP improved oxidative stress and the inflammatory response in allergic asthma mice by regulating the Nrf2/HO-1 and NF-κB signaling pathways, which may be closely correlation with maintaining the stability of the gut microbiota.

Bile Acids in Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is the most common, reversible, and closely related to pregnancy condition characterized by elevated levels of bile acids (BAs) in blood serum and an increased risk of adverse perinatal outcomes. Due to the complex interactions between the mother and the fetus in metabolism and transplacental BAs transport, ICP is classified as a fetal-maternal disease. The disease is usually mild in pregnant women, but it can be fatal to the fetus, leading to numerous complications, including intrauterine death. The pathophysiology of the disease is based on inflammatory mechanisms caused by elevated BA levels. Although ICP cannot be completely prevented, its early diagnosis and prompt management significantly reduce the risk of fetal complications, the most serious of which is unexpected intrauterine death. It is worth emphasizing that all diagnostics and management of ICP during pregnancy are based on BA levels. Therefore, it is important to standardize the criteria for diagnosis, as well as recommendations for management depending on the level of BAs, which undoubtedly determines the impact on the fetus. The purpose of this review is to present the potential and importance of BAs in the detection and rules of medical procedure in ICP.

Serum profiles of inflammatory cytokines associated with intrahepatic cholestasis of pregnancy

BACKGROUND

The pathogenesis of intrahepatic cholestasis of pregnancy (ICP) is not clear, and some researchers have compared the differences in serum levels of inflammatory cytokines between ICP patients and normal pregnant women, but there are few studies and different conclusions.

AIM

To investigate the levels of inflammatory cytokines such as interleukins (IL) -4, IL-6, IL-8, and tumor necrosis factor alpha (TNF-α) in patients with ICP and their potential role in pathophysiology.

METHODS

This case-control study was conducted in Shanghai First Maternity and Infant Health Hospital, and we recruited ICP patients and age-matched healthy pregnant women as a control group. Plasma samples from 40 subjects with ICP and 40 subjects without ICP were tested for concentration of the following inflammatory cytokines: interferon-gamma, IL-1 alpha, IL-1 beta, IL-2, IL-4, IL-6, IL-8, IL-10, and TNF-α. Analyzed inflammatory cytokines were then assessed, either individually or in combination with regard to ICP.

RESULTS

The cytokine composition of the ICP and CTL group was significantly different. We compared levels of inflammatory cytokines with regard to the presence of ICP symptoms. Levels of IL-4, IL-6, and TNF-α were significantly lower in ICP subjects, and IL-8 were significantly higher in ICP subjects, compared with CTL subjects. The TNF-α showed the best performance for ICP identification (area under the curve [AUC]: 0.829). Performance was increased when TNF-α was combined with IL-4 and IL-8 analysis (AUC, 0.901). Spearman correlation and linear regression analysis revealed that the TNF-α concentrations correlated with IL-4 and IL-6 levels, and inversely correlated to TBA, ALT, AST, and IL-8 levels.

CONCLUSION

IL-4, IL-6, and TNF-α were significantly decreased, while IL-8 was significantly increased in the ICP group compared with the healthy control group. TNF showed the best single marker discriminatory potential; however, combining TNF-α, IL-4, and IL-8 analyses increased performance for ICP identification.

Dysregulated Hepatic Expression of Glucose Transporter Type-1, Toll-Like Receptor 4, and Nuclear Factor Kappa B in Estrogen-Induced Cholestasis Pregnant Rats with Placental Ischemia-Reperfusion Stress

Objective

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.

Increased serum delta neutrophil index levels are associated with intrahepatic cholestasis of pregnancy

OBJECTIVE

This study aims to compare the maternal serum delta neutrophil index (DNI) levels in intrahepatic cholestasis of pregnancy (ICP) and healthy pregnancies.

METHODS

This study consisted of a group of patients (n = 40) diagnosed with isolated ICP who gave birth in our hospital and a control group (n = 60) between December 1, 2015, and June 30, 2018. The diagnosis of ICP was made based on pruritus and elevated fasting serum bile acids and liver enzymes. Laboratory tests of both groups in the hospitalization process were retrospectively examined. Maternal and neonatal characteristics, pregnancy outcomes, and DNI values of the two groups were compared. Statistical analyses were performed using SPSS version 20.

RESULTS

Mean maternal serum DNI levels were significantly higher in women with ICP than in the control group (0.49 ± 4.8 vs -3.99 ± 3.02, p = <0.01). Receiver operating characteristic (ROC) curve analysis was used to define the DNI value where ICP can be best predicted.

CONCLUSION

DNI, a new inflammatory marker, was found to be higher in women with ICP than in normal pregnancies.

Molecular Pathogenesis of Intrahepatic Cholestasis of Pregnancy

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease. The maternal symptoms are characterized by skin pruritus and elevated bile acids, causing several adverse outcomes for fetuses, including an increased risk of preterm birth, meconium-stained amniotic fluid, neonatal depression, respiratory distress syndrome, and stillbirth. Genetic, hormonal, immunological, and environmental factors contribute to the pathogenesis of ICP, and the estrogen-bile acid axis is thought to play a dominant role. The advances in the past 10 years uncover more details of this axis. Moreover, dysregulation of extracellular matrix and oxygen supply, organelle dysfunction, and epigenetic changes are also found to cause ICP, illuminating more potential drug targets for interfering with. Here, we summarize the molecular pathogenesis of ICP with an emphasis on the advancement in the past 10 years, aiming to give an updated full view of this field.

Ursodeoxycholic acid improves pregnancy outcome in patients with intrahepatic cholestasis during pregnancy: A protocol for systematic review and meta-analysis

BACKGROUND

Intrahepatic cholestasis of pregnancy (ICP) is a common complication in the third trimester of pregnancy, which may result in premature delivery, fetal distress, stillbirth, and other adverse pregnancy outcomes. Ursodeoxycholic acid (UDCA) is a first-line treatment for ICP and has been controversial in improving adverse pregnancy outcomes. The purpose of this protocol is to systematically evaluate the effect of UDCA on pregnancy outcomes in patients with intrahepatic cholestasis during pregnancy.

METHODS

To search the databases PubMed, Embase, Web of Science, the Cochrane Library, CNKI, WanFang, VIP, CBMDIsc by computer, then to include randomized controlled clinical studies on UDCA for treatment of intrahepatic cholestasis during pregnancy from the establishment of the database to October 1, 2020. Two researchers independently extract and evaluate the data of the included studies, and meta-analysis is conducted on the included literatures using RevMan5.3 software.

RESULTS

This protocol evaluates the outcome of UDCA in improving ICP by incidence of postpartum hemorrhage in pregnant women preterm birth rates meconium contamination rate in amniotic fluid incidence of fetal distress scale of newborns scoring <7 in 5-min Apgar incidence of neonatal admission to neonatal intensive care unit.

CONCLUSION

This protocol will provide an evidence-based basis for clinical use of UDCA in the treatment of intrahepatic cholestasis during pregnancy.

ETHICS AND DISSEMINATION

Private information from individuals will not be published. This systematic review also does not involve endangering participant rights. Ethical approval was not required. The results may be published in a peer-reviewed journal or disseminated at relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605 / OSF.IO / BE67H.

Targeting the alternative bile acid synthetic pathway for metabolic diseases

The gut microbiota is profoundly involved in glucose and lipid metabolism, in part by regulating bile acid (BA) metabolism and affecting multiple BA-receptor signaling pathways. BAs are synthesized in the liver by multi-step reactions catalyzed via two distinct routes, the classical pathway (producing the 12α-hydroxylated primary BA, cholic acid), and the alternative pathway (producing the non-12α-hydroxylated primary BA, chenodeoxycholic acid). BA synthesis and excretion is a major pathway of cholesterol and lipid catabolism, and thus, is implicated in a variety of metabolic diseases including obesity, insulin resistance, and nonalcoholic fatty liver disease. Additionally, both oxysterols and BAs function as signaling molecules that activate multiple nuclear and membrane receptor-mediated signaling pathways in various tissues, regulating glucose, lipid homeostasis, inflammation, and energy expenditure. Modulating BA synthesis and composition to regulate BA signaling is an interesting and novel direction for developing therapies for metabolic disease. In this review, we summarize the most recent findings on the role of BA synthetic pathways, with a focus on the role of the alternative pathway, which has been under-investigated, in treating hyperglycemia and fatty liver disease. We also discuss future perspectives to develop promising pharmacological strategies targeting the alternative BA synthetic pathway for the treatment of metabolic diseases.

The Role of Melatonin, IL-8 and IL-10 in Intrahepatic Cholestasis of Pregnancy

INTRODUCTION

Intrahepatic cholestasis of pregnancy is a pregnancy-specific liver disease that usually emerges during the third trimester of pregnancy. It is characterized by itching and elevated serum total bile acid levels, and it may lead to severe fetal complications. This study aimed to investigate the role of interleukin-8, a pro-inflammatory cytokine; interleukin-10, an anti-inflammatory cytokine; and melatonin in intrahepatic cholestasis of pregnancy.

MATERIALS AND METHODS

This prospective, case-controlled study was conducted with 51 women with intrahepatic cholestasis of pregnancy (40 mild and 11 severe cases) and 43 healthy pregnant women. Serum interleukin-8, interleukin-10, and melatonin levels were evaluated.

RESULTS

Melatonin and interleukin -10 were significantly lower in subjects with intrahepatic cholestasis of pregnancy (p=0.001; p=0.001, respectively p<0.05). Interleukin-8 levels were found to be significantly higher in the cholestasis group than control group (p=0.001, p<0.05).

CONCLUSIONS

Because interleukin-8, interleukin-10, and melatonin were found to be significantly correlated with intrahepatic cholestasis of pregnancy, we believe this finding could shed light on the etiology of the disease.

Review: Pathogenesis of cholestatic liver diseases

Cholestatic liver diseases (CLD) begin to develop after an impairment of bile flow start to affect the biliary tree. Cholangiocytes actively participate in the liver response to injury and repair and the intensity of this reaction is a determinant factor for the development of CLD. Progressive cholangiopathies may ultimately lead to end-stage liver disease requiring at the end orthotopic liver transplantation. This narrative review will discuss cholangiocyte biology and pathogenesis mechanisms involved in four intrahepatic CLD: Primary biliary cholangitis, primary sclerosing cholangitis, cystic fibrosis involving the liver, and polycystic liver disease.

Bile acids aggravate nonalcoholic steatohepatitis and cardiovascular disease in SHRSP5/Dmcr rat model

BACKGROUND AND AIMS

Nonalcoholic steatohepatitis (NASH) is linked to an increased risk of cardiovascular disease, regardless of the risk factors in metabolic syndrome. However, the intermediary factors between NASH and cardiovascular disease are still unknown. A previous study revealed that serum and hepatic bile acid (BA) levels are increased in some NASH patients. We aimed to examine whether NASH and cardiovascular disease were aggravated by BA using an animal model.

METHOD AND RESULTS

From 10 to 18 weeks of age, SHRSP5/Dmcr rats divided into 3 groups were fed 3 types of high-fat and high-cholesterol (HFC) diets which were changed in the cholic acid (CA) concentration (0%, 2%, or 4%). The nitro oxide synthase inhibition (L-NAME) was administered intraperitoneally from 16 to 18 weeks of age. The 4% CA groups showed the worst LV dysfunction and myocardial fibrosis, and demonstrated severe hepatic fibrosis and lipid depositions. In addition, a large amount of lipid accumulation was observed in the aortas of the 4% CA group, and NFκB and VCAM-1 gene expression levels were increased. These findings were not seen in the 0% CA group.

CONCLUSION

In the SHRSP5/Dmcr rat model, NASH and cardiovascular disease were aggravated with increasing BAs concentrations in an HFC diet.

Baicalin Protects Against 17α-Ethinylestradiol-Induced Cholestasis via the Sirtuin 1/Hepatic Nuclear Receptor-1α/Farnesoid X Receptor Pathway

Estrogen-induced cholestasis (EIC) is characterized by impairment of bile flow and accumulated bile acids (BAs) in the liver, always along with the liver damage. Baicalin is a major flavonoid component of Scutellaria baicalensis, and has been used in the treatment of liver diseases for many years. However, the role of baicalin in EIC remains to be elucidated. In this study, we demonstrated that baicalin showed obvious hepatoprotective effects in EIC rats by reducing serum biomarkers and increasing the bile flow rate, as well as by alleviating liver histology and restoring the abnormal composition of hepatic BAs. In addition, baicalin protected against estrogen-induced liver injury by up-regulation of the expression of hepatic efflux transporters and down-regulation of hepatic uptake transporters. Furthermore, baicalin increased the expression of hepatic BA synthase (CYP27A1) and metabolic enzymes (Bal, Baat, Sult2a1) in EIC rats. We showed that baicalin significantly inhibited hepatic inflammatory responses in EIC rats through reducing elevated levels of TNF-α, IL-1β, IL-6, and NF-κB. Finally, we confirmed that baicalin maintains hepatic BA homeostasis and alleviates inflammation through sirtuin 1 (Sirt1)/hepatic nuclear receptor-1α (HNF-1α)/farnesoid X receptor (FXR) signaling pathway. Thus, baicalin protects against estrogen-induced cholestatic liver injury, and the underlying mechanism involved is related to activation of the Sirt1/HNF-1α/FXR signaling pathway.

Transcriptome Profiling of Placenta through Pregnancy Reveals Dysregulation of Bile Acids Transport and Detoxification Function

Placenta performs the function of several adult organs for the fetus during intrauterine life. Because of the dramatic physiological and metabolic changes during pregnancy and the strong association between maternal metabolism and placental function, the possibility that variation in gene expression patterns during pregnancy might be linked to fetal health warrants investigation. Here, next-generation RNA sequencing was used to investigate the expression profile, including mRNAs and long non-coding RNAs (lncRNAs) of placentas on day 60 of gestation (G60), day 90 of gestation (G90), and on the farrowing day (L0) in pregnant swine. Bioinformatics analysis of differentially expressed mRNAs and lncRNAs consistently showed dysregulation of bile acids transport and detoxification as pregnancy progress. We found the differentially expressed mRNAs, particularly bile salt export pump (ABCB11), organic anion-transporting polypeptide 1A2 (OATP1A2), carbonic anhydrase II (CA2), Na⁺-HCO₃⁻ cotransporter (NBC1), and hydroxysteroid sulfotransferases (SULT2A1) play an important role in bile acids transport and sulfation in placentas during pregnancy. We also found the potential regulation role of ALDBSSCG0000000220 and XLOC_1301271 on placental SULT2A1. These findings have uncovered a previously unclear function and its genetic basis for bile acids metabolism in developing placentas and have important implications for exploring the potential physiological and pathological pathway to improve fetal outcomes.

Bile salts regulate CYP7A1 expression and elicit a fibrotic response and abnormal lipid production in 3D liver microtissues

Disrupted regulation and accumulation of bile salts (BS) in the liver can contribute towards progressive liver damage and fibrosis. Here, we investigated the role of BS in the progression of cholestatic injury and liver fibrosis using 3D scaffold-free multicellular human liver microtissues (MTs) comprising the cell lines HepaRG, THP-1 and hTERT-HSCs. This in vitro model has been shown to recapitulate cellular events leading to fibrosis including hepatocellular injury, inflammation and activation of HSCs, ultimately leading to increased deposition of extracellular matrix (ECM). In order to better differentiate the contribution of individual cells during cholestasis, the effects of BS were evaluated either on each of the three cell types individually or on the multicellular MTs. Our data corroborate the toxic effects of BS on HepaRG cells and indicate that BS exposure elicited a slight increase in cytokines without causing stellate cell activation. Contrarily, using the MTs, we could demonstrate that low concentrations of BS led to cellular damage and triggered a fibrotic response. This indicates that cellular interplay is required to achieve BS-triggered activation of HSC. Moreover, BS were capable of down-regulating CYP7A1 expression in MTs and elicited abnormal lipid production (accumulation) concordant with clinical cases where chronic cholestasis results in hypercholesterolemia.

Ursodeoxycholic acid inhibits uptake and vasoconstrictor effects of taurocholate in human placenta

Intrahepatic cholestasis of pregnancy (ICP) causes increased transfer of maternal bile acids to the fetus and an increased incidence of sudden fetal death. Treatment includes ursodeoxycholic acid (UDCA), but it is not clear if UDCA protects the fetus. This study explores the placental transport of the bile acid taurocholate (TC) by the organic anion-transporting polypeptide, (OATP)4A1, its effects on the placental proteome and vascular function, and how these are modified by UDCA. Various methodological approaches including placental villous fragments and Xenopus laevis oocytes were used to investigate UDCA transport. Placental perfusions and myography investigated the effect of TC on vasculature. The effects of acute TC exposure on placental tissue were investigated using quantitative proteomics. UDCA inhibited OATP4A1 activity in placental villous fragments and oocytes. TC induced vasoconstriction in placental and rat vasculature, which was attenuated by UDCA. Quantitative proteomic analysis of villous fragments showed direct effects of TC on multiple placental pathways, including oxidative stress and autophagy. The effects of TC on the placental proteome and vasculature demonstrate how bile acids may cause fetal distress in ICP. UDCA inhibition of OATP4A1 suggests it will protect the mother and fetus against the vascular effects of TC by inhibiting its cellular uptake. UDCA may protect the fetus in ICP by inhibiting OATP4A1-mediated bile acid transfer and TC-induced placental vasoconstriction. Understanding the physiologic mechanisms of UDCA may allow better therapeutic interventions to be designed specifically for the fetus in the future.-Lofthouse, E. M., Torrens, C., Manousopoulou, A., Nahar, M., Cleal, J. K., O'Kelly, I. M., Sengers, B. G., Garbis, S. D., Lewis, R. M. Ursodeoxycholic acid inhibits uptake and vasoconstrictor effects of taurocholate in human placenta.

Lithocholic acid activates mTOR signaling inducing endoplasmic reticulum stress in placenta during intrahepatic cholestasis of pregnancy

AIMS

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific disorder, which increases risks of adverse fetal outcomes. However, the pathophysiology is not fully understood. Here, we explored the roles of mTOR signaling and ER stress in placenta during ICP.

MATERIALS AND METHODS

Placental tissues were collected from normal and ICP pregnancies. mTOR signaling and endoplasmic reticulum stress were detected by immunohistochemistry in the placenta. The human placenta trophoblast cell line HTR-8/SVneo was used in vitro experiment.

KEY FINDINGS

ICP placenta displayed histological abnormalities with fewer trophoblasts. Moreover, the expression of Bip and the phosphorylation of pS6(S235/236) or pAkt(S473) were higher comparing with normal placenta. In in vitro studies, the bile acids specifically to lithocholic acid rather than taurocholic acid or ursodeoxycholic acid, drastically increased the phosphorylation of pS6K1(T389), pS6(S235/236), or pAkt(S473), whereas the mTOR inhibitor can prohibit the upregulation. Similarly, the expressions of IRE1α and BiP increased sharply under lithocholic acid (20 μM) administration, while the same inhibitor can also decrease the expression. Additionally, transmission electron microscopy showed enlarged endoplasmic reticulum lumen under the lithocholic acid treatment. Furthermore, the cell viability reduced sharply under treatment with different dose of lithocholic acid. The mTOR inhibitor can reverse the decrease of cell viability to some extent.

SIGNIFICANCE

Bile acid can activate mTOR signaling which resulted in endoplasmic reticulum stress, leading to trophocyte viability decrease. mTOR pathway activation may be associated with the pathophysiology of ICP.

Paeonia lactiflora Pall. regulates the NF-κB-NLRP3 inflammasome pathway to alleviate cholestasis in rats

OBJECTIVES

Cholestasis is a critical risk factor for severe hepatic disease or cirrhosis. The anti-inflammatory effect of Paeonia lactiflora Pall. (PLP), named Chishao in traditional Chinese medicine (TCM), on alpha-naphthylisothiocyanate (ANIT)-induced cholestasis model was tried to be elucidated in this research.

METHODS

Therapeutic effect indices on hepatic function, including ALT, AST, TBIL, DBIL, ALP, TBA and γ-GT, were measured. To further investigate the protective mechanism of PLP, the mRNA and protein expression levels of NF-κB-NLRP3 inflammasome pathway were detected.

RESULTS

Our results showed that compared with the model group, PLP could significantly reduce the increased serum indices such as ALT, AST, TBIL, DBIL, ALP, TBA and γ-GT induced by ANIT in a dose-dependent way. Moreover, we found that PLP downregulated the mRNA expression levels including IKK, p65, NLRP3, caspase-1 and IL-1β, especially at the large dose. Furthermore, PLP also significantly inhibited NF-κB-NLRP3 inflammasome pathway by decreasing the protein levels of p65, p-p65, p-IKK, NLRP3, caspase-1 and IL-1β.

CONCLUSIONS

The results indicated that PLP could ameliorate ANIT-induced cholestasis in rats and the anti-inflammatory effect of PLP might be related to regulating NF-κB-NLRP3 inflammasome pathway. This study will provide scientific evidence for PLP as a potential drug candidate for cholestasis.

PPARγ provides anti-inflammatory and protective effects in intrahepatic cholestasis of pregnancy through NF-κB pathway

AIMS

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific hepatic disorder with potentially deleterious consequences of fetuses. Although the intimate relationship between ICP and peroxisome proliferator-activated receptor γ (PPARγ) has been previously reported in physiological and pathological conditions, the detailed mechanisms in the process of intrahepatic cholestasis of pregnancy has been unclear. The aims of this study are to assess the role of PPARγ regulating the reactive oxygen species (ROS) and inflammation in the process of the ICP.

METHODS

Clinical data of the pregnant women were collected. And the serum of cytokines, hepatic function, the expression of PPARγ and NF-κB were measured. The rat and fetal rat ICP model were constructed and detection of the expression of PPARγ and NF-κB, evaluation the level of ROS and inflammation.

RESULTS

The clinical data showed that the new-born information in severe ICP group were significantly different as compared to that in control group (P < 0.05), and part of information in mild ICP group were also difference to that in control group (P < 0.05). The expression of PPARγ and NF-κB were significantly higher in clinical pregnant women, rat, fetal rat ICP model groups and taurocholate acid (TCA) treated HTR-8/SVneo cell (P < 0.01). PPARγ inhibited the production of ROS and decreased the level of inflammation. PPARγ down-regulated the NF-κB pathway.

CONCLUSIONS

PPARγ provides the anti-inflammatory and protective effects in intrahepatic cholestasis of pregnancy through NF-κB pathway, which might be a probably one of the mechanisms of ICP.

Magnesium sulphate can alleviate oxidative stress and reduce inflammatory cytokines in rat placenta of intrahepatic cholestasis of pregnancy model

PURPOSE

In our study, we try to investigate whether magnesium sulphate (MgSO₄) could provide protection against oxidative damage and inflammatory response in rat placenta of intrahepatic cholestasis of pregnancy (ICP) model.

METHODS

The rat model of ICP was established by injecting s.c. 17α-ethinyl estradiol (EE) daily for 5 days. MgSO₄, as an therapeutic drug for ICP, was injected i.p. daily for 3 days. Age-matched pregnant rats served as controls. The level of serum total bile acid (TBA) was measured. The data including the number and weight of offsprings on day 20 of pregnancy were collected. We observed ultrastructural changes of mitochondria and endoplasmic reticulum (ER) in placenta by transmission electron microscope. The antioxidant proteins peroxiredoxin-6 (Prdx6) and nuclear factor erythroid 2-related factor-2 (Nrf2) were analyzed by Western Blot. The inflammatory cytokines including IL-1β, TNF-α and IFN-γ were investigated by real-time PCR (RT-PCR) and enzyme-linked immune-sorbent assay (ELISA).

RESULTS

The weight of offsprings on day 20 of pregnancy increased in ICP rats treated with MgSO₄ (ICP + MG group) compared with that in ICP rats (ICP group). However, the level of TBA was not reduced. The damage of mitochondria and ER was observed in placenta, which was much more slighter in ICP + MgSO₄ group as compared with that in ICP group. Prdx6 and Nrf2 were increased, while the inflammatory cytokines including IL-1β, TNF-α and IFN-γ were decreased in ICP + MgSO₄ group compared with that in ICP group.

CONCLUSIONS

MgSO₄ had beneficial effect on improving growth of offsprings in rat model of ICP. The protective effect of MgSO₄ on alleviating oxidative damage and inflammatory response in placenta may play an important role in the process. MgSO₄ may improve the function of placenta.

The role of sphingosine 1-phosphate receptor 2 in bile-acid-induced cholangiocyte proliferation and cholestasis-induced liver injury in mice

Bile duct obstruction is a potent stimulus for cholangiocyte proliferation, especially for large cholangiocytes. Our previous studies reported that conjugated bile acids (CBAs) activate the protein kinase B (AKT) and extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling pathways through sphingosine 1-phosphate receptor (S1PR) 2 in hepatocytes and cholangiocarcinoma cells. It also has been reported that taurocholate (TCA) promotes large cholangiocyte proliferation and protects cholangiocytes from bile duct ligation (BDL)-induced apoptosis. However, the role of S1PR2 in bile-acid-mediated cholangiocyte proliferation and cholestatic liver injury has not been elucidated. Here, we report that S1PR2 is the predominant S1PR expressed in cholangiocytes. Both TCA- and sphingosine-1-phosphate (S1P)-induced activation of ERK1/2 and AKT were inhibited by JTE-013, a specific antagonist of S1PR2, in cholangiocytes. In addition, TCA- and S1P-induced cell proliferation and migration were inhibited by JTE-013 and a specific short hairpin RNA of S1PR2, as well as chemical inhibitors of ERK1/2 and AKT in mouse cholangiocytes. In BDL mice, expression of S1PR2 was up-regulated in whole liver and cholangiocytes. S1PR2 deficiency significantly reduced BDL-induced cholangiocyte proliferation and cholestatic injury, as indicated by significant reductions in inflammation and liver fibrosis in S1PR2 knockout mice. Treatment of BDL mice with JTE-013 significantly reduced total bile acid levels in serum and cholestatic liver injury.

CONCLUSION

This study suggests that CBA-induced activation of S1PR2-mediated signaling pathways plays a critical role in obstructive cholestasis and may represent a novel therapeutic target for cholestatic liver diseases. (Hepatology 2017;65:2005-2018).

Bile acids and gestation

There are numerous profound maternal physiological changes that occur from conception onwards and adapt throughout gestation in order to support a healthy pregnancy. By the time of late gestation, when circulating pregnancy hormones are at their highest concentrations, maternal adaptations include relative hyperlipidemia, hypercholanemia and insulin resistance. Bile acids have now been established as key regulators of metabolism, and their role in gestational changes in metabolism is becoming apparent. Bile acid homeostasis is tightly regulated by the nuclear receptor FXR, which has been shown to have reduced activity during pregnancy. This review focuses on the gestational alterations in bile acid homeostasis that occur in normal pregnancy, which in some women can become pathological, leading to the development of intrahepatic cholestasis of pregnancy. As well as their important role in maternal metabolic health, we will review bile acid metabolism in the feto-placental unit.

Antiinflammatory and Hepatoprotective Medicinal Herbs as Potential Substitutes for Bear Bile

Practitioners of traditional Chinese medicine (TCM) commonly prescribe medicinal formulations relying on the purported synergism of a combination of plant species, sometimes incorporating animal parts and minerals. Bear bile, obtained from either wild or farmed bears, is a commonly used constituent of traditional medicine formulations. With several bear species now listed under Convention on International Trade in Endangered Species of Wild Fauna and Flora as threatened with extinction and with bear farming being actively campaigned against on ethical grounds, it is important to seek and promote alternatives to the use of bear bile as medicine. This chapter describes and evaluates the scientific data relating to the efficacy of bear bile and potential alternatives to its use, including the use of bile from other animal species, the use of synthetic chemical alternatives, and the use of herbal substitutes. Scientific studies have confirmed the efficacy of bear bile as an antiinflammatory and a hepatoprotective agent. Ursodeoxycholic acid (UDCA), the active component of bear bile is used in a synthetic form in Western medicine and can serve as an alternative to bear bile in the treatment and management of certain cholestatic liver conditions. In TCM practice, bile from domesticated animal species (such as cattle, chicken, and pig) has been used as a substitute for bear bile. Following evaluation of TCM literature and pharmacological/clinical data, the authors propose six plant species, either as single herbs or in combination, Gardenia jasminoides (zhī zi; ), Scutellaria baicalensis (huáng qín; ), Coptis chinensis (huáng lián, ), Phellodendron amurense (huáng băi; ), Andrographis paniculata (chuan xin lian; ), and Rheum palmatum (dà huang; ), two medicinal Kampo formulations, Orengedokuto, Dia-Orengedokuto (which originated from traditional Chinese herbal formula Huanglian Jiedu Tang, ), and two individual phytochemicals (berberine and andrographolide) as alternatives to bear bile. The proposed herbal alternatives are frequently found listed in traditional formulations also containing bear bile, usually with different therapeutic roles ascribed to them. The existing evidence base for the effectiveness of herbal alternatives is sufficiently strong for TCM practitioners and consumers to consider using these without the addition of bear bile. This consideration is driven by the imperative to protect populations of bears from overexploitation in the wild and when farmed. However, for the identified alternatives to be accepted by users, it is essential that researchers and TCM practitioners collaborate effectively to initiate consumer behavior change.