Biliary Fibrosis Research Articles

Current therapies and novel approaches for biliary diseases.

Chronic liver diseases that inevitably lead to hepatic fibrosis, cirrhosis and/or hepatocellular carcinoma have become a major cause of illness and death worldwide. Among them, cholangiopathies or cholestatic liver diseases comprise a large group of conditions in which injury is primarily focused on the biliary system. These include congenital diseases (such as biliary atresia and cystic fibrosis), acquired diseases (such as primary sclerosing cholangitis and primary biliary cirrhosis), and those that arise from secondary damage to the biliary tree from obstruction, cholangitis or ischaemia. These conditions are associated with a specific pattern of chronic liver injury centered on damaged bile ducts that drive the development of peribiliary fibrosis and, ultimately, biliary cirrhosis and liver failure. For most, there is no established medical therapy and, hence, these diseases remain one of the most important indications for liver transplantation. As a result, there is a major need to develop new therapies that can prevent the development of chronic biliary injury and fibrosis. This mini-review briefly discusses the pathophysiology of liver fibrosis and its progression to cirrhosis. We make a special emphasis on biliary fibrosis and current therapeutic options, such as angiotensin converting enzyme-2 (known as ACE2) over-expression in the diseased liver as a novel potential therapy to treat this condition.

Surgical therapy for hepatolithiasis

Background: Hepatolithiasis [1] is very common in East Asia but infrequent in Western countries.[2] Is defined as the presence of multiple stones inside the bile ducts proximally to the biliary carrefour. Intrahepatic lithiasis could be classified in 2 types: Ectasia of Intrahepatic biliary duct withuot fibrosis (Caroli's Disease) and Obstructive dilatation of the intrahepatic bile duct secondary to ischemic stricture. Caroli's Disease (CD) is a rare congenital condition [3]. Malignancy is a complication of long – term CD, and some patients are presenting with [4] cholangiocarcinoma Methods: Between 1998 – 2016, 9 patients were operated on, 7 female and 2 male with a median age of 49,2 y.o (31 – 69). Most frequent symptoms were pain (5/55,5%), Abnormal LFT (3/33%) and Dyspepsia (1/11,1%). Hepatic distribution was: 5 patients in segments II, III and IV, and 4 in segment II and III. Open surgery was perfomed in 7 patients, and laparoscopic approach was carried out in 2. Results: Operative mortality was zero and morbidity rate was 1/11,1% (reoperated on due to bile leak and biliary peritonitis). Pathologycal examination showed CD in all cases; one of them had antral methaplasia. The mean follow-up period was 116,2 months (2-221). None presented recurrence of the symptoms. Conclusion: Surgical therapy is a safe and effective management for hepatolithiasis. The possibility of developing cholangiocarcinoma in inveterate patients is real, and hepatic resection removes the risk.

Transient c-Src Suppression During Endodermal Commitment of Human Induced Pluripotent Stem Cells Results in Abnormal Profibrotic Cholangiocyte-Like Cells.

Directed differentiation of human induced pluripotent stem cells (iPSCs) toward hepatobiliary lineages has been increasingly used as models of human liver development/diseases. As protein kinases are important components of signaling pathways regulating cell fate changes, we sought to define the key molecular mediators regulating human liver development using inhibitors targeting tyrosine kinases during hepatic differentiation of human iPSCs. A library of tyrosine kinase inhibitors was used for initial screening during the multistage differentiation of human iPSCs to hepatic lineage. Among the 80 kinase inhibitors tested, only Src inhibitors suppressed endoderm formation while none had significant effect on later stages of hepatic differentiation. Transient inhibition of c-Src during endodermal induction of human iPSCs reduced endodermal commitment and expression of endodermal markers, including SOX17 and FOXA2, in a dose-dependent manner. Interestingly, the transiently treated cells later developed into profibrogenic cholangiocyte-like cells expressing both cholangiocyte markers, such as CK7 and CK19, and fibrosis markers, including Collagen1 and smooth muscle actin. Further analysis of these cells revealed colocalized expression of collagen and yes-associated protein (YAP; a marker associated with bile duct proliferation/fibrosis) and an increased production of interleukin-6 and tumor necrosis factor-α. Moreover, treatment with verteporfin, a YAP inhibitor, significantly reduced expression of fibrosis markers. In summary, these results suggest that c-Src has a critical role in cell fate determination during endodermal commitment of human iPSCs, and its alteration in early liver development in human may lead to increased production of abnormal YAP expressing profibrogenic proinflammatory cholangiocytes, similar to those seen in livers of patients with biliary fibrosis. Stem Cells 2019;37:306-317.

SOX9 regulated matrix proteins are increased in patients serum and correlate with severity of liver fibrosis

Extracellular matrix (ECM) deposition and resultant scar play a major role in the pathogenesis and progression of liver fibrosis. Identifying core regulators of ECM deposition may lead to urgently needed diagnostic and therapetic strategies for the disease. The transcription factor Sex determining region Y box 9 (SOX9) is actively involved in scar formation and its prevalence in patients with liver fibrosis predicts progression. In this study, transcriptomic approaches of Sox9-abrogated myofibroblasts identified >30% of genes regulated by SOX9 relate to the ECM. Further scrutiny of these data identified a panel of highly expressed ECM proteins, including Osteopontin (OPN), Osteoactivin (GPNMB), Fibronectin (FN1), Osteonectin (SPARC) and Vimentin (VIM) as SOX9 targets amenable to assay in patient serum. In vivo all SOX-regulated targets were increased in human disease and mouse models of fibrosis and decreased following Sox9-loss in mice with parenchymal and biliary fibrosis. In patient serum samples, SOX9-regulated ECM proteins were altered in response to fibrosis severity, whereas comparison with established clinical biomarkers demonstrated superiority for OPN and VIM at detecting early stages of fibrosis. These data support SOX9 in the mechanisms underlying fibrosis and highlight SOX9 and its downstream targets as new measures to stratify patients with liver fibrosis.

Nuclear Translocation of RELB Is Increased in Diseased Human Liver and Promotes Ductular Reaction and Biliary Fibrosis in Mice

Cholangiocyte proliferation and ductular reaction contribute to the onset and progression of liver diseases. Little is known about the role of the transcription factor nuclear factor-κB (NF-κB) in this process. We investigated the activities of the RELB proto-oncogene NF-κB subunit in human cholangiocytes and in mouse models of liver disease characterized by a ductular reaction. We obtained liver tissue samples from patients with primary sclerosing cholangitis, primary biliary cholangitis, hepatitis B or C virus infection, autoimmune hepatitis, alcoholic liver disease, or without these diseases (controls) from a tissue bank in Germany. Tissues were analyzed by immunohistochemistry for levels of RELB and lymphotoxin β (LTB). We studied mice with liver parenchymal cell (LPC)-specific disruption of the cylindromatosis (CYLD) lysine 63 deubiquitinase gene (Cyld), with or without disruption of Relb (CyldΔLPC mice and Cyld/RelbΔLPC mice) and compared them with C57BL/6 mice (controls). Mice were fed 5-diethoxycarbonyl-1,4-dihydrocollidine (DDC) or standard chow diets to induce biliary injury or were given injections of CCl4 to induce non-cholestatic liver fibrosis. Liver tissues were analyzed by histology, immunohistochemistry, immunoblots, in situ hybridization, and quantitative real-time polymerase chain reaction. Cholangiocytes were isolated from normal human liver, incubated with LTB receptor agonist, and transfected with small interfering RNAs to knock down RELB. In liver tissues from patients with primary sclerosing cholangitis, primary biliary cholangitis, chronic infection with hepatitis B or C virus, autoimmune hepatitis, or alcoholic liver disease, we detected increased nuclear translocation of RELB and increased levels of LTB in cholangiocytes that formed reactive bile ducts compared with control liver tissues. Human cholangiocytes, but not those with RELB knockdown, proliferated with exposure to LTB. The phenotype of CyldΔLPC mice, which included ductular reaction, oval cell activation, and biliary fibrosis, was completely lost from Cyld/RelbΔLPC mice. Compared with livers from control mice, livers from CyldΔLPC mice (but not Cyld/RelbΔLPC mice) had increased levels of mRNAs encoding cytokines (LTB; CD40; and tumor necrosis factor superfamily [TNFSF] members TNFSF11 [RANKL], TNFSF13B [BAFF], and TNFSF14 [LIGHT]) produced by reactive cholangiocytes. However, these strains of mice developed similar levels of liver fibrosis in response to CCl4 exposure. CyldΔLPC mice and Cyld/RelbΔLPC mice had improved liver function on the DDC diet compared with control mice fed the DDC diet. Reactive bile ducts in patients with chronic liver diseases have increased levels of LTB and nuclear translocation of RELB. RELB is required for the ductular reaction and development of biliary fibrosis in CyldΔLPC mice. Deletion of RELB and CYLD from LPCs protects mice from DDC-induced cholestatic liver fibrosis.

Knockout of secretin receptor reduces biliary damage and liver fibrosis in Mdr2−/− mice by diminishing senescence of cholangiocytes

Secretin receptor (SR), only expressed by cholangiocytes, plays a key role in the regulation of biliary damage and liver fibrosis. The aim of this study was to determine the effects of genetic depletion of SR in Mdr2−/− mice on intrahepatic biliary mass, liver fibrosis, senescence, and angiogenesis. 12 wk SR−/−, Mdr2−/−, and SR−/−/Mdr2−/− mice with corresponding wild-type mice were used for the in vivo studies. Immunohistochemistry or immunofluorescence was performed in liver sections for (i) biliary expression of SR; (ii) hematoxylin and eosin; (iii) intrahepatic biliary mass by CK-19; (iv) fibrosis by Col1a1 and α-SMA; (v) senescence by SA-β-gal and p16; and (vi) angiogenesis by VEGF-A and CD31. Secretin (Sct) and TGF-β1 levels were measured in serum and cholangiocyte supernatant by ELISA. In total liver, isolated cholangiocytes or HSCs, we evaluated the expression of fibrosis markers (FN-1 and Col1a1); senescence markers (p16 and CCL2); microRNA 125b and angiogenesis markers (VEGF-A, VEGFR-2, CD31, and vWF) by immunoblots and/or qPCR. In vitro, we measured the paracrine effect of cholangiocyte supernatant on the expression of senescent and fibrosis markers in human hepatic stellate cells (HHSteCs). The increased level of ductular reaction, fibrosis, and angiogenesis in Mdr2−/− mice was reduced in SR−/−/Mdr2−/− mice. Enhanced senescence levels in cholangiocytes from Mdr2−/− mice were reversed to normal in SR−/−/Mdr2−/− mice. However, senescence was decreased in HSCs from Mdr2−/− mice but returned to normal values in SR−/−/Mdr2−/− mice. In vitro treatment of HHSteCs with supernatant from cholangiocyte lacking SR (containing lower biliary levels of Sct-dependent TGF-β1) have decreased fibrotic reaction and increased cellular senescence. Sct-induced TGF-β1 secretion was mediated by microRNA 125b. Our data suggest that differential modulation of angiogenesis-dependent senescence of cholangiocytes and HSCs may be important for the treatment of liver fibrosis in cholangiopathies.In this study the authors demonstrate that the secretin/secretin receptor axis plays a regulatory role in biliary proliferation and liver fibrosis through differential changes in the senescence of cholangiocytes and hepatic stellate cells in a mouse model of primary sclerosing cholangitis. Targeting senescent cholangiocytes by modulation of the secretin/secretin receptor axis may provide a key therapeutic approach in the treatment of cholestatic liver diseases.

Ursodeoxycholate inhibits mast cell activation and reverses biliary injury and fibrosis in Mdr2−/− mice and human primary sclerosing cholangitis

Ursodeoxycholic acid (UDCA) is used to treat biliary disorders; and, bile acids alter mast cell (MC) histamine release. MCs infiltrate Mdr2−/− mice liver (model of primary sclerosing cholangitis (PSC)). MC-derived histamine increases inflammation, hepatic stellate cell (HSC) activation and fibrosis. The objective was to determine the effects of UDCA treatment on MC infiltration, biliary damage, inflammation and fibrosis in Mdr2−/− mice and human PSC. Wild-type and Mdr2−/− mice were fed bile acid control diet or UDCA (0.5% wt/wt). Human samples were collected from control and PSC patients treated with placebo or UDCA (15 mg/kg/BW). MC infiltration was measured by immunhistochemistry and quantitative polymerase chain reaction (qPCR) for c-Kit, chymase, and tryptase. The HDC/histamine/histamine receptor (HR)-axis was evaluated by EIA and qPCR. Intrahepatic bile duct mass (IBDM) and biliary proliferation was evaluated by CK-19 and Ki-67 staining. Fibrosis was detected by immunostaining and qPCR for fibrotic markers. Inflammatory components were measured by qPCR. HSC activation was measured by SYP-9 staining. Inflammation was detected by qPCR for CD68. In vitro, MCs were treated with UDCA (40 μM) prior to HA secretion evaluation and coculturing with cholangiocytes or HSCs. BrDU incorporation and fibrosis by qPCR was performed. UDCA reduced MC number, the HDC/histamine/HR-axis, IBDM, HSC activation, inflammation, and fibrosis in Mdr2−/− mice and PSC patients. In vitro, UDCA decreases MC-histamine release, which was restored by blocking ASBT and FXRβ. Proliferation and fibrosis decreased after treatment with UDCA-treated MCs. We conclude that UDCA acts on MCs reducing histamine levels and decreases the inflammatory/hyperplastic/fibrotic reaction seen in PSC. Ursodeoxycholic acid (UDCA) is used to treat biliary disorders; and, bile acids alter mast cell (MC) histamine release. Following liver injury like primary sclerosing cholangitis in mice and humans, MCs infiltrate. MC-derived histamine increases biliary damage, fibrosis, and inflammation. UDCA treatment decreases these parameters via reduced MC activation.The bile acid rsodeoxycholic acid (UDCA) is the choice of treatment for primary biliary cholangitis patients with abnormal liver enzymes; however, its mechanism is not clear, and is the focus of this investigation. Bile acids alter mast cell (MC) histamine release. Following liver injury, such as that seen in primary sclerosing cholangitis, MCs infiltrate the liver. MC-derived histamine increases biliary damage, fibrosis, and inflammation. UDCA treatment decreases these parameters via reduced MC activation.

ABCB4 Gene Aberrations in Human Liver Disease: An Evolving Spectrum.

ATP-binding cassette subfamily B member 4 (ABCB4) is a phospholipid translocator at the canalicular membrane of the hepatocyte, which "flops" phosphatidylcholine into bile. Dysfunction of this transporter due to ABCB4 gene variants can cause liver diseases and has been called ABCB4 deficiency. Several diseases including progressive familial intrahepatic cholestasis type 3 (PFIC3), low phospholipid-associated cholelithiasis (LPAC), a subgroup of patients developing intrahepatic cholestasis of pregnancy (ICP), drug-induced liver injury and chronic cholangiopathy with biliary fibrosis and cirrhosis were attributed to ABCB4 deficiency and characterized in the past decade. LPAC and ICP are usually caused by monoallelic variants, whereas patients affected by PFIC3 are homozygous or compound heterozygous carriers of ABCB4 variants. Treatment with ursodeoxycholic acid is often effective, but as the more severe forms of ABCB4 deficiency progress, nevertheless, new diagnostic and therapeutic approaches are warranted. Current functional classifications for ABCB4 deficiency-associated mutations can guide the development of novel genotype-based targeted pharmacotherapies for these conditions. Recently, increasing evidence from genome-wide association studies is emerging on associations of ABCB4 variants with hepatobiliary malignancies.

Oriental Cholangiohepatitis: Hong Kong Disease in the United States

Oriental cholangiohepatitis, also known as Hong Kong disease, is a chronic disease initially triggered by a parasitic infection that results in biliary tree strictures and multiple stones formation in the intrahepatic and extrahepatic ducts. This leads to biliary stasis which ultimately causes recurrent pyogenic cholangitis (RPC). Although the disease is exclusively endemic in Asian countries, several cases has been identified in the United states. A 25 year old Burmese male who immigrated to the USA 3 years ago presented to the hospital with a sudden onset of severe sharp right upper quadrant abdominal pain, fever and jaundice. His only medical history was Opisthorchis viverrini liver fluke infection that was previously treated with praziquantel. On physical exam, he was febrile, tachycardic and hypotensive. He also had altered mental status, scleral icterus and right quadrant abdominal tenderness. Laboratory data showed WBCs 16.1 k/ul, alkaline phosphatase 152 IU/l, AST 58 IU/dl, ALT 71 IU/l, and total bilirubin 1.6 mg/dl (Direct bilirubin 1 mg/dl). Abdominal CT showed dilated intrahepatic bile ducts. MRCP showed numerous intrahepatic filling defects. The patient met all criteria for Reynolds pentad and was diagnosed with septic shock secondary to cholangitis. Intravenous fluids and empiric broad spectrum antibiotics were started. An ERCP was performed which illustrated filling defects in the proximal common bile duct. Pus was drained from the biliary ducts. Blood cultures grew Escherichia coli. Stool for ova and parasite was negative. The patient's symptoms resolved and was discharged in good condition. Over the following two years, the patient was admitted 4 times with recurrent cholangitis that was treated with intravenous antibiotics and biliary drainage with ERCP. He underwent a common bile duct resection with hepaticojejunostomy. The patient did not have any recurrence within 2 years after surgery.1349_A.tif Figure 1: MRCP Showing common bile duct dilation with minimal stone/debris1349_B.tif Figure 2: MRCP Showing intrahepatic bile ducts strictures1349_C.tif Figure 3: MRCP Showing moderate intrahepatic bile duct dilatation CBD stones and dilation with multiple filling defectsOriental cholangiohepatitis can present with RPC which could be life threatening. While treatment with praziquantel is successful in eradicating the offending organism in 90% of the cases, this does not result in resolution of biliary fibrosis. Due to the influx of immigrants, oriental cholangiohepatitis should be suspected in patients from endemic areas. Patients with RPC should be referred for early surgical evaluation to prevent associated morbidity and mortality.

Interleukin 2 Promotes Hepatic Regulatory T Cell Responses and Protects From Biliary Fibrosis in Murine Sclerosing Cholangitis.

In the multidrug resistance protein 2 (Mdr2)-/- mouse model, low phospholipid bile instigates biliary epithelial injury, sterile inflammation, and fibrosis, thereby recapitulating disease mechanisms implicated in biliary atresia (BA) and primary sclerosing cholangitis. We hypothesize that T lymphocytes contribute to the biliary injury and fibrosis in murine sclerosing cholangitis (SC) and that they are susceptible to suppression by regulatory T cells (Tregs). In juvenile Mdr2-/- mice, intrahepatic CD8+ lymphocytes were expanded, and contraction of intrahepatic Tregs coincided with rising serum alanine transferase and alkaline phosphatase (ALP) levels between days 14-30 of life. Antibody-mediated depletion of intrahepatic CD8+ lymphocytes during that time reduced ALP levels and the expression of osteopontin (Opn), a pro-fibrogenic cytokine. Depletion of intrahepatic Tregs with anti-CD25 antibody between days 7-30 increased intrahepatic CD8+ T cells, Opn expression, and fibrosis. Conversely, expansion of intrahepatic Tregs with interleukin 2/anti-interleukin 2 immune complexes (IL-2c) downregulated hepatic expression of Opn and Tnf, reduced frequency of intrahepatic CD8+ lymphocytes, and diminished biliary injury and fibrosis. Treatment with IL-2c upregulated hepatic Treg expression of CD39, an ectonucleotidase capable of hydrolyzing pro-inflammatory adenosine triphosphate. In vitro, Tregs expressing CD39 suppressed the proliferation of hepatic CD8+ lymphocytes from Mdr2-/- mice more efficiently than those lacking CD39. In infants with BA, infiltration of interlobular bile ducts with CD8+ cells was associated with biliary expression of Opn and its transcription was negatively correlated with mRNA expression of Treg-associated genes. Conclusion: Hepatic CD8+ T lymphocytes drive biliary injury and fibrosis in murine SC. Their proliferation is controlled by hepatic Tregs through the purinergic pathway, which is responsive to IL-2c, suggesting that Treg-directed low-dose Il-2 treatment may be considered as therapy for SC.

Loss of Prolyl-Hydroxylase 1 Protects against Biliary Fibrosis via Attenuated Activation of Hepatic Stellate Cells

Liver fibrosis, eventually progressing to cirrhosis necessitating liver transplantation, poses a significant clinical problem. Oxygen shortage (hypoxia) and hypoxia-inducible transcription factors (HIFs) have been acknowledged as important drivers of liver fibrosis. The significance of oxygen-sensing HIF prolyl-hydroxylase (PHD) enzymes in this context has, however, remained elusive. In this study, we demonstrate that loss of PHD1 (PHD1-/-) attenuates the development of liver fibrosis in mice subjected to chronic bile duct injury, induced by 3,5-diethoxycarbonyl-1,4-dihydrocollidine. This effect was accompanied with reduced recruitment of inflammatory leukocytes and attenuated occurrence of profibrotic myofibroblasts in PHD1-/- livers. Further analyses focused on the significance of PHD1 in the activation of hepatic stellate cells (HSCs), which represent the driving force in liver fibrosis. Primary HSCs isolated from PHD1-/- mice displayed significantly attenuated myofibroblast differentiation and profibrogenic properties compared with HSCs isolated from wild-type mice. Consistently, the expression of various profibrogenic and promitogenic factors was reduced in PHD1-/- HSCs, without alterations in HIF-1α protein levels. Of importance, PHD1 protein was expressed in HSCs within human livers, and PHD1 transcript expression was significantly increased with disease severity in hepatic tissue from patients with liver fibrosis. Collectively, these findings indicate that PHD1 deficiency protects against liver fibrosis and that these effects are partly due to attenuated activation of HSCs. PHD1 may represent a therapeutic target to alleviate liver fibrosis.

Rapamycin and Zoledronic acid exert a potent antifibrotic effect in murine biliary fibrosis

Rapamycin and Zoledronic acid exert a potent antifibrotic effect in murine biliary fibrosis

Preoperative Evaluation in Bariatric Surgery.

An adequate preoperative workup is critical for the success of bariatric surgery. A key component of the preoperative evaluation involves a comprehensive patient education about surgical outcomes and the postoperative behavioral regimen required. A complete medical evaluation should include the study of the cardiovascular, pulmonary, and gastrointestinal systems as well as a metabolic status assessment. The nutrition professional should be in charge of the nutritional assessment, preoperative weight loss efforts, and diet education regarding postoperative eating behaviors. A psychological evaluation is also needed because psychosocial factors have a significant impact on the long-term outcomes of bariatric surgery, including adherence to recommended postoperative lifestyle regimen, emotional adjustment, and weight loss outcomes. We recommend preoperative abdominal ultrasound to assess for biliary tract pathology, steatosis, fibrosis, and presence of nonalcoholic steatohepatitis. A routine preoperative esophagogastroduodenoscopy is also recommended to evaluate common gastrointestinal disorders associated with obesity. Preoperative weight loss should be strongly encouraged.

Pretreatment prediction of response to ursodeoxycholic acid in primary biliary cholangitis: development and validation of the UDCA Response Score

Treatment guidelines recommend a stepwise approach to primary biliary cholangitis: all patients begin treatment with ursodeoxycholic acid (UDCA) monotherapy and those with an inadequate biochemical response after 12 months are subsequently considered for second-line therapies. However, as a result, patients at the highest risk can wait the longest for effective treatment. We determined whether UDCA response can be accurately predicted using pretreatment clinical parameters. We did logistic regression analysis of pretreatment variables in a discovery cohort of patients in the UK with primary biliary cholangitis to derive the best-fitting model of UDCA response, defined as alkaline phosphatase less than 1·67 times the upper limit of normal (ULN), measured after 12 months of treatment with UDCA. We validated the model in an external cohort of patients with primary biliary cholangitis and treated with UDCA in Italy. Additionally, we assessed correlations between model predictions and key histological features, such as biliary injury and fibrosis, on liver biopsy samples. 2703 participants diagnosed with primary biliary cholangitis between Jan 1, 1998, and May 31, 2015, were included in the UK-PBC cohort for derivation of the model. The following pretreatment parameters were associated with lower probability of UDCA response: higher alkaline phosphatase concentration (p<0·0001), higher total bilirubin concentration (p=0·0003), lower aminotransferase concentration (p=0·0012), younger age (p<0·0001), longer interval from diagnosis to the start of UDCA treatment (treatment time lag, p<0·0001), and worsening of alkaline phosphatase concentration from diagnosis (p<0·0001). Based on these variables, we derived a predictive score of UDCA response. In the external validation cohort, 460 patients diagnosed with primary biliary cholangitis were treated with UDCA, with follow-up data until May 31, 2016. In this validation cohort, the area under the receiver operating characteristic curve for the score was 0·83 (95% CI 0·79-0·87). In 20 liver biopsy samples from patients with primary biliary cholangitis, the UDCA response score was associated with ductular reaction (r=-0·556, p=0·0130) and intermediate hepatocytes (probability of response was 0·90 if intermediate hepatocytes were absent vs 0·51 if present). We have derived and externally validated a model based on pretreatment variables that accurately predicts UDCA response. Association with histological features provides face validity. This model provides a basis to explore alternative approaches to treatment stratification in patients with primary biliary cholangitis. UK Medical Research Council and University of Milan-Bicocca.

The small molecule drug diminazene aceturate inhibits liver injury and biliary fibrosis in mice

There is no established medical therapy to treat biliary fibrosis resulting from chronic inflammation in the biliary tree. We have recently shown that liver-specific over-expression of angiotensin converting enzyme 2 (ACE2) of the renin angiotensin system (RAS) ameliorated liver fibrosis in mice. Diminazene aceturate (DIZE), a small molecule drug approved by the US Food and Drug Administration, which is used to treat human trypanosomiasis, has been shown to have antifibrotic properties by enhancing ACE2 activity. In this study we sought to determine the therapeutic potential of DIZE in biliary fibrosis using bile duct ligated and multiple drug resistant gene-2 knockout mice. Additionally, human hepatic stellate (LX-2) and mouse Kupffer (KUP5) cell lines were used to delineate intracellular pathways. DIZE treatment, both in vivo and in vitro, markedly inhibited the activation of fibroblastic stellate cells which was associated with a reduced activation of Kupffer cells. Moreover, DIZE-inhibited NOX enzyme assembly and ROS generation, activation of profibrotic transcription factors including p38, Erk1/2 and Smad2/3 proteins and proinflammatory and profibrotic cytokine release. These changes led to a major reduction in biliary fibrosis in both models without affecting liver ACE2 activity. We conclude that DIZE has a potential to treat biliary fibrosis.

Therapeutic Efficacy of Adipose-Derived Stromal Vascular Fraction Cells is associated with CD34 Positivity in Acute-on-Chronic Liver Failure

Background Adipose-derived stromal vascular fraction (SVF) cells, a rich source of primary stem/stromal cells, are promising for administering cell therapy for patients with acute-on-chronic liver failure (ACLF). We evaluated the therapeutic effects of CD34+/CD34− SVF cells in hepatocyte cotransplantation in a rat model of ACLF. Method ACLF was induced in Sprague–Dawley rats by temporary bile duct ligation (chronic) and D-galactosamine administration (acute). Donor hepatocytes and SVF cells were isolated from Tg(UBC–emGFP) rats and human adipose tissues, respectively. Sorted CD34+ and CD34− SVF cells were separated using a magnetic bead system. Rat hepatocytes and SVF cells (labeled with the PKH26 fluorescent dye) were intraportally transplanted into ACLF rats. The surviving animals were sacrificed at 1 and 2 weeks after the transplantation. Results ACLF was evidenced by the onset of acute coagulopathy and hepatocyte necrosis in fibrotic livers. Compared with the control group, the unsorted group showed less biliary ductular proliferation and fibrosis at 1 week after the transplantation. Furthermore, prominent biliary ductular proliferation and significantly progression of fibrosis (P = .005) were observed in the CD34− group than in the CD34+ group. At 2 weeks, the serum level of alkaline phosphatase was significantly higher in the CD34− group than in the CD34+ group (P = .007). The transplanted SVF cells were found in the periportal regions at 1 week, whereas donor hepatocytes were not detected and proliferation of endogenous hepatocytes was observed at times. Conclusion Compared with CD34− SVF cells, cotransplantation of CD34+ SVF cells resulted in the early amelioration of liver fibrosis and biliary ductular proliferation. Heterogeneous therapeutic effects of SVF cells were associated with CD34 positivity, which poses translational significance in future cell therapy.

Blocking H1/H2 histamine receptors inhibits damage/fibrosis in Mdr2-/- mice and human cholangiocarcinoma tumorigenesis.

Primary sclerosing cholangitis (PSC) patients are at risk of developing cholangiocarcinoma (CCA). We have shown that (1) histamine increases biliary hyperplasia through H1/H2 histamine receptors (HRs) and (2) histamine levels increase and mast cells (MCs) infiltrate during PSC and CCA. We examined the effects of chronic treatment with H1/H2HR antagonists on PSC and CCA. Wild-type and multidrug-resistant knockout (Mdr2-/- ) mice were treated by osmotic minipumps with saline, mepyramine, or ranitidine (10 mg/kg body weight/day) or a combination of mepyramine/ranitidine for 4 weeks. Liver damage was assessed by hematoxylin and eosin. We evaluated (1) H1/H2HR expression, (2) MC presence, (3) L-histidine decarboxylase/histamine axis, (4) cholangiocyte proliferation/bile duct mass, and (5) fibrosis/hepatic stellate cell activation. Nu/nu mice were implanted with Mz-ChA-1 cells into the hind flanks and treated with saline, mepyramine, or ranitidine. Tumor growth was measured, and (1) H1/H2HR expression, (2) proliferation, (3) MC activation, (4) angiogenesis, and (5) epithelial-mesenchymal transition (EMT) were evaluated. In vitro, human hepatic stellate cells were evaluated for H1HR and H2HR expression. Cultured cholangiocytes and CCA lines were treated with saline, mepyramine, or ranitidine (25 μM) before evaluating proliferation, angiogenesis, EMT, and potential signaling mechanisms. H1/H2HR and MC presence increased in human PSC and CCA. In H1/H2HR antagonist (alone or in combination)-treated Mdr2-/- mice, liver and biliary damage and fibrosis decreased compared to saline treatment. H1/H2HR antagonists decreased tumor growth, serum histamine, angiogenesis, and EMT. In vitro, H1/H2HR blockers reduced biliary proliferation, and CCA cells had decreased proliferation, angiogenesis, EMT, and migration. Conclusion: Inhibition of H1/H2HR reverses PSC-associated damage and decreases CCA growth, angiogenesis, and EMT; because PSC patients are at risk of developing CCA, using HR blockers may be therapeutic for these diseases. (Hepatology 2018).

Effects of vedolizumab, adalimumab and infliximab on biliary inflammation in individuals with primary sclerosing cholangitis and inflammatory bowel disease.

Primary sclerosing cholangitis (PSC) is a chronic, progressive cholestatic biliary disease associated with inflammatory bowel disease (IBD) with no known cure. To evaluate the effect of biological therapies on PSC progression in IBD patients. We performed a retrospective cohort study of 88 cases (75 unique patients with 12 patients treated >1 biologics) of IBD (48 ulcerative colitis, 24 Crohn's disease and 3 indeterminate colitis) with concomitant PSC who received biological therapy (42 infliximab, 19 adalimumab, 27 vedolizumab) between June 2002 and October 2017. Hepatic biochemistries were compared using the paired t-test (patients served as their own controls) ≤3months before and 6-8 and 12-14months after biological initiation. Radiographic information of biliary stenosis and liver fibrosis were obtained via abdominal ultrasound, abdominal magnetic resonance imaging and magnetic resonance elastography. Use of adalimumab was associated with a significant decrease in alkaline phosphatase (ALP) after 6-8 months (P=0.03; mean change -70U/L, standard deviation [SD] 88U/L) compared to vedolizumab (mean change +50U/L, SD 142 U/L) or infliximab (mean change +37 U/L, SD 183U/L) but the change was not significant after 12-14 months (P=0.24). No significant decreases were observed with AST, ALT, total or direct bilirubin, elastography score or radiographic imaging of biliary tree dilation/strictures with any biological therapy after 6-8 or 12-14 months. Current evidence suggests that biological therapies used for the treatment of IBD are not effective treatments for PSC. Further study is needed to elucidate any potential beneficial effect of adalimumab on PSC.

557 - Melatonin and Dark Therapy Reduce Biliary Damage, Liver Fibrosis and Angiogenesis in a Murine Model of Early Stage Primary Biliary Cholangitis (PBC)

557 - Melatonin and Dark Therapy Reduce Biliary Damage, Liver Fibrosis and Angiogenesis in a Murine Model of Early Stage Primary Biliary Cholangitis (PBC)

Melatonin or Dark Therapy Reduce Biliary Damage, Inflammation and Liver Fibrosis in a Murine Model of Early Stage Primary Biliary Cholangitis

BackgroundPrimary biliary cholangitis (PBC) is characterized by increased biliary damage, inflammation and liver fibrosis. Early stage PBC is marked by biliary proliferation, whereas late stage PBC shows ductopenia. We have shown that dominant‐negative transforming growth factor b receptor II (dnTGFβRII) mice at 12 wk of age mimic early stage PBC. We have found that melatonin therapy or prolonged exposure to complete darkness reduces biliary hyperplasia and liver fibrosis in models of cholestasis. However, the impact of melatonin or dark therapy on PBC‐related injury is unknown. The aim of our study was to evaluate the effects of melatonin or dark therapy in a mouse model of early stage PBC.MethodsWe used background‐matched, male wild‐type (WT) and dnTGFβRII at 12 wk of age that were given drinking water containing melatonin (0.03%) or placed in complete darkness for 1 wk along with the related controls. Liver damage was evaluated by H&amp;E. Intrahepatic bile duct mass (IBDM) was measured by CK‐19 staining. Biliary senescence was evaluated by staining for p16 and p21, and SA‐β‐galactosidase activity. Biliary and liver inflammation were determined by IL‐6 and F4/80 (Kupffer cell marker) staining. Liver fibrosis was determined by Sirius Red staining and immunofluorescence for collagen type‐1a. Hepatic stellate cell (HSC) activation was shown by SYP‐9 and α‐SMA staining. Human control and early stage PBC serum samples were obtained, and serum melatonin levels were measured by EIA.ResultsdnTGFβRII at 12 wk of age (early stage PBC mouse model) treated with melatonin or complete darkness had decreased (i) IBDM, (ii) biliary senescence, (iii) liver fibrosis, (iv) biliary and liver inflammation, and (v) HSC activation/liver fibrosis. Human early stage PBC samples had decreased serum melatonin levels.ConclusionInhibition of melatonin signaling perpetuates biliary damage associated with PBC. Restoration of melatonin‐dependent signaling via melatonin treatment or dark therapy may be therapeutic for patients with early stage PBC.Support or Funding InformationNIH NIDDK R01, VA MeritThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.