Biliary Epithelial Cells Research Articles

Single-Cell RNA Sequencing Analysis in Murine Biliary Atresia Model Reveals Subpopulation of Biliary Epithelial Cells with Proinflammatory and Fibrogenic Traits

INTRODUCTION: Understanding the pathogenesis of liver fibrosis is critical to impacting outcomes of infants with biliary atresia (BA). In BA, Prominin-1 (Prom1)-expressing hepatic progenitor cell (HPC) populations give rise to biliary epithelial cells (BECs) with ductular reactions (DR). Loss of Prom1 function significantly decreases DRs and fibrosis. Hypothesis: Prom1-expressing HPCs give rise to BECs manifesting activated fibrogenic pathways in BA. METHODS: Experimental BA was induced in neonatal Balb/c mice with intraperitoneal injection of rhesus rotavirus (RRV) vs saline on postnatal day (p) 3. Livers were collected at p3, 10, and 17. EPCAM+/CD31–/CD45–/TER119– live BECs were isolated by fluorescence-activated cell sorting for single-cell RNA sequencing. RESULTS: A total of 44,877 cells were sequenced (saline: 29,195 cells, n = 11; RRV: 15,682 cells, n = 6), graph-based clustering identified 19 clusters of transcriptionally distinct cell types/states. Four distinct BEC subtypes were identified: stem/progenitor, immature, hepatocyte-like, and mature (Figure). All demonstrated activation of inflammation and fibrogenic pathways with RRV treatment. UMAP clustering revealed a unique population of Prom1-expressing immature BECs in RRV p17 samples. Ingenuity pathway analysis (IPA) of this population showed upregulation of several pathways specific to innate immune response, ie natural killer cell and Toll-like receptor signaling. IPA also showed evidence of NFκB signaling with upregulation of proinflammatory cytokines, IL-1β, IL-6, and TNF, and profibrogenic cytokines, Tgfβ1 and Ccl2, in this population.FigureCONCLUSION: A subset of Prom1-expressing immature BECs upregulate proinflammatory and profibrogenic cytokines that likely contribute to fibrosis in BA. These cells and these signaling pathways represent potential therapeutic targets.

Laparoscopic vs. open anatomical hepatectomy for intrahepatic cholangiocarcinoma: A retrospective cohort study.

Intrahepatic cholangiocarcinoma is a highly malignant and invasive cancer originating from biliary epithelial cells. The current study was designed to evaluate the feasibility, safety, and clinical outcomes of laparoscopic anatomical hepatectomy in patients with intrahepatic cholangiocarcinoma. After screening, 95 patients who underwent anatomical hepatectomy for intrahepatic cholangiocarcinoma at our center were enrolled and divided into two groups according to the surgical approach; the baseline characteristics, pathological findings, surgical outcomes, and long-term outcomes were compared. Moreover, univariate and multivariate analyses were performed to identify independent prognostic factors for overall survival (OS) and disease-free survival (DFS). There were no significant differences in baseline characteristics or pathological findings between the two groups. Regarding short-term outcomes, the intraoperative blood loss, incision length, and length of postoperative hospital stay were more favorable in the laparoscopic anatomical hepatectomy group than the open anatomical hepatectomy group (P < 0.05). The two groups differed significantly in the extent of liver resection, with a lower lymph node dissection rate and lymph node yield in the laparoscopic anatomical hepatectomy group (P < 0.05). Furthermore, the postoperative complication rate was similar in the two groups (P > 0.05). The median postoperative follow-up times were 10.7 and 13.8 months in the laparoscopic anatomical hepatectomy and open anatomical hepatectomy groups, respectively. Regarding the long-term follow-up results, OS and DFS were similar in the two groups (P > 0.05). On multivariate analysis, the independent prognostic factors for OS were CA-199, CEA, HGB, tumor diameter, and T stage, and those for DFS were CA-199 (P < 0.05), and T stage (P < 0.05). laparoscopic anatomical hepatectomy for intrahepatic cholangiocarcinoma is safe and feasible when performed by experienced surgeons. Compared with open anatomical hepatectomy, laparoscopic anatomical hepatectomy provides better short-term outcomes and a comparable long-term prognosis.

Triptolide increases resistance to bile duct ligation-induced liver injury and fibrosis in mice by inhibiting RELB.

Cholestasis is a common, chronic liver disease that may cause fibrosis and cirrhosis. Tripterygium wilfordii Hook.f (TWHF) is a species in the Euonymus family that is commonly used as a source of medicine and food in Eastern and Southern China. Triptolide (TP) is an epoxy diterpene lactone of TWHF, as well as the main active ingredient in TWHF. Here, we used a mouse model of common bile duct ligation (BDL) cholestasis, along with cultured human intrahepatic biliary epithelial cells, to explore whether TP can relieve cholestasis. Compared with the control treatment, TP at a dose of 70 or 140 μg/kg reduced the serum levels of the liver enzymes alanine transaminase, aspartate aminotransferase, and alkaline phosphatase in mice; hematoxylin and eosin staining also showed that TP reduced necrosis in tissues. Both in vitro and in vivo analyses revealed that TP inhibited cholangiocyte proliferation by reducing the expression of RelB. Immunohistochemical staining of CK19 and Ki67, as well as measurement of Ck19 mRNA levels in hepatic tissue, revealed that TP inhibited the BDL-induced ductular reaction. Masson 3 and Sirius Red staining for hepatic hydroxyproline showed that TP alleviated BDL-induced hepatic fibrosis. Additionally, TP substantially inhibited BDL-induced hepatic inflammation. In summary, TP inhibited the BDL-induced ductular reaction by reducing the expression of RelB in cholangiocytes, thereby alleviating liver injury, fibrosis, and inflammation.

COVID-19 and the liver: a narrative review of the present state of knowledge.

Novel corona virus disease (COVID-19) is an ongoing pandemic that has spread across the globe. The virus primarily infects type-2 pneumocytes in alveoli and causes lung disease, with severity ranging from mild pneumonia to acute respiratory distress syndrome. The virus also invades gastrointestinal epithelial cells, hepatocytes, and biliary epithelial cells. Derangement of liver function tests is noted in about one third of patients and appears to correlate with more severe disease. There are multiple mechanisms by which the virus can cause liver injury; immune-mediated inflammation and direct viral cytotoxicity are believed to be the predominant mechanisms. Liver injury appears to be transient, usually recovering with resolution of illness. Limited available studies and experience from prior corona virus pandemics seem to suggest that immunosuppressed patients have similar outcomes compared to non-immunosuppressed patients. Age and comorbid conditions seem to influence outcome, irrespective of immune status. Additionally, patients with preexisting comorbid conditions are more prone to acquire infection and should strictly adhere to travel and social distancing advisories. Telemedicine should be utilized to provide uninterrupted care for patients with liver disease, and clinic or hospital visits should be advised only in sick patients with advanced liver disease. In conclusion, liver dysfunction is not uncommon in COVID-19, it generally improves with resolution of disease, and patients with chronic liver disease (CLD) need continued follow up, uninterrupted by the ongoing pandemic, preferably in virtual clinic settings.

S2969 Distinction Between Mitochondrial Antibody Positive and Negative Primary Biliary Cholangitis: Case Report and Literature Review

Introduction: Anti-mitochondrial antibody-positive primary biliary cholangitis (AMA-pos PBC) is an autoimmune disorder in which monoclonal antibodies are produced against epitopes with in the mitochondrial membranes of biliary epithelial cells, resulting in progressive non-suppurative biliary cholangitis. Up to 5 % of PBC patients lack these auto antibodies, termed as anti-mitochondrial antibody negative (AMA-neg) PBC. This is a somewhat new entity and a variant of AMA-pos PBC but not an overlap syndrome. There have not been good studies describing this phenomenon or associated terminology in the literature. Case Description/Methods: An 87-year-old woman was referred to our clinic after her medical oncologist found elevated isolated levels of serum alkaline phosphatase (714 units/L). She reported fatigue but denied any other symptoms. The physical examination was benign, except for bilateral lower extremity swelling secondary to lymphedema. Her serum alkaline phosphatase level decreased to 413 units/L after an initial dose of prednisone 40 mg daily, and she was maintained on 10 mg daily. Her antinuclear antibody titer was greater than 1:2560 in a centromere pattern. Anti- mitochondrial antibody was not detected. Total IgG level was 871 mg/dL (normal, < 1600 mg/dL), serum anti-smooth muscle antibody was negative, and the hepatitis panel was normal. Computed tomography of the abdomen and pelvis without contrast showed normal liver parenchyma and no acute intra-abdominal pathology. Histopathological examination indicated florid duct lesions. Background parenchyma showed no significant steatosis, and the inflammatory changes were limited primarily to the portal areas. Periodic acid-Schiff staining highlighted the intact hepatic parenchyma and architecture. The patient was diagnosed with AMA-neg PBC and responded well to Urosdeoxycholic acid therapy. (Figure) (Table). Discussion: This case highlights the importance of recognizing AMA-neg PBC as a variant of AMA-pos PBC and being able to differentiate them. Autoimmune cholangitis is a vague and imprecise term that cannot be used in this context. All AMA-negative PBC patients should be tested for other PBC-specific autoantibodies. Although prognosis and bile duct damage and loss are worse in AMA-neg PBC for unknown reasons, treatment remains the same for both.Figure 1.: A: The position of AMA-neg PBC in the spectrum of autoimmune hepatobiliary cholangiopathy PBC, primary biliary cholangitis; ANA, antimitochondrial antibody; IgM, immunoglobulin M; UDCA, ursodeoxycholic acid; AMA-neg, antimitochondrial antibody negative; ANA, antinuclear antibodies; IgG, Immunoglobulin G; ASMA, anti-smooth muscle antibody; anti-LKM-1, anti-liver kidney microsomal antibodies; Anti-LC-1, anti-liver cytosol antibodies; anti-SLA/LP antibodies, anti-soluble liver antigen/liver pancreas antibodies; MRCP, magnetic resonance cholangiogram; ERCP, endoscopic retrograde cholangio-pancreatogram. B and C:Two photomicrographs showing histologic features typical of the florid duct lesion seen in primary biliary cholangitis.. The portal areas show granulomatous inflammation and lymphocytic cholangitis of the bile ducts (pointed yellow arrows) (hematoxylin and eosin stain, 200X original magnification). Table 1. - Diagnostic criteria of AMA-Pos PBC The diagnosis of AMA-pos PBC can be established when two of the criteria listed in Table 1 are met[5] Evidence Criteria 1) Biochemical evidence of cholestasis Elevated alkaline phosphatase levels 2) Serological:AMA-Pos PBCAMA-Neg PBC Mitochondrial antibody positiveMitochondrial antibody negative/Presence of other PBC specific autoantibodies i.e., sp100 or gp210 3) Histopathological Nonsuppurative destructive cholangitis and destruction of interlobular bile ducts.

205 (PB085) - Anticancer activity of (±)-kusunokinin derivatives as a new HSP90 inhibitor

Background: Cholangiocarcinoma (CCA) is aggressive cancer arising from the malignant transformation of biliary epithelial cells. To date, surgical resection is the only potential option for CCA patients due to CCA being often chemotherapy-resistant. Therefore, finding a new potential compound to treat CCA is necessary. Previously, synthetic (±)-kusunokinin (sKU) and its derivative (bursehernin) represented cytotoxicity effect against well-differentiated CCA (KKU-M213) and low effect on undifferentiated CCA (KKU-K100) cells.

Extracellular vesicles of Clonorchis sinensis promote IL-6 and TNF-α secretion via the Toll-like receptor 9-mediated ERK pathway in biliary epithelial cells

Clonorchis sinensis is closely associated with cholangitis, cholecystitis, biliary fibrosis and cholangiocarcinoma. The present study elucidated the role of extracellular vesicles of C. sinensis (CsEVs) in activating Toll-like receptor 9 (TLR9) and regulating inflammatory responses. The results showed that TLR9 expression was increased in the livers of C. sinensis-infected mice. CsEVs were cup-shaped or saucer-shaped and 80–120 nm in diameter. CsEVs activated TLR9 and promoted IL-6 and TNF-α expression in mouse biliary epithelial cells (BECs), and TLR9 siRNA interference reduced the secretion of the two cytokines. CsEV stimulation promoted the phosphorylation of ERK, p38, AKT, and p65, and TLR9 siRNA interference regulated the phosphorylated ERK, AKT and p65 levels. The ERK inhibitor decreased the CsEVs-induced IL-6 and TNF-α secretion. The present study elucidated for the first time that CsEVs induced IL-6 and TNF-α production in BECs via the TLR9-mediated ERK pathway.

Knockout of liver fluke granulin, Ov-grn-1, impedes malignant transformation during chronic infection with Opisthorchis viverrini.

Infection with the food-borne liver fluke Opisthorchis viverrini is the principal risk factor for cholangiocarcinoma (CCA) in the Mekong Basin countries of Thailand, Lao PDR, Vietnam, Myanmar and Cambodia. Using a novel model of CCA, involving infection with gene-edited liver flukes in the hamster during concurrent exposure to dietary nitrosamine, we explored the role of the fluke granulin-like growth factor Ov-GRN-1 in malignancy. We derived RNA-guided gene knockout flukes (ΔOv-grn-1) using CRISPR/Cas9/gRNA materials delivered by electroporation. Genome sequencing confirmed programmed Cas9-catalyzed mutations of the targeted genes, which was accompanied by rapid depletion of transcripts and the proteins they encode. Gene-edited parasites colonized the biliary tract of hamsters and developed into adult flukes. However, less hepatobiliary tract disease manifested during chronic infection with ΔOv-grn-1 worms in comparison to hamsters infected with control gene-edited and mock-edited parasites. Specifically, immuno- and colorimetric-histochemical analysis of livers revealed markedly less periductal fibrosis surrounding the flukes and less fibrosis globally within the hepatobiliary tract during infection with ΔOv-grn-1 genotype worms, minimal biliary epithelial cell proliferation, and significantly fewer mutations of TP53 in biliary epithelial cells. Moreover, fewer hamsters developed high-grade CCA compared to controls. The clinically relevant, pathophysiological phenotype of the hepatobiliary tract confirmed a role for this secreted growth factor in malignancy and morbidity during opisthorchiasis.

Linking Human Betaretrovirus with Autoimmunity and Liver Disease in Patients with Primary Biliary Cholangitis.

Primary biliary cholangitis (PBC) is an autoimmune liver disease characterized by the production of diagnostic antimitochondrial antibodies (AMA) reactive to the pyruvate dehydrogenase complex. A human betaretrovirus (HBRV) resembling mouse mammary tumor virus has been characterized in patients with PBC. However, linking the viral infection with the disease is not a straight-forward process because PBC is a complex multifactorial disease influenced by genetic, hormonal, autoimmune, environmental, and other factors. Currently, PBC is assumed to have an autoimmune etiology, but the evidence is lacking to support this conjecture. In this review, we describe different approaches connecting HBRV with PBC. Initially, we used co-cultivation of HBRV with biliary epithelial cells to trigger the PBC-specific phenotype with cell surface expression of cryptic mitochondrial autoantigens linked with antimitochondrial antibody expression. Subsequently, we have derived layers of proof to support the role of betaretrovirus infection in mouse models of autoimmune biliary disease with spontaneous AMA production and in patients with PBC. Using Hill’s criteria, we provide an overview of how betaretrovirus infection may trigger autoimmunity and propagate biliary disease. Ultimately, the demonstration that disease can be cured with antiviral therapy may sway the argument toward an infectious disease etiology in an analogous fashion that was used to link H. pylori with peptic ulcer disease.

Oncostatin M: From Intracellular Signaling to Therapeutic Targets in Liver Cancer.

Primary liver cancers represent the third-most-common cause of cancer-related mortality worldwide, with an incidence of 80-90% for hepatocellular carcinoma (HCC) and 10-15% for cholangiocarcinoma (CCA), and an increasing morbidity and mortality rate. Although HCC and CCA originate from independent cell populations (hepatocytes and biliary epithelial cells, respectively), they develop in chronically inflamed livers. Evidence obtained in the last decade has revealed a role for cytokines of the IL-6 family in the development of primary liver cancers. These cytokines operate through the receptor subunit gp130 and the downstream Janus kinase/signal transducer and activator of transcription (JAK/STAT) signaling pathways. Oncostatin M (OSM), a member of the IL-6 family, plays a significant role in inflammation, autoimmunity, and cancer, including liver tumors. Although, in recent years, therapeutic approaches for the treatment of HCC and CCA have been implemented, limited treatment options with marginal clinical benefits are available. We discuss how OSM-related pathways can be selectively inhibited and therapeutically exploited for the treatment of liver malignancies.

Albendazole-induced autophagy blockade contributes to elevated apoptosis in cholangiocarcinoma cells through AMPK/mTOR activation

Albendazole (ABZ) is a broad-spectrum anti-parasitic drug that exhibits antitumor effects against several carcinomas. The effects of ABZ on cholangiocarcinoma (CCA) and its underlying mechanisms are still unclear. Our study aims to investigate the role of ABZ in inducing autophagy-mediated apoptosis of cholangiocarcinoma cells. The antitumor effects of ABZ were evaluated against CCA cells and HIBEC intrahepatic biliary epithelial cells. Furthermore, the apoptosis rates, and autophagy flux in RBE and FRH-0201 cells treated with ABZ were investigated. ABZ inhibited proliferation, induced cell death and apoptosis in CCA cells in vitro. In vivo, tumors from ABZ- treated BALB/c nude mice were significantly smaller than untreated mice. ABZ also induced the initiation of autophagy via AMPK/mTOR pathways, resulting in the formation of autophagosome. In addition, ABZ blocked autophagic flux by inhibiting the fusion of autophagosome-lysosome, which increased the apoptotic death of CCA cells. However, the apoptotic death of CCA cells induced by ABZ was reversed by 3-methyladenine (3-MA), an autophagosome formation inhibitor, but increased by chloroquine (CQ), an autophagosome-lysosome fusion inhibitor.Our work provides novel mechanisms for anti-tumor effects of ABZ on CCA, suggesting that ABZ may be used as a potent autophagy inhibitor in the treatment of CCA.

Cellular Homeostasis and Repair in the Biliary Tree.

During biliary tree homeostasis, BECs are largely in a quiescent state and their turnover is slow for maintaining normal tissue homeostasis. BTSCs continually replenish new BECs in the luminal surface of EHBDs. In response to various types of biliary injuries, distinct cellular sources, including HPCs, BTSCs, hepatocytes, and BECs, repair or regenerate the injured bile duct. BEC, biliary epithelial cell; BTSC, biliary tree stem/progenitor cell; EHBD, extrahepatic bile ducts; HPC, hepatic progenitor cell.The biliary tree comprises intrahepatic bile ducts and extrahepatic bile ducts lined with epithelial cells known as biliary epithelial cells (BECs). BECs are a common target of various cholangiopathies for which there is an unmet therapeutic need in clinical hepatology. The repair and regeneration of biliary tissue may potentially restore the normal architecture and function of the biliary tree. Hence, the repair and regeneration process in detail, including the replication of existing BECs, expansion and differentiation of the hepatic progenitor cells and biliary tree stem/progenitor cells, and transdifferentiation of the hepatocytes, should be understood. In this paper, we review biliary tree homeostasis, repair, and regeneration and discuss the feasibility of regenerative therapy strategies for cholangiopathy treatment.

A composite scaffold fabricated with an acellular matrix and biodegradable polyurethane for the in vivo regeneration of pig bile duct defects

Bile duct regeneration is urgently needed to restore the normal function of the damaged biliary system. In this study, an artificial bile duct (ABD) was fabricated for extrahepatic bile duct regeneration based on biodegradable polyurethane (BPU) and ureter acellular matrix (UAM) to endow it with favorable biocompatibility and eliminate bile leakage during in vivo bile duct regeneration. The mechanical properties, in vitro simulation of bile flow and cytocompatibility of BPU-UAM ABD were evaluated in vitro, and surgical implantation in the biliary defect site in minipigs was implemented to reveal the in vivo degradation of BPU-UAM and regeneration of the new bile duct. The results indicated that BPU-UAM ABD with a mechanical strength of 11.9 MPa has excellent cytocompatibility to support 3T3 fibroblast survival and proliferation in extraction medium and on the scaffolds. The in vivo implantation of BPU-UAM ABD revealed the change of collagen content throughout the new bile duct regeneration. Biliary epithelial cells were observed at day 70, and continuous biliary epithelial layer formation was observed after 100 days of implantation. Altogether, the BPU-UAM ABD fabricated in this study possesses excellent properties for application study in the regeneration of bile duct. Statement of significanceExtrahepatic bile duct defects carry considerable morbidity and mortality because they are the only pathway for bile to go down into the intestinal tract. At present, no artificial bile duct can promote biliary regeneration. In this study, BPU-UAM ABD was built based on biodegradable polyurethane and ureter acellular matrix to form a continuous compact layer of polyurethane in the internal wall of UAM and avoid bile leakage and experimental failure during in vivo implantation. Our work verified the effectiveness of the synthesized biodegradable polyurethane emulsion-modified urethral acellular matrix in bile regeneration and continuous biliary epithelial layer formation. This study provided a new approach for the curing of bile duct defects and inducing new bile tissue formation.

Novel Drug Candidate Prediction for Intrahepatic Cholangiocarcinoma via Hub Gene Network Analysis and Connectivity Mapping

Simple SummaryOnly about 15% of intrahepatic cholangiocarcinoma (ICC) patients meet the criteria for resection at the time of diagnosis. For patients with advanced and/or metastatic disease, the development of novel therapeutic strategies is urgently needed. The aim of our study was to identify possible novel therapeutic targets and drugs for ICC by using transcriptomic profiles from the Gene Expression Omnibus databases and The Cancer Genome Atlas. The weighted co-expression gene network was constructed to screen hub genes. Potential drug candidates with promise in the treatment of ICC were identified by analyzing key protein–protein interaction (PPI) networks of the hub genes to identify potential interacting drugs based on the Connectivity Map database.Intrahepatic cholangiocarcinoma (ICC) is an aggressive malignancy, and there is a need for effective systemic therapies. Gene expression profile-based analyses may allow for efficient screening of potential drug candidates to serve as novel therapeutics for patients with ICC. The RNA expression profile of ICC and normal biliary epithelial cells were downloaded from the Gene Expression Omnibus (GEO) and The Cancer Genome Atlas (TCGA) databases. Function annotation and enrichment pathway analyses of the differentially expressed genes (DEGs) were finished using the Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) databases. A weighted gene co-expression network (WGCN) was constructed by WGCN analysis (WGCNA). Key genes from the DEGs and co-expression gene modules were analyzed to generate a protein–protein interaction (PPI) network. The association between the top 10 screened hub genes and the overall and disease-free survival of ICC patients was examined. The Connectivity Map (cMap) analysis was performed to identify possible drugs for ICC using hub genes. A total of 151 key genes were selected from the overlapping genes of 1287 GSE-DEGs, 8183 TCGA-DEGs and 1226 genes in the mixed modules. A total of 10 hub genes of interest (CTNNB1, SPP1, COL1A2, COL3A1, SMAD3, SRC, VCAN, PKLR, GART, MRPS5) were found analyzing protein–protein interaction. Using the cMap, candidate drugs screened with potential efficacy for ICC included three tyrosine kinase inhibitors (dasatinib, NVP-BHG712, tivantinib), two cannabinoid receptor agonists (palmitoylethanolamide, arachidonamide), two antibiotics (moxifloxacin, amoxicillin), one estrogen receptor agonist (levonorgestrel), one serine/threonine protein kinase inhibitor (MK-2206) and other small molecules. Key genes from network and PPI analysis allowed us to identify potential drugs for ICC. The identification of novel gene expression profiles and related drug screening may accelerate the identification of potential novel drug therapies for ICC.

Bile Duct Regeneration with an Artificial Bile Duct Made of Gelatin Hydrogel Nonwoven Fabrics.

Although choledochojejunostomy is the standard technique for biliary reconstruction, there are various associated problems that need to be solved such as reflux cholangitis. Interposition with an artificial bile duct (ABD) to replace the resected bile duct maintains a physiological conduit for bile and may solve this problem. This study investigated the usefulness of an ABD made of gelatin hydrogel nonwoven fabric (GHNF). GHNF was prepared by the solution blow spinning method. The migration and activity of murine fibroblast L929 cells were examined in GHNF sheets. L929 cells migrated into GHNF sheets, where they proliferated and synthesized collagen, suggesting GHNF is a promising scaffold for bile duct regeneration. ABDs made of GHNF were implanted in place of resected bile duct segments in rats. The rats were killed at 2, 6, and 12 weeks postimplantation. The implantation site was histologically evaluated for bile duct regeneration. At postoperative 2 weeks, migrating cells were observed in the ABD pores. The implanted ABD was mostly degraded and replaced by collagen fibers at 6 weeks. Ki67-positive bile duct epithelial cells appeared within the implanted ABD. These were most abundant within the central part of the ABD after 6 weeks. The percentages of Ki67-positive cells were 31.7 ± 9.1% in the experimental group and 0.8 ± 0.6% in the sham operation group at 6 weeks (p < 0.05), indicating that mature biliary epithelial cells at the stump proliferated to regenerate the biliary epithelium. Biliary epithelial cells had almost completely covered the bile duct lumen at 12 weeks (epithelialization ratios: 10.4 ± 6.9% at 2 weeks, 93.1 ± 5.1% at 6 weeks, 99.2 ± 1.6% at 12 weeks). The regenerated epithelium was positive for the bile duct epithelium marker cytokeratin 19. Bile duct regeneration was accompanied by angiogenesis, as evidenced by the appearance of CD31-positive vascular structures. Capillaries were induced 2 weeks after implantation. The number of capillaries reached a maximum at 6 weeks and decreased to the same level as that of normal bile ducts at 12 weeks. These results showed that an ABD of GHNF contributed to successful bile duct regeneration in rats by facilitating the cell migration required for extracellular matrix synthesis, angiogenesis, and epithelialization. Impact Statement Development of an artificial bile duct (ABD) enables physiological biliary reconstruction and may solve clinical problems associated with choledochojejunostomy. In this study, we created ABDs with gelatin hydrogel nonwoven fabric and implanted them in place of resected bile duct in rats. We evaluated the process of bile duct regeneration as well as decomposition of the ABD and demonstrated successful regeneration of resected bile duct, highlighting the possibility of this novel biliary reconstruction method to replace choledochojejunostomy.

Abstract 6175: Developing antibody-drug conjugates against cholangiocarcinoma using a novel molecular target

Abstract As a rare malignancy, cholangiocarcinoma (CCA) is a lethal disease with a 5-year overall survival rate of merely 5%. Highly invasive and asymptomatic characteristics of CCA cause most patients diagnosed at advanced stages, severely deteriorating their clinical outcomes. The drug treatment options for CCA are limited and surgical resection of CCA frequently suffers from a high recurrence rate of 66%. Albeit Pemigatinib, a FGFR2 inhibitor, has recently been approved by FDA as the first CCA-targeted therapeutic, only less than 10% of patients with CCA carry FGFR2 fusion mutations that can benefit from this drug. Ivosidenib, another targeted drug against IDH1 mutation, only works for 13% CCA patients carrying this mutation. Therefore, discovering new molecular targets and developing associated targeted drugs remain a significant and unmet medical need in CCA therapy. In this study, we first screened potential molecular targets for CCA by comparing the expression levels of a panel of cancer-related cell membrane antigens between human CCA cells and normal human intrahepatic biliary epithelial cells through flow cytometry. CD54 was identified as a remarkable molecular target of CCA with strong binding force to its antibodies and high endocytosis efficiency by flow cytometry and confocal fluorescent microscopy. Meanwhile, we confirmed that CD54 was absent in most normal human tissues but was highly upregulated in CCA tumor tissues through immunohistochemical (IHC) staining. Based on this newly discovered CCA target, we constructed a series of CD54 antibody-drug conjugates (ADCs) using different chemical linkers and payloads. We next evaluated and compared the half maximum inhibitory concentrations (IC50s) of each ADC in ablating human CCA cells in vitro in order to identify an optimized ADC formulation. Furthermore, we validated its anti-tumor efficacy against primary and peritoneal metastatic CCA tumors in vivo in comparison with conventional chemotherapy. Eventually, we determined the biodistribution and safety profile of this CD54 ADC in order to ensure that it is well-tolerated under the effective dose. In general, we identified CD54 as a novel molecular target for CCA through antibody library screening, and explored its potential in the development of CCA-targeted ADCs, providing a promising targeted therapeutic for clinical treatment of CCA. Citation Format: Bing Zhu, Shi-Li Yao, Xin-Yan Wang, Rui Xu, Peng Guo, Jie-Er Ying. Developing antibody-drug conjugates against cholangiocarcinoma using a novel molecular target [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2022; 2022 Apr 8-13. Philadelphia (PA): AACR; Cancer Res 2022;82(12_Suppl):Abstract nr 6175.

Primary Biliary Cholangitis and Primary Sclerosing Cholangitis: Current Knowledge of Pathogenesis and Therapeutics.

Cholangiopathies encompass various biliary diseases affecting the biliary epithelium, resulting in cholestasis, inflammation, fibrosis, and ultimately liver cirrhosis. Primary biliary cholangitis (PBC) and primary sclerosing cholangitis (PSC) are the most important progressive cholangiopathies in adults. Much research has broadened the scope of disease biology to genetic risk, epigenetic changes, dysregulated mucosal immunity, altered biliary epithelial cell function, and dysbiosis, all of which interact and arise in the context of ill-defined environmental triggers. An in-depth understanding of the molecular pathogenesis of these cholestatic diseases will help clinicians better prevent and treat diseases. In this review, we focus on the main underlying mechanisms of disease initiation and progression, and novel targeted therapeutics beyond currently approved treatments.

Inflammasomes and Pyroptosis of Liver Cells in Liver Fibrosis.

Inflammasomes are multiprotein complexes that can sense danger signals and activate caspase-1 to mediate pro-inflammatory cytokines release and pyroptotic cell death. There are two main canonical and non-canonical signaling pathways that trigger inflammasome activation. Inflammasomes are expressed and assembled in parenchymal and nonparenchymal cells in response to liver injury in the liver. Additionally, the hepatocytes, biliary epithelial cells (cholangiocytes), hepatic stellate cells (HSCs), hepatic macrophages, and liver sinusoidal endothelial cells (LSECs) contribute to liver fibrosis via different mechanisms. However, the underlying mechanism of the inflammasome and pyroptosis in these liver cells in liver fibrosis remains elusive. This review summarizes the activation and function of inflammasome complexes and then discusses the association between inflammasomes, pyroptosis, and liver fibrosis. Unlike other similar reviewers, we will focus on the effect of inflammasome activation and pyroptosis in the various liver cells during the development of liver fibrosis. We will also highlight the latest progress of pharmacological intervention in inflammasome-mediated liver fibrosis.

Identification of the chloride channel, leucine-rich repeat-containing protein 8, subfamily a (LRRC8A), in mouse cholangiocytes.

Chloride (Cl- ) channels in the apical membrane of biliary epithelial cells (BECs), also known as cholangiocytes, provide the driving force for biliary secretion. Although two Cl- channels have been identified on a molecular basis, the Cystic Fibrosis Transmembrane Conductance Regulator and Transmembrane Member 16A, a third Cl- channel with unique biophysical properties has been described. Leucine-Rich Repeat-Containing Protein 8, subfamily A (LRRC8A) is a newly identified protein capable of transporting Cl- in other epithelium in response to cell swelling. The aim of the present study was to determine if LRRC8A represents the volume-regulated anion channel in mouse BECs. Studies were performed in mouse small (MSC) and large (MLC) cholangiocytes. Membrane Cl- currents were measured by whole-cell patch-clamp techniques and cell volume measurements were performed by calcein-AM fluorescence. Exposure of either MSC or MLC to hypotonicity (190 mOsm) rapidly increased cell volume and activated Cl- currents. Currents exhibited outward rectification, time-dependent inactivation at positive membrane potentials, and reversal potential at 0 mV (ECl ). Removal of extracellular Cl- or specific pharmacological inhibition of LRRC8A abolished currents. LRRC8A was detected in both MSC and MLC by reverse transcription polymerase chain reaction and confirmed by western blot. Transfection with LRRC8A small interfering RNA decreased protein levels by >70% and abolished volume-stimulated Cl- currents. These results demonstrate that LRRC8A is functionally present in mouse BECs, contributes to volume-activated Cl- secretion, and, therefore, may be a target to modulate bile formation in the treatment of cholestatic liver disorders.

Zn(II) Complex with Blue Luminescence and Its Promotion Activity on the Differentiation of Mesenchymal Stem Cells into Biliary Epithelial Cells

A new dual ligand-based Zn(II) compound, [Zn(Hbtc)(bmiph)]n·n(H2O) (1, where H3btc is 1,3,5-benzenetricarboxylic acid and bmiph is 1,4-bis(2-methyl-1H-imidazolyl)benzene), was prepared hydrothermally and characterized structurally through single-crystal X-ray diffraction. At environmental temperature, with 330 nm excitation, complex 1 showed intense blue luminescence with the CIE coordinate at (0.193, 0.1278). The promotion activity of 1 on the differentiation of mesenchymal stem cells into biliary epithelial cells was explored, and the corresponding mechanism was studied simultaneously. The vascular endothelial growth factor content in the serum was examined using ELISA. The relative expression of cirRNA29 in mesenchymal stem cells was measured using real-time RT-PCR.