Clinical symptoms, biochemistry, and liver histology during the native liver period of progressive familial intrahepatic cholestasis type 2.

BACKGROUND: Progressive familial intrahepatic cholestasis type 2 (PFIC2) is an ultra-rare disease caused by mutations in the ABCB11 gene. This study aimed to understand the course of PFIC2 during the native liver period. METHODS: From November 2014 to October 2015, a survey to identify PFIC2 patients was conducted in 207 hospitals registered with the Japanese Society of Pediatric Gastroenterology, Hepatology, and Nutrition. Investigators retrospectively collected clinical data at each facility in November 2018 using pre-specified forms. RESULTS: Based on the biallelic pathogenic variants in ABCB11 and/or no hepatic immunohistochemical detection of BSEP, 14 Japanese PFIC2 patients were enrolled at seven facilities. The median follow-up was 63.2 [47.7-123.3] months. The median age of disease onset was 2.5 [1-4] months. Twelve patients underwent living donor liver transplantation (LDLT), with a median age at LDLT of 9 [4-57] months. Two other patients received sodium 4-phenylbutyrate (NaPB) therapy and survived over 60 months with the native liver. No patients received biliary diversion. The cases that resulted in LDLT had gradually deteriorated growth retardation, biochemical tests, and liver histology since the initial visit. In the other two patients, jaundice, growth retardation, and most of the biochemical tests improved after NaPB therapy was started, but pruritus and liver fibrosis did not. CONCLUSIONS: Japanese PFIC2 patients had gradually worsening clinical findings since the initial visit, resulting in LDLT during infancy. NaPB therapy improved jaundice and growth retardation but was insufficient to treat pruritus and liver fibrosis.

Intrahepatic Cholangiolitis in Cystic Fibrosis (ICCF): An Under-Appreciated Cause of Persistent Cholestasis in Infancy.

Liver histology in infants with cystic fibrosis (CF) and persistent cholestasis is seldom reported in detail. We extend previous observation of a distinctive intrahepatic cholangiopathy (ICCF) to 3 additional infants homozygous for CFTR pathological variants and a fourth infant with a heterozygous CFTR variant, summarizing our experience in 10 infants with CFTR variants and persistent cholestasis. Cholangiograms demonstrate abnormal extrahepatic ducts in 2 infants with CF, 1 with uniform dilatation interpreted as a choledochal cyst and the other with narrow patent ducts. Liver histology in 3 CF homozygotes had prominent ductular reaction with a focally destructive cholangiolitis (inflammation of small bile ducts). The CFTR heterozygote had generalized portal edema with ductular reaction and paucity but no cholangitis. Cholestasis slowly subsided in all infants. ICCF is characterized by severe ductular reaction, prominent cholangiocyte injury, and multifocal necrotizing cholangiolitis. Local aggregates of portal ceroid might suggest previous bile leakage from damaged ducts. ICCF in liver biopsies from infants with cystic fibrosis and persistent cholestasis is unrelated to the specific CFTR genotype. Liver biopsy findings and intraoperative cholangiogram help rule out biliary atresia. ICCF is an early manifestation of CF, a likely prototype for pathogenesis of cystic fibrosis liver disease later in life.

Engineered FGF19ΔKLB protects against intrahepatic cholestatic liver injury in ANIT-induced and Mdr2-/- mice model.

BACKGROUND: The major safety concern of the clinical application of wild type FGF19 (FGF19WT) emerges given that its extended treatment causes hepatocellular carcinoma. Therefore, we previously generated a safer FGF19 variant - FGF19ΔKLB, which have same effects on glycemic control and bile acid production but much less mitogenic activity. However, it remains unclear as to whether FGF19ΔKLB ameliorates intrahepatic cholestasis. RESULTS: We found that, similar to that of FGF19WT, the chronic administration of FGF19ΔKLB protects mice from cholestatic liver injury in these two models. The therapeutic benefits of FGF19ΔKLB on cholestatic liver damage are attributable, according to the following mechanistic investigation, to the reduction of BA production, liver inflammation, and fibrosis. More importantly, FGF19ΔKLB did not induce any tumorigenesis effects during its prolonged treatment. CONCLUSIONS: Together, our findings raise hope that FGF19ΔKLB may represent a useful therapeutic strategy for the treatment of intrahepatic cholestasis.

Body mass index implications in intrahepatic cholestasis of pregnancy and placental histopathological alterations.

INTRODUCTION AND OBJECTIVES: Intrahepatic cholestasis is a frequent disease during pregnancy. It is unknown if liver function alterations produce specific placental lesions. The aim of this study was to evaluate placental histopathological changes in patients with intrahepatic cholestasis of pregnancy (ICP), and to explore correlations between the placental histopathology and hepatic function alteration or patient comorbidities, and body mass index. PATIENTS AND METHODS: A retrospective cohort study included women with ICP, most of them showing comorbidities such as overweight/obesity, preeclampsia and gestational diabetes. They were attended at the National Institute of Perinatology in Mexico City for three years. Placental histopathological alterations were evaluated according to the Amsterdam Placental Workshop Group Consensus Statement. Data was analyzed using Graph-Pad Prism 5. RESULTS: The results indicated that the placenta of ICP patients showed many histopathological alterations; however, no correlations were observed between the increase in bile acids or liver functional parameters and specific placental lesions. The most frequent comorbidities found in ICP patients were obesity, overweight and preeclampsia. Surprisingly, high percentage of ICP patients did not respond to UDCA treatment independently of the BMI group to which they belonged. CONCLUSION: The data suggest that ICP contribute to placental lesions. In addition, in patients with normal weight, an increase of chorangiosis and a reduced accelerated villous maturation without syncytial knots were observed in comparison with overweight and obese patients. It is necessary to improve the medical strategies in the treatment and liver disfunction surveillance of ICP patients.

Congenital Bile Acid Synthesis Defect Type 3 With Severe Neonatal Cholestasis.

Congenital bile acid synthesis defect type 3 is a rare metabolic liver disease with only eight patients reported in literature. We describe clinical, pathological and molecular features for a ninth patient. A 4-month-old infant presented to us with conjugated hyperbilirubinemia. His liver biopsy revealed giant cell change, steatosis, and activity with diffuse fibrosis. Immunostaining with bile salt export pump showed preserved canalicular pattern and γ-glutamyl transferase 1 staining showed unusual complete membranous pattern. Genetic workup revealed homozygous single base pair duplication in exon 3 of the CYP7B1 gene. He succumbed to liver disease at 7 months of age.

Antisense oligonucleotides rescue an intronic splicing variant in the ABCB11 gene that causes progressive familial intrahepatic cholestasis type 2.

BACKGROUND: Progressive familial intrahepatic cholestasis type 2 (PFIC2) is a rare disorder caused by variants in the ABCB11 gene encoding the bile salt export pump (BSEP). We investigated the molecular defect in a PFIC2 infant and rescued the splicing defect with antisense oligonucleotides (ASOs). METHODS: Whole-exome sequencing (WES) revealed compound heterozygous variants in the ABCB11 gene in a PFIC2 patient. Liver biopsy was immunostained for BSEP. The splicing effect of the candidate variants was investigated by minigene assay. ASOs were designed to rescue aberrant splicing. RESULTS: A Chinese girl of two nonconsanguineous healthy parents suffered from low glutamyl transpeptidase cholestasis and showed no response to the ursodeoxycholic acid. WES revealed that the patient was compound heterozygous for two novel variants in the ABCB11 gene: c.76+29T>G and c.390-2A>G. Liver immunohistochemistry showed the absence of BSEP. The variant c.76+29T>G was confirmed to retain 42 bp in the mature mRNA. The variant c.390-2A>G was confirmed to cause exon 6 skipping. We designed two ASOs and identified one of them that efficiently induced pseudoexon exclusion. CONCLUSION: We reported two novel variants of the ABCB11 gene, c.76+29T>G and c.390-2A>G, in a PFIC2 infant, thereby expanding the genotype of PFIC2. Our findings provide evidence for ASOs as a therapeutic approach for PFIC2 patients carrying intronic variants.

Circ_0060731 mediated miR-21-5p-PDCD4/ESR1 pathway to induce apoptosis of placental trophoblasts in intrahepatic cholestasis of pregnancy.

PURPOSE: Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy complication. However, the pathogenesis of ICP is currently unclear. METHODS: We analyzed the placenta samples of 10 normal and 10 ICP pregnant women. the expressions of circ0060731, miR-21-5p, and their downstream target genes PDCD4, ESR1, and apoptotic protein cleaved-caspase3 were detected in the cell model. RESULTS: The expression of Circ_0060731, PDCD4, ESR1, and caspase-3 was higher in the ICP placenta tissue than in the control group, and the expression of miR-21-5p was lower in the ICP group than in the control group. In HTR8/Svneo cells treated with TCA, the expression/levels of Circ_0060731, PDCD4, ESR1, and caspase-3 were significantly higher in the ICP group than in the control group, and miR-21-5p was significantly lower in the ICP group than in the control group. Lentiviral knockdown of miR-21-5p significantly increased the expressions of its downstream genes of PDCD4 and ESR1, and also increased cell apoptosis. Overexpression of miR-21-5p significantly reduced the expression of PDCD4 and ESR1 and reduced cell apoptosis. The dual-luciferase experiment showed that both PDCD4 and ERS1 were the target genes of miR-21-5p. CONCLUSION: Circ_0060731 mediated miR-21-5p-PDCD4/ESR1 pathway could induce apoptosis of placental trophoblasts in intrahepatic cholestasis of pregnancy.

Recognition of asymptomatic hypercholanemia of pregnancy: Different clinical features, fetal outcomes and bile acids metabolism from intrahepatic cholestasis of pregnancy.

OBJECTIVE: To explore the clinical features, fetal outcomes and serum bile acids (BAs) metabolism in asymptomatic hypercholanemia of pregnancy (AHP), as well as the comparison with those in intrahepatic cholestasis of pregnancy (ICP) and normal pregnancies. METHODS: A study containing 676 pregnant women was performed to investigate the clinical informations, routine biochemical features and obstetric outcomes of AHP by the comparison with ICP and normal pregnancies. Within the study subjects, 203 pregnant women received prospective determination for 55 serum individual BAs based on a validated UPLC-QTOF-MS/MS method. The differences in clinical features and serum BAs metabolism among the three groups were then investigated. RESULTS: The risk of adverse fetal outcomes in AHP (28.3%) was significantly higher than that in normal pregnancies (8.9%, p < 0.001), but lower than that in ICP group (52.1%, p < 0.001). Multivariate statistics analysis indicated a distinctive serum BAs metabolic profiling among the three groups (PLS-DA, R2Y = 0.580, Q2 = 0.537). Levels of serum BAs especially for deoxycholic acid species were found remarkably elevated in AHP as compared to those in ICP. CONCLUSIONS: AHP group had distinguished clinical features and serum BAs metabolism as compared to ICP group and normal pregnancies.

Intrahepatic Cholestasis, Refractory Epilepsy, Skeletal Dysplasia, Endocrine Failure, and Dysmorphic Features in a Child With a Monoallelic 2q24-32.2 Deletion Encompassing ABCB11.

We report a newborn who presented with multiple limb and facial anomalies, endocrine disorders, and progressively worsening low-GGT cholestasis. A liver biopsy revealed hepatocellular cholestasis with giant cell transformation. Immunohistochemical staining revealed complete absence of BSEP protein compared to control liver. A large 2q24-32.2 deletion leading to loss of 78 OMIM genes. Multiple structural anomalies, epilepsy and endocrine anomalies have been described with hemizygous loss of these genes. This deletion also resulted in complete heterozygous deletion of ABCB11, which encodes the bile salt export pump (BSEP). Genetic analysis did not reveal any pathogenic variants, deletions, or duplications in the other ABCB11 allele. A heterozygous variant in NR1H4, which causes the autosomal recessive progressive familial intrahepatic cholestasis type 5, was also detected. The possible explanations for the PFIC type 2 phenotype in heterozygous loss of ABCB11 include genetic modifiers or di-genic disease with a compound ABCB11 deletion and an NR1H4 missense variant; or undetected pathogenic variants in the other ABCB11 or NR1H4 alleles.

Liver pathology in pregnancy.

Liver dysfunction occurs in up to 3% of pregnancies and can be due to pregnancy-associated liver injury, exacerbation of pre-existing liver disease, or co-incident with pregnancy. The most common form of pregnancy-associated liver injury is intrahepatic cholestasis of pregnancy (ICP). This condition is typically benign and self-limited, but is associated with fetal morbidity and mortality with high levels of serum bile acids. Acute fatty liver of pregnancy (AFLP) and the hypertensive disorders of pregnancy (including pre-eclampsia, eclampsia, and hemolysis, elevated liver enzymes, and low platelets [HELLP] syndrome) are more commonly associated with maternal and fetal complications and may necessitate expedient delivery. Histologically, ICP shows nonspecific features of cholestasis, while AFLP and the hypertensive disorders have more characteristic histologic findings. While not a true liver disease, hyperemesis gravidarum can cause elevated liver enzymes. Pregnant patients are at increased risk of developing severe hepatitis E and herpesvirus infections, Budd-Chiari syndrome, and gallstones, and they may also experience worsening of known chronic liver disease. Mass lesions in pregnancy including hemangiomas, focal nodular hyperplasia, and hepatocellular adenomas and carcinomas can present unique challenges for diagnosis and management. This review will explore the pathophysiology, presentation, histologic features, and management of these conditions.

Placental Expression of Bile Acid Transporters in Intrahepatic Cholestasis of Pregnancy.

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-related condition characterized by increased maternal circulating bile acids (BAs) having adverse fetal effects. We investigated whether the human placenta expresses specific regulation patterns to prevent fetal exposition to harmful amounts of BAs during ICP. Using real-time quantitative PCR, we screened placentae from healthy pregnancies (n = 12) and corresponding trophoblast cells (n = 3) for the expression of 21 solute carriers and ATP-binding cassette transporter proteins, all acknowledged as BA- and/or cholestasis-related genes. The placental gene expression pattern was compared between healthy women and ICP patients (n = 12 each). Placental SLCO3A1 (OATP3A1) gene expression was significantly altered in ICP compared with controls. The other 20 genes, including SLC10A2 (ASBT) and EPHX1 (EPOX, mEH) reported for the first time in trophoblasts, were comparably abundant in healthy and ICP placentae. ABCG5 was undetectable in all placentae. Placental SLC10A2 (ASBT), SLCO4A1 (OATP4A1), and ABCC2 mRNA levels were positively correlated with BA concentrations in ICP. Placental SLC10A2 (ASBT) mRNA was also correlated with maternal body mass index. We conclude that at the transcriptional level only a limited response of BA transport systems is found under ICP conditions. However, the extent of the transcriptional response may also depend on the severity of the ICP condition and the magnitude by which the maternal BA levels are increased.

Liposome Extract of Stachys pilifera Benth Effectively Improved Liver Damage due to Bile Duct Ligation Rats.

Herbal medicines harbor essential therapeutic agents for the treatment of cholestasis. In this study, we have assessed the anticholestatic potential of Stachys pilifera Benth's (SPB's) hydroalcoholic extract encapsulated into liposomes using bile duct ligation- (BDL-) induced hepatic cholestasis in rats. Aspartate aminotransferase (AST), alanine aminotransferase (ALT), alkaline phosphatase (ALP), malondialdehyde (MDA), total thiol (T-SH) content, protein carbonyl (PCO), total bilirubin (TBIL), albumin (ALB), and nitric oxide (NO) metabolite levels were measured in either liver tissue or plasma to assess liver damage. Moreover, expression of proinflammatory cytokines (IL-1ß and TNF-α) and liver fibrosis markers (TGF-ß and SM-α) which are driving forces of many liver disorders was also determined. The activity of AST, ALT, and ALP was significantly enhanced in the BDL group in comparison to the control group; however, treatment with liposomal (SPB) hydroalcoholic extract significantly reduced AST and ALT's activity. Increases in MDA, TBIL, and NO levels and T-SH content due to BDL were restored to control levels by liposomal (SPB) hydroalcoholic extract treatment. Similarly, hepatic and plasma oxidative marker MDA levels, significantly enhanced by BDL, were significantly decreased by liposomal (SPB) hydroalcoholic extract treatment. Moreover, histopathological findings further demonstrated a significant decrease in hepatic damage in the liposomal (SPB) hydroalcoholic extract-treated BDL group. In addition, liposomal (SPB) hydroalcoholic extract treatment decreased the liver expression of inflammatory cytokines (IL-1ß, TNF-α) and liver fibrosis markers (TGF-ß and SM-α). Since liposomal (SPB) hydroalcoholic extract treatment alleviated the BDL-induced injury of the liver and improved the hepatic structure and function more efficiently in comparison to free SPB hydroalcoholic extract, probable liposomal (SPB) hydroalcoholic extract exhibits required potential therapeutic value in protecting the liver against BDL-caused oxidative injury.

The spectrum of Progressive Familial Intrahepatic Cholestasis diseases: Update on pathophysiology and emerging treatments.

The Progressive Familial Intrahepatic Cholestasis (PFIC) disease spectrum encompasses a variety of genetic diseases that affect the bile production and the secretion of bile acids. Typically, the first presentation of these diseases is in early childhood, frequently followed by a severe course necessitating liver transplantation before adulthood. Except for transplantation, treatment modalities have been rather limited and frequently only aim at the symptoms of cholestasis, such as cholestatic pruritus. In recent years, progress has been made in understanding the pathophysiology of these diseases and new treatment modalities have been emerging. Herewith we summarize the latest developments in the field and formulate the current key questions and opportunities for further progress.

Tight junction stabilization prevents HepaRG cell death in drug-induced intrahepatic cholestasis.

Entacapone (ENT), a catechol-O-methyltransferase inhibitor, causes liver injury by inducing bile canaliculi (BC) dilation through inhibition of the myosin light kinase pathway. Loss of tight junctions (TJs) induces hepatocyte depolarization, which causes bile secretory failure, leading to liver damage. To understand the influence of TJ structural changes as a consequence of BC dynamics, we compared the datasets of time-lapse and immunofluorescence images for TJ protein ZO-1 in hepatocytes cultured with ENT, forskolin (FOR), ENT/FOR, and those cultured without any drugs. Retrospective analysis revealed that the drastic change in BC behaviors caused TJ disruption and apoptosis in cells cultured with ENT. Exposure to FOR or sodium taurocholate facilitated TJ formation in the cells cultured with ENT and suppressed BC dynamic changes, leading to the inhibition of TJ disruption and apoptosis. Our findings clarify that hepatocyte TJ stabilization protects against cell death induced by BC disruption.

Fibrotic Events in the Progression of Cholestatic Liver Disease.

Cholestatic liver diseases including primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are associated with active hepatic fibrogenesis, which can ultimately lead to the development of cirrhosis. However, the exact relationship between the development of liver fibrosis and the progression of cholestatic liver disease remains elusive. Periductular fibroblasts located around the bile ducts seem biologically different from hepatic stellate cells (HSCs). The fibrotic events in these clinical conditions appear to be related to complex crosstalk between immune/inflammatory mechanisms, cytokine signalling, and perturbed homeostasis between cholangiocytes and mesenchymal cells. Several animal models including bile duct ligation (BDL) and the Mdr2-knockout mice have improved our understanding of mechanisms underlying chronic cholestasis. In the present review, we aim to elucidate the mechanisms of fibrosis in order to help to identify potential diagnostic and therapeutic targets.

Dolomiaea souliei ethyl acetate extract protected against α-naphthylisothiocyanate-induced acute intrahepatic cholestasis through regulation of farnesoid x receptor-mediated bile acid metabolism.

BACKGROUND: Cholestasis is characterized by accumulation of bile components in liver and systemic circulation. Restoration of bile acid homeostasis via activating farnesoid x receptor (FXR) is a promising strategy for the treatment of cholestasis. FXR-SHP (small heterodimer partner) axis plays an important role in maintaining bile acid homeostasis. PURPOSE: To investigate the anti-cholestasis effect of Dolomiaea souliei (Franch.) C.Shih (D. souliei) and clarify its underlying mechanism against α-naphthylisothiocyanate (ANIT) induced acute intrahepatic cholestasis. METHODS: ANIT-induced Sprague-Dawley rats were employed to investigate the anti-cholestasis effect of D. souliei ethyl acetate extract (DSE). Ursodeoxycholic acid (UDCA) was used as positive control. Bile flow and blood biochemical parameters were measured. Liver histopathological examination was conducted via hematoxylin-eosin staining. Western blot analysis was carried out to evaluate the protein levels related to bile acids metabolism and inflammation. The interactions between FXR and costunolide or dehydrocostus lactone, were conducted by molecular docking experiments. The effect of costunolide and dehydrocostus lactone on aspartate aminotransferase (AST), alanine aminotransferase (ALT) levels and FXR expression were also evaluated using guggulsterone-induced L02 cells. RESULTS: DSE could promote bile excretions and protect against ANIT-induced liver damage in cholestasis rats. Protein levels of FXR, SHP, Na+/taurocholate cotransporter (NTCP), bile salt export pump (BSEP), multidrug resistance-associated protein 2 (MRP2) were increased and the expressions of cholesterol 7α-hydroxylase (CYP7A1) and sterol 27-hydroxylase (CYP27A1) were decreased by DSE. Meanwhile, the anti-inflammatory factors, tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), interleukin-6 (IL-6) were also significantly increased, and the pro-inflammatory factor, interleukin-10 (IL-10), was significantly decreased in rats of DSE groups. Molecular docking revealed that costunolide and dehydrocostus lactone could be well docked into the FXR protein molecule, and hydrophobic interactions played the main function. Costunolide could reverse the increased AST and ALT levels and increase the FXR expression in guggulsterone-induced L02 cells. CONCLUSION: DSE had an anti-cholestasis effect by activating FXR-SHP axis, inhibiting synthesis of bile acid, and increasing bile secretion, together with inflammatory response and improving liver injury. Costunolide may be the main active component. This study provided a potential therapeutic mechanism for D. souliei as an anti-cholestasis medicine in the treatment of cholestasis liver diseases.

Intrahepatic cholestasis induced by α-naphthylisothiocyanate can cause gut-liver axis disorders.

Clinical studies have shown that Intrahepatic cholestasis is closely related to intestinal injury. The gut-liver axis theory suggests that the intestine and liver are closely related, and that bile acids are important mediators linking the intestine and liver. We compared two cholestasis models: a single injection model that received a single subcutaneous ANIT injection (75 mg/kg), and a multiple subcutaneous injection model that received an injection of ANIT (50 mg/kg) every other day for 2 weeks. We used Transmetil (ademetionine 1,4-butanedisulfonate) to relieve intrahepatic cholestasis in the multiple injection group. In the multiple injection group, we found increased hepatic bile duct hyperplasia, increased fibrosis of the liver, increased small intestine inflammation and oxidative damage, increased harmful bile acids, decreased bile acids transporter levels. After treatment with Transmetil, the liver and gut injuries were relieved. These results suggest that intrahepatic cholestasis can cause disorders of the gut-liver axis.

Concomitant congenital CMV infection and inherited liver diseases.

Inherited liver diseases may present in infancy as cholestatic jaundice progressing to severe hepatic dysfunction. Congenital cytomegalovirus (cCMV) infection may initially involve the liver, yet in otherwise healthy hosts rarely leads to long-term hepatic disease. We report a series of three patients, diagnosed with hereditary liver diseases: progressive familial intrahepatic cholestasis (PFIC) type IV, alpha 1 anti-trypsin deficiency (A1ATD) and Alagille syndrome (ALGS), who were also diagnosed with cCMV infection. All patients were treated with valgancilovir for symptomatic cCMV infection (6-12 months), followed by suppressive dosing in the 2 patients with PFIC and A1ATD. Following 15-24 months of follow-up - the patients with PFIC and A1ATD developed severe liver failure, and the third had ongoing cholestatic disease with stable synthetic function. We propose a significant contribution of cCMV infection to the course of the inherited primary disease, possibly leading to further compromise of the liver. We recommend screening patients with inherited liver disease for cCMV, and considering anti-viral treatment with valganciclovir to delay hepatic disease progression.

Dual ß-Catenin and γ-Catenin Loss in Hepatocytes Impacts Their Polarity through Altered Transforming Growth Factor-ß and Hepatocyte Nuclear Factor 4α Signaling.

Hepatocytes are highly polarized epithelia. Loss of hepatocyte polarity is associated with various liver diseases, including cholestasis. However, the molecular underpinnings of hepatocyte polarization remain poorly understood. Loss of ß-catenin at adherens junctions is compensated by γ-catenin and dual loss of both catenins in double knockouts (DKOs) in mice liver leads to progressive intrahepatic cholestasis. However, the clinical relevance of this observation, and further phenotypic characterization of the phenotype, is important. Herein, simultaneous loss of ß-catenin and γ-catenin was identified in a subset of liver samples from patients of progressive familial intrahepatic cholestasis and primary sclerosing cholangitis. Hepatocytes in DKO mice exhibited defects in apical-basolateral localization of polarity proteins, impaired bile canaliculi formation, and loss of microvilli. Loss of polarity in DKO livers manifested as epithelial-mesenchymal transition, increased hepatocyte proliferation, and suppression of hepatocyte differentiation, which was associated with up-regulation of transforming growth factor-ß signaling and repression of hepatocyte nuclear factor 4α expression and activity. In conclusion, concomitant loss of the two catenins in the liver may play a pathogenic role in subsets of cholangiopathies. The findings also support a previously unknown role of ß-catenin and γ-catenin in the maintenance of hepatocyte polarity. Improved understanding of the regulation of hepatocyte polarization processes by ß-catenin and γ-catenin may potentially benefit development of new therapies for cholestasis.