Adverse Outcome Pathways Mechanistically Describing Hepatotoxicity.

Adverse outcome pathways (AOPs) describe toxicological processes from a dynamic perspective by linking a molecular initiating event to a specific adverse outcome via a series of key events and key event relationships. In the field of computational toxicology, AOPs can potentially facilitate the design and development of in silico prediction models for hazard identification. Various AOPs have been introduced for several types of hepatotoxicity, such as steatosis, cholestasis, fibrosis, and liver cancer. This chapter provides an overview of AOPs on hepatotoxicity, including their development, assessment, and applications in toxicology.

Biliary drainage in palliative and curative intent European patients with hilar cholangiocarcinoma and malignant hilar obstruction: a retrospective single center analysis.

BACKGROUND AND AIMS: Relief of cholestasis in hilar cholangiocarcinoma is commonly undertaken in both curative and palliative treatment plans. There are numerous open questions with regard to the ideal biliary drainage strategy - including what constitutes clinical success (CS). In the existing data, curative patients and patients from the Western world are underrepresented. PATIENTS AND METHODS: We performed a retrospective analysis of patients with complex malignant hilar obstruction (Bismuth-Corlette II and higher) due to cholangiocarcinoma who underwent biliary drainage at a German referral center between 2010 and 2020. We aimed to define CS and complication rates and directly compare outcomes in curative and palliative patients. RESULTS: 56 curative and 72 palliative patients underwent biliary drainage. In patients with curative intent, CS was achieved significantly more often regardless of what definition of CS was applied (e.g., total serum bilirubin (TSB) < 2 mg/dl: 66.1% vs. 27.8%, p = < 0.001, > 75% reduction of TSB: 57.1% vs. 29.2%, p = 0.003). This observation held true only when subgroups with the same Bismuth-Corlette stage were compared. Moreover, palliative patients experienced a significantly greater percentage of adverse events (33.3% vs. 12.5%, p = 0.01). Curative intent treatment and TSB at presentation were predictive factors of CS regardless of what definition of CS was applied. The observed CS rates are comparable to published studies involving curative patients, but inferior to reported CS rates in palliative series mostly from Asia. CONCLUSIONS: Biliary drainage in complex malignant hilar obstruction due to cholangiocarcinoma is more likely to be successful and less likely to cause adverse events in curative patients compared to palliative patients.

An alternative method in the diagnosis of intrabiliary lesions: Percutaneous endobiliary brush biopsy.

Background and Aim: Biliary strictures can occur as a result of various benign or malignant processes. The aim of this study is to evaluate the effectiveness and reliability of percutaneous endobiliary brush biopsy in the diagnosis of intrabiliary lesions. Materials and Methods: This retrospective, single-center study was conducted between January 2022 and April 2023, involving a total of 16 patients. Of the patients, 10 were male (62.5%), and 6 were female (37.5%). The average age of the patients was 68.1±8. All patients underwent the procedure using an endobiliary biopsy brush under ultrasound and fluoroscopic guidance. Results: Technical success was achieved in all patients (100%). Cell detection was not observed in biopsy samples from 2 patients (12.5%), resulting in a diagnostic success rate of 87.5%. Access was made to the right biliary system in 14 patients (87.5%) and to the left biliary system in 2 patients (12.5%). Biopsy locations included the common bile duct in 12 patients (75%), hepatic hilum in 2 patients (12.5%), and bilioenteric anastomosis line in 2 patients (12.5%). The mean fluoroscopy time was 16.2±7.1 minutes. The average radiation dose was 660±370 mSv. Pathological diagnosis revealed malignancy in 8 patients (50%) and benign findings in 6 patients (37.5%). Liver abscess requiring drainage developed in 2 patients (12.5%). Conclusion: Percutaneous endobiliary brush biopsy performed under imaging guidance is an effective and reliable method for the diagnosis of biliary lesions.

Presence of cholestasis and its impact on survival in SARS-CoV-2 associated acute respiratory distress syndrome.

Data on cholestasis and biliary injury in patients with COVID-19 are scarce. The primary aim of this study was to evaluate the prevalence of cholestasis and factors associated with its development and outcome in critically ill patients with COVID-19 associated acute respiratory distress syndrome (ARDS). In this retrospective exploratory study, COVID-19 patients with ARDS admitted to an intensive care unit (ICU) at the Medical University of Vienna were evaluated for the development of cholestasis defined as an alkaline phosphatase level of 1.67x upper limit of normal for at least three consecutive days. Simple and multiple logistic regression analysis was used to evaluate parameters associated with development of cholestasis and survival. Of 225 included patients 119 (53%) developed cholestasis during ICU stay. Patients with cholestasis had higher peak levels of alkaline phosphatase, gamma-glutamyl transferase, bilirubin and inflammation parameters. Factors independently associated with cholestasis were extracorporeal membrane oxygenation support, ketamine use, high levels of inflammation parameters and disease severity. Presence of cholestasis and peak ALP levels were independently associated with worse ICU and 6-month survival. Development of cholestasis is a common complication in critically ill COVID-19 patients and represents a negative prognostic marker for survival. It is associated with disease severity and specific treatment modalities of intensive care.

Vanishing Bile Duct Syndrome: A Differential Diagnosis for Painless Jaundice.

Vanishing bile duct syndrome (VBDS) is a clinicopathological term coined to describe an acquired liver disease characterised by progressive destruction and disappearance of intrahepatic biliary ducts. We report the case of a 69-year-old female who presented with painless jaundice, fatigue, and weight loss. Initial blood workup revealed hyperbilirubinemia, transaminitis, elevated alkaline phosphatase, and a raised international normalised ratio. Para-aortic lymphadenopathy on computed tomography of the abdomen was biopsied to confirm the diagnosis of Hodgkin's lymphoma. Vanishing bile duct syndrome is a paraneoplastic phenomenon of Hodgkin's lymphoma, a recognised cause of cholestatic jaundice, and our patient's liver biopsy was diagnostic of the same. Despite treatment with steroids, ursodeoxycholic acid, and chemotherapy, our patient passed away. This case report aims to highlight VBDS as a differential diagnosis for painless jaundice in the context of cholestatic liver dysfunction. We believe reporting such cases irrespective of their outcome will help raise awareness of VBDS among clinicians, thus bettering the rate at which it is diagnosed and treated, thereby improving patient outcomes.

Comprehensive Analysis of scRNA-Seq and Bulk RNA-Seq Reveals Transcriptional Signatures of Macrophages in Intrahepatic Cholestasis of Pregnancy.

Purpose: Intrahepatic cholestasis of pregnancy (ICP) is a disorder that characterized by maternal pruritus, abnormal liver function, and an elevation in total bile acid concentrations during pregnancy. Immune factors have been recognized as playing a vital role in the mechanism of ICP. However, the underlying mechanisms regulating dysfunctional immune cells and immune genes remain to be fully elucidated. Patients and Methods: Single-cell RNA sequencing and bulk RNA sequencing data of the placenta were downloaded from the SRA database. The AUCell package, Monocle package and SCENIC package were utilized to explored immune cell activity, cell trajectory and transcription factor, respectively. GO, KEGG, and GSEA were employed to explore potential biological mechanisms. Cell-cell communications were further investigated using the CellChat package. RT-PCR, and Western blot were used to verify the gene expression in placenta. Results: In placenta cells, macrophages were found to be significantly increased in ICP. Additionally, macrophages exhibited the highest immune gene score and were divided into four subclusters (MF1-4). Our analysis revealed significant elevations in MF2, associated with LPS response and antigen presentation, and MF4, associated with TNF and cytokine production. MF3 displayed an anti-inflammatory phenotype. MF1, closely related to ribosomes and proteins, exhibited a sharp decrease. Although ICP maintained an anti-inflammatory state, macrophage trajectories showed a gradual progression toward inflammation. Subsequently, we confirmed that cytokine- and chemokine-related signaling pathways were emphasized in macrophages. Within the CXCL signaling pathway, the increased expression of CXCL1 in macrophages can interact with CXCR2 in neutrophils, potentially inducing macrophage infiltration, stimulating neutrophil chemotaxis, and leading to an inflammatory response and cellular damage. Conclusion: In conclusion, we firstly revealed the transcriptional signatures of macrophages in ICP and discovered a tendency toward an inflammatory state. This study also provides new evidence that the CXCL1-CXCR2 axis may play an important role in the pathogenesis of ICP.

Safety and Efficacy of a Composite Lipid Emulsion with Fish Oil in Hospitalized Neonates and Infants Requiring Prolonged Parenteral Nutrition - A Randomized, Double-Blind, Multicenter, Controlled Trial.

BACKGROUND: Intravenous lipids are critical to the care of extremely premature and other high-risk infants. OBJECTIVE: The study evaluated safety and efficacy of parenteral nutrition (PN) with composite intravenous lipid emulsion (CO-ILE) with fish oil compared to pure soybean oil lipid emulsion (SOLE). METHODS: Randomized, controlled, double-blind, multicenter study (NCT02579265) in neonates/ infants anticipated to require ≥28 days of PN due to gastrointestinal malformations or injury. Duration of the initial and extended treatment phase was 28 days and 84 days (for patients with PN indication after day 28). RESULTS: 83/ 78 patients (mean postnatal age: 11.4/ 8.3 days, 54/ 59 preterm) received CO-ILE and SOLE, respectively. 33 patients per group completed 28 days on treatment. Risk of having conjugated bilirubin values > 2 mg/dL confirmed by a second sample 7 days after the first during the initial treatment phase (primary outcome) was 2.4% (2 of 83) with CO-ILE and 3.8% (3 of 78) with SOLE (risk ratio 0.59 [95% CI: 0.09, 3.76]). Between days 29 and 84, the number of patients with confirmed conjugated bilirubin values > 2 mg/dL did not increase in the CO-ILE group (n=2) and increased in the SOLE group (n=9). At the end of the initial treatment phase, conjugated bilirubin concentrations were 45.6% lower under CO-ILE than under SOLE (p=0.006). There was no clinical or laboratory evidence of essential fatty acid deficiency in patients in the CO-ILE group. Median time to discharge alive was 56.7 and 66.4 days with CO-ILE and SOLE, respectively (hazard ratio: 1.16; 95% CI: 0.81, 1.68). CONCLUSIONS: CO-ILE was associated with a possible lower risk of cholestasis and significantly lower conjugated bilirubin at the end of the initial treatment phase in high-risk neonates and infants as compared to patients treated with SOLE. In summary, these data indicate that CO-ILE can be considered safe and may be preferable over SOLE in high-risk neonates. CLINICAL TRIAL REGISTRY NUMBER: Clinicaltrials.gov, study ID NCT02579265.

Arsenic and young liver: a case report of hepatic steatosis due to arsenic toxicity.

Arsenic toxicity is rare in developed countries. It may be difficult to diagnose due to its heterogenous symptom presentation. We present a case of severe hepatic steatosis and cholestatic hepatitis associated with arsenic toxicity in an adult.

Are Systemic Inflammation Markers Reliable for Diagnosing Intrahepatic Cholestasis of Pregnancy? A Retrospective Cohort Study.

PROBLEM: This study aims to evaluate the effectiveness of inflammation indexes (systemic immune-inflammation index [SII], systemic inflammation response index [SIRI], pan-immune inflammation value [PIV], and neutrophil-to-lymphocyte ratio [NLR]) in the diagnosis of intrahepatic cholestasis of pregnancy (ICP). METHOD OF STUDY: A retrospective study was conducted, reviewing medical records of patients diagnosed with ICP who delivered between October 1, 2022, and May 31, 2023, at the Perinatology clinic of Etlik City Hospital, Ankara. A control group of healthy pregnant women with uncomplicated pregnancies was also included. Demographic data, clinical characteristics, and laboratory results, including systemic inflammation indices and liver enzyme levels, were collected and analyzed. RESULTS: A total of 242 participants were included, with 121 ICP patients and 121 controls. White blood cell count, neutrophil count, and monocyte count showed significant differences between the two groups (p = 0.011, p = 0.004, and p = 0.039, respectively). Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels were significantly elevated in the ICP group (p < 0.001 for both). SII and NLR were higher in the ICP group compared to controls (p = 0.032 and p = 0.010, respectively). Receiver operating characteristic (ROC) analysis revealed moderate predictive values for SII (area under the curve [AUC] = 0.581, p = 0.030) and NLR (AUC = 0.598, p = 0.009), with no significant difference in their predictive power (p = 0.502). CONCLUSIONS: Systemic inflammation indices such as SII and NLR offer a cost-effective and rapid means of diagnosing ICP, potentially complementing or surpassing traditional biomarkers like bile acid levels and liver function tests (LFTs). These indices can be easily integrated into routine clinical practice, providing timely intervention to improve maternal and fetal outcomes. Further research is warranted to confirm these findings and establish standardized protocols for their use in ICP management.

Paclitaxel chemotherapy disrupts microbiota-enterohepatic bile acid metabolism in mice.

Balanced interactions between the enteric microbiota and enterohepatic organs are essential to bile acid homeostasis, and thus normal gastrointestinal function. Disruption of these interactions by cancer treatment instigates bile acid malabsorption, leading to treatment delays, malnutrition, and decreased quality of life. However, the nature of chemotherapy-induced bile acid malabsorption remains poorly characterized with limited treatment options. Therefore, this study sought to characterize changes in hepatic, enteric, and microbial bile acid metabolism in a mouse model of chemotherapy-induced toxicity. Consistent with clinical bile acid malabsorption, chemotherapy increased fecal excretion of primary bile acids and water, while diminishing microbiome diversity, secondary bile acid formation, and small intestinal bile acid signaling. We identified new contributors to pathology of bile acid malabsorption in the forms of lipopolysaccharide-induced cholestasis and colonic crypt hyperplasia from reduced secondary bile acid signaling. Chemotherapy reduced markers of hepatic bile flow and bile acid synthesis, elevated markers of fibrosis and endotoxemia, and altered transcription of genes at all stages of bile acid metabolism. Primary hepatocytes exposed to lipopolysaccharide (but not chemotherapy) replicated chemotherapy-induced transcriptional differences, while gut microbial transplant into germ-free mice replicated very few differences. In the colon, chemotherapy-altered bile acid profiles (particularly higher tauromuricholic acid and lower hyodeoxycholic acid) coincided with crypt hyperplasia. Exposing primary colonoids to hyodeoxycholic acid reduced proliferation, while gut microbiota transplant enhanced proliferation. Together, these investigations reveal complex involvement of the entire microbiota-enterohepatic axis in chemotherapy-induced bile acid malabsorption. Interventions to reduce hepatic lipopolysaccharide exposure and enhance microbial bile acid metabolism represent promising co-therapies to cancer treatment.

Endoscopic ultrasound-guided biliary drainage after failed endoscopic retrograde cholangiopancreatography: The road is open for almighty biliopancreatic endoscopists!

Commentary on the article written and published by Peng et al, investigating the role of endoscopic ultrasound (EUS)-guided biliary drainage for palliation of malignant biliary obstruction after failed endoscopic retrograde cholangiopancreatography (ERCP). For 40 years endoscopic biliary drainage was synonymous with ERCP, and EUS was used mainly for diagnostic purposes. The advent of therapeutic EUS has revolutionized the field, especially with the development of a novel device such as electrocautery-enhanced lumen-apposing metal stents. Complete biliopancreatic endoscopists with both skills in ERCP and in interventional EUS, would be ideally suited to ensure patients the best drainage technique according to each individual situation.

Hepatic bile acid accretion correlates with cholestatic liver injury and therapeutic response in Cyp2c70 knockout mice with a humanized bile acid composition.

Cyp2c70 knockout (KO) mice lack the liver enzyme responsible for synthesis of 6-hydroxylated muricholate bile acid species and possess a more hydrophobic human-like bile acid composition. Cyp2c70 KO mice develop cholestatic liver injury that can be prevented by administration of an ileal bile acid transporter (IBAT) inhibitor. In this study, we investigated the potential of an ileal bile acid transporter (IBAT) inhibitor (SC-435) and steroidal FXR agonist (cilofexor) to modulate established hepatobiliary injury and the consequent relationship of intrahepatic bile acid content and hydrophobicity to the cholestatic liver injury phenotype. Oral administration of SC-435, cilofexor, or combined treatment for 2 weeks markedly reduced serum markers of liver injury and improved histological and gene expression markers of fibrosis, liver inflammation, and ductular reaction in male and female Cyp2c70 KO mice, with greatest benefit in the combination treatment group. The IBAT inhibitor and FXR agonist significantly reduced intrahepatic bile acid content but not hepatic bile acid pool hydrophobicity, and markers of liver injury were strongly correlated with intrahepatic total bile acid and taurochenodeoxycholic acid accretion. Biomarkers of liver injury increased linearly with similar hepatic thresholds for pathological accretion of hydrophobic bile acids in male and female Cyp2c70 KO mice. These findings further support targeting intrahepatic bile acid retention as a component of treatments for cholestatic liver disease.

Pregnancy cholestasis typically occurs in the third trimester of pregnancy and is a significant clinical condition.

AIM: The aim of this study is to determine the albumin/bilirubin ratio index and the aspartate aminotransferase (AST)/alanine aminotransferase ratio (ALT) index in patients diagnosed with cholestasis during pregnancy, and to demonstrate their correlation with liver damage. Additionally, potential strategies to prevent liver damage will be elucidated. MATERIALS AND METHOD: Our study is a retrospective study. A total of 4019 pregnant women aged between 18 and 40 years, presenting with itching complaints at 32-36 weeks of gestation, were screened at the Department of Obstetrics and Gynecology, Istanbul Training and Research Hospital of Health Sciences University between January 1, 2018, and December 31, 2023. Among them, 104 pregnant women without any other accompanying diseases were diagnosed with Gestational Cholestasis. Among the 104 diagnosed women, 78 met the inclusion criteria and were included in the study. Twenty-six women were excluded from the study due to missing albumin and total bilirubin values or due to blood samples being taken at different times. The serum albumin/bilirubin ratio index and the alanine aminotransferase/aspartate aminotransferase ratio index were calculated and statistically compared between pregnant women diagnosed with cholestasis and healthy pregnant women at the same gestational week. FINDINGS: We found that AST, ALT, albumin, and total bilirubin levels were significantly higher in pregnant women diagnosed with cholestasis compared to the control group (p < 0.05). The AST/ALT index in the case group was significantly lower compared to the control group. However, there were no significant differences found between the case and control groups regarding the albumin/total bilirubin index and ALBI grade. When comparing ALBI grades in cases, no significant differences were found in terms of patients' age, gestational week, AST, ALT, and AST/ALT index. When compared according to ALBI grades, the albumin level was higher in patients with ALBI grade I compared to grade II, and in patients with grade II compared to grade III. The total bilirubin level was significantly higher in patients with ALBI grade III compared to grades I and II, but there was no significant difference between grades I and II. No significant differences were found among the groups separated according to ALBI grades when FBA values were compared. CONCLUSION: In this study, the negative correlation between lower AST/ALT ratio and FBA values in patients with severe cholestasis suggests the need for careful consideration regarding future liver damage. The lack of difference in ALBI score between the case and control groups, as well as the absence of correlation with FBA values, indicates the necessity to evaluate ALBI score based on patients' long-term prognosis.

Parenteral nutrition results in peripheral ileal to hepatic circadian discordance in mice.

BACKGROUND: We have developed a mouse model of Parenteral Nutrition Associated Liver Disease in which PN infusion results in cholestatic liver injury. In the liver, the master circadian genes Arntl/Bmal drive rhythmic gene expression and regulate circadian expression of hepatic functions including bile acid synthesis. The aim of this study was to examine the effect of continuous PN on ileal and hepatic expression of circadian regulatory (CR) genes, FXR signaling and bile acid synthesis in mice. METHODS: WT mice were exposed to continuous soy oil lipid emulsion-based PN infusion through a central venous catheter for 4 days (PN). Water was provided ad libitum, but no nutrients were provided enterally. On d4, mice were sacrificed every 6 hours (7AM, 1PM, 7PM and 1AM), and ileal, hepatic tissue and serum harvested. From tissue samples, the relative expression of circadian transcription factors and FXR signaling was assessed. RESULTS: Administration of 4d PN increased hepatic injury, inflammatory cytokine expression and gut permeability. In the ileum, PN activated FXR and induced expression of Fgf15 and Nr0b2. In the liver, expression of FXR-downstream targets was dysregulated. PN administrations impacted hepatic and ileal circadian transcription factor mRNA expression which was discordant between the two organs. CONCLUSIONS: Dysregulation of circadian regulatory machinery is in part due to discordance of the gut-liver axis during PN. Pharmacologic targeting of CR as a therapeutic strategy for PNALD thus deserves further investigation.

Syphilitic hepatitis in infants, the forgotten disease that hepatologists have to brush up on: from a case series to a revision of literature.

Clinical manifestations of congenital syphilis (CS) include liver disease with/without impaired liver function, identified as syphilitic hepatitis. Hepatic involvement may be dramatic; therefore, early diagnosis is crucial to provide treatment and prevent fatal outcomes. A new resurgence of CS cases has been described in recent years worldwide. We reported our experience with a case series of infants hospitalized for liver disease with a final diagnosis of CS, highlighting the wide spectrum of liver involvement, the rapid progression in cases with late diagnosis, and the pitfalls of the management of this forgotten but reemerging disease. A retrospective analysis of CS patients with hepatic presentation in the period 2008-2023 was conducted. We collected five cases (three female) with a median age of 13.8 days (range 1-84 days). In three cases, mothers were not screened for syphilis during pregnancy, and in two cases, they were seronegative in the first trimester screening. None practiced specific therapy during pregnancy. Hepatic involvement was characterized by hepatosplenomegaly, in four cases associated with cholestatic jaundice and in three cases with liver failure. Rapid plasma reagin (RPR) and Treponema pallidum hemagglutination assay (TPHA) were positive in all cases in mothers and infants. CS presented with multiorgan involvement and was fatal in one case.Conclusions: It is important to consider CS in infants with cholestasis and acute liver failure, but also in sick infants with isolated hepatomegaly. Early recognition of infants with CS is critical to identify missed cases during pregnancy and to start early treatment.

L-Glutamine mitigates bile acid-induced inhibition of growth factor activity in rat hepatocyte cultures.

Bile acid-induced hepatotoxicity is inevitable in Cholestasis pathogenesis and L-Glutamine (L-Gln) has been reported to prevent total parenteral nutrition (TPN)-induced cholestasis in premature neonates. While mechanisms remain unknown, we hypothesize that bile acids impair growth factor (GF) function in hepatocytes which L-glutamine prevents through NAPDH oxidase (NOX) modulation. Glycochenodeoxycholic acid (GCDC, 0-100 µM) when added to primary hepatocyte cultures significantly (p < 0.01) decreased the FBS-induced BrdU incorporation, however inhibition of Fibroblast Growth factor (FGF)- or Hepatocyte growth factor (HGF)-induced DNA synthesis was more pronounced (p < 0.001). L-Gln markedly attenuated GCDC-mediated inhibition of DNA synthesis in both FBS and GF-treated cells. GCDC significantly increased the NADPH oxidase activity and NOX-1 protein expression that were markedly reduced by L-Gln and protein kinase c (PKC) inhibitor, LY-333531. Apocynin (APCN) and diphenyliodonium (DPI) significantly blocked the GCDC-mediated inhibition of GF-induced DNA synthesis. This study demonstrates that bile acid-induced hepatotoxicity involves dysfunction of certain growth factors via protein kinase c (PKC)- mediated NOX modulation which can be corrected, at least partly, by L-glutamine.

Hepatocellular carcinoma associated with progressive intrahepatic familial cholestasis type 2: a case report.

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is an autosomal recessive disorder typically presenting in infancy with cholestasis and rapidly progressing to cirrhosis. PFIC has been associated with an elevated risk of hepatocellular carcinoma (HCC), a neoplasm that is uncommon in children. PFIC type 4 has the strongest link to this type of cancer, although a few cases have also been connected to PFIC2. Herein, we report the case of a 2-year-old boy who underwent liver transplantation due to PFIC2. Histological examination showed cirrhosis and four small HCCs. Over a 20-year period following the transplantation, there was no recurrence of the disease or HCC. Although rare, HCC development can occur in PFIC and may complicate the prognosis. Liver transplantation offers a potential cure for both the metabolic disease and the neoplasm.

Protective effects of cilostazol via the HNF1α/FXR signalling pathway and anti-apoptotic mechanisms in a rat model of estrogen-induced intrahepatic cholestasis.

Currently, there is a lack of targeted medications for estrogen-induced intrahepatic cholestasis (EIC) and the primary objective in managing this condition is to safeguard liver function. Consequently, this study was conducted to examine the pharmacological efficacy of cilostazol (CTZ) in the management of EIC and explore its underlying mechanisms through the use of an animal model. Thirty female Sprague-Dawley rats were divided into five groups of six animals each: Normal group, 17-ethinylestradiol (EE)-induced intrahepatic cholestasis group, EE + ursodeoxycholic acid (UDCA)-treated group, EE + CTZ (5 mg/kg)-treated group, and EE + CTZ (10 mg/kg)-treated group. It was found that the therapeutic efficacy of UDCA and low dosage of CTZ (5 mg/kg) was comparable. Nevertheless, when CTZ was administered at a dose of 10 mg/kg, it resulted in the normalization of all liver function parameters, oxidative stress, and pro-inflammatory markers, together with improvement in the histopathological derangements and hepatocytic apoptosis. These effects were mediated through the activation of the hepatocyte nuclear factor-1 alpha (HNF1α)/Farnesoid X receptor (FXR) pathway with subsequent down-regulation of the bile acids (BAs) synthesis enzyme; cholesterol 7α-hydroxylase (CYP7A1), and up-regulation of the BAs-metabolizing enzyme; cytochrome P450 (CYP)3A1 and the bile salt export pump; BSEP. Therefore, the administration of CTZ in a dose-dependent manner can protect against EIC through regulating the HNF1α/FXR pathway and anti-apoptotic mechanisms. This implies that CTZ exhibits considerable promise as a therapeutic agent for the treatment of cholestatic liver disorders.

Current Landscape and Evolving Therapies for Primary Biliary Cholangitis.

Primary Biliary Cholangitis (PBC) is a chronic autoimmune liver disorder characterized by progressive cholestatic that, if untreated, can progress to liver fibrosis, cirrhosis and liver decompensation requiring liver transplant. Although the pathogenesis of the disease is multifactorial, there is a consensus that individuals with a genetic predisposition develop the disease in the presence of specific environmental triggers. A dysbiosis of intestinal microbiota is increasingly considered among the potential pathogenic factors. Cholangiocytes, the epithelial cells lining the bile ducts, are the main target of a dysregulated immune response, and cholangiocytes senescence has been recognized as a driving mechanism, leading to impaired bile duct function, in disease progression. Bile acids are also recognized as playing an important role, both in disease development and therapy. Thus, while bile acid-based therapies, specifically ursodeoxycholic acid and obeticholic acid, have been the cornerstone of therapy in PBC, novel therapeutic approaches have been developed in recent years. In this review, we will examine published and ongoing clinical trials in PBC, including the recently approved peroxisome-proliferator-activated receptor (PPAR) agonist, elafibranor and seladelpar. These novel second-line therapies are expected to improve therapy in PBC and the development of personalized approaches.

Regulation of intestinal senescence during cholestatic liver disease modulates barrier function and liver disease progression.

Background & Aims: Senescence has been reported to have differential functions in cholangiocytes and hepatic stellate cells (HSCs) during human and murine cholestatic disease, being detrimental in biliary cells and anti-fibrotic in HSCs. Cholestatic liver disease is associated with loss of intestinal barrier function and changes in the microbiome, the mechanistic cause of which is undetermined. Methods: Intestinal samples were analysed from controls and patients with primary sclerosing cholangitis, as well as wild-type (WT) and p16-3MR transgenic mice. Cholestatic liver disease was induced by bile duct ligation (BDL) and DDC diet feeding. Fexaramine was used as an intestinal-restricted FXR agonist and antibiotics were given to eliminate the intestinal microbiome. Senescent cells were eliminated in p16-3MR mice with ganciclovir and in WT mice with the senolytic drug ABT-263. In vitro studies were done in intestinal CaCo-2 cells and organoids were generated from intestinal crypts isolated from mice. Results: Herein, we show increased senescence in intestinal epithelial cells (IECs) in patients with primary sclerosing cholangitis and in mice after BDL and DDC diet feeding. Intestinal senescence was increased in response to reduced exposure to bile acids and increased presence of lipopolysaccharide in vitro and in vivo during cholestatic liver disease. Senescence of IECs was associated with lower proliferation but increased intestinal stem cell activation, as supported by increased organoid growth from intestinal stem cells. Elimination of senescent cells with genetic and pharmacological approaches exacerbated liver injury and fibrosis during cholestatic liver disease, which was associated with increased IEC apoptosis and permeability. Conclusions: Senescence occurs in IECs during cholestatic disease and the elimination of senescent cells has a detrimental impact on the gut-liver axis. Our results point to cell-specific rather than systemic targeting of senescence as a therapeutic approach to treat cholestatic liver disease. Impact and implications: Cholestatic liver disease associates with the dysregulation of intestinal barrier function, while the mechanisms mediating the disruption of the gut-liver axis remain largely undefined. Here, we demonstrate that senescence, a cellular response to stress, is activated in intestinal cells during cholestatic liver disease in humans and mice. Mechanistically, we demonstrate that the reduction of bile acids and the increased presence of bacterial products mediate the activation of intestinal senescence during cholestatic liver disease. Importantly, the elimination of these senescent cells promotes further damage to the intestine that aggravates liver disease, with increased tissue damage and fibrosis. Our results provide evidence that therapeutic strategies to treat cholestatic liver disease by eliminating senescent cells may have unwanted effects in the intestine and support the need to develop cell/organ-specific approaches.