Lithocholic Acid-induced Cholestasis Research Articles

A novel model construction of lithocholic acid-induced cholestasis and transcriptome analysis in snakehead fish (Channa argus)

The snakehead fish (Channa argus) is very susceptible to hepatobiliary syndrome during the farming, usually accompanied by abnormal function of the liver, gallbladder and intestine. In this study, we aimed to establish a lithocholic acid (LCA)-induced cholestasis model to confirm the model by liver transcriptome analysis, and to explore the effects of dietary supplementation with 0, 0.05%, 0.1%, 0.2%, 0.4% and 0.6% LCA on serum biomarkers, histopathological and the mRNA expressions levels of bile acid metabolism-related genes in C. argus. Biochemical analysis results showed that the levels of ALT, AST, TBA and ALP in serum were markedly increased (P < 0.05) in C. argus with cholestasis induced by 0.2%, 0.4% and 0.6% LCA. In this study, 101.09 GB of clean data a total of 83,513 unigenes and 107,325 transcripts was obtained by liver transcriptome sequencing of C. argus using the Illumina HiSeq XTen/NovaSeq 6000 platforms. A total of 206 differentially expressed genes (DEGs), i.e., 112 up-regulated DEGs and 94 down-regulated DEGs, were identified between the control and LCA treatment groups based on the liver transcriptome analysis. Notably, the key bile acid metabolism-related DEGs, such as bsep, shp, fxr, mrp2, mrp3, mrp4, cyp7a1, cyp8b1, cyp27a1 and hmgcr were found in the liver transcriptome. Overall, this study is the first time to investigate the establishment of an LCA-induced cholestasis model in aquatic animals, as evidenced by the deaths of fish, serum biomarkers, and the liver histopathological status. These data help our comprehension of the pattern of bile acid metabolism in aquatic animals, and provide a certain insight into treatments for hepatobiliary syndrome in C. argus

The Function of Multidrug Resistance-associated Protein 3 in the Transport of Bile Acids under Normal Physiological and Lithocholic Acid-induced Cholestasis Conditions.

The role of multidrug resistance-associated protein 3 (Mrp3) in the transport of bile acid (BA) in drug-induced cholestasis has not been well studied. In this study, wild type and Mrp3 knockout (Mrp3-/-) mice under normal physiological and lithocholic acid (LCA)-induced cholestatic conditions were employed to investigate the role of Mrp3 in BA transport. The levels of BA in serum, liver, gallbladder, intestine, kidney, feces and urine were quantified in both wild type and Mrp3-/- mice via ultra-high performance liquid chromatography triple quadrupole mass spectrometry (UHPLC-MS/MS). Quantitative real-time PCR (RT-PCR) analysis was used to measure the expression of genes related to the transport and synthesis of BA. The results showed that the liver did not suffer more serious damage as a result of cholestasis when Mrp3 was depleted. The level of some individual bile acids changed apparently in the compartments of enterohepatic circulation (EHC) between the two control and model groups, respectively, but the level of serum total bile acid was only slightly reduced for Mrp3-/- groups. In addition, the level of BA-related efflux transporters and synthases increased significantly when Mrp3 was knocked out under normal physiological conditions, but a negligible alteration appeared under cholestatic conditions. Our results indicated that Mrp3 could be responsible for the transport of some specific bile acids, and part of the Mrp3 role could be compensated for by other transporters. Moreover, Mrp3 deficiency has a direct effect on the expression of BA-related synthases and efflux transporters under normal physiological conditions, but this effect could be less prominent under cholestatic conditions. This study could provide much valuable insight into the physiological function of Mrp3 in the transport of bile acids.

Lignans from Schisandra sphenanthera protect against lithocholic acid-induced cholestasis by pregnane X receptor activation in mice.

Cholestasis is a clinical syndrome caused by toxic bile acid retention that will lead to serious liver diseases. Ursodeoxycholic acid (UDCA) and obeticholic acid (OCA) are the only two FDA-approved drugs for its treatment. Thus, there is a clear need to develop new therapeutic approaches for cholestasis. Here, anti-cholestasis effects of the lignans from a traditional Chinese herbal medicine, Schisandra sphenanthera, were investigated as well as the involved mechanisms. Adult male C57BL/6J mice were randomly divided into 9 groups including the control group, LCA group, LCA with specific lignan treatment of Schisandrin A (SinA), Schisandrin B (SinB), Schisandrin C (SinC), Schisandrol A (SolA), Schisandrol B (SolB), Schisantherin A (StnA) and Schisantherin B (StnB), respectively. Mice were treated with each drug (qd) for 7 days, while the administration of lithocholic acid (LCA) (bid) was launched from the 4th day. Twelve hours after the last LCA injection, mice were sacrificed and samples were collected. Serum biochemical measurement and histological analysis were conducted. Metabolomics analysis of serum, liver, intestine and feces were performed to study the metabolic profile of bile acids. RT-qPCR and Western blot analysis were conducted to determine the hepatic expression of genes and proteins related to bile acid homeostasis. Dual-luciferase reporter gene assay was performed to investigate the transactivation effect of lignans on human pregnane X receptor (hPXR). RT-qPCR analysis was used to detect induction effects of lignans on hPXR-targeted genes in HepG2 cells. Lignans including SinA, SinB, SinC, SolA, SolB, StnA, StnB were found to significantly protect against LCA-induced intrahepatic cholestasis, as evidenced by significant decrease in liver necrosis, serum alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) activity. More importantly, serum total bile acids (TBA) and total bilirubin (Tbili) were also significantly reduced. Metabolomics analysis revealed these lignans accelerated the metabolism of bile acids and increased the bile acid efflux from liver into the intestine or feces. Gene analysis revealed these lignans induced the hepatic expressions of PXR-target genes such as Cyp3a11 and Ugt1a1. Luciferase reporter gene assays illustrated that these bioactive lignans can activate hPXR. Additionally, they can all upregulate hPXR-regulate genes such as CYP3A4, UGT1A1 and OATP2. These results clearly demonstrated the lignans from Schisandra sphenanthera exert hepatoprotective effects against LCA-induced cholestasis by activation of PXR. These lignans may provide an effective approach for the prevention and treatment of cholestatic liver injury.

Ameliorative effect of curcumin and vitamin B6 against lithocholic acid-induced cholestasis and liver injury in mice

Ameliorative effect of curcumin and vitamin B6 against lithocholic acid-induced cholestasis and liver injury in mice

Protective effects of yangonin from an edible botanical Kava against lithocholic acid-induced cholestasis and hepatotoxicity

Accumulation of toxic bile acids in liver could cause cholestasis and liver injury. The purpose of the current study is to evaluate the hepatoprotective effect of yangonin, a product isolated from an edible botanical Kava against lithocholic acid (LCA)-induced cholestasis, and further to elucidate the involvement of farnesoid X receptor (FXR) in the anticholestatic effect using in vivo and in vitro experiments. The cholestatic liver injury model was established by intraperitoneal injections of LCA in C57BL/6 mice. Serum biomarkers and H&E staining were used to identify the amelioration of cholestasis after yangonin treatment. Mice hepatocytes culture, gene silencing experiment, real-time PCR and Western blot assay were used to elucidate the mechanisms underlying yangonin hepatoprotection. The results indicated that yangonin promoted bile acid efflux and reduced hepatic uptake via an induction in FXR-target genes Bsep, Mrp2 expression and an inhibition in Ntcp, all of which are responsible for bile acid transport. Furthermore, yangonin reduced bile acid synthesis through repressing FXR-target genes Cyp7a1 and Cyp8b1, and increased bile acid metabolism through an induction in gene expression of Sult2a1, which are involved in bile acid synthesis and metabolism. In addition, yangonin suppressed liver inflammation through repressing inflammation-related gene NF-κB, TNF-α and IL-1β. In vitro evidences showed that the changes in transporters and enzymes induced by yangonin were abrogated when FXR was silenced. In conclusions, yangonin produces protective effect against LCA-induced hepatotoxity and cholestasis due to FXR-mediated regulation. Yangonin may be an effective approach for the prevention against cholestatic liver diseases.

Glycyrrhetic Acid Derivative TY501 Protects Against Lithocholic Acid-Induced Cholestasis.

The aim of the study is to investigate the protective effects of TY501 against LCA-induced cholestasis in mice and to explore the potential mechanisms. It was demonstrated that TY501(5, 15 or 45 mg/kg, i.g.) can markedly reduced the level of ALT, AST and ALP which increased by LCA treatment. Meanwhile, TY501 also lowered total bile acids, total bilirubin and total cholesterol levels in serum. Furthermore, TY501 can protect HepG2 cell cultures from LCA-induced cytotoxicity. RT-PCR and Western Blot analysis showed that TY501 recovered the expression of BSEP, MRP2 and NTCP which were down-regulated by LCA. Moreover, mRNA and protein of FXR was also observed in TY501 treated mice significantly accumulation in nucleus. Taken together, It can be concluded that TY501 exerted beneficial effects on LCA-induced cholestasis, possibly via activation of FXR mediated upregulation of BSEP, MRP2 and NTCP.

Hepatoprotective Effects of Schisandra sphenanthera Extract against Lithocholic Acid-Induced Cholestasis in Male Mice Are Associated with Activation of the Pregnane X Receptor Pathway and Promotion of Liver Regeneration.

We previously reported that the ethanol extract of Schisandra sphenanthera [Wuzhi (WZ) tablet] significantly protects against acetaminophen-induced hepatoxicity. However, whether WZ exerts a protective effect against cholestasis remains unclear. In this study, the protective effect of WZ on lithocholic acid (LCA)-induced intrahepatic cholestasis in mice was characterized and the involved mechanisms were investigated. WZ pretreatment (350 mg/kg) with LCA significantly reversed liver necrosis and decreased serum alanine aminotransferase, aspartate aminotransferase, and alkaline phosphatase activity. More importantly, serum total bile acids and total bilirubin were also remarkably reduced. Quantitative reverse-transcription polymerase chain reaction and Western blot analysis showed that hepatic expression of pregnane X receptor (PXR) target genes such as CYP3A11 and UDP-glucuronosyltransferase (UGT) 1A1 were significantly increased by WZ treatment. Luciferase assays performed in LS174T cells illustrated that WZ extract and its six bioactive lignans could all activate human PXR. In addition, WZ treatment significantly promoted liver regeneration via inhibition of p53/p21 to induce cell proliferation-associated proteins such as cyclin D1 and proliferating cell nuclear antigen. In conclusion, WZ has a protective effect against LCA-induced intrahepatic cholestasis, partially owing to activation of the PXR pathway and promotion of liver regeneration.

Low Protein Diets Potentiate Lithocholic Acid-Induced Cholestasis in Rats

Earlier studies showed that low protein diets (LPD) reduce bile flow and bile acid secretion. We therefore examined the effect of LPD on lithocholic acid (LCA)-induced intrahepatic cholestasis. Female Sprague-Dawley rats were fed LPD (8% casein) soon after weaning for 4 or 12 wk, and then were injected intravenously with a single dose of LCA (4 mumol/100 g body wt). Bile was collected for 30-min periods, and bile flow as well as biliary lipid secretory rates were measured. Bile acid metabolism was also studied and the results were compared with those obtained in rats fed an adequate protein diet (26% casein). The LPD produced significantly lower bile flow and bile acid secretion, which were attributed to a reduced bile acid pool and a reduction in synthesis. They also enhanced the LCA-induced decline in bile flow, and rate of biliary output of total bile acids, phospholipids and cholesterol. The LPD were also associated with impaired LCA secretion in bile and increased retention in plasma and liver. Studies of LCA metabolism in rats fed a LPD indicated lower hepatic LCA hydroxylation, a greater percent contribution of glyco conjugates and lower levels of tauro conjugates. The present findings suggest that the reduced bile acid pool size, diminished LCA excretion and biotransformation to less toxic bile acids may explain the greater cholestasis in LPD-fed rats.

Do intracellular Ca 2+ activity and hepatic glutathione play a role in the pathogenesis of lithocholic acid-induced cholestasis?

The possible relevance of alterations in intracellular Ca 2+ and hepatic glutathione levels (GSH) in the pathogenesis of cholestasis induced by lithocholic acid (LCA) was examined by comparing effects of LCA and acetaminophen on these parameters and bile flow (BF) in rats. Intracellular Ca 2+ activity was measured via glycogen phosphorylase a determination in rats given an intravenous bolus injection of either LCA ( 12 μmol/100 g body wt.), acetaminophen (60 mg/100 g body wt.), or a mixed solution of LCA and acetaminophen. BF was reduced immediately after LCA administration, with a maximum decrease occurring at 60 min followed by an increase to normal values at 210 min. On the other hand, glycogen phosphorylase a activity was elevated during all time periods after LCA treatment. Hepatic glutathione followed the BF curves being markedly depleted at the peak of cholestasis (60 min) and normal in the total recovery period (210 min). In contrast, acetaminophen had no effect on BF but significantly increased glycogen phosphorylase a activity and depleted hepatic glutathione levels. These results suggest that cholestatic effect of LCA is not due to changes in intracellular Ca 2+ or hepatic glutathione levels.

The effect of colchicine on the development of lithocholic acid-induced cholestasis. A study of the role of microtubules in intracellular cholesterol transport.

The pathogenesis of lithocholic acid (LCA-Na)-induced cholestasis involves a rapid accumulation of cholesterol in the bile canalicular membrane. Since microtubules play an important role in the intracellular transport of many materials, including cholesterol, the present study was undertaken to assess the extent to which they participate in the development of LCA-Na-induced cholestasis. Rats were pretreated with either colchicine (0.2 mumol/100 g body wt.) or saline solution 90 min before injection with LCA-Na (12 mumol/100 g body wt.). Colchicine, although not increasing bile flow by itself, significantly reduced the cholestasis caused by LCA-Na (57-32% reduction in bile flow) without affecting its metabolism into less toxic bile acids or its distribution in blood, liver or bile. Bile canalicular membranes isolated from animals treated with a combination of colchicine and LCA-Na contained less cholesterol than those treated with LCA-Na alone. However, membranes obtained from rats treated with colchicine alone contained much less cholesterol than did controls. It was found that the total amount of cholesterol accumulated within the bile canalicular membrane following LCA-Na treatment (LCA-Na + colchicine versus colchicine alone compared with LCA-Na versus controls) was unchanged by colchicine treatment. In view of these findings it is suggested that the total amount of cholesterol present within the bile canalicular membrane determines the extent of LCA-Na-induced cholestasis, LCA-Na probably moves cholesterol to the bile canalicular membrane via a microtubule independent pathway, and microtubules are unlikely to function in the transcellular transport of LCA-Na.

Effect of lithocholic acid on cholesterol synthesis and transport in the rat liver

The cellular origin of cholesterol which accumulates in liver cell plasma membrane fractions enriched in bile canalicular structures after lithocholic acid treatment was determined in vivo. Rats were given [ 3H]cholesterol followed 16 h later by [2- 14C]mevalonic acid, [2- 14C]acetic acid or lithocholic acid. Lithocholic acid injection enhanced the de novo synthesis of cholesterol in the microsomes and both compounds were transported to the bile canalicular membranes. However, in vitro studies demonstrated that lithocholic acid is capable of stripping cholesterol from microsomal membranes even in the absence of increased de novo synthesis. This suggests that transfer of cholesterol from subcellular organelles (microsomes) to bile canalicular membranes may be the initial step in the development of lithocholic acid-induced cholestasis.

Resistance of the suckling guinea pig to lithocholic acid-induced cholestasis.

Although immaturity of the liver and synthesis of monohydroxy bile acids have been implicated as pathogenic factors in neonatal cholestasis, there is no direct evidence to show that these bile acids induce cholestasis in the newborn. In the present investigation, we compared the effects of lithocholic acid (LCA) injection on bile flow in suckling (2-week-old) and adult (12-week-old) guinea pigs. Bile flow was not modified by LCA in 2-week-old animals, but it was reduced by 50 to 80% in the adults, the decrease being dose-dependent. In the newborn, the injected LCA was mainly secreted in bile (greater than 90%), while in the adults it was distributed between the liver and bile. The percentage of biliary bile acids (as determined by gas-liquid chromatography) in the two groups was similar before and after LCA injection. Morphologic lesions characteristic of LCA-induced cholestasis were observed only in the adult guinea pigs. This study demonstrates that the newborn guinea pig is less susceptible to cholestasis induced by 90 to 180 mumoles per kg body weight of lithocholate and that, in the neonatal liver, there is no defect in the transport of this bile acid from blood to bile.

Lithocholic acid-induced cholestasis in newborn rats

Susceptibility to lithocholic acid-induced cholestasis was examined in developing rats aged 14, 21 and 70 days. After bile duct cannulation, bile was collected for 30 min prior to, and 120 min following an i.v. injection of [ 14C]lithocholic acid (LCA). The liver weight/body weight ratio of newborns was significantly smaller than that of adults (3.13±0.09 at 14 days vs. 4.76±0.20 at 70 days). Therefore, when the LCA dosage was calculated per g body weight, the livers of newborns were exposed to larger amounts of LCA. The dosage was then given per liver/body weight ratio for an accurate comparison with adults. Bile flow was reduced by 7–18% in newborns, while a maximum decrease of 90% was recorded in adults by 2 h post injection, the latter drop in bile flow being proportional to LCA retention in the liver. In contrast, LCA retention was minimal in young rats with 91–95% of it being excreted via the bile. The decreased susceptibility of newborns to cholestasis appears to be related to their capacity to excrete LCA.