Core biomarkers analysis benefit for diagnosis on human intrahepatic cholestasis of pregnancy.

BACKGROUND: The pregnant women with intrahepatic cholestasis were at high risk of fetal distress, preterm birth and unexpected stillbirth. Intrahepatic cholestasis of pregnancy (ICP) was mainly caused by disorder of bile acid metabolism, whereas the specific mechanism was obscure. METHODS: We performed proteomics analysis of 10 ICP specimens and 10 placenta specimens from patients without ICP through data-independent acquisition (DIA) technique to disclose differentially expressed proteins. We executed metabolomic analysis of 30 ICP specimens and 30 placenta specimens from patients without ICP through UPLC-MS/MS to identify differentially expressed metabolites. Enrichment and correlation analysis was used to obtain the direct molecular insights of ICP development. The ICP rat models were constructed to validate pathological features. RESULTS: The heatmap of proteomics analysis showed the top 30 up-regulated and 30 down-regulated proteins. The metabolomic analysis revealed 20 richer and 4 less abundant metabolites in ICP samples compared with placenta specimens from patients without ICP, and enrichment pathways by these metabolites included primary bile acid biosynthesis, cholesterol metabolism, bile secretion, nicotinate and nicotinamide metabolism, purine metabolism and metabolic pathways. Combined analysis of multiple omics results demonstrated that bile acids such as Glycohyocholic acid, Glycine deoxycholic acid, beta-Muricholic acid, Noncholic acid, cholic acid, Gamma-Mercholic Acid, alpha-Muricholic acid and Glycochenodeoxycholic Aicd were significantly associated with the expression of GLRX3, MYL1, MYH7, PGGT1B, ACTG1, SP3, LACTB2, C2CD5, APBB2, IPO9, MYH2, PPP3CC, PIN1, BLOC1S1, DNAJC7, RASAL2 and ATCN3 etc. The core protein ACAT2 was involved in lipid metabolic process and animal model showed that ACAT2 was up-regulated in placenta and liver of pregnant rats and fetal rats. The neonates had low birth weight and Safranin O-Fast green FCF staining of animal models showed that poor osteogenic and chondrogenic differentiation of fetal rats. CONCLUSION: Multiple metabolites-alpha-Muricholic acid, beta-Muricholic acid, Glycine deoxycholic acid and Glycochenodeoxycholic Acid etc. were perfect biomarkers to predict occurrence of ICP. Bile acids were significantly associated with varieties of protein expression and these proteins were differentially expressed in ICP samples. Our study provided several biomarkers for ICP detection and potential therapeutic targets for ICP development.

Identification of new correctors for traffic-defective ABCB4 variants by a high-content screening approach.

ABCB4 is located at the canalicular membrane of hepatocytes and is responsible for the secretion of phosphatidylcholine into bile. Genetic variations of this transporter are correlated with rare cholestatic liver diseases, the most severe being progressive familial intrahepatic cholestasis type 3 (PFIC3). PFIC3 patients most often require liver transplantation. In this context of unmet medical need, we developed a high-content screening approach to identify small molecules able to correct ABCB4 molecular defects. Intracellularly-retained variants of ABCB4 were expressed in cell models and their maturation, cellular localization and function were analyzed after treatment with the molecules identified by high-content screening. In total, six hits were identified by high-content screening. Three of them were able to correct the maturation and canalicular localization of two distinct intracellularly-retained ABCB4 variants; one molecule was able to significantly restore the function of two ABCB4 variants. In addition, in silico molecular docking calculations suggest that the identified hits may interact with wild type ABCB4 residues involved in ATP binding/hydrolysis. Our results pave the way for their optimization in order to provide new drug candidates as potential alternative to liver transplantation for patients with severe forms of ABCB4-related diseases, including PFIC3.

Loss of ß-catenin reveals a role for glutathione in regulating oxidative stress during cholestatic liver disease.

BACKGROUND: Cholestasis is an intractable liver disorder that results from impaired bile flow. We have previously shown that the Wnt/ß-catenin signaling pathway regulates the progression of cholestatic liver disease through multiple mechanisms, including bile acid metabolism and hepatocyte proliferation. To further explore the impact of these functions during intrahepatic cholestasis, we exposed mice to a xenobiotic that causes selective biliary injury. METHODS: α-naphthylisothiocyanate (ANIT) was administered to liver-specific knockout (KO) of ß-catenin and wild-type mice in the diet. Mice were killed at 6 or 14 days to assess the severity of cholestatic liver disease, measure the expression of target genes, and perform biochemical analyses. RESULTS: We found that the presence of ß-catenin was protective against ANIT, as KO mice had a significantly lower survival rate than wild-type mice. Although serum markers of liver damage and total bile acid levels were similar between KO and wild-type mice, the KO had minor histological abnormalities, such as sinusoidal dilatation, concentric fibrosis around ducts, and decreased inflammation. Notably, both total glutathione levels and expression of glutathione-S-transferases, which catalyze the conjugation of ANIT to glutathione, were significantly decreased in KO after ANIT. Nuclear factor erythroid-derived 2-like 2, a master regulator of the antioxidant response, was activated in KO after ANIT as well as in a subset of patients with primary sclerosing cholangitis lacking activated ß-catenin. Despite the activation of nuclear factor erythroid-derived 2-like 2, KO livers had increased lipid peroxidation and cell death, which likely contributed to mortality. CONCLUSIONS: Loss of ß-catenin leads to increased cellular injury and cell death during cholestasis through failure to neutralize oxidative stress, which may contribute to the pathology of this disease.

Altered placental macrophage numbers and subsets in pregnancies complicated with intrahepatic cholestasis of pregnancy (ICP) compared to healthy pregnancies.

INTRODUCTION: Intrahepatic cholestasis of pregnancy (ICP) can result in adverse outcomes for both mother and fetus. Inflammatory (M1 subset) or anti-inflammatory (M2 subset) macrophage polarisation is associated with various complications of pregnancy. However, the influence of ICP on macrophage numbers and polarisation remains unknown. This study analyses macrophage density and distribution in placentas of patients with ICP compared to controls. Clinical parameters were correlated to macrophage distribution and ursodeoxycholic acid use (UDCA). METHODS: This study included routinely collected placental tissue samples of 42 women diagnosed with ICP and of 50 control pregnancies. Immunohistochemical staining was performed on placental tissue using CD68 antibody as a pan-macrophage marker, CD206 antibody as an M2 and HLA-DR antibody as an M1 macrophage marker. Macrophage density (cells/mm2) and distribution (CD206+/CD68+ or CD206+/CD68+HLA-DR+) in both decidua (maternal tissue) and villous parenchyma (fetal tissue) were compared between groups. Macrophage density and distribution were correlated to clinical parameters for ICP patients. RESULTS: The density of CD68+ macrophages differed significantly between groups in villous parenchyma. In both decidua and villous parenchyma, CD206+/CD68+ ratio was significantly lower in ICP patients compared to controls (p = 0.003 and p=<0.001, respectively). No difference was found based on UDCA use or in CD68+HLA-DR+ cell density. Significant correlations were found between macrophage density and peak serum bile acids and liver enzymes. DISCUSSION: In ICP patients, an immune shift was observed in both decidual and villous tissue, indicated by a lower CD206+/CD68+ ratio. ICP seems to affect placental tissue, however more research is required to understand its consequences.

The role of Ca2+ signalling and InsP3R in the pathogenesis of intrahepatic cholestasis of pregnancy.

BACKGROUND: In order to contribute new insights for future prevention and treatment of intrahepatic cholestasis of pregnancy (ICP), and to promote positive pregnancy outcomes, we evaluated serum Ca2+ levels and inositol 1,4,5-trisphosphate receptor (InsP3R) expression in the liver tissue of a rat ICP model. METHODS: After establishing the model by injection of oestradiol benzoate and progesterone into pregnant rats, animals were divided into normal control (n = 5) and ICP model groups (n = 5). The expression of InsP3R protein in the liver, and serum levels of Ca2+, glycocholic acid and bile acid were detected. RESULTS: InsP3R mRNA and protein were significantly lower in the ICP model group compared to the normal group, as determined by qPCR and immunohistochemistry, respectively. Serum enzyme-linked immunosorbent assay results revealed significantly higher levels of glycocholic acid and bile acid in the ICP model group compared to the normal group, while Ca2+ levels were significantly lower. The levers of Ca2+ were significantly and negatively correlated with the levels of glycocholic acid. The observed decrease in Ca2+ was associated with an increase in total bile acids, but there was no significant correlation. CONCLUSIONS: Our results revealed that the expression of InsP3R and serum Ca2+ levels was significantly decreased in the liver tissue of ICP model rats. Additionally, Ca2+ levels were found to be negatively correlated with the level of glycocholic acid.

This study investigated the relationship between serum Ca²⁺ levels, inositol 1,4,5-trisphosphate receptor (InsP3R) expression and intrahepatic cholestasis of pregnancy (ICP) in a rat model. The results indicated a significant decrease in InsP3R expression and Ca²⁺ in the disease group compared to the control group, alongside elevated levels of glycocholic acid and bile acid. The levels of Ca²⁺ exhibited a negative correlation with the levels of glycocholic acid. These findings indicated that the decrease of InsP3R expression and Ca²⁺ levels may be related to the pathogenesis of ICP. The study provides further insight into the treatment of this disease.

Genome-wide characterization of circulating metabolic biomarkers.

Genome-wide association analyses using high-throughput metabolomics platforms have led to novel insights into the biology of human metabolism1-7. This detailed knowledge of the genetic determinants of systemic metabolism has been pivotal for uncovering how genetic pathways influence biological mechanisms and complex diseases8-11. Here we present a genome-wide association study for 233 circulating metabolic traits quantified by nuclear magnetic resonance spectroscopy in up to 136,016 participants from 33 cohorts. We identify more than 400 independent loci and assign probable causal genes at two-thirds of these using manual curation of plausible biological candidates. We highlight the importance of sample and participant characteristics that can have significant effects on genetic associations. We use detailed metabolic profiling of lipoprotein- and lipid-associated variants to better characterize how known lipid loci and novel loci affect lipoprotein metabolism at a granular level. We demonstrate the translational utility of comprehensively phenotyped molecular data, characterizing the metabolic associations of intrahepatic cholestasis of pregnancy. Finally, we observe substantial genetic pleiotropy for multiple metabolic pathways and illustrate the importance of careful instrument selection in Mendelian randomization analysis, revealing a putative causal relationship between acetone and hypertension. Our publicly available results provide a foundational resource for the community to examine the role of metabolism across diverse diseases.

Current understanding of essential trace elements in intrahepatic cholestasis of pregnancy.

Trace elements are important components in the body and have fundamental roles in maintaining a healthy and balanced pregnancy process. Either deficiency or excess of trace elements, including selenium, iron, zinc, copper, and magnesium can lead to pregnancy complications. As a rare disorder during pregnancy of unknown aetiology, intrahepatic cholestasis of pregnancy (ICP) poses a significant risk to the fetus of perinatal mortality. ICP is a multifactorial complication of which the pathogenesis is still an enigma. Epidemiological studies have demonstrated the association of ICP with some trace elements. Evidence from retrospective studies in humans further revealed the possible contributing roles of trace elements in the pathogenesis of ICP. The published literature on the association of trace elements with ICP was reviewed. Recent advances in molecular biological techniques from animal studies have helped to elucidate the possible mechanisms by how these trace elements function in regulating oxidative reactions, inflammatory reactions and immune balance in the maternal-fetal interface, as well as the influence on hepato-intestinal circulation of bile acid. The scenario regarding the role of trace elements in the pathogenesis of ICP is still developing. The administration or depletion of these trace elements may have promising effects in alleviating the symptoms and improving the pregnancy outcomes of ICP.

The Phospholipid Flippase ATP8B1 is Involved in the Pathogenesis of Ulcerative Colitis via Establishment of Intestinal Barrier Function.

AIMS: Patients with mutations in ATP8B1 develop progressive familial intrahepatic cholestasis type 1 [PFIC1], a severe liver disease that requires life-saving liver transplantation. PFIC1 patients also present with gastrointestinal problems, including intestinal inflammation and diarrhoea, which are aggravated after liver transplantation. Here we investigate the intestinal function of ATP8B1 in relation to inflammatory bowel diseases. METHODS: ATP8B1 expression was investigated in intestinal samples of patients with Crohn's disease [CD] or ulcerative colitis [UC] as well as in murine models of intestinal inflammation. Colitis was induced in ATP8B1-deficient mice with dextran sodium sulphate [DSS] and intestinal permeability was investigated. Epithelial barrier function was assessed in ATP8B1 knockdown Caco2-BBE cells. Co-immunoprecipitation experiments were performed in Caco2-BBE cells overexpressing ATP8B1-eGFP. Expression and localization of ATP8B1 and tight junction proteins were investigated in cells and in biopsies of UC and PFIC1 patients. RESULTS: ATP8B1 expression was decreased in UC and DSS-treated mice, and was associated with a decreased tight junctional pathway transcriptional programme. ATP8B1-deficient mice were extremely sensitive to DSS-induced colitis, as evidenced by increased intestinal barrier leakage. ATP8B1 knockdown cells showed delayed barrier establishment that affected Claudin-4 [CLDN4] levels and localization. CLDN4 immunohistochemistry showed a tight junctional staining in control tissue, whereas in UC and intestinal PFIC1 samples, CLDN4 was not properly localized. CONCLUSION: ATP8B1 is important in the establishment of the intestinal barrier. Downregulation of ATP8B1 levels in UC, and subsequent altered localization of tight junctional proteins, including CLDN4, might therefore be an important mechanism in UC pathophysiology.

The role of ERp29/FOS/EMT pathway in excessive apoptosis of placental trophoblast cells in intrahepatic cholestasis of pregnancy.

BACKGROUND: Abnormal bile acid metabolism leading to changes in placental function during pregnancy. To determine whether endoplasmic reticulum protein 29 (ERp29) can mediate the pregnancy effects of cholestasis by altering the level of trophoblast cell apoptosis. METHODS: ERp29 in serum of 66 intrahepatic cholestasis of pregnancy (ICP) pregnant women and 74 healthy were detected by ELISA. Subcutaneous injection of ethinyl estradiol (E2) was used to induce ICP in pregnant rats. Taurocholic acid (TCA) was used to simulate the ICP environment, and TGF-ß1 was added to induce the epithelial mesenchymal transformation (EMT) process. The scratch, migration, and invasion test were used to detect the EMT process. ERp29 overexpression/knockdown vector were constructed and transfected to verify the role of ERp29 in the EMT process. Downstream gene was obtained through RNA-seq. RESULTS: Compared with the healthy pregnant women, the expression levels of ERp29 in serum of ICP pregnancy women were significantly increased (P < 0.001). ERp29 in the placenta tissue of the ICP pregnant rats increased significantly, and the level of apoptosis increased. The placental tissues of the ICP had high expression of E-cadherin and low expression of N-cadherin, snail1, vimentin. After HTR-8/SVneo cells were induced by TCA, EMT was inhibited, while the ERp29 increased. Cell and animal experiments showed that, knockdown of ERp29 reduced the inhibition of EMT, the ICP progress was alleviated. Overexpression of FOS salvaged the inhibitory effects of ERp29 on cell EMT. DISCUSSION: The high level of ERp29 in placental trophoblast cells reduced FOS mRNA levels, inhibited the EMT process and aggravated the occurrence and development of ICP.

Exosomes from Intrahepatic Cholestasis of Pregnancy Induce Cell Apoptosis Through the miRNA-6891-5p/YWHAE Pathway.

BACKGROUND: Intrahepatic cholestasis of pregnancy (ICP) is associated with adverse pregnancy outcomes; however, the underlying mechanisms are not fully understood. AIMS: This study aimed to determine the role of exosomal miR-6891-5p in placental trophoblast dysfunction in ICP and identify new biomarkers for ICP diagnosis. METHODS: Serum samples were collected from ICP patients and healthy pregnant women, and serum exosomes were extracted and identified. Fluorescent dye labeling of exosomes and cell-verified cell phagocytosis were performed. In vitro experiments were conducted by adding taurocholic acid to simulate the ICP environment. Cell proliferation and apoptosis levels were detected using flow cytometry and the cell counting kit-8 assay. Mimics were constructed to overexpress miR-6891-5p in cells, and the binding site between miR-6891-5p and YWHAE was verified using luciferase reporter genes. RESULTS: miR-6891-5p expression was significantly decreased in serum exosomes of ICP patients. Co-culturing with exosomes derived from ICP patients' serum (ICP-Exos) decreased HTR-8/SVeno cell proliferation and increased apoptosis levels. miR-6891-5p upregulation in HTR-8/SVeno cells significantly increased cell viability and reduced cell apoptosis levels, as determined by the cell counting kit-8 assay and flow cytometry. A double luciferase assay confirmed that miR-6891-5p affected the expression of the downstream YWHAE protein. CONCLUSIONS: This study indicates that serum exosomes from ICP patients can impact the apoptosis of placental trophoblast HTR-8/SVeno cells through the miR-6891-5P/YWHAE pathway and can serve as specific molecular markers for ICP diagnosis.

Clinical outcomes of ABCB4 heterozygosity in infants and children with cholestatic liver disease.

OBJECTIVES: Biallelic variants in the adenosine triphosphate binding cassette subfamily B member 4 (ABCB4) gene which encodes the multidrug resistance 3 protein (MDR3) leads to progressive familiar intrahepatic cholestasis type 3. However, monoallelic variants are increasingly recognized as contributing to liver disease in adults. Our aim was to describe the clinical characteristics of MDR3 heterozygous variants in a large cohort of infants and children with cholestatic liver disease. METHODS: The clinical and genotypic data on pediatric patients seen at King's College Hospital, London, between 2004 and 2022 and found to harbour heterozygous variants in ABCB4 were reviewed. RESULTS: Ninety-two patients amongst 1568 tested were identified with a monoallelic variant (5.9%). The most common presenting problem was conjugated hyperbilirubinemia (n = 46; 50%) followed by cholelithiasis (n = 12; 13%) and cholestatic hepatitis (n = 10; 11%). The median values of liver biochemistry at presentation were: GGT 105 IU/L and total bilirubin 86 µmol/L. Thirty-two genetic variants were identified including 22 missense (69%), 4 deletions (13%), 5 splice site (16%) and 1 termination (3%). At a median follow up of 1 year there was resolution of liver disease. CONCLUSIONS: Rare variants in ABCB4 were found amongst infants and children with cholestatic liver disease. The presenting problems were variable and abnormalities tended to normalize over time. Those with severe mutations could develop liver disease later in life when exposed to further insult and should be counseled appropriately.

Molecular basis of progressive familial intrahepatic cholestasis 3. A proteomics study.

Progressive familial intrahepatic cholestasis type 3 (PFIC3) is a severe rare liver disease that affects between 1/50,000 and 1/100,000 children. In physiological conditions, bile is produced by the liver and stored in the gallbladder, and then it flows to the small intestine to play its role in fat digestion. To prevent tissue damage, bile acids (BAs) are kept in phospholipid micelles. Mutations in phosphatidyl choline transporter ABCB4 (MDR3) lead to intrahepatic accumulation of free BAs that result in liver damage. PFIC3 onset usually occurs at early ages, progresses rapidly, and the prognosis is poor. Currently, besides the palliative use of ursodeoxycholate, the only available treatment for this disease is liver transplantation, which is really challenging for short-aged patients. To gain insight into the pathogenesis of PFIC3 we have performed an integrated proteomics and phosphoproteomics study in human liver samples to then validate the emerging functional hypotheses in a PFIC3 murine model. We identified 6246 protein groups, 324 proteins among them showing differential expression between control and PFIC3. The phosphoproteomic analysis allowed the identification of 5090 phosphopeptides, from which 215 corresponding to 157 protein groups, were differentially phosphorylated in PFIC3, including MDR3. Regulation of essential cellular processes and structures, such as inflammation, metabolic reprogramming, cytoskeleton and extracellular matrix remodeling, and cell proliferation, were identified as the main drivers of the disease. Our results provide a strong molecular background that significantly contributes to a better understanding of PFIC3 and provides new concepts that might prove useful in the clinical management of patients.

Proteomic Biomarkers of Intrahepatic Cholestasis of Pregnancy.

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease, which can lead to adverse fetal outcomes, including preterm labor and intrauterine death. The pathogenesis of ICP is still unclear. We hypothesized that pathological index leads to abnormal placenta changes in ICP. Investigation of these differences in protein expression in parallel profiling is essential to understand the comprehensive pathophysiological mechanism underlying ICP. The present study screened differentially expressed proteins (DEPs) as novel diagnostic markers for ICP. Proteomic profiles of placental tissues from 32 ICP patients and 24 healthy volunteers (controls) were analyzed. Our founding was valid by following western blotting and immunohistochemistry staining, respectively. The association of the key protein expression with clinicopathological features of ICP was further analyzed. A total of 178 DEPs were identified between the ICP and control groups. Functional enrichment analysis showed these proteins were significantly enriched in the PPAR singling pathway by KEGG and PPARα/RXRα activation by IPA. Apolipoprotein A2 (APOA2) was the only upregulated protein, which uniquely identified in ICP groups and related to both pathways. Validation of western blotting and immunohistochemical staining analysis showed significantly higher APOA2 expression in the ICP group than in the control group. Furthermore, the expression of APOA2 is associated with clinicopathological features in ICP groups. Receiver operating characteristic (ROC) curve analyses showed that the AUC of APOA2 was 0.8984 (95% confidence interval (CI): 0.772-1.000). This study has identified up-regulated APOA2 associated with PPAR singling pathway and PPARα/RXRα activation in ICP. Thus, APOA2 may be involved in ICP pathogenesis, serving as a novel biomarker for its diagnosis.

Rare variant contribution to cholestatic liver disease in a South Asian population in the United Kingdom.

This study assessed the contribution of five genes previously known to be involved in cholestatic liver disease in British Bangladeshi and Pakistani people. Five genes (ABCB4, ABCB11, ATP8B1, NR1H4, TJP2) were interrogated by exome sequencing data of 5236 volunteers. Included were non-synonymous or loss of function (LoF) variants with a minor allele frequency < 5%. Variants were filtered, and annotated to perform rare variant burden analysis, protein structure, and modelling analysis in-silico. Out of 314 non-synonymous variants, 180 fulfilled the inclusion criteria and were mostly heterozygous unless specified. 90 were novel and of those variants, 22 were considered likely pathogenic and 9 pathogenic. We identified variants in volunteers with gallstone disease (n = 31), intrahepatic cholestasis of pregnancy (ICP, n = 16), cholangiocarcinoma and cirrhosis (n = 2). Fourteen novel LoF variants were identified: 7 frameshift, 5 introduction of premature stop codon and 2 splice acceptor variants. The rare variant burden was significantly increased in ABCB11. Protein modelling demonstrated variants that appeared to likely cause significant structural alterations. This study highlights the significant genetic burden contributing to cholestatic liver disease. Novel likely pathogenic and pathogenic variants were identified addressing the underrepresentation of diverse ancestry groups in genomic research.

Yinchen decoction protects against cholic acid diet-induced cholestatic liver injury in mice through liver and ileal FXR signaling.

ETHNOPHARMACOLOGICAL RELEVANCE: Cholestasis is a pathophysiological syndrome characterized by the accumulation of bile acids (BAs) that leads to severe liver disease. Artemisia capillaris is documented in Chinese Pharmacopoeia as the authentic resources for Yinchen. Although Yinchen (Artemisia capillaris Thunb.) decoction (YCD) has been used in China for thousands of years to treat jaundice, the underlying mechanisms to ameliorate cholestatic liver injury have not been elucidated. AIM OF THE STUDY: To investigate the molecular mechanism of how YCD protects against 1% cholic acid (CA) diet-induced intrahepatic cholestasis through FXR signaling. MATERIALS AND METHODS: Wild-type and Fxr-deficient mice were fed a diet containing 1% CA to establish the intrahepatic cholestasis model. The mice received low-, medium-, or high-dose YCD for 10 days. Plasma biochemical markers were analyzed, liver injury was identified by histopathology, and hepatic and plasma BA content was analyzed. Western blot was used to determine the expression levels of transporters and enzymes involved in BA homeostasis in the liver and intestine. RESULTS: In wild-type mice, YCD significantly improved plasma transaminase levels, multifocal hepatocellular necrosis, and hepatic and plasma BA contents, upregulated the expression of hepatic FXR and downstream target enzymes and transporters. Meanwhile, YCD significantly induced the expressions of intestinal FXR and FGF15 and hepatic FGFR4. In contrast, the hepatic protective effect of YCD on cholestasis was abolished in Fxr-deficient mice. CONCLUSION: YCD protects against cholestatic liver injury induced by a CA diet by restoring the homeostasis of BAs via activation of the liver FXR/SHP and ileal FXR/FGF15 signaling pathways. Furthermore, chlorogenic acid and caffeic acid may be the pharmacological agents in YCD responsible for protecting against cholestatic liver injury.

SWATH proteomics analysis of placental tissue with intrahepatic cholestasis of pregnancy.

INTRODUCTION: Intrahepatic cholestasis of pregnancy (ICP) usually occurs in the second and third trimesters. The disease's etiology and diagnostic criteria are currently unknown. Based on a sequence window to obtain all theoretical fragment ions (SWATH) proteomic approach, this study sought to identify potential proteins in placental tissue that may be involved in the pathogenesis of ICP and adverse fetal pregnancy outcomes. METHODS: The postpartum placental tissue of pregnant women with ICP were chosen as the case group (ICP group) (subdivided into mild ICP group (MICP group) and severe ICP group (SICP group)), and healthy pregnant women were chosen as the control group (CTR). The hematoxylin-eosin (HE) staining was used to observe the histologic changes of placenta. The SWATH analysis combined with liquid chromatography-tandem mass spectrometry (LC-MS) was used to screen the differentially expressed proteins (DEPs) in ICP and CTR groups, and bioinformatics analysis was used to find out the biological process of these differential proteins. RESULTS: Proteomic studies showed there were 126 DEPs from pregnant women with ICP and healthy pregnant women. Most of the identified proteins were functionally related to humoral immune response, cell response to lipopolysaccharide, antioxidant activity and heme metabolism. A subsequent examination of placentas from patients with mild and severe ICP revealed 48 proteins that were differentially expressed. Through death domain receptors and fibrinogen complexes, these DEPs primarily regulate extrinsic apoptotic signaling pathways, blood coagulation, and fibrin clot formation. The differential expressions of HBD, HPX, PDE3A, and PRG4 were down-regulated by Western blot analysis, which was consistent with proteomics. DISCUSSION: This preliminary study helps us to understand the changes in the placental proteome of ICP patients, and provides new insights into the pathophysiology of ICP.

Molecular and Clinical Links between Drug-Induced Cholestasis and Familial Intrahepatic Cholestasis.

Idiosyncratic Drug-Induced Liver Injury (iDILI) represents an actual health challenge, accounting for more than 40% of hepatitis cases in adults over 50 years and more than 50% of acute fulminant hepatic failure cases. In addition, approximately 30% of iDILI are cholestatic (drug-induced cholestasis (DIC)). The liver's metabolism and clearance of lipophilic drugs depend on their emission into the bile. Therefore, many medications cause cholestasis through their interaction with hepatic transporters. The main canalicular efflux transport proteins include: 1. the bile salt export pump (BSEP) protein (ABCB11); 2. the multidrug resistance protein-2 (MRP2, ABCC2) regulating the bile salts' independent flow by excretion of glutathione; 3. the multidrug resistance-1 protein (MDR1, ABCB1) that transports organic cations; 4. the multidrug resistance-3 protein (MDR3, ABCB4). Two of the most known proteins involved in bile acids' (BAs) metabolism and transport are BSEP and MDR3. BSEP inhibition by drugs leads to reduced BAs' secretion and their retention within hepatocytes, exiting in cholestasis, while mutations in the ABCB4 gene expose the biliary epithelium to the injurious detergent actions of BAs, thus increasing susceptibility to DIC. Herein, we review the leading molecular pathways behind the DIC, the links with the other clinical forms of familial intrahepatic cholestasis, and, finally, the main cholestasis-inducing drugs.

Overview of Progressive Familial Intrahepatic Cholestasis.

Bile acid transport is a complex physiologic process, of which disruption at any step can lead to progressive intrahepatic cholestasis (PFIC). The first described PFIC disorders were originally named as such before identification of a genetic cause. However, advances in clinical molecular genetics have led to the identification of additional disorders that can cause these monogenic inherited cholestasis syndromes, and they are now increasingly referred to by the affected protein causing disease. The list of PFIC disorders is expected to grow as more causative genes are discovered. Here forth, we present a comprehensive overview of known PFIC disorders.

Serum Exosomes MicroRNAs Are Novel Non-Invasive Biomarkers of Intrahepatic Cholestasis of Pregnancy.

Background: Intrahepatic cholestasis of pregnancy (ICP) is closely related to the occurrence of adverse outcomes. Currently, total bile acids (TBAs) are the only diagnostic index for ICP, and its sensitivity and specificity have certain limitations. In this study, we aimed to develop potential biomarkers for the diagnosis of ICP. Methods: Sixty pregnant women diagnosed with ICP and 48 healthy pregnant controls were enrolled in this study. We used the Agilent microRNA (miRNA) array followed by quantitative reverse transcriptase polymerase chain reaction assays to identify and validate the serum exosome miRNA profiles in ICP and healthy pregnant controls. We employed bioinformatics to identify metabolic processes associated with differentially expressed serum exosome miRNAs. Results: The expression levels of hsa-miR-4271, hsa-miR-1275, and hsa-miR-6891-5p in maternal serum exosomes were significantly lower in ICP patients compared to controls; the diagnostic accuracy of hsa-miR-4271, hsa-miR-1275, and hsa-miR-6891-5p was evaluated with the area under the receiver operating characteristic curve (AUC) values of 0.861, 0.886, and 0.838, respectively. Multiple logistic regression analysis showed that a combination of the levels of hsa-miR-4271and hsa-miR-1275 afforded a significantly higher AUC (0.982). The non-error rate of a combination of all three exosome miRNAs was the highest (95%), thus more reliable ICP diagnosis. The expression levels of all three exosome miRNAs were negatively associated with TBAs. Furthermore, according to bioinformatics analysis, the three exosome miRNAs were related to lipid metabolism, apoptosis, oxidative stress, and the Mitogen Activated Protein Kinase (MAPK) signaling pathway. Conclusions: This study may identify the novel non-invasive biomarkers for ICP and provided new insights into the important role of the exosome miRNA regulation in ICP.

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.