Dysregulated Activation of Hippo-YAP1 Signaling Induces Oxidative Stress and Aberrant Development of Intrahepatic Biliary Cells in Biliary Atresia.

The canonical Hippo-YAP1 signaling pathway is crucial for liver development and regeneration, but its role in repair and regeneration of intrahepatic bile duct in biliary atresia (BA) remains largely unknown. YAP1 expression in the liver tissues of patients with BA and Rhesus rotavirus-induced experimental BA mouse models were examined using quantitative reverse transcriptase-PCR and double immunofluorescence. Mouse EpCAM-expressing cell-derived liver organoids were generated and treated with Hippo-YAP1 pathway activators (Xmu-mp-1 and TRULI) or an inhibitor (Peptide17).

Animal and organoid models to elucidate the anti-fibrotic effect of steroid on biliary atresia.

Purpose: We performed animal and organoid study to evaluate the anti-fibrotic effect of steroid on biliary atresia (BA) and the underlying patho-mechanism.

Methods: BA animal models were created by inoculation of mice on post-natal day 1 with rhesus rotavirus (RRV). They received either 20 µl phosphate-buffered saline (PBS) or steroid from day 21 to day 34.

Pathological role of methionine in the initiation and progression of biliary atresia.

Methionine (Met) is an essential amino acid, and its excessive dietary intake and/or its metabolism disturbance could lead to accumulation/depletion of hepatic Met and some of the key intermediates of these pathways, which would interfere normal liver function and would be associated with liver diseases. Biliary atresia (BA) is a life-threatening disease characterized by inflammatory fibrosclerosing changes of the intrahepatic and extrahepatic biliary systems and is the primary cause of obstructive neonatal cholestasis with a rapid course of liver failure. However, its pathogenesis remains unknown.

Identification of cancer-related genes FGFR2 and CEBPB in choledochal cyst via RNA sequencing of patient-derived liver organoids.

Background: Choledochal cysts (CC) are congenital bile duct anomalies with 6-30% risk for developing bile duct cancer. However, the molecular mechanisms underlying cancer risk of CC are unknown. We sought to identify the gene expression changes underlying the cancer risk of CC patients.

Does the Choice of Suture Materials Affect the Vas Deferens after Hernia Ring Closure in Inguinal Hernia Surgery: An Experimental Study in Rats.

Introduction: Laparoscopic inguinal hernia repair is a commonly performed procedure in children. Currently, monofilament polypropylene and braided silk are the two most frequently used materials. Studies have suggested more tissue inflammatory reactions with the use of multifilament non-absorbable sutures.

Bioengineering Liver Organoids for Diseases Modelling and Transplantation.

Organoids as three-dimension (3D) cellular organizations partially mimic the physiological functions and micro-architecture of native tissues and organs, holding great potential for clinical applications. Advances in the identification of essential factors including physical cues and biochemical signals for controlling organoid development have contributed to the success of growing liver organoids from liver tissue and stem/progenitor cells. However, to recapitulate the physiological properties and the architecture of a native liver, one has to generate liver organoids that contain all the major liver cell types in correct proportions and relative 3D locations as found in a native liver.

Embryology and anatomy of Hirschsprung disease.

Bowel has its own elegant nervous system - the enteric nervous system (ENS) which is a complex network of neurons and glial clones. Derived from neural crest cells (NCCs), this little brain controls muscle contraction, motility, and bowel activities in response to stimuli. Failure of developing enteric ganglia at the distal bowel results in intestinal obstruction and Hirschsprung disease (HSCR).

Plasma amyloid-beta levels correlated with impaired hepatic functions: An adjuvant biomarker for the diagnosis of biliary atresia.

Background: Biliary atresia (BA) is an infantile fibro-obstructive cholestatic disease with poor prognosis. An early diagnosis and timely Kasai portoenterostomy (KPE) improve clinical outcomes. Aggregation of amyloid-beta (Aβ) around hepatic bile ducts has been discovered as a factor for BA pathogenesis, yet whether plasma Aβ levels correlate with hepatic dysfunctions and could be a biomarker for BA remains unknown.

Temporal and spatial development of intestinal smooth muscle layers of human embryos and fetuses.

The sequential occurrence of three layers of smooth muscle layers (SML) in human embryos and fetus is not known. Here, we investigated the process of gut SML development in human embryos and fetuses and compared the morphology of SML in fetuses and neonates. The H&E, Masson trichrome staining, and Immunohistochemistry were conducted on 6-12 gestation week human embryos and fetuses and on normal neonatal intestine.

Pathogenesis of Choledochal Cyst: Insights from Genomics and Transcriptomics.

Choledochal cysts (CC) is characterized by extra- and/or intra-hepatic b\ile duct dilations. There are two main theories, "pancreaticobiliary maljunction" and "congenital stenosis of bile ducts" proposed for the pathogenesis of CC. Although family cases or CC associated with other anomalies have been reported, the molecular pathogenesis of CC is still poorly understood.

Human liver organoid derived intra-hepatic bile duct cells support SARS-CoV-2 infection and replication.

Although the main route of infection for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the respiratory tract, liver injury is also commonly seen in many patients, as evidenced by deranged parenchymal liver enzymes. Furthermore, the severity of liver damage has been shown to correlate with higher mortality. Overall, the mechanism behind the liver injury remains unclear.

Identification of a wide spectrum of ciliary gene mutations in nonsyndromic biliary atresia patients implicates ciliary dysfunction as a novel disease mechanism.

Background: Biliary atresia (BA) is the most common obstructive cholangiopathy in neonates, often progressing to end-stage cirrhosis. BA pathogenesis is believed to be multifactorial, but the genetic contribution, especially for nonsyndromic BA (common form: > 85%) remains poorly defined.

Methods: We conducted whole exome sequencing on 89 nonsyndromic BA trios to identify rare variants contributing to BA etiology.

Biomarkers for the diagnosis and post-Kasai portoenterostomy prognosis of biliary atresia: a systematic review and meta-analysis.

To evaluate the accuracy of biomarkers for the early diagnosis of biliary atresia (BA) and prognostic stratification after Kasai portoenterostomy (KPE). We conducted a systematic review of PubMed, Web of Science, Embase, Scopus and OVID for English literature reporting BA biomarkers published before August 2020. Screening, data extraction, and quality assessment were performed in duplicate.

Gut lumen formation defect can cause intestinal atresia: evidence from histological studies of human embryos and intestinal atresia septum.

Intestinal atresia (IA), a common cause of neonatal intestinal obstruction, is a developmental defect, which disrupts the luminal continuity of the intestine. Here, we investigated (i) the process of lumen formation in human embryos; and (ii) how a defective lumen formation led to IA. We performed histological and histochemical study on 6-10 gestation week human embryos and on IA septal regions.

Deletion of interleukin enhancer binding factor 2 (ILF2) resulted in defective biliary development and bile flow blockage.

Purpose: Biliary atresia (BA) is a devastating obstructive bile duct disease of newborns. BA has the highest incidence in Asians (1/5000), and its pathogenesis is unclear. We identified BA-private rare copy number variants (CNVs; 22 duplications and 6 deletions).

Transamniotic mesenchymal stem cell therapy for neural tube defects preserves neural function through lesion-specific engraftment and regeneration.

Neural tube defects (NTDs) lead to prenatal mortality and lifelong morbidity. Currently, surgical closure of NTD lesions results in limited functional recovery. We previously suggested that nerve regeneration was critical for NTD therapy.

Beta-amyloid deposition around hepatic bile ducts is a novel pathobiological and diagnostic feature of biliary atresia.

Background And Aims: Biliary atresia (BA) is a poorly understood and devastating obstructive bile duct disease of newborns. It is often diagnosed late, is incurable and frequently requires liver transplantation. In this study, we aimed to investigate the underlying pathogenesis and molecular signatures associated with BA.

Conditional deletion of platelet derived growth factor receptor alpha (Pdgfra) in urorectal mesenchyme causes mesenchyme apoptosis and urorectal developmental anomalies in mice.

In mammals, urorectal development starts at early embryonic stage, defective urorectal development results in anorectal malformations, which are common congenital developmental defects of the anus and the urethra in newborns. The etiology and embryology of the defects are still largely unknown. Platelet-derived growth factor receptor alpha (Pdgfra) is a cell surface receptor tyrosine kinase, upon binding to its ligands (Pdgfa-d), mediates intracellular signaling and regulates embryonic development.

Stage specific requirement of platelet-derived growth factor receptor-α in embryonic development.

Background: Platelet-derived growth factor receptor alpha (PDGFRα) is a cell-surface receptor tyrosine kinase for platelet-derived growth factors. Correct timing and level of Pdgfra expression is crucial for embryo development, and deletion of Pdgfra caused developmental defects of multiple endoderm and mesoderm derived structures, resulting in a complex phenotypes including orofacial cleft, spina bifida, rib deformities, and omphalocele in mice. However, it is not clear if deletion of Pdgfra at different embryonic stages differentially affects these structures.

Depletion of the IKBKAP ortholog in zebrafish leads to hirschsprung disease-like phenotype.

Aim: To investigate the role of IKBKAP (inhibitor of kappa light polypeptide gene enhancer in B-cells, kinase complex-associated protein) in the development of enteric nervous system (ENS) and Hirschsprung disease (HSCR).

Methods: In this study, we injected a morpholino that blocked the translation of ikbkap protein to 1-cell stage zebrafish embryos. The phenotype in the ENS was analysed by antibody staining of the pan-neuronal marker HuC/D followed by enteric neuron counting.

Homeobox b5 (Hoxb5) regulates the expression of Forkhead box D3 gene (Foxd3) in neural crest.

Patterning of neural crest (NC) for the formation of specific structures along the anterio-posterior (A-P) body axis is governed by a combinatorial action of Hox genes, which are expressed in the neuroepithelium at the time of NC induction. Hoxb5 was expressed in NC at both induction and migratory stages, and our previous data suggested that Hoxb5 played a role in the NC development. However, the underlying mechanisms by which Hoxb5 regulates the early NC development are largely unknown.

HOXB5 binds to multi-species conserved sequence (MCS+9.7) of RET gene and regulates RET expression.

RET gene is crucial for the development of enteric nervous system, and dys-regulation of RET expression causes Hirschsprung disease. HOXB5 regulates RET transcription, and perturbations in transcriptional regulation by HOXB5 caused reduced RET expression and defective enteric nervous system development in mice. The mechanisms by which HOXB5 regulate RET transcription are unclear.