Features of liver injury in 138 Chinese patients with NICCD.

OBJECTIVES: To find biochemical and molecular markers can assist in identifying serious liver damage of neonatal intrahepatic cholestasis caused by citrin deficiency (NICCD) patients. METHODS: 138 patients under 13 days to 1.1 year old diagnosed of NICCD in our center from 2004 to 2020. Base on the abnormal liver laboratory tests, we divided 138 patients into three groups: acute liver failure (ALF), liver dysfunction, and non-liver dysfunction groups, then compared their clinical, biochemical and, molecular data. RESULTS: 96 % of 138 patients had high levels of citrulline and high ratio of threonine to serine, which is the distinctive feature of plasma amino acid profile for NICCD. A total of 18.1 % of 138 patients had evidence of ALF who presented the most severity hepatic damage, 51.5 % had liver dysfunction, and the remaining 30.4 % presented mild clinical symptoms (non-liver dysfunction). In ALF group, the levels of citrulline, tyrosine, TBIL, ALP, and γ-GT was significantly elevated, and the level of ALB and Fisher ratio was pronounced low. Homozygous mutations of 1,638_1660dup, IVS6+5G.A, or IVS16ins3kb in SLC25A13 gene were only found in ALF and liver dysfunction groups. Supportive treatment including medium-chain triglyceride supplemented diet and fresh frozen plasma could be life-saving and might reverse ALF. CONCLUSIONS: High level of citrulline, tyrosine, TBIL, ALP, γ-GT, and ammonia, low level of albumin, and low Fisher ratio were predictors to suggest severe liver damage in NICCD patients who may go on to develop fatal metabolic disorder. Early identification and proper therapy is particularly important for these patients.

Biallelic Mutations in Ubiquitin-Specific Peptidase 53 (USP53) Causing Progressive Intrahepatic Cholestasis. Report of a Case With Review of Literature.

Whole-exome sequencing studies have recently identified novel genes implicated in normal- or low-GGT pediatric cholestasis including ubiquitin-specific peptidase 53 (USP53). We identified novel biallelic mutations in the USP53 gene in a 7-month-old infant with pruritus and progressive intrahepatic cholestasis. His liver biopsy showed portal and perivenular fibrosis with bland bilirubinostasis. His parents were asymptomatic heterozygous for the same mutation. He is currently on vitamin supplements and cholestyramine and his family has also been counseled for liver transplantation. Our report confirms that patients with biallelic mutation in USP53 develop cholestatic liver disease.

Severe vitamin deficiencies in pregnancy complicated by progressive familial intrahepatic cholestasis.

Progressive familial intrahepatic cholestasis (PFIC) is a rare disease of impaired bile acid excretion which can lead to nutritional deficiencies. Vitamin deficiencies during pregnancy can result in adverse maternal and fetal outcomes. A 20-year-old primiparous woman at 30 4/7 weeks with PFIC type 2 presented with worsening cholestasis, coagulopathy and fat-soluble vitamin deficiency. She developed visual deficits and was found to have severe vitamin A deficiency. Her coagulopathy and visual deficits improved following vitamin K and A supplementation, respectively. She delivered at 32 2/7 weeks following preterm labour. This case highlights several unique aspects in the care of pregnant women with liver disease. These patients are at risk for fat-soluble vitamin deficiencies which can result in significant coagulopathy and rarely, visual deficits due to vitamin A deficiency. Prompt treatment is necessary to prevent permanent sequelae.

SLC25A13 c.1610_1612delinsAT mutation in an Indian patient and literature review of 79 cases of citrin deficiency for genotype-phenotype associations.

Here, we report SLC25A13 c.1610_1612delinsAT mutation from India in a 13-year old boy who presented with recurrent episodes of delirium and hyperammonemia. This is the second case with this mutation; the first case was of Pakistani origin. The boy responded to diet modification, sodium benzoate and arginine supplementation. Furthermore, we have aimed to establish genotype-phenotype correlation of 79 cases of citrin deficiency (46 males and 33 females) reported in 24 studies from all over the world. Inverse association was observed between age of onset and jaundice (r = -0.73). Late age of onset was associated with delirium (r = 0.61), aggressive behaviour (r = 0.67), altered sensorium (r = 0.67) and tremors (r = 0.65). The most common mutations associated with citrin deficiency were c.851_854del4, IVS16ins3kb, 1638-1660dup with a frequency of 42.41%, 16.46% and 6.33%, respectively. The c.851_854del4 mutation showed positive association with alpha feto protein (r = 0.40), ammonia (r = 0.50) and tyrosine (r = 0.40) while showing inverse association with threonine (r = -0.55). The IVS16ins3kb mutation was associated with high total (r = 0.65) and conjugated bilirubin (r = 0.54) along with high aspartate transaminase (r = 0.49) while citrulline levels are lower (r = -0.36). To conclude, all cases of intrahepatic cholestasis and neuropsychiatric abnormalities should be evaluated for citrin deficiency. However, the ethnic group-specific mutation frequencies should be considered in implementing screening.

[Protective effect of emodin pretreatment in young rats with intrahepatic cholestasis].

OBJECTIVE: To investigate the protective effect of emodin in young rats with intrahepatic cholestasis. METHODS: A total of 120 young Sprague-Dawley rats were randomly divided into control, model, and high-, medium-, and low-dose emodin groups, with 24 rats in each group. The rats in the control and model groups were given sodium carboxymethyl cellulose solution by gavage, while the other groups were given different doses of emodin solution by gavage. On the 5th day of experiment, alpha-naphthylisothiocyanate (ANIT, 50 mg/kg) was applied by gavage to establish the model of intrahepatic cholestasis in all groups except the control group. At 24, 48, and 72 hours after gavage, 8 rats in each group were sacrificed. Colorimetry was used to measure the serum levels of total bilirubin (TBIL), direct bilirubin (DBIL), total bile acid (TBA), alkaline phosphatase (ALP), gamma glutamyl transpeptidase (GGT), alanine aminotransferase (ALT), and aspartate aminotransferase (AST) in each group, and hematoxylin-eosin staining was applied to observe the morphological changes of the liver under a light microscope at different time points. RESULTS: Compared with the control group, the model group had significantly increased serum levels of TBIL, DBIL, TBA, ALP, GGT, ALT, and AST at the 24-hour, 48-hour, and 72-hour time points (P<0.01). In the model group, the serum levels of TBIL, DBIL, TBA, ALT, and AST showed varying degrees of increase at 48 hours after establishment of model, compared with the values at 24 and 72 hours (P<0.05). At 24, 48, and 72 hours, the high-, medium-, and low-dose emodin groups had varying degrees of reductions in the serum levels of TBIL and TBA compared with the model group (P<0.05); the high- and low-dose emodin groups had significantly increased serum levels of TBA compared with the medium-dose emodin group (P<0.05). The model group had the most severe pathological changes at 48 hours. Compared with the model group, the high-, medium-, and low-dose emodin groups showed certain improvement in pathological changes of the liver at each time point, and the medium-dose emodin group had better improvement compared with the high- and low-dose emodin groups. CONCLUSIONS: Emodin can effectively improve ANIT-induced intrahepatic cholestasis in young rats, and medium-dose emodin shows the best effect.

A functional classification of ABCB4 variations causing progressive familial intrahepatic cholestasis type 3.

UNLABELLED: Progressive familial intrahepatic cholestasis type 3 is caused by biallelic variations of ABCB4, most often (≥70%) missense. In this study, we examined the effects of 12 missense variations identified in progressive familial intrahepatic cholestasis type 3 patients. We classified these variations on the basis of the defects thus identified and explored potential rescue of trafficking-defective mutants by pharmacological means. Variations were reproduced in the ABCB4 complementary DNA and the mutants, thus obtained, expressed in HepG2 and HEK293 cells. Three mutants were either fully (I541F and L556R) or largely (Q855L) retained in the endoplasmic reticulum, in an immature form. Rescue of the defect, i.e., increase in the mature form at the bile canaliculi, was obtained by cell treatments with cyclosporin A or C and, to a lesser extent, B, D, or H. Five mutations with little or no effect on ABCB4 expression at the bile canaliculi caused a decrease (F357L, T775M, and G954S) or almost absence (S346I and P726L) of phosphatidylcholine secretion. Two mutants (T424A and N510S) were normally processed and expressed at the bile canaliculi, but their stability was reduced. We found no defect of the T175A mutant or of R652G, previously described as a polymorphism. In patients, the most severe phenotypes appreciated by the duration of transplant-free survival were caused by ABCB4 variants that were markedly retained in the endoplasmic reticulum and expressed in a homozygous status. CONCLUSION: ABCB4 variations can be classified as follows: nonsense variations (I) and, on the basis of current findings, missense variations that primarily affect the maturation (II), activity (III), or stability (IV) of the protein or have no detectable effect (V); this classification provides a strong basis for the development of genotype-based therapies.

Hepatotoxicity from anabolic androgenic steroids marketed as dietary supplements: contribution from ATP8B1/ABCB11 mutations?

BACKGROUND: Though possession of androgenic anabolic steroids (AAS) is illegal, non-prescription use of AAS persists. METHODS: We describe two Caucasian males (aged 25 and 45 years) with cholestatic hepatitis following ingestion of the dietary supplement Mass-Drol ('Celtic Dragon') containing the AAS 2α-17α-dimethyl-etiocholan-3-one,17ß-ol. RESULTS: Despite substantial hyperbilirubinaemia peak gamma-glutamyl transferase (GGT) remained normal. Besides 'bland' intralobular cholestasis, liver biopsy in both found deficiency of canalicular expression of ectoenzymes as seen in ATP8B1 disease. In the older patient, bile salt export pump marking (encoded by ABCB11) was focally diminished. We hypothesized that AAS had either induced inhibition of normal ATP8B1/ABCB11 expression or triggered initial episodes of benign recurrent intrahepatic cholestasis (BRIC) type 1/or 2. On sequencing, ATP8B1 was normal in both patients although the younger was heterozygous for the c.2093G>A mutation in ABCB11, a polymorphism previously encountered in drug-induced liver injury. CONCLUSION: AAS marketed as dietary supplements continue to cause hepatotoxicity in the UK; underlying mechanisms may include unmasking of genetic cholestatic syndromes.

Suppression of BSEP and MRP2 in mouse liver by miroestrol and deoxymiroestrol isolated from Pueraria candollei.

Miroestrol and deoxymiroestrol are highly active phytoestrogens isolated from the tuberous root of Pueraria candollei var. mirifica (Leguminosae). Modulatory effects of miroestrol and deoxymiroestrol on the mRNAs of BSEP and MRP2 genes involved in bile salt transportation, in C57BL/6 mice were investigated. In contrast to estradiol, miroestrol and deoxymiroestrol suppressed the expression of BSEP and MRP2 mRNA in both male and female mice. The results suggest for the first time that the use of miroestrol and deoxymiroestrol-containing products as alternative medicines or health supplements should be concerned according to their effects on key genes that regulate the bile salt export pump, which could result in the risk of hepatotoxicity and intrahepatic cholestasis.

Discovery and structural development of small molecules that enhance transport activity of bile salt export pump mutant associated with progressive familial intrahepatic cholestasis type 2.

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is caused by hereditary mutations of bile salt export pump (BSEP), such as E297G BSEP, which is a folding-defective mutant that is unable to traffic beyond the endoplasmic reticulum (ER). 4-Phenylbutyric acid (4-PBA) enhances the cell surface expression and transport capacity of E297G BSEP, but has a relatively high dose (1mM or more) is required to show the effect. Here, we show that bile acids possibly act as pharmacological chaperones, promoting the proper folding and trafficking of E297G BSEP. We also describe the discovery and structural development of non-steroidal compounds with potent pharmacological chaperone activity for E297G BSEP.

[Effect of emodin on P-gp expression in intrahepatic cholestatic rats].

OBJECTIVE: To investigate the effect and mechanism of emodin on acute intrahepatic cholestasis induced by alpha-naphthylisothiocyanate (ANIT) in rats. METHOD: Acute cholestatic model in rats was induced by ANIT. Normal control group, emodin group without ANIT treatment, model group and emodin group with ANIT treatment were set up. Liver function and pathological changes of hepatic tissue were examined. Real-time fluorescent quantitative RT-PCR was used to detect the mRNA levels of the hepatic transport protein genes mdr1a (multidrug resistance protein 1a), mdr1b (multidrug resistance protein 1b) mdr2 (multidrug resistance protein 2), The expression of P-gp were determined by Western blotting analysis. RESULT: Compared to the model group, Emodin treatment resulted in significant reductions in serum total bilirubin (TBiL), direct bilirubin (DBiL), alanine aminotransferase (ALT) and aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bile acid (TBA) (P < 0.01 or P < 0.05). By examining the liver pathology, it was found that hepatic cellular change and necrosis, inflammatory cell infiltration and bile duct proliferation were notably alleviated in emodin model with ANIT treatment. Analysis of gene expression in livers from emodin-treated cholestatic rats revealed that mdr1a, mdr1b and mdr2 could be up-regulated (P < 0.01 or P < 0.05), expression of P-gp was increased in accordance with its mRNA (P < 0.05). CONCLUSION: Emodin has a protective effect on hepatocytes and a restoring activity on cholestatic hepatitis. Mechanism of its action may be related to induce expression of the bile-metabolism-related transporter P-gp in the liver to prevent bile acids and other toxic compounds overaccumulation in hepatocytes and hepatic toxicity.

Strain background modifies phenotypes in the ATP8B1-deficient mouse.

BACKGROUND: Mutations in ATP8B1 (FIC1) underlie cases of cholestatic disease, ranging from chronic and progressive (progressive familial intrahepatic cholestasis) to intermittent (benign recurrent intrahepatic cholestasis). The ATP8B1-deficient mouse serves as an animal model of human ATP8B1 deficiency. METHODOLOGY/PRINCIPAL FINDINGS: We investigated the effect of genetic background on phenotypes of ATP8B1-deficient and wild-type mice, using C57Bl/6 (B6), 129, and (B6-129) F1 strain backgrounds. B6 background resulted in greater abnormalities in ATP8B1-deficient mice than did 129 and/or F1 background. ATP8B1-deficient pups of B6 background gained less weight. In adult ATP8B1-deficient mice at baseline, those of B6 background had lower serum cholesterol levels, higher serum alkaline phosphatase levels, and larger livers. After challenge with cholate-supplemented diet, these mice exhibited higher serum alkaline phosphatase and bilirubin levels, greater weight loss and larger livers. ATP8B1-deficient phenotypes in mice of F1 and 129 backgrounds are usually similar, suggesting that susceptibility to manifestations of ATP8B1 deficiency may be recessive. We also detected differences in hepatobiliary phenotypes between wild-type mice of differing strains. CONCLUSIONS/SIGNIFICANCE: Our results indicate that the ATP8B1-deficient mouse in a B6 background may be a better model of human ATP8B1 deficiency and highlight the importance of informed background strain selection for mouse models of liver disease.

Two common PFIC2 mutations are associated with the impaired membrane trafficking of BSEP/ABCB11.

Progressive familial intrahepatic cholestasis type 2 (PFIC2) is caused by a mutation in the bile salt export pump (BSEP/ABCB11) gene. However, the mechanisms for the deficiency in the function of two mutations (E297G and D482G), which are frequently found in European patients, have not yet been identified. In the present study, we examined the transport activity and cellular localization of these two mutants in human embryonic kidney 293 and Madin-Darby canine kidney II cells, respectively. Introduction of E297G and D482G mutations into the human BSEP gene by site-directed mutagenesis resulted in a significant reduction in the BSEP expression level, which was associated with impaired membrane trafficking. Most of the D482G BSEP and some of the E297G BSEP underwent only core glycosylation and appeared to be predominantly located in the endoplasmic reticulum. The inhibition of proteasome function by MG132 resulted in the cellular accumulation of the core glycosylation form of the two mutants. In contrast, transport studies for taurocholate and glycocholate with membrane vesicles isolated from complementary DNA-transfected cells indicated that both mutations did not significantly affect the transport function of BSEP per se. In conclusion, E297G and D482G mutations result in impaired membrane trafficking, whereas the transport functions of these mutants remain largely unchanged.

Treatment of progressive familial intrahepatic cholestasis: liver transplantation or partial external biliary diversion.

Progressive intrahepatic familial cholestasis (PFIC), previously called Byler's disease, is a syndrome in which children develop severe cholestasis progressing to biliary cirrhosis and chronic liver failure, usually during the first decade of life. Clinical features include jaundice, hepatomegaly, splenomegaly, growth retardation and severe pruritus. Laboratory tests demonstrate elevated bilirubin and bile acids, without an increase in serum gamma-glutamyl-transpeptidase or cholesterol. This study was performed to evaluate our experience with medical therapy as well as two types of surgical treatment used in children with PFIC, particularly partial external biliary diversion (PEBD) as an alternative method of therapy to liver transplantation (OLTx). Between 1979 and 1998 we have treated 46 children with PFIC (27 boys and 19 girls), aged 10 months to 19 yr (at the time of this study). Medical treatment with ursodeoxycholic (UDCA) was used in 39 patients for the period between 6 and 82 months. PEBD (cholecysto-jejuno-cutaneostomy) was performed in 16 patients, OLTx in eight children (including one after unsuccessful PEBD). Retrospective analysis of the clinical course and selected laboratory tests (bilirubin, ASPAT, ALAT, bile acids), and histopathological examinations were performed. Results of treatment were assessed by means of influence of the type of treatment on clinical symptoms, laboratory tests, progress of liver cirrhosis and hepatic failure, as well as physical development and survival. Medical therapy was effective in the long term in four (10%) of the patients resulting in clinical and biochemical normalization. Both surgical methods of therapy of PFIC, PEBD and OLTx, resulted in an 80% success rate and therefore should be used as complementary therapies. In patients before established liver cirrhosis, PEBD should be the first choice of treatment. Patients presenting with cirrhosis or after ineffective PEBD should qualify for OLTx. With this strategy most children with PIFC can be cured.

Familial intrahepatic cholestasis associated with progressive neuromuscular disease and vitamin E deficiency.

Three Japanese patients with familial progressive intrahepatic cholestasis developed complications involving neurologic abnormalities characterized by ataxia and pigmentary retinopathy. Serum vitamin E concentrations were extremely low in all patients, suggesting a long-term vitamin E deficiency. High dose oral supplementation of alpha-tocopherol produced normal serum vitamin E levels in two patients. Parenteral administration of vitamin E resulted in no clinical improvement in one patient who first received the treatment at 14 years of age. In the other two patients, the progression of neurological abnormalities was slowed by vitamin E supplementation. Cholestyramine treatment resulted in an apparent decrease in serum vitamin E levels despite oral alpha-tocopherol supplementation.