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Hepatology Communications Sep 2023We previously showed that loss of yes-associated protein 1 (YAP) in early liver development (YAPKO) leads to an Alagille syndrome-like phenotype, with failure of...
BACKGROUND
We previously showed that loss of yes-associated protein 1 (YAP) in early liver development (YAPKO) leads to an Alagille syndrome-like phenotype, with failure of intrahepatic bile duct development, severe cholestasis, and chronic hepatocyte adaptations to reduce liver injury. TAZ, a paralog of YAP, was significantly upregulated in YAPKO hepatocytes and interacted with TEA domain family member (TEAD) transcription factors, suggesting possible compensatory activity.
METHODS
We deleted both Yap1 and Wwtr1 (which encodes TAZ) during early liver development using the Foxa3 promoter to drive Cre expression, similar to YAPKO mice, resulting in YAP/TAZ double knockout (DKO) and YAPKO with TAZ heterozygosity (YAPKO TAZHET). We evaluated these mice using immunohistochemistry, serum biochemistry, bile acid profiling, and RNA sequencing.
RESULTS
DKO mice were embryonic lethal, but their livers were similar to YAPKO, suggesting an extrahepatic cause of death. Male YAPKO TAZHET mice were also embryonic lethal, with insufficient samples to determine the cause. However, YAPKO TAZHET females survived and were phenotypically similar to YAPKO mice, with increased bile acid hydrophilicity and similar global gene expression adaptations but worsened the hepatocellular injury. TAZ heterozygosity in YAPKO impacted the expression of canonical YAP targets Ctgf and Cyr61, and we found changes in pathways regulating cell division and inflammatory signaling correlating with an increase in hepatocyte cell death, cell cycling, and macrophage recruitment.
CONCLUSIONS
YAP loss (with or without TAZ loss) aborts biliary development. YAP and TAZ play a codependent critical role in foregut endoderm development outside the liver, but they are not essential for hepatocyte development. TAZ heterozygosity in YAPKO livers increased cell cycling and inflammatory signaling in the setting of chronic injury, highlighting genes that are especially sensitive to TAZ regulation.
Topics: Animals; Male; Mice; Adaptor Proteins, Signal Transducing; Carcinoma, Hepatocellular; Cell Cycle Proteins; Cholestasis; Endoderm; Intracellular Signaling Peptides and Proteins; Liver Neoplasms; Trans-Activators; Transcription Factors; YAP-Signaling Proteins; Female
PubMed: 37556373
DOI: 10.1097/HC9.0000000000000220 -
Stem Cell Research Sep 2023Alagille syndrome (ALGS) is an autosomal dominant disease affecting the liver, heart and other organs with high variability. About 95% of ALGS cases are associated with...
Alagille syndrome (ALGS) is an autosomal dominant disease affecting the liver, heart and other organs with high variability. About 95% of ALGS cases are associated with pathogenic variants in JAG1, encoding the Jagged1 ligand that binds to Notch receptors. The iPSC line NCHi012-A was derived from an ALGS patient with cholestatic liver disease and mild pulmonary stenosis, who is heterozygous for a 2 bp deletion in the JAG1 coding sequence. We report here an initial characterization of NCHi012-A to evaluate its morphology, pluripotency, differentiation potential, genotype, karyotype and identity to the source patient.
Topics: Humans; Alagille Syndrome; Induced Pluripotent Stem Cells; Receptors, Notch; Heart; Jagged-1 Protein
PubMed: 37549562
DOI: 10.1016/j.scr.2023.103177 -
International Journal of Molecular... Jul 2023Alagille syndrome (ALGS) is a multisystem condition characterized by cholestasis and bile duct paucity on liver biopsy and variable involvement of the heart, skeleton,...
Alagille syndrome (ALGS) is a multisystem condition characterized by cholestasis and bile duct paucity on liver biopsy and variable involvement of the heart, skeleton, eyes, kidneys, and face and caused by pathogenic variants in the or gene. The variable expressivity of the clinical phenotype and the lack of genotype-phenotype correlations lead to significant diagnostic difficulties. Here we present an analysis of 18 patients with cholestasis who were diagnosed with ALGS. We used an NGS panel targeting coding exons of 52 genes, including the and genes. Sanger sequencing was used to verify the mutation in the affected individuals and family members. The specific facial phenotype was seen in 16/18 (88.9%). Heart defects were seen in 8/18 (44.4%) patients (pulmonary stenosis in 7/8). Butterfly vertebrae were seen in 5/14 (35.7%) patients. Renal involvement was detected in 2/18 (11.1%) cases-one patient had renal cysts, and one had obstructive hydronephrosis. An ophthalmology examination was performed on 12 children, and only one had posterior embryotoxon (8.3%). A percutaneous liver biopsy was performed in nine cases. Bile duct paucity was detected in six/nine cases (66.7%). Two patients required liver transplantation because of cirrhosis. We identified nine novel variants in the gene-eight frameshift variants (c.1619_1622dupGCTA (p.Tyr541X), c.1160delG (p.Gly387fs), c.964dupT (p.C322fs), c.120delG (p.L40fs), c.1984dupG (p.Ala662Glyfs), c.3168_3169delAG (p.R1056Sfs*51), c.2688delG (p.896CysfsTer49), c.164dupG (p.Cys55fs)) and one missense variant, c.2806T > G (p.Cys936Gly). None of the patients presented with variants. In accordance with the classical criteria, only six patients could meet the diagnostic criteria in our cohort without genetic analysis. Genetic testing is important in the diagnosis of ALGS and can help differentiate it from other types of cholestasis.
Topics: Humans; Alagille Syndrome; Cholestasis; Mutation; Mutation, Missense; Phenotype; Jagged-1 Protein
PubMed: 37511516
DOI: 10.3390/ijms241411758 -
Hepatology (Baltimore, Md.) Dec 2023Refractory pruritus and other complications of cholestasis are indications for liver transplantation (LT) in patients with Alagille syndrome (ALGS). We evaluated...
BACKGROUND AND AIMS
Refractory pruritus and other complications of cholestasis are indications for liver transplantation (LT) in patients with Alagille syndrome (ALGS). We evaluated predictors of event-free survival and transplant-free survival in patients with ALGS treated with maralixibat (MRX), an ileal bile acid transporter inhibitor.
APPROACH AND RESULTS
We assessed patients with ALGS from 3 clinical trials of MRX with up to 6 years of follow-up. Event-free survival was defined as the absence of LT, surgical biliary diversion, hepatic decompensation, or death; transplant-free survival was the absence of LT or death. Forty-three potential predictors were evaluated, including age, pruritus (ItchRO[Obs] 0-4 scale), biochemistries, platelets, and serum bile acids. Harrell's concordance statistic assessed goodness-of-fit, and then, Cox proportional hazard models confirmed the statistical significance of the predictors identified. A further analysis was performed to identify cutoffs using a grid search. Seventy-six individuals met the criteria of receiving MRX for ≥48 weeks with laboratory values available at week 48 (W48). The median duration of MRX was 4.7 years (IQR: 1.6-5.8); 16 had events (10 LT, 3 decompensation, 2 death, and 1 surgical biliary diversion). The 6-year event-free survival improved with a clinically meaningful >1-point ItchRO(Obs) reduction from baseline to W48 (88% vs. 57%; p = 0.005), W48 bilirubin < 6.5 mg/dL (90% vs. 43%; p < 0.0001), and W48 serum bile acid < 200 µmol/L (85% vs. 49%; p = 0.001). These parameters were also predictive of 6-year transplant-free survival.
CONCLUSIONS
Improvement in pruritus by 48 weeks, and lower W48 bilirubin and serum bile acid levels were associated with fewer events. These data may help identify potential markers of disease progression for ALGS patients treated with MRX.
Topics: Humans; Alagille Syndrome; Progression-Free Survival; Retrospective Studies; Bilirubin; Pruritus; Bile Acids and Salts
PubMed: 37278241
DOI: 10.1097/HEP.0000000000000502 -
Stem Cell Research Aug 2023Pathogenic variants in Jagged-1 (JAG1), which encodes the ligand of the Notch receptor, had been demonstrated to cause Alagille syndrome. However, there is no evidence...
Pathogenic variants in Jagged-1 (JAG1), which encodes the ligand of the Notch receptor, had been demonstrated to cause Alagille syndrome. However, there is no evidence to support any genotype-phenotype correlations. Here, we generated a gene-edited human embryonic stem cell (hESC) line (H9) carrying the c.1615C > T mutation in JAG1 that was identified in a patient with Alagille syndrome (ALGS). This modified cell line was accomplished by using cytosine base editor (CBE), and may serve as a valuable model for JAG1 mutaion related disease, and facilitate to gain more insight into the biological function of JAG1.
Topics: Humans; Alagille Syndrome; Human Embryonic Stem Cells; Jagged-1 Protein; Phenotype; Mutation; Cell Line
PubMed: 37245339
DOI: 10.1016/j.scr.2023.103120 -
Retinal Cases & Brief Reports Mar 2024To report a case of atypical Alagille syndrome with progressive chorioretinal atrophy.
PURPOSE
To report a case of atypical Alagille syndrome with progressive chorioretinal atrophy.
METHODS
Case Report.
RESULTS
A 42-year-old Japanese man presented with atypical Alagille syndrome. At the first visit, funduscopy revealed anterior circumferential chorioretinal atrophy in the peripheral retina and peripapillary region with posterior pole sparing in both eyes. Fundus autofluorescence showed hypoautofluorescence in the peripheral and peripapillary regions, but normal findings in the macular region. After follow-up for 3 years, hypopigmented area with well visualized large choroidal vessels extended to mid-peripheral region. On Fundus autofluorescence images, hypoautofluorescence newly appeared in macular region in both eyes. Perivascular hypoautofluorescence and granular hyperautofluorescence scattering within the posterior pole were also observed. BCVA deteriorated and concentric visual field contraction worsened progressively.
CONCLUSION
Alagille syndrome is known to have many ophthalmic manifestations, most of which are stable with minimal threat to vision. In the present case, chorioretinal atrophy progressed during 3-year follow-up, suggesting that progression of chorioretinal atrophy with vision loss may occur over time in Alagille syndrome.
Topics: Male; Humans; Adult; Alagille Syndrome; Follow-Up Studies; Retina; Retinal Degeneration; Atrophy; Fluorescein Angiography; Retrospective Studies; Choroid Diseases
PubMed: 36730824
DOI: 10.1097/ICB.0000000000001368