Intrahepatic cholestasis in common chronic liver diseases

The biochemical pattern defines MASLD phenotypes linked to distinct histology and prognosis

BACKGROUND

MASLD can manifest as hepatocellular damage, which can result in mild elevation of aminotransferases. However, in some patients, MASLD presents with cholestatic pattern.

OBJECTIVE

To assess the impact of the biochemical pattern on the natural course of MASLD, including liver damage in histology, the accuracy of non-invasive tests(NITs), and prognosis.

METHODS

Multicenter study enrolling 2156 patients with biopsy-proven MASLD, who were classified based on their[ALT/ULN)]/[(ALP/ULN)] levels at the time of biopsy: (a) hepatocellular pattern(H), > 5; (b) mixed pattern(M),2-5; (c) cholestatic pattern(C), < 2.

OUTCOMES

(a) histological evaluation of the single components of NAS, MASH, and fibrosis; (b) NITs and transient elastography assessing advanced fibrosis; (c) prognosis determined by the appearance of decompensated cirrhosis and death.

RESULTS

Out of the 2156 patients, 22.9% exhibited the H-pattern, whilst 31.7% exhibited the C-pattern. Severe steatosis, ballooning, lobular inflammation, and MASH (56.4% H vs. 41.9% M vs. 31.9% C) were more common in H-pattern (p = 0.0001),whilst C-pattern was linked to cirrhosis (5.8% H vs. 5.6% M vs. 10.9% C; p = 0.0001). FIB-4(0.74(95% CI 0.69-0.79) vs. 0.83 (95% CI 0.80-0.85); p = 0.005) and Hepamet Fibrosis Score(0.77 (95% CI 0.69-0.85) vs. 0.84 (95% CI 0.80-0.87); p = 0.044)exhibited lower AUROCs in the H-pattern. The C-pattern[HR 2.37 (95% CI 1.12-5.02); p = 0.024], along with age, diabetes, and cirrhosis were independently associated with mortality. Most patients maintained their initial biochemical pattern during the second evaluation.

CONCLUSIONS

The H-pattern exhibited greater necro-inflammation in the histology than the C-pattern, whereas the latter showed more cirrhosis. The accuracy of NITs in detecting fibrosis was decreased in H-pattern. The occurrence of decompensated events and mortality was predominant in C-pattern. Therefore, identifying MASLD phenotypes based on the biochemical presentation could be relevant for clinical practice.

Quantitative Evaluation by Digital Pathology of Immunohistochemical Expression of CK7, CK19, and EpCAM in Advanced Stages of NASH

(1) Background: Nonalcoholic Steatohepatitis/Nonalcoholic Fatty Liver Disease (NASH/NAFLD) is the most recurrent chronic liver disease. NASH could present with a cholestatic (C) or hepatic (H) pattern of damage. Recently, we observed that increased Epithelial Cell Adhesion Molecule (EpCAM) expression was the main immunohistochemical feature to distinguish C from H pattern in NASH. (2) Methods: In the present study, we used digital pathology to compare the quantitative results of digital image analysis by QuPath software (Q-results), with the semi-quantitative results of observer assessment (S-results) for cytokeratin 7 and 19, (CK7, CK19) as well as EpCAM expression. Patients were classified into H or C group on the basis of the ratio between alanine transaminase (ALT) and alkaline phosphatase (ALP) values, using the "R-ratio formula". (3) Results: Q- and S-results showed a significant correlation for all markers (p < 0.05). Q-EpCAM expression was significantly higher in the C group than in the H group (p < 0.05). Importantly ALP, an indicator of hepatobiliary disorder, was the only biochemical parameter significantly correlated with Q-EpCAM. Instead, Q-CK7, but not Q-CK19, correlated only with γGlutamyl-Transferase (γGT). Of note, Stage 4 fibrosis correlated with Q-EpCAM, Q-CK19, and ALP but not with γGT or ALT. Conclusions: Image analysis confirms the relation between cholestatic-like pattern, associated with a worse prognosis, with increased ALP values, EpCAM positive biliary metaplasia, and advanced fibrosis. These preliminary data could be useful for the implementation of AI algorithms for the assessment of cholestatic NASH.

The Role of Inflammation in Cholestatic Liver Injury

Cholestasis is a common clinical event in which bile formation and excretion are blocked, leading to retention of bile acids or bile salts; whether it occurs intra- or extrahepatically, primary or secondary, its pathogenesis is still unclear and is influenced by a combination of factors. In a variety of inflammatory and immune cells such as neutrophils, macrophages (intrahepatic macrophages are also known as Kupffer cells), mast cells, NK cells, and even T cells in humoral immunity and B cells in cellular immunity, inflammation can be a "second strike" against cholestatic liver injury. These cells, stimulated by a variety of factors such as bile acids, inflammatory chemokines, and complement, can be activated and accumulate in the cholestatic liver, and with the involvement of inflammatory mediators and modulation by cytokines, can lead to destruction of hepatocytes and bile duct epithelial cells and exacerbate (and occasionally retard) the progression of cholestatic liver disease. In this paper, we summarized the new research advances proposed so far regarding the relationship between inflammation and cholestasis, aiming to provide reference for researchers and clinicians in the field of cholestatic liver injury research.

Farnesoid X receptor is an important target for the treatment of disorders of bile acid and fatty acid metabolism in mice with nonalcoholic fatty liver disease combined with cholestasis

BACKGROUND AND AIM

The prevalence of nonalcoholic fatty liver disease (NAFLD) has been rising globally. NAFLD patients combined with cholestasis have more obvious liver fibrosis, impaired bile acid (BA), and fatty acid (FA) metabolism and severer liver injury; however, its therapeutic options are limited, and the underlying metabolic mechanisms are understood. Here, we aimed to investigate the effects of farnesoid X receptor (FXR) on BA and FA metabolism in NAFLD combined with cholestasis and related signaling pathways.

METHODS

A mouse model of NAFLD combined with cholestasis was established by joint intervention with high-fat diet (HFD) and alpha-naphthylisothiocyanate. The effects of FXR on BA and FA metabolism were evaluated by serum biochemical analysis. Liver damage was identified by histopathology. The expression of nuclear hormone receptor, membrane receptor, FA transmembrane transporter, and BA transporter protein in mice were measured by western blot.

RESULTS

NAFLD mice combined with cholestasis developed more severe cholestasis and dysregulated BA and FA metabolism. Meanwhile, the expression of FXR protein was decreased in NAFLD mice combined with cholestasis compared to the controls. Fxr-/- mice showed liver injury. HFD aggravated the liver injury with decreased BSEP expression, increased expression of NTCP, LXRα, SREBP-1c, FAS, ACC1, and CD36, and significantly increased BA and FA accumulation.

CONCLUSION

All the results suggested that FXR plays a key role in both FA and BA metabolism in NAFLD combined with cholestasis and thus may be a potential target for the treatment of disorders of BA and FA metabolism in NAFLD combined with cholestasis.

miR-194 Up-Regulates Cytochrome P450 Family 7 Subfamily A Member 1 Expression via β-Catenin Signaling and Aggravates Cholestatic Liver Diseases

miR-194 is abundantly expressed in hepatocytes, and its depletion induces hepatic resistance to acetaminophen-induced acute injuries. In this study, the biological role of miR-194 in cholestatic liver injury was investigated by using miR-194/miR-192 cluster liver-specific knockout (LKO) mice, in which no liver injuries or metabolic disorders were predisposed. Bile duct ligation (BDL) and 1-naphthyl isothiocyanate (ANIT) were applied to LKO and matched control wild-type (WT) mice to induce hepatic cholestasis. Periportal liver damage, mortality rate, and liver injury biomarkers in LKO mice were significantly less than in WT mice after BDL and ANIT injection. Intrahepatic bile acid level was significantly lower in the LKO liver within 48 hours of BDL- and ANIT-induced cholestasis compared with WT. Western blot analysis showed that β-catenin (CTNNB1) signaling and genes involved in cellular proliferation were activated in BDL- and ANIT-treated mice. The expression levels of cytochrome P450 family 7 subfamily A member 1 (CYP7A1), pivotal in bile synthesis, and its upstream regulator hepatocyte nuclear factor 4α were reduced in primary LKO hepatocytes and liver tissues compared with WT. The knockdown of miR-194 using antagomirs reduced CYP7A1 expression in WT hepatocytes. In contrast, the knockdown of CTNNB1 and overexpression of miR-194, but not miR-192, in LKO hepatocytes and AML12 cells increased CYP7A1 expression. In conclusion, the results suggest that the loss of miR-194 ameliorates cholestatic liver injury and may suppress CYP7A1 expression via activation of CTNNB1 signaling.

Knockout of secretin ameliorates biliary and liver phenotypes during alcohol-induced hepatotoxicity

BACKGROUND

Alcohol-related liver disease (ALD) is characterized by ductular reaction (DR), liver inflammation, steatosis, fibrosis, and cirrhosis. The secretin (Sct)/secretin receptor (SR) axis (expressed only by cholangiocytes) regulates liver phenotypes in cholestasis. We evaluated the role of Sct signaling on ALD phenotypes.

METHODS

We used male wild-type and Sct^-/- mice fed a control diet (CD) or ethanol (EtOH) for 8 wk. Changes in liver phenotypes were measured in mice, female/male healthy controls, and patients with alcoholic cirrhosis. Since Cyp4a10 and Cyp4a11/22 regulate EtOH liver metabolism, we measured their expression in mouse/human liver. We evaluated: (i) the immunoreactivity of the lipogenesis enzyme elongation of very-long-chain fatty acids 1 (Elovl, mainly expressed by hepatocytes) in mouse/human liver sections by immunostaining; (ii) the expression of miR-125b (that is downregulated in cholestasis by Sct) in mouse liver by qPCR; and (iii) total bile acid (BA) levels in mouse liver by enzymatic assay, and the mRNA expression of genes regulating BA synthesis (cholesterol 7a-hydroxylase, Cyp27a1, 12a-hydroxylase, Cyp8b1, and oxysterol 7a-hydroxylase, Cyp7b11) and transport (bile salt export pump, Bsep, Na⁺-taurocholate cotransporting polypeptide, NTCP, and the organic solute transporter alpha (OSTa) in mouse liver by qPCR.

RESULTS

In EtOH-fed WT mice there was increased biliary and liver damage compared to control mice, but decreased miR-125b expression, phenotypes that were blunted in EtOH-fed Sct^-/- mice. The expression of Cyp4a10 increased in cholangiocytes and hepatocytes from EtOH-fed WT compared to control mice but decreased in EtOH-fed Sct^-/- mice. There was increased immunoreactivity of Cyp4a11/22 in patients with alcoholic cirrhosis compared to controls. The expression of miR-125b decreased in EtOH-fed WT mice but returned at normal values in EtOH-fed Sct^-/- mice. Elovl1 immunoreactivity increased in patients with alcoholic cirrhosis compared to controls. There was no difference in BA levels between WT mice fed CD or EtOH; BA levels decreased in EtOH-fed Sct^-/- compared to EtOH-fed WT mice. There was increased expression of Cyp27a1, Cyp8b1, Cyp7b1, Bsep, NTCP and Osta in total liver from EtOH-fed WT compared to control mice, which decreased in EtOH-fed Sct^-/- compared to EtOH-fed WT mice.

CONCLUSIONS

Targeting Sct/SR signaling may be important for modulating ALD phenotypes.

Cholestasis: exploring the triangular relationship of gut microbiota-bile acid-cholestasis and the potential probiotic strategies

Cholestasis is a condition characterized by the abnormal production or excretion of bile, and it can be induced by a variety of causes, the factors of which are extremely complex. Although great progress has been made in understanding cholestasis pathogenesis, the specific mechanisms remain unclear. Therefore, it is important to understand and distinguish cholestasis from different etiologies, which will also provide indispensable theoretical support for the development of corresponding therapeutic drugs. At present, the treatment of cholestasis mainly involves several bile acids (BAs) and their derivatives, most of which are in the clinical stage of development. Multiple lines of evidence indicate that ecological disorders of the gut microbiota are strongly related to the occurrence of cholestasis, in which BAs also play a pivotal role. Recent studies indicate that probiotics seem to have certain effects on cholestasis, but further confirmation from clinical trials is required. This paper reviews the etiology of and therapeutic strategies for cholestasis; summarizes the similarities and differences in inducement, symptoms, and mechanisms of related diseases; and provides information about the latest pharmacological therapies currently available and those under research for cholestasis. We also reviewed the highly intertwined relationship between gut microbiota-BA-cholestasis, revealing the potential role and possible mechanism of probiotics in the treatment of cholestasis.

Predictive value of serum bile acids as metabolite biomarkers for liver cirrhosis: a systematic review and meta-analysis

INTRODUCTION

A large number of studies have explored the potential biomarkers for detecting liver cirrhosis in an early stage, yet consistent conclusions are still warranted.

OBJECTIVES

To conduct a review and a meta-analysis of the existing studies that test the serum level of bile acids in cirrhosis as the potential biomarkers to predict cirrhosis.

METHODS

Six databases had been searched from inception date to April 12, 2021. Screening and selection of the records were based on the inclusion criteria. The risk of bias was assessed with the Newcastle-Ottawa quality assessment scale (NOS). Mean difference (MD) and confidence intervals 95% (95% CI) were calculated by using the random effect model for the concentrations of bile acids in the meta-analysis, and I² statistic was used to measure studies heterogeneity. This study was registered on PROSPERO.

RESULTS

A total of 1583 records were identified and 31 studies with 2679 participants (1263 in the cirrhosis group, 1416 in the healthy control group) were included. The quality of included studies was generally high, with 25 studies (80.6%) rated over 7 stars. A total of 45 bile acids or their ratios in included studies were extracted. 36 increased in the cirrhosis group compared with those of the healthy controls by a qualitative summary, 5 decreased and 4 presented with mixing results. The result of meta-analysis among 12 studies showed that 13 bile acids increased, among which four primary conjugated bile acids showed the most significant elevation in the cirrhosis group: GCDCA (MD = 11.38 μmol/L, 95% CI 8.21-14.55, P < 0.0001), GCA (MD = 5.72 μmol/L, 95% CI 3.47-7.97, P < 0.0001), TCDCA (MD = 3.57 μmol/L, 95% CI 2.64-4.49, P < 0.0001) and TCA (MD = 2.14 μmol/L, 95% CI 1.56-2.72, P < 0.0001). No significant differences were found between the two groups in terms of DCA (MD = - 0.1 μmol/L, 95% CI - 0.18 to - 0.01, P < 0.0001) and LCA (MD = - 0.01 μmol/L, 95% CI - 0.01 to - 0.02, P < 0.0001), UDCA (MD = - 0.14 μmol/L, 95% CI - 0.04 to - 0.32, P < 0.0001), and TLCA (MD = 0 μmol/L, 95% CI 0-0.01, P < 0.0001). Subgroup analysis in patients with hepatitis B cirrhosis showed similar results.

CONCLUSION

Altered serum bile acids profile seems to be associated with cirrhosis. Some specific bile acids (GCA, GCDCA, TCA, and TCDCA) may increase with the development of cirrhosis, which possibly underlay their potential role as predictive biomarkers for cirrhosis. Yet this predictive value still needs further investigation and validation in larger prospective cohort studies.

A cholestatic pattern predicts major liver-related outcomes in patients with non-alcoholic fatty liver disease

BACKGROUND & AIMS

NAFLD patients usually have an increase in AST/ALT levels, but cholestasis can also be observed. We aimed to assess in subjects with NAFLD the impact of the (cholestatic) C pattern on the likelihood of developing major liver-related outcomes (MALO).

METHODS

Five hundred and eighty-two consecutive patients with biopsy-proven NAFLD or a clinical diagnosis of NAFLD-related compensated cirrhosis were classified as hepatocellular (H), C and mixed (M) patterns, by using the formula (ALT/ALT Upper Limit of Normal-ULN)/(ALP/ALP ULN). MALO were recorded during follow-up. An external cohort of 1281 biopsy-proven NAFLD patients was enrolled as validation set.

RESULTS

H, M and C patterns were found in 153 (26.3%), 272 (46.7%) and 157 (27%) patients respectively. During a median follow-up of 78 months, only 1 (0.6%) patient with H pattern experienced MALO, whilst 15 (5.5%) and 38 (24.2%) patients in M and C groups had MALO. At multivariate Cox regression analysis, age >55 years (HR 2.55, 95% CI 1.17-5.54; p = .01), platelets <150 000/mmc (HR 0.14, 95% CI 0.06-0.32; p < .001), albumin <4 g/L(HR 0.62, 95% CI 0.35-1.08; p = .09), C versus M pattern (HR 7.86, 95% CI 1.03-60.1; p = .04), C versus H pattern(HR 12.1, 95% CI 1.61-90.9; p = .01) and fibrosis F3-F4(HR 35.8, 95% CI 4.65-275.2; p < .001) were independent risk factors for MALO occurrence. C versus M pattern(HR 14.3, 95% CI 1.90-105.6; p = .008) and C versus H pattern (HR 15.6, 95% CI 2.10-115.1; p = .0068) were confirmed independently associated with MALO occurrence in the validation set. The immunohistochemical analysis found a significantly higher prevalence of moderate-high-grade ductular metaplasia combined with low-grade ductular proliferation in C pattern when compared with the biochemical H pattern. Gene expression analysis showed a lower expression of NR1H3, RXRα and VCAM1 in patients with the C pattern.

CONCLUSIONS

The presence of a cholestatic pattern in patients with NAFLD predicts a higher risk of MALO independently from other features of liver disease.

Network pharmacology analysis and molecular docking to unveil the potential mechanisms of San-Huang-Chai-Zhu formula treating cholestasis

Objective

Chinese medicine formulae possess the potential for cholestasis treatment. This study aimed to explore the underlying mechanisms of San-Huang-Chai-Zhu formula (SHCZF) against cholestasis.

Methods

The major chemical compounds of SHCZF were identified by high-performance liquid chromatography. The bioactive compounds and targets of SHCZF, and cholestasis-related targets were obtained from public databases. Intersected targets of SHCZF and cholestasis were visualized by Venn diagram. The protein-protein interaction and compound-target networks were established by Cytoscape according to the STRING database. The biological functions and pathways of potential targets were characterized by Gene Ontology and Kyoto Encyclopedia of Genes and Genomes enrichment analysis. The biological process-target-pathway network was constructed by Cytoscape. Finally, the interactions between biological compounds and hub target proteins were validated via molecular docking.

Results

There 7 major chemical compounds in SHCZF. A total of 141 bioactive compounds and 83 potential targets were screened for SHCZF against cholestasis. The process of SHCZF against cholestasis was mainly involved in AGE-RAGE signaling pathway in diabetic complications, fluid shear stress and atherosclerosis, and drug metabolism-cytochrome P450. ALB, IL6, AKT1, TP53, TNF, MAPK3, APOE, IL1B, PPARG, and PPARA were the top 10 hub targets. Molecular docking showed that bioactive compounds of SHCZF had a good binding affinity with hub targets.

Conclusions

This study predicted that the mechanisms of SHCZF against cholestasis mainly involved in AGE-RAGE signaling pathway in diabetic complications, fluid shear stress and atherosclerosis, and drug metabolism-cytochrome P450. Moreover, APOE, AKT1, and TP53 were the critical hub targets for bioactive compounds of SHCZF.

Pharmacokinetics and food impact assessment of ademetionine enteric-coated tablet as an endogenous substance drug in healthy Chinese volunteers

WHAT IS KNOWN AND OBJECTIVES

Ademetionine 1,4-Butanedisulfonate (SAMe) enteric-coated tablets are widely used for treatment of pre-cirrhotic and cirrhotic intrahepatic cholestasis, as well as intrahepatic cholestasis of pregnancy (ICP), but incomplete clinical data and interference from endogenous substances pose numerous challenges for clinical trial of ademetionine. The objective of this study was to evaluate the pharmacokinetic profile of SAMe enteric-coated tablets and to assess its food impact and safety in healthy Chinese subjects.

METHODS

A randomized, open-label, single-dose study was carried out to determine the pharmacokinetics of SAMe enteric-coated tablets administered in both fasted and postprandial conditions. Baseline collection and data adjustment were required to reduce the effect of endogenous substances. Relevant pharmacokinetic data from subjects administered the reference formulation will be disclosed and utilized in this thesis.

RESULTS

Twenty-four subjects with a body mass index (BMI) of 19-24 kg/m² were enrolled in the study and all completed the trial. The impact of food on the drug was noticeable, with faster absorption in the fasting group (T_max , 4.50 ± 1.07 and 7.50 ± 1.58 for the fasting and postprandial groups, respectively) but higher exposure in the postprandial group (AUC_0-inf , 4021.02 ± 3377.13 and 5087.28 ± 3539.26 for the fasting and postprandial groups, respectively). No serious adverse effects were observed in the fasted and postprandial conditions.

WHAT IS NEW AND CONCLUSIONS

The pharmacokinetic profile of SAMe enteric-coated tablets in healthy Chinese subjects was partially complemented in this study. SAMe enteric-coated tablets showed promising safety in fasted and postprandial conditions. However, the impact of food on the drug was significant and might access to the absorption site and affect biochemical reactions.

Oxidative Stress and Localization Status of Hepatocellular Transporters: Impact on Bile Secretion and Role of Signaling Pathways

Significance: Most hepatopathies are primarily or secondarily cholestatic in nature. Oxidative stress (OS) is a frequent trait among them, and impairs the machinery to generate bile by triggering endocytic internalization of hepatocellular transporters, thus causing cholestasis. This is critical, since it leads to accelerated transporter degradation, which could explain the common post-transcriptional downregulation of transporter expression in human cholestatic diseases. Recent Advances: The mechanisms involved in OS-induced hepatocellular transporter internalization are being revealed. Filamentous actin (F-actin) cytoskeleton disorganization and/or detachment of crosslinking actin proteins that afford transporter stability have been characterized as causal factors. Activation of redox-sensitive signaling pathways leading to changes in phosphorylation status of these structures is involved, including Ca²⁺-mediated activation of "classical" and "novel" protein kinase C (PKC) isoforms or redox-signaling cascades downstream of NADPH oxidase. Critical Issues: Despite the well-known occurrence of hepatocellular transporter internalization in human hepatopathies, the cholestatic implications of this phenomenon have been overlooked. Accordingly, no specific treatment has been established in the clinical practice for its prevention/reversion. Future Directions: We need to improve our knowledge on the pro-oxidant triggering factors and the multiple signaling pathways that mediate this oxidative injury in each cholestatic hepatopathy, so as to envisage tailor-made therapeutic strategies for each case. Meanwhile, administration of antioxidants or heme oxygenase-1 induction to elevate the hepatocellular levels of the endogenous scavenger bilirubin are promising alternatives that need to be re-evaluated and implemented. They may complement current treatments in cholestasis aimed to enhance transcriptional carrier expression, by providing membrane stability to the newly synthesized carriers. Antioxid. Redox Signal. 35, 808-831.

Prognostic factors of unresectable hepatocellular carcinoma treated with yttrium-90 radioembolization: results from a large cohort over 13 years at a single center

Background

A previous study of patients with unresectable hepatocellular carcinoma (HCC) was extended to further examine factors associated with overall survival (OS) after selective internal radiation therapy with yttrium-90 resin microspheres (Y90 SIRT).

Methods

Data from patients of any age diagnosed with unresectable HCC and treated with Y90 SIRT at our institution from 2004 through 2017 were retrospectively analyzed. Among other criteria, patients had to have Eastern Cooperative Oncology Group performance status 0 to 2, not have received Y90 SIRT previously, and not have extrahepatic disease. Primary outcome was OS; secondary outcomes included tumor response and adverse events (AEs). Kaplan-Meier survival analyses and multivariable Cox proportional hazards models were used to evaluate prognostic factors for OS.

Results

Of the 226 patients, 59% were White, 77% were male, and the mean age at first SIRT procedure was 65.1±9.4 years. More than half had received previous treatment for HCC. The most common etiology was hepatitis C (n=138/224 available, 62%), followed by alcohol use (n=45, 20%), and nonalcoholic steatohepatitis (n=27, 12%). The mean model for end-stage liver disease score at baseline was 8.8±2.2. Patients were followed-up for a median of 12.2 months (95% CI, 0.0-62.6). Median OS was 16.6 months (95% CI, 13.1 to not reached). Bilobar disease, higher albumin-bilirubin score at baseline, prior treatment with sorafenib, alcohol use etiology, and higher administered dose were associated with shorter survival, whereas subsequent liver transplant [in 26 patients (11.5%)] was associated with longer survival. Of the 186 patients with AEs data, 75 (40.3%) patients reported an event and, of these, 13 (17.3%) patients had grade 4 bilirubin values.

Conclusions

In a large, diverse population treated at a single center over 13 years, Y90 SIRT produced a median OS of 16.6 months in patients with unresectable HCC and enabled subsequent transplantation in a subset of patients. Factors affecting the length of survival should be considered when making treatment decisions for unresectable HCC.

Gut microbiome in liver pathophysiology and cholestatic liver disease

An increasing amount of evidence has shown critical roles of gut microbiome in host pathophysiology. The gut and the liver are anatomically and physiologically connected. Given the critical role of gut-liver axis in the homeostasis of the liver, gut microbiome interplays with a diverse spectrum of hepatic changes, including steatosis, inflammation, fibrosis, cholestasis, and tumorigenesis. In clinic, cholestasis manifests with fatigue, pruritus, and jaundice, caused by the impairment in bile formation or flow. Studies have shown that the gut microbiome is altered in cholestatic liver disease. In this review, we will explore the interaction between the gut microbiome and the liver with a focus on the alteration and the role of gut microbiome in cholestatic liver disease. We will also discuss the prospect of exploiting the gut microbiome in the development of novel therapies for cholestatic liver disease.

Retrospective Analysis of the Clinical Efficacy of N-Acetylcysteine in the Treatment of Hepatitis B Virus Related Acute-on-Chronic Liver Failure

Objective: HBV-related acute-on-chronic liver failure (HBV-ACLF) has a high mortality due to severe intrahepatic cholestasis and coagulation dysfunction, thus new treatment measures are urgently needed to improve the therapeutic effect. This study aimed to observe the efficacy of N-acetylcysteine (NAC) in the treatment of HBV-ACLF.

Methods: The data of patients with HBV-ACLF admitted to West China Hospital from October 2019 to August 2020 were collected retrospectively, and they were divided into treatment group and control group according to whether they had received additional NAC treatment. The improvement of biochemistry, coagulation function and disease severity score after 14 days of hospitalization were analyzed between two groups.

Results: A total of 90 HBV-ACLF patients were included, including 42 patients in treatment group and 48 patients in control group. Compared with baseline, serum TBil, DBil, TBA, GGT and ALP in two groups both decreased significantly, while PTA increased significantly. Interesting, the decrease of serum TBil, DBil and TBA and the increase of PTA in treatment group were all significantly than these in control group. Additionally, more patients in treatment group than control group changed from CTP grade C to grade B. Subgroup analysis of CTP grade C patients showed that the decrease of serum TBil, DBil and TBA and the increase of PTA in treatment group were significantly than these in control group.

Conclusion: The NAC treatment may help to improve intrahepatic cholestasis and coagulation dysfunction of HBV-ACLF.

Intestinal microbiota participates in nonalcoholic fatty liver disease progression by affecting intestinal homeostasis

Nonalcoholic fatty liver disease (NAFLD) is a chronic liver disease with a pathogenesis that has not been fully elucidated. With the development of the theory of the gut-liver axis and the deepening of related research, the role of the intestinal tract in the pathogenesis of NAFLD has been investigated more. Intestinal microbiota, intestinal metabolites, and intestinal epithelial and immune-based barriers constitute the intestinal environment, which uses crosstalk to maintain the homeostasis of the intestinal environment. This paper reviews the progress in the study of intestinal microbiota, intestinal environment, and NAFLD and suggests that repair of intestinal functional balance may be a new idea for early prevention and intervention of NAFLD.

Increased liver stiffness by transient elastography and acoustic radiation force impulse imaging in patients with extrahepatic cholestasis

BACKGROUND

Transient elastography and acoustic radiation force impulse (ARFI) imaging are noninvasive tools for liver stiffness measurement (LSM), which may be influenced by cholestasis.

AIM

The aim of the study was to evaluate the performance of transient elastography and ARFI in extrahepatic cholestasis and correlate changes in LSM with biochemical activity.

MATERIALS AND METHODS

A total of 38 patients with extrahepatic cholestasis prospectively underwent transient elastography and ARFI. Changes in LSM by transient elastography/ARFI were evaluated after 1 week of ERCP and correlated with biochemical parameters. The optimal ARFI cutoffs according to stages of clinical interest were analyzed.

RESULTS

Biliary obstruction was calcular in 21 (55.3%) and noncalcular in 17 (44.7%) (benign n = 15, malignant n = 2). After 1 week, adequate biliary drainage reduced total bilirubin from 7.7 to 2.2 mg/dL (P < 0.001) which significantly correlated with reduction of LSM by transient elastography from 12.38 ± 6.68 kPa to 8.08 ± 3.21 kPa (P < 0.001), and by ARFI from 1.73 ± 0.51 m/s to 1.56 ± 0.70 m/s (P = 0.014). The LSM percentage change showed a decrease (nonsignificant, P = 0.843) by 25.83% using transient elastography and a significant decrease (P < 0.001) by 18.42% using ARFI in the improved patients. At initial visit, transient elastography positively correlated with ARFI, bilirubin and platelets, also, transient elastography had a positive correlation with ARFI, bilirubin, alkaline phosphatase (ALP), γ-glutamyl transpeptidase (GGT) in follow-up visit. LSM by ARFI (visit 1) negatively correlated with ALT, while in (visit 2), ARFI positively correlated with bilirubin, ALP, GGT and negatively correlated with albumin.

CONCLUSION

The increased LSM in patients with extrahepatic cholestasis is reduced after adequate biliary drainage, implying that increased values are not solely due to liver fibrosis, but due to biliary congestion leading temporarily to increased elasticity.

Oral-Gut Microbiome Axis in Gastrointestinal Disease and Cancer

It is well-known that microbiota dysbiosis is closely associated with numerous diseases in the human body. The oral cavity and gut are the two largest microbial habitats, playing a major role in microbiome-associated diseases. Even though the oral cavity and gut are continuous regions connected through the gastrointestinal tract, the oral and gut microbiome profiles are well-segregated due to the oral-gut barrier. However, the oral microbiota can translocate to the intestinal mucosa in conditions of the oral-gut barrier dysfunction. Inversely, the gut-to-oral microbial transmission occurs as well in inter- and intrapersonal manners. Recently, it has been reported that oral and gut microbiomes interdependently regulate physiological functions and pathological processes. Oral-to-gut and gut-to-oral microbial transmissions can shape and/or reshape the microbial ecosystem in both habitats, eventually modulating pathogenesis of disease. However, the oral-gut microbial interaction in pathogenesis has been underappreciated to date. Here, we will highlight the oral-gut microbiome crosstalk and its implications in the pathogenesis of the gastrointestinal disease and cancer. Better understanding the role of the oral-gut microbiome axis in pathogenesis will be advantageous for precise diagnosis/prognosis and effective treatment.

Oral–Gut Microbiome Axis in Gastrointestinal Disease and Cancer

It is well-known that microbiota dysbiosis is closely associated with numerous diseases in the human body. The oral cavity and gut are the two largest microbial habitats, playing a major role in microbiome-associated diseases. Even though the oral cavity and gut are continuous regions connected through the gastrointestinal tract, the oral and gut microbiome profiles are well-segregated due to the oral–gut barrier. However, the oral microbiota can translocate to the intestinal mucosa in conditions of the oral–gut barrier dysfunction. Inversely, the gut-to-oral microbial transmission occurs as well in inter- and intrapersonal manners. Recently, it has been reported that oral and gut microbiomes interdependently regulate physiological functions and pathological processes. Oral-to-gut and gut-to-oral microbial transmissions can shape and/or reshape the microbial ecosystem in both habitats, eventually modulating pathogenesis of disease. However, the oral–gut microbial interaction in pathogenesis has been underappreciated to date. Here, we will highlight the oral–gut microbiome crosstalk and its implications in the pathogenesis of the gastrointestinal disease and cancer. Better understanding the role of the oral–gut microbiome axis in pathogenesis will be advantageous for precise diagnosis/prognosis and effective treatment.

A systematic review on pharmacokinetics, cardiovascular outcomes and safety profiles of statins in cirrhosis

Background/Aims

There is increased interest in the therapeutic use of statins in cirrhosis, but preferred statin and safety outcomes are still not well known. In this systematic review we aimed to address pharmacokinetics (PK), safety, and effects on cardiovascular (CV) outcomes of statins in cirrhosis.

Methods

Our systematic search in several electronic databases and repositories of two regulatory bodies up to 2020-06-11 yielded 22 articles and 2 drug monographs with relevant data.

Results

Rosuvastatin and pitavastatin showed minimal PK changes in Child–Pugh A cirrhosis. Only rosuvastatin was assessed in a repeated dosing PK study. Atorvastatin showed pronounced PK changes in cirrhosis. No PK data was found for simvastatin, the most commonly used statin in cirrhosis trials. There was insufficient data to assess CV effects of statins in cirrhosis. Clinical trials in cirrhosis were limited to simvastatin, atorvastatin, and pravastatin. In patients taking simvastatin 40 mg, pooled frequency of rhabdomyolysis was 2%, an incidence 40-fold higher than that reported in non-cirrhosis patients, while this was no rhabdomyolysis observed in patients on simvastatin 20 mg, atorvastatin 20 mg, or pravastatin 40 mg. Drug-induced liver injury was of difficult interpretation due to co-existence of muscle damage. No overt liver failure was reported.

Conclusions

Simvastatin 40 mg should be avoided in decompensated cirrhosis. Safety data on simvastatin 20 mg or other statins are based on small study sample size. This rarity of evidence combined with lack of data in dose adjustment methods in cirrhosis is a barrier for using statins for CV indications or for investigational use for liver indications.

Supplementary information

The online version contains supplementary material available at 10.1186/s12876-021-01704-w.

Targeted treatment of alcoholic liver disease based on inflammatory signalling pathways

Targeted therapy is an emerging treatment strategy for alcoholic liver disease (ALD). Inflammation plays an important role in the occurrence and development of ALD, and is a key choice for its targeted treatment, and anti-inflammatory treatment has been considered beneficial for liver disease. Surprisingly, immune checkpoint inhibitors have become important therapeutic agents for hepatocellular carcinoma (HCC). Moreover, studies have shown that the combination of inflammatory molecule inhibitors and immune checkpoint inhibitors can exert better effects than either alone in mouse models of HCC. This review discusses the mechanism of hepatic ethanol metabolism and the conditions under which inflammation occurs. In addition, we focus on the potential molecular targets in inflammatory signalling pathways and summarize the potential targeted inhibitors and immune checkpoint inhibitors, providing a theoretical basis for the targeted treatment of ALD and the development of new combination therapy strategies for HCC.

Intestinal Microbiome-Macrophage Crosstalk Contributes to Cholestatic Liver Disease by Promoting Intestinal Permeability in Mice

BACKGROUND AND AIMS

Mounting evidence supports an association between cholestatic liver disease and changes in the composition of the microbiome. Still, the role of the microbiome in the pathogenesis of this condition remains largely undefined.

APPROACH AND RESULTS

To address this, we have used two experimental models, administering alpha-naphtylisocyanate or feeding a 0.1% 3,5-diethoxycarbonyl-1,4-dihydrocollidine diet, to induce cholestatic liver disease in germ-free mice and germ-free mice conventionalized with the microbiome from wild-type, specific pathogen-free animals. Next, we have inhibited macrophage activation by depleting these cells using clodronate liposomes and inhibiting the inflammasome with a specific inhibitor of NOD-, LRR-, and pyrin domain-containing protein 3. Our results demonstrate that cholestasis, the accumulation of bile acids in the liver, fails to promote liver injury in the absence of the microbiome in vivo. Additional in vitro studies supported that endotoxin sensitizes hepatocytes to bile-acid-induced cell death. We also demonstrate that during cholestasis, macrophages contribute to promoting intestinal permeability and to altered microbiome composition through activation of the inflammasome, overall leading to increased endotoxin flux into the cholestatic liver.

CONCLUSIONS

We demonstrate that the intestinal microbiome contributes to cholestasis-mediated cell death and inflammation through mechanisms involving activation of the inflammasome in macrophages.

Fatigue and Pruritus in Patients with Advanced Fibrosis Due to Nonalcoholic Steatohepatitis: The Impact on Patient-Reported Outcomes

Fatigue and pruritus are common in patients with chronic liver diseases of all etiologies, but clinical awareness is mostly restricted to those with cholestatic liver diseases. We assessed the impact of fatigue and pruritus on patient‐reported outcomes (PROs) of patients with advanced nonalcoholic steatohepatitis (NASH). Specifically, PROs (Short Form–36, Chronic Liver Disease Questionnaire–NASH, Euro‐Qol 5 Dimension, and Work Productivity and Activity Impairment instruments) were assessed at baseline in patients with histologically confirmed bridging fibrosis (F3) or compensated cirrhosis (F4) due to NASH enrolled in STELLAR 3 and 4. Presence of fatigue and pruritus were indicated by a score of 4 or less on the respective items of the Chronic Liver Disease Questionnaire–NASH (scale range, 1‐7). Among the included 1,669 patients with advanced NASH (mean age = 58 ± 9 years, 48% F3, 42% with psychiatric comorbidities), 33% and 27% had fatigue and pruritus, respectively. Patients with NASH with fatigue were younger, more likely to be female, cirrhotic, and diabetic, and had higher body mass index and more comorbidities (all P < 0.05). All PRO scores of patients with fatigue were significantly impaired (mean up to −31% of a PRO range size in comparison to patients without fatigue). In multivariate analysis, predictors of fatigue included diabetes, history of depression or nervous system comorbidities, and lower serum albumin (P < 0.05). Patients with pruritus had demographic characteristics similar to those with fatigue, but a higher prevalence of dermatologic comorbidities. All PROs were impaired (by up to −19% of a range size, all P < 0.01) in patients with NASH with pruritus. Female gender, lower serum albumin, and a history of depression, nervous system, and dermatologic comorbidities were associated with increased risk of pruritus (P < 0.05). Conclusion: Clinically significant fatigue and pruritus are common in patients with advanced NASH, and these symptoms negatively affect PROs.

Quizalofop-p-Ethyl Induces Adipogenesis in 3T3-L1 Adipocytes

Exposure to endocrine disrupting chemicals is an established risk factor for obesity. The most commonly used pesticide active ingredients have never been tested in an adipogenesis assay. We tested for the first time the potential of glyphosate, 2, 4-dichlorophenoxyacetic acid, dicamba, mesotrione, isoxaflutole, and quizalofop-p-ethyl (QpE) to induce lipid accumulation in murine 3T3-L1 adipocytes. Only QpE caused a dose-dependent statistically significant triglyceride accumulation from a concentration of 5 up to 100 µM. The QpE commercial formulation Targa Super was 100 times more cytotoxic than QpE alone. Neither the estrogen receptor antagonist ICI 182, 780 nor the glucocorticoid receptor antagonist RU486 was able to block the QpE-induced lipid accumulation. RNAseq analysis of 3T3-L1 adipocytes exposed to QpE suggests that this compound exerts its lipid accumulation effects via a peroxisome proliferator-activated receptor gamma (PPARγ)-mediated pathway, a nuclear receptor whose modulation influences lipid metabolism. QpE was further shown to be active in a PPARγ reporter gene assay at 100 µM, reaching 4% of the maximal response produced by rosiglitazone, which acts as a positive control. This indicates that lipid accumulation induced by QpE is only in part caused by PPARγ activation. The lipid accumulation capability of QpE we observe suggest that this pesticide, whose use is likely to increase in coming years may have a hitherto unsuspected obesogenic property.

Gut microbiota in non-alcoholic fatty liver disease and alcohol-related liver disease: Current concepts and perspectives

The term, gut-liver axis, is used to highlight the close anatomical and functional relationship between the intestine and the liver. It has been increasingly recognized that the gut-liver axis plays an essential role in the development and progression of liver disease. In particular, in non-alcoholic fatty liver disease and alcohol-related liver disease, the two most common causes of chronic liver disease, a dysbiotic gut microbiota can influence intestinal permeability, allowing some pathogens or bacteria-derived factors from the gut reaching the liver through the enterohepatic circulation contributing to liver injury, steatohepatitis, and fibrosis progression. Pathways involved are multiple, including changes in bile acid metabolism, intestinal ethanol production, generation of short-chain fatty acids, and other by-products. Bile acids act through dedicated bile acid receptors, farnesoid X receptor and TGR5, in both the ileum and the liver, influencing lipid metabolism, inflammation, and fibrogenesis. Currently, both non-alcoholic fatty liver disease and alcohol-related liver disease lack effective therapies, and therapeutic targeting of gut microbiota and bile acids enterohepatic circulation holds promise. In this review, we summarize current knowledge about the role of gut microbiota in the pathogenesis of non-alcoholic fatty liver disease and alcohol-related liver disease, as well as the relevance of microbiota or bile acid-based approaches in the management of those liver diseases.

Early treatment efficacy of S-adenosylmethionine in patients with intrahepatic cholestasis: A systematic review

BACKGROUND

S-adenosylmethionine (AdoMet) is a metabolically pleiotropic molecule used to treat intrahepatic cholestasis (IHC) and chronic liver diseases. While the efficacy of AdoMet has been demonstrated previously, it has not been systematically investigated within the early weeks of treatment.

AIM

To systematically review the early treatment efficacy of AdoMet in adult patients with IHC.

METHODS

Studies reporting the efficacy of intravenous, intramuscular, or oral forms of AdoMet within 8 wk of treatment initiation were considered; three randomized and six non-randomized studies were eligible for inclusion (PROSPERO registration number CRD42018090936). Of the three randomized studies, two were double-blind and placebo-controlled, and one was comparator-controlled with unclear blinding and a relatively high risk of bias. Mean serum levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), and gamma-glutamyl transferase (γGT) following AdoMet treatment vs placebo, comparator, or baseline were summarized to determine differences in liver enzymes. Changes in patient-reported clinical symptoms of cholestasis were also summarized.

RESULTS

Both placebo-controlled randomized studies reported significant reductions in serum ALT levels with AdoMet vs placebo within 2 wk. One of these also reported significant ALP reductions, and the other reported significant AST and γGT reductions within 2 wk. The comparator-controlled randomized study, which had a number of notable limitations, reported significant reductions in serum ALT and AST levels with AdoMet vs potassium magnesium aspartate within 4 wk, but not within2 wk. All of the non-randomized studies (4/4) that investigated ALT, AST, ALP and/or γGT reported significant reductions in at least two of these parameters within 2 wk. Of the five studies that evaluated fatigue, reductions were observed within 2 wk in one randomized and two non-randomized studies. The remaining two non-randomized studies reported improvements in fatigue within 6 and 8 wk. Of the four studies reporting symptoms of depression, two non-randomized studies observed improvements within 2 wk and the other two observed improvements within 17 d and 8 wk.

CONCLUSION

Data from both randomized and non-randomized studies suggest that AdoMet improves some biochemical liver parameters and symptoms of cholestasis within 2 wk, with further improvements observed in some studies after 4 and 8 wk of treatment.

Protective effect of Echinochrome against intrahepatic cholestasis induced by alpha-naphthylisothiocyanate in rats

Abstract The present study was designed to evaluate the protective effects of echinochrome (Ech) on intrahepatic cholestasis in rats induced by a single (i.p.) injection of alpha-naphthylisothiocyanate (ANIT) (75 mg/kg body weight). The rats were pre-treated orally for 48hr (one dose / 24hr) with Ech (1, 5 and 10 mg/kg body weight) or ursodeoxycholic acid (UDCA) 80 mg/kg body weight drug then, injected with ANIT. ANIT markedly increased serum activities of alanine amino transaminase (ALT), aspartate amino transaminase (AST) and alkaline phosphatase (ALP), which was accompanied by a massive inflammation of epithelial cells on bile duct at 24h after ANIT injection. ANIT also increased the levels of total protein (TP), total bilirubin (TB), direct bilirubin (DB), indirect bilirubin (IB), however decrease albumin content (ALB). In addition ANIT increased hepatic MDA and NO level and decreased GSH level and GST activity. The Ech exerted hepatoprotective and anticholestatic effects as assessed by a significant decrease in the activities of serum AST, ALT and ALP, and the levels of TP, TB, DB and IB as well as liver MDA level and NO level. In conclusion, Ech was found to possess hepatoprotective effect against intrahepatic cholestasis induced by hepatotoxin such as ANIT.

Cholestasis induced by bile duct ligation promotes changes in the intestinal microbiome in mice

Increasing evidence point to the relevance of intestinal disfunction and changes in the microbiome composition during chronic liver disease. More specifically, recent studies have highlighted that cholestatic diseases associate with a reduction in the microbiome diversity in patients. Still, the dynamics of the changes in the microbiome composition observed, as well as their implication in contributing to the pathogenesis of this disease remain largely undefined. Hence, experimental mouse models resembling the human pathogenesis are crucial to move forward our understanding on the mechanisms underpinning cholestatic disease and to enable the development of effective therapeutics. Our results show that the bile duct ligation (BDL) experimental model of cholestasis leads to rapid and significant changes in the microbiome diversity, with more than 100 OTUs being significantly different in faecal samples obtained from WT mice at 3 days and 7 days after BDL when compared to control animals. Changes in the microbial composition in mice after BDL included the enrichment of Akkermansia, Prevotella, Bacteroides and unclassified Ruminococcaceae in parallel with a drastic reduction of the presence of Faecalibacterium prausnitzii. In conclusion, our results support that bile duct ligation induces changes in the microbiome that partly resemble the gut microbial changes observed during human cholestatic disease.

Intrahepatic cholestasis in nonalcoholic fatty liver disease

AIM

To determine the frequency of intrahepatic cholestasis and its impact on the clinical features of the different forms of non-alcoholic fatty liver disease (NAFLD).

MATERIALS AND METHODS

The study involved 163 patients with NAFLD: 92 (56.4%) with hepatic steatosis (HS), 56 (34.4%) with steatohep- atitis (SH) and 15 (9.2%) with liver cirrhosis (LC). Diagnosis is based on clinical, laboratory, ultrasound and histological data. Insulin, tu- mor necrosis factor α (TNF-α), fragments of cytokeratin-18 (FCK-18) were determined by ELISA. The index of insulin resistance (HOMA- IR) was calculated. NAFLD fibrosis score (NAFLD-FS) was determined, taking into account the patient's age, body mass index, presence or absence of carbohydrate metabolism disturbances, levels of ASAT, ALAT, albumin and blood platelets.

RESULTS

Cholestatic syndrome was detected in 49 (30.1%) NAFLD patients: in 23 (25%) with HS, in 19 (33.9%) with SH and in 7 (46.7%) with LC. Patients with HS, SH and LC with signs of cholestasis as compared to patients with the same forms of NAFLD without cholestasis had significantly higher levels of the following indicators: aminotransferases, triglycerides, HOMA-IR, TNF-α, FCK-18, NAFLD-FS, - the number of platelets is reduced, indirectly confirming the more rapid development of fibrosis in cholestasis. These findings were consistent with published data on the violation in cholestasis regulatory functions of bile acids, which are ligands of hepatocyte nuclear receptor, re- sponsible for normal homeostasis.

CONCLUSION

In all forms of NAFLD with cholestasis were detected more pronounced liver cell inflammation, hepatocyte necrosis and apoptosis, fibrosis, disturbance of carbohydrate and lipid metabolism, which contributed to a progressive course of NAFLD and confirmed the need for medical correction of cholestasis, starting with the earliest form of NAFLD - hepatosteatosis.

Liver stiffness measurement by acoustic radiation forced impulse and transient elastography in patients with intrahepatic cholestasis

BACKGROUND

Transient elastography (TE) and acoustic radiation force impulse (ARFI) imaging enable a noninvasive assessment of liver stiffness measurement (LSM) and liver fibrosis/cirrhosis staging. However, their use in cholestatic diseases is still scarce.

AIM

The aim of this study was to evaluate the performance of TE and ARFI for the initial assessment of hepatic fibrosis in intrahepatic cholestatic (IHC) diseases and assess LSM changes after 3 months of specific therapy.

PATIENTS AND METHODS

This prospective study was carried out on 50 IHC patients. Assessment at baseline and after 3 months of LSM by TE and ARFI was performed.

RESULTS

Overall, 60% of the patients were women (36.5±9.2 years). IHC etiologies were 23 (46%) autoimmune hepatitis, eight (16%) primary sclerosing cholangitis, eight (16%) drug induced, and five (10%) primary biliary cirrhosis. TE could diagnose ≥F2, ≥F3, and F4 stages at cutoffs of at least 6.7, 9.4, and 14.0 kPa, sensitivity/specificity were 100/50% for ≥F2, 88.2/83% for ≥F3, and 90/100% for F4. Moreover, the sensitivity and specificity of ARFI were 93/50% for ≥F2 (cutoff: 1.53 m/s); 71/67% for ≥F3 (cutoff 1.77 m/s); and 90/100% for F4 (cutoff: 2.43 m/s).Follow-up showed a significant decrease in TE and ARFI values by 27 and 22.3% (P<0.001 and <0.001, respectively) and, accordingly, fibrosis stages decreased significantly by both TE and ARFI (P=0.002 and <0.001, respectively).

CONCLUSION

TE and ARFI represent noninvasive methods with adequate diagnostic performance for the assessment of fibrosis, and monitoring disease progression and treatment response in intrahepatic cholestasis.

Fatigue in chronic liver disease: New insights and therapeutic approaches

The management of fatigue associated with chronic liver disease is a complex and major clinical challenge. Although fatigue can complicate many chronic diseases, it is particularly common in diseases with an inflammatory component. Fatigue can have both peripheral (i.e., neuromuscular) and central (i.e., resulting from changes in neurotransmission within the brain) causes. However, fatigue in chronic liver disease has strong social/contextual components and is often associated with behavioural alterations including depression and anxiety. Given the increasing awareness of patient-reported outcomes as important components of treatment outcomes and clinical research, there is a growing need to better understand and manage this poorly understood yet debilitating symptom. Although several pathophysiological mechanisms for explaining the development of fatigue have been generated, our understanding of fatigue in patients with chronic liver disease remains incomplete. A better understanding of the pathways and neurotransmitter systems involved may provide specific directed therapies. Currently, the management of fatigue in chronic liver disease can involve a combined use of methods to beneficially alter behavioural components and pharmacological interventions, of which several treatments have potential for the improved management of fatigue in chronic liver disease. However, evidence and consensus are lacking on the best approach and the most appropriate biochemical target(s) whilst clinical trials to address this issue have been few and limited by small sample size. In this review, we outline current understanding of the impact of fatigue and related symptoms in chronic liver disease, discuss theories of pathogenesis, and examine current and emerging approaches to its treatment.

Validation of hepatobiliary transport PET imaging in liver function assessment: Evaluation of 3β-[18F]FCA in mouse models of liver disease

Recently, our research group reported on the development of 3β-[¹⁸F]Fluorocholic acid (3β-[¹⁸F]FCA), a ¹⁸F labeled bile acid to detect drug interference with the bile acid transporters (drug-induced cholestasis). It was hypothesized that 3β-[¹⁸F]FCA could also be used as a non-invasive tool to monitor (regional) liver function in vivo in different liver diseases through altered expression of bile acid transporters.

METHODS

Hepatobiliary transport of 3β-[¹⁸F]FCA was evaluated in four murine liver disease models. Acute liver injury was induced by oral gavage of an acetaminophen (APAP) overdose (300 mg/kg). Chronic cholangiopathy and non-alcoholic steatohepatitis (NASH) were induced by feeding mice 3,5-diethoxycarbonyl- 1,4-dihydrocollidine (DDC) diet or methionine and choline deficient (MCD) diet, respectively. Hepatocellular carcinoma (HCC) was evoked by intraperitoneal injection of 35 mg/kg diethylnitrosamine (DEN) once a week for 23 weeks. Gene expression of the murine bile acid transporters was determined by RT-qPCR.

RESULTS

Hepatobiliary transport of 3β-[¹⁸F]FCA was not significantly altered after an APAP overdose. Mice fed the DDC or MCD diet showed impaired transport of 3β-[¹⁸F]FCA compared to baseline, which was associated with altered expression of the bile acid transporters ntcp, oatp4 and mrp2. After recovery from DDC- and MCD-induced liver injury, 3β-[¹⁸F]FCA parameters returned to baseline. Global hepatobiliary transport of 3β-[¹⁸F]FCA in HCC bearing mice was not significantly different compared to control mice. However, HCC lesions showed reduced hepatic uptake of the tracer (tumor-to-background: 0.45 ± 0.13), which was in line with decreased in expression of basolateral bile acid uptake transporters nctp and oatp4 in tumor tissue.

CONCLUSION

3β-[¹⁸F]FCA is a useful tool to assess and longitudinally follow-up liver function in several mouse models for liver diseases that are associated with altered expression of the bile acid transporters. These results point towards the (pre)clinical utility of 3β-[¹⁸F]FCA as a PET tracer to monitor altered liver functionality in patients with chronic liver diseases.

Taurocholic acid is an active promoting factor, not just a biomarker of progression of liver cirrhosis: evidence from a human metabolomic study and in vitro experiments

BACKGROUND

Previous studies have indicated that bile acid is associated with progression of liver cirrhosis. However, the particular role of specific bile acid in the development of liver cirrhosis is not definite. The present study aims to identify the specific bile acid and explore its possible mechanisms in promoting liver cirrhosis.

METHODS

Thirty two cirrhotic patients and 27 healthy volunteers were enrolled. Age, gender, Child-Pugh classification and serum of patients and volunteers were collected. Liquid chromatography tandem mass spectrometry (LC-MS) was utilized to determine concentrations of 12 bile acids in serum. Principal component analysis, fold change analysis and heatmap analysis were used to identify the most changed bile acid. And pathway analysis was used to identify the most affected pathway in bile acid metabolism. Spearman rank correlation analysis was employed to assess correlation between concentrations of bile acids and Child-Pugh classification. Hepatic stellate cells (LX-2) were cultured in DMEM. LX-2 cells were also co-cultured with HepG2 cells in the transwell chambers. LX-2 cells were treated with Na+/taurocholate in different concentrations. Western blot was used to evaluate the expression of alpha smooth muscle actin (α-SMA), type I collagen, and Toll-like receptor 4 (TLR4) in LX-2 cells.

RESULTS

Concentrations of 12 bile acids in serum of patients and healthy volunteers were determined with LC-MS successively. Principal component analysis, fold change analysis and heatmap analysis identified taurocholic acid (TCA) to be the most changed bile acid. Pathway analysis showed that TCA biosynthesis increased significantly. Spearman rank correlation analysis showed that concentration of TCA in serum of cirrhotic patients was positively associated with Child-Pugh classification. TCA increased the expression of α-SMA, type I collagen, and TLR4 in LX-2 cells. Moreover, the above effect was strengthened when LX-2 cells were co-cultured with HepG2 cells.

CONCLUSIONS

Increased TCA concentration in serum of liver cirrhotic patients is mainly due to increased bile acid biosynthesis. TCA is an active promoter of the progression of liver cirrhosis. TCA promoting liver cirrhosis is likely through activating hepatic stellate cells via upregulating TLR4 expression. TCA is a potential therapeutic target for the prevention and treatment of liver cirrhosis.

Triggering and resolution of inflammation in NASH

Nonalcoholic steatohepatitis (NASH) is considered the progressive form of nonalcoholic fatty liver disease (NAFLD) and is characterized by liver steatosis, inflammation, hepatocellular injury and different degrees of fibrosis. A central issue in this field relates to the identification of those factors that trigger inflammation, thus fuelling the transition from nonalcoholic fatty liver to NASH. These triggers of liver inflammation might have their origins outside the liver (such as in adipose tissue or the gut) as well as inside the organ (for instance, lipotoxicity, innate immune responses, cell death pathways, mitochondrial dysfunction and endoplasmic reticulum stress), both of which contribute to NASH development. In this Review, we summarize the currently available information on the key upstream triggers of inflammation in NASH. We further delineate the mechanisms by which liver inflammation is resolved and the implications of a defective pro-resolution process. A better knowledge of these mechanisms should help to design targeted therapies able to halt or reverse disease progression.

Evaluating Hepatobiliary Transport with 18F-Labeled Bile Acids: The Effect of Radiolabel Position and Bile Acid Structure on Radiosynthesis and In Vitro and In Vivo Performance

Introduction

An in vivo determination of bile acid hepatobiliary transport efficiency can be of use in liver disease and preclinical drug development. Given the increased interest in bile acid Positron Emission Tomography- (PET-) imaging, a further understanding of the impact of 18-fluorine substitution on bile acid handling in vitro and in vivo can be of significance.

Methods

A number of bile acid analogues were conceived for nucleophilic substitution with [¹⁸F]fluoride: cholic acid analogues of which the 3-, 7-, or 12-OH function is substituted with a fluorine atom (3α-[¹⁸F]FCA; 7β-[¹⁸F]FCA; 12β-[¹⁸F]FCA); a glycocholic and chenodeoxycholic acid analogue, substituted on the 3-position (3β-[¹⁸F]FGCA and 3β-[¹⁸F]FCDCA, resp.). Uptake by the bile acid transporters NTCP and OATP1B1 was evaluated with competition assays in transfected CHO and HEK cell lines and efflux by BSEP in membrane vesicles. PET-scans with the tracers were performed in wild-type mice (n = 3 per group): hepatobiliary transport was monitored and compared to a reference tracer, namely, 3β-[¹⁸F]FCA.

Results

Compounds 3α-[¹⁸F]FCA, 3β-[¹⁸F]FGCA, and 3β-[¹⁸F]FCDCA were synthesized in moderate radiochemical yields (4–10% n.d.c.) and high radiochemical purity (>99%); 7β-[¹⁸F]FCA and 12β-[¹⁸F]FCA could not be synthesized and included further in this study. In vitro evaluation showed that 3α-FCA, 3β-FGCA, and 3β-FCDCA all had a low micromolar Ki-value for NTCP, OATP1B1, and BSEP. In vivo, 3α-[¹⁸F]FCA, 3β-[¹⁸F]FGCA, and 3β-[¹⁸F]FCDCA displayed hepatobiliary transport with varying efficiency. A slight yet significant difference in uptake and efflux rate was noticed between the 3α-[¹⁸F]FCA and 3β-[¹⁸F]FCA epimers. Conjugation of 3β-[¹⁸F]FCA with glycine had no significant effect in vivo. Compound 3β-[¹⁸F]FCDCA showed a significantly slower hepatic uptake and efflux towards gallbladder and intestines.

Conclusion

A set of ¹⁸F labeled bile acids was synthesized that are substrates of the bile acid transporters in vitro and in vivo and can serve as PET-biomarkers for hepatobiliary transport of bile acids.

Prognostic Significance of Elevated Cholestatic Enzymes for Fibrosis and Hepatocellular Carcinoma in Hospital Discharged Chronic Viral Hepatitis Patients

Chronic viral hepatitis (CVH) is the root cause of liver fibrosis and subsequent hepatocellular carcinoma (HCC). We conducted a cross-sectional, observational study based on medical records and primary data collection from patients with CVH who were admitted in five hospitals across China between February and September 2013 to determine the prevalence of elevated cholestatic enzymes (ALP and/or GGT above ULN) in discharged Chinese patients with CVH as a primary outcome and secondarily evaluated the relationship of these enzymes with fibrosis and disease severity. Majority of the patients (56%) had cholestatic enzyme elevation at discharge, with high prevalence of liver fibrosis (37.6% vs. 20.1%, p < 0.001) and cirrhosis (Child-Pugh B: 56.9% vs. 48.7%; Child-Pugh C: 17.4% vs. 12.5%; p < 0.001) in addition to significantly higher odds of liver fibrosis (OR 1.54; p = 0.024) and a trend towards higher odds of moderate-to-severe cirrhosis (OR 1.24; p = 0.317) compared to those who had normal enzyme levels. Elevated cholestatic enzyme levels serve as important prognosticators of liver fibrosis in CVH patients. Therefore, pre-discharge testing of cholestatic enzymes is recommended to identify CVH patients and provide prophylactic care.

Detection of Autoantibodies to Vascular Endothelial Growth Factor Receptor-3 in Bile Duct Ligated Rats and Correlations with a Panel of Traditional Markers of Liver Diseases

There is a need for new noninvasive biomarkers (NIBMs) able to assess cholestasis and fibrosis in chronic cholestatic liver diseases (CCLDs). Tumorigenesis can arise from CCLDs. Therefore, autoantibodies to tumor-associated antigens (TAA) may be early produced in response to abnormal self-antigen expression caused by cholestatic injury. Vascular endothelial growth factor receptor-3 (VEGFR-3) has TAA potential since it is involved in cholangiocytes and lymphatic vessels proliferations during CCLDs. This study aims to detect autoantibodies directed at VEGFR-3 during bile duct ligation- (BDL-) induced cholestatic injury in rat sera and investigate whether they could be associated with traditional markers of liver damage, cholestasis, and fibrosis. An ELISA was performed to detect anti-VEGFR-3 autoantibodies in sera of rats with different degree of liver injury and results were correlated with aminotransferases, total bilirubin, and the relative fibrotic area. Mean absorbances of anti-VEGFR-3 autoantibodies were significantly increased from week one to week five after BDL. The highest correlation was observed with total bilirubin (R (2) = 0.8450, P = 3.04e - 12). In conclusion, anti-VEGFR-3 autoantibodies are early produced during BDL-induced cholestatic injury, and they are closely related to cholestasis, suggesting the potential of anti-VEGFR-3 autoantibodies as NIBMs of cholestasis in CCLDs and justifying the need for further investigations in patients with CCLD.

Current Capabilities and Limitations of Stable Isotope Techniques and Applied Mathematical Equations in Determining Whole-Body Vitamin A Status

BACKGROUND

Retinol isotope dilution (RID) methodology provides a quantitative estimate of total body vitamin A (VA) stores and is the best method currently available for assessing VA status in adults and children. The methodology has also been used to test the efficacy of VA interventions in a number of low-income countries. Infections, micronutrient deficiencies (eg, iron and zinc), liver disease, physiological age, pregnancy, and lactation are known or hypothesized to influence the accuracy of estimating total body VA stores using the isotope dilution technique.

OBJECTIVE

Our objectives were to review the strengths and limitations of RID methods, to discuss what is known about the impact of various factors on results, and to summarize contributions of model-based compartmental analysis to assessing VA status.

METHODS

Relevant published literature is reviewed and discussed.

RESULTS

Various equations and compartmental modeling have been used to estimate the total body VA stores using stable isotopes, including a newer 3-day equation that provides an estimate of total body VA stores in healthy adults. At present, there is insufficient information on absorption of the isotope tracer, and there is a need to further investigate how various factors impact the application of RID techniques in field studies.

CONCLUSIONS

Isotope dilution methodology can provide useful estimates of total body VA stores in apparently healthy populations under controlled study conditions. However, more research is needed to determine whether the method is suitable for use in settings where there is a high prevalence of infection, iron deficiency, and/or liver disease.

Pathophysiology and Diseases of the Proximal Pathways of the Biliary System

CONTEXT

Diseases of the proximal pathways of the biliary system can be divided into those that affect the interlobular bile ducts and those that affect the bile canaliculi. The former include primary biliary cirrhosis, small-duct variant of primary sclerosing cholangitis, graft-versus-host disease, and drug-induced liver injury, whereas the latter include progressive familial intrahepatic cholestasis, benign recurrent intrahepatic cholestasis, intrahepatic cholestasis of pregnancy, and drug-induced liver injury.

OBJECTIVE

To summarize the current state of knowledge of diseases of the proximal pathways of the biliary system, with special emphasis on clinical presentation, pathological features, and differential diagnosis.

DATA SOURCES

Clinicopathological information was extracted from pertinent published literature.

CONCLUSIONS

Care of the patient with cholestasis hinges on identifying the etiology. Diagnostic steps in cholestatic conditions comprise a thorough patient history, abdominal imaging, distinct serological studies, and liver biopsy. Primary biliary cirrhosis is characterized by distinctive serological and histological findings. The small-duct variant of primary sclerosing cholangitis is very rare and difficult to diagnose; imaging of the bile ducts is not helpful. Graft-versus-host disease is characterized by damage and loss of intrahepatic bile ducts. Drugs can cause injury variably at the level of bile canaliculus or the interlobular bile duct. Loss of bile ducts may be seen with primary biliary cirrhosis, primary sclerosing cholangitis, graft-versus-host disease, and drug-induced liver injury. Progressive familial intrahepatic cholestasis and progressive familial intrahepatic cholestasis represent 2 extreme ends of the spectrum of abnormalities in transporters responsible for bile formation. Intrahepatic cholestasis of pregnancy has a variable incidence in different parts of the world and may be due to abnormalities in transporter molecules.

Protective effect of bicyclol against bile duct ligation-induced hepatic fibrosis in rats

AIM: To evaluate the protective effect of bicyclol against bile duct ligation (BDL)-induced hepatic fibrosis in rats.

METHODS: Sprague-Dawley male rats underwent BDL and sham-operated animals were used as healthy controls. The BDL rats were divided into two groups which received sterilized PBS or bicyclol (100 mg/kg per day) orally for two consecutive weeks. Serum, urine and bile were collected for biochemical determinations. Liver tissues were collected for histological analysis and a whole genome oligonucleotide microarray assay. Reverse transcription-polymerase chain reaction and Western blotting were used to verify the expression of liver fibrosis-related genes.

RESULTS: Treatment with bicyclol significantly reduced liver fibrosis and bile duct proliferation after BDL. The levels of alanine aminotransferase (127.7 ± 72.3 vs 230.4 ± 69.6, P < 0.05) and aspartate aminotransferase (696.8 ± 232.6 vs 1032.6 ± 165.8, P < 0.05) were also decreased by treatment with bicyclol in comparison to PBS. The expression changes of 45 fibrogenic genes and several fibrogenesis-related pathways were reversed by bicyclol in the microarray assay. Bicyclol significantly reduced liver mRNA and/or protein expression levels of collagen 1a1, matrix metalloproteinase 2, tumor necrosis factor, tissue inhibitors of metalloproteinases 2, transforming growth factor-β1 and α-smooth muscle actin.

CONCLUSION: Bicyclol significantly attenuates BDL-induced liver fibrosis by reversing fibrogenic gene expression. These findings suggest that bicyclol might be an effective anti-fibrotic drug for the treatment of cholestatic liver disease.

Anti-fibrotic effect of Holothuria arenicola extract against bile duct ligation in rats

BACKGROUND

Holothuria arenicola is the most important and abundant sea cucumber species in the Mediterranean Sea on the Egyptian coast. The present study aims to assess the anti-oxidative and anticholestatic effects of the sea cucumber Holothuria arenicola extract (HaE) in a model of bile duct ligation in male albino rats.

METHODS

Fifty four male Wistar albino rats were assigned into two main groups, the Sham-operated control and bile duct ligated (BDL) group. After 14 days of surgery, the animals of the group I (Sham control) received distilled water only for 7, 14 and 28 days. Second group (BDL group) was divided into 2 subgroups, animals of these subgroups treated for 7, 14 and 28 consecutive days as follow: subgroup I (BDL), rats of this subgroup administered distilled water orally. Subgroup II (HaE), animals of this subgroup treated orally with HaE (200 mg/kg body weight).

RESULTS

The HaE revealed significant antifibrotic effect as evident by decreasing the levels of total conjugated and unconjugated bilirubin and the activities of serum aminotransferases (ASAT and ALAT) and alkaline phosphatase (ALP) as well as malondialdehyde (MDA) level, and increasing the serum albumin, glutathione reduced (GSH) levels. Treatment with HaE normalized the antioxidant enzyme, glutathione-S-transferase (GST), superoxide dismutase (SOD) and catalase (CAT) activities activities.

CONCLUSION

The present prospective study correlated the antifibrotic effect of HaE to its direct antioxidant effect that can be related to its contents of phenolic compounds specially chlorogenic acid, pyrogallol, rutin and coumaric acid.

Idiopathic non cirrhotic portal hypertension and spleno-portal axis abnormalities in patients with severe primary antibody deficiencies

Background and Aim. Portal hypertension has been reported in association with acquired and primary immune deficiencies without a comprehensive description of associated spleno-portal axis abnormalities. Pathological mechanisms are poorly defined. Methods. Observational, single centre study with the aim of assessing the prevalence of spleno-portal axis abnormalities in an unselected cohort of 123 patients with primary antibody deficiencies and without known causes of liver diseases regularly followed up for a mean time of 18 ± 14 years. A cumulative period of 1867 patients-year was analysed. Clinical and immunological data, abdominal ultrasounds, CT scans, and endoscopy features were included in the analysis. Results. Twenty-five percent of patients with primary antibody deficiencies had signs of portal vein enlargement but only 4% of them had portal hypertension, with portal systemic collaterals. Liver biopsies showed liver sinusoids congestive dilatation, endothelization, and micronodularity fulfilling the criteria for noncirrhotic portal hypertension. Patients with portal vein enlargement had severe clinical and immunological phenotypes. Conclusions. In primary antibody deficient patients, infections, inflammations, splenomegaly, increased blood venous flow, and lymphocyte abnormalities contribute to establishment of liver damage possibly leading to noncirrhotic portal hypertension. Patients with primary antibody deficiency should be considered a good model to give insight into the pathological mechanisms underlying noncirrhotic portal hypertension.

Pharmacotherapy of acute alcoholic hepatitis in clinical practice

Severe alcoholic hepatitis (AH) is an acute form of alcohol induced liver disease with a poor prognosis that is seen in the patients who consume large quantities of alcohol. The diagnosis of AH is based on the appropriate alcohol intake history and is supported with clinical and histological features, and several scoring systems. Glucocorticoids are the mainstay for treating severe AH with pentoxifylline used as an alternative to steroids in addition to total alcohol abstinence. Liver transplantation is a possible therapeutic option for severe AH. Among the anti-craving medications able to improve abstinence rate, baclofen seems to be effective and safe in the alcoholic patients affected by severe liver damage.