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Cholestatic patients often present with clinical features suggestive of adrenal insufficiency. In the bile duct-ligated (BDL) model of cholestasis, the hypothalamic-pituitary-adrenal (HPA) axis is suppressed. The consequences of this suppression on cholangiocyte proliferation are unknown. We evaluated 1) HPA axis activity in various rat models of cholestasis and 2) effects of HPA axis modulation on cholangiocyte proliferation. Expression of regulatory molecules of the HPA axis was determined after BDL, partial BDL, and α-naphthylisothiocyanate (ANIT) intoxication. The HPA axis was suppressed by inhibition of hypothalamic corticotropin-releasing hormone (CRH) expression by central administration of CRH-specific Vivo-morpholinos or by adrenalectomy. After BDL, the HPA axis was reactivated by 1) central administration of CRH, 2) systemic ACTH treatment, or 3) treatment with cortisol or corticosterone for 7 days postsurgery. There was decreased expression of 1) hypothalamic CRH, 2) pituitary ACTH, and 3) key glucocorticoid synthesis enzymes in the adrenal glands. Serum corticosterone and cortisol remained low after BDL (but not partial BDL) compared with sham surgery and after 2 wk of ANIT feeding. Experimental suppression of the HPA axis increased cholangiocyte proliferation, shown by increased cytokeratin-19- and proliferating cell nuclear antigen-positive cholangiocytes. Conversely, restoration of HPA axis activity inhibited BDL-induced cholangiocyte proliferation. Suppression of the HPA axis is an early event following BDL and induces cholangiocyte proliferation. Knowledge of the role of the HPA axis during cholestasis may lead to development of innovative treatment paradigms for chronic liver disease.

Background and objectives Cholangiocarcinoma is a devastating cancer of biliary origin with limited treatment options. The growth factor, progranulin, is overexpressed in a number of tumours. The study aims were to assess the expression of progranulin in cholangiocarcinoma and to determine its effects on tumour growth. Methods The expression and secretion of progranulin were evaluated in multiple cholangiocarcinoma cell lines and in clinical samples from patients with cholangiocarcinoma. The role of interleukin 6 (IL-6)-mediated signalling in the expression of progranulin was assessed using a combination of specific inhibitors and shRNA knockdown techniques. The effect of progranulin on proliferation and Akt activation and subsequent effects of FOXO1 phosphorylation were assessed in vitro. Progranulin knockdown cell lines were established, and the effects on cholangiocarcinoma growth were determined. Results Progranulin expression and secretion were upregulated in cholangiocarcinoma cell lines and tissue, which were in part via IL-6-mediated activation of the ERK1/2/RSK1/C/EBPβ pathway. Blocking any of these signalling molecules, by either pharmacological inhibitors or shRNA, prevented the IL-6-dependent activation of progranulin expression. Treatment of cholangiocarcinoma cells with recombinant progranulin increased cell proliferation in vitro by a mechanism involving Akt phosphorylation leading to phosphorylation and nuclear extrusion of FOXO1. Knockdown of progranulin expression in cholangiocarcinoma cells decreased the expression of proliferating cellular nuclear antigen, a marker of proliferative capacity, and slowed tumour growth in vivo. Conclusions Evidence is presented for a role for progranulin as a novel growth factor regulating cholangiocarcinoma growth. Specific targeting of progranulin may represent an alternative for the development of therapeutic strategies.

Clinical trials are abundant in adult cardiovascular medicine; however, they are rare in pediatric cardiology. Pediatric cardiac trial design may be impacted by the heterogeneous nature of the underlying cardiac defects, as well as by a strong emotional response from parents whose child will undergo a surgical intervention. The purpose of this study was to assess factors that may have an impact on parents considering enrollment of their child in a clinical trial at the time of surgical intervention. A voluntary, self-administered questionnaire (14 questions) was provided to parents of children 16 years of age or younger during the preadmission testing period. Demographic and procedure-related variables were collected for each patient. A total of 119 surveys were analyzed over a 1.5-year period. Only 8% of the parents had their child participate in a clinical trial in the past. Fifty-six percent of the parents preferred that their child's cardiologist or surgeon explain clinical trial details, with 23% preferring the principal investigator and 3% preferring the research coordinator. Fifty percent of the parents were favorably disposed to participate in a clinical trial if the drug or device was currently used by their child's doctor, and 19% were encouraged to participate if the drug or device was approved for use in adults. The majority of parents (64%) preferred to be asked about participating in a trial within 1 month prior to the planned procedure, and 40% preferred to discuss trial details at a remote time in an outpatient location. Sixty-three percent of parents believed that most of the medications currently used in children were already approved by the Food and Drug Administration. Most parents (91%) believed that clinical trials conducted in children will help improve pediatric health care; 74% believed that their child may receive potential benefit from enrolling in a trial. Finally, 43% believed that funding for trials should come from government and health care agencies, as opposed to pharmaceutical companies (24%). This survey reveals the importance of the attending physician and timing in educating parents regarding a cardiac critical care clinical trial. These data may impact the design and successful conduct of future trials.

Background Since limited in vitro tools exist for evaluating the pathophysiology of extrahepatic bile ducts, we aim to develop an extrahepatic cholangiocyte culture system from normal rats. Methods Extrahepatic ducts were dissected from rats, cut in half length-wise and cultured on collagen-I coated plates. Transepithelial electrical resistance was measured. At ∼85% confluence, in extrahepatic cholangiocytes we measured: (i) cell size and distribution, and expression for cytokeratin-19, secretin, secretin receptor and somatostatin receptor type II (SSTR2), cystic fibrosis transmembrane conductance regulator (CFTR), chloride bicarbonate anion exchanger 2 (AE2), vascular endothelial growth factor-A (VEGF-A) and nerve growth factor (NGF); and (ii) the effect of secretin and/or somatostatin on 3′-5′-cyclic adenosine monophosphate (cAMP) levels and proliferation. Results Cytokeratin-positive extrahepatic cholangiocytes were cultured for 6 passages to form a cell monolayer. Cholangiocytes proliferated to confluence over a 2-week period. The size of extrahepatic cholangiocytes averaged ∼16 μm. Extrahepatic ducts and cholangiocytes were positive for secretin, secretin receptor and SSTR2, CFTR, AE2, VEGF-A and NGF. In extrahepatic cholangiocyte cultures, secretin increased cAMP (prevented by somatostatin), chloride efflux and proliferation. Conclusions Extrahepatic cholangiocyte cultures may be important for studying diseases targeting extrahepatic cholangiocytes such as biliary atresia.

Hepatic encephalopathy is a serious neurological complication of liver failure. Serum bile acids are elevated after liver damage and may disrupt the blood-brain barrier and enter the brain. Our aim was to assess the role of serum bile acids in the neurological complications after acute liver failure. C57Bl/6 or cytochrome p450 7A1 knockout (Cyp7A1(-/-)) mice were fed a control, cholestyramine-containing, or bile acid-containing diet before azoxymethane (AOM)-induced acute liver failure. In parallel, mice were given an intracerebroventricular infusion of farnesoid X receptor (FXR) Vivo-morpholino before AOM injection. Liver damage, neurological decline, and molecular analyses of bile acid signaling were performed. Total bile acid levels were increased in the cortex of AOM-treated mice. Reducing serum bile acids via cholestyramine feeding or using Cyp7A1(-/-) mice reduced bile acid levels and delayed AOM-induced neurological decline, whereas cholic acid or deoxycholic acid feeding worsened AOM-induced neurological decline. The expression of bile acid signaling machinery apical sodium-dependent bile acid transporter, FXR, and small heterodimer partner increased in the frontal cortex, and blocking FXR signaling delayed AOM-induced neurological decline. In conclusion, circulating bile acids may play a pathological role during hepatic encephalopathy, although precisely how they dysregulate normal brain function is unknown. Strategies to minimize serum bile acid concentrations may reduce the severity of neurological complications associated with liver failure.

Background & Aims Hepatic encephalopathy (HE) is a neurologic disorder that develops during liver failure. Few studies exist investigating systemic-central signalling during HE outside of inflammatory signalling. The transcription factor Gli1, which can be modulated by hedgehog signalling or transforming growth factor β1 (TGFβ1) signalling, has been shown to be protective in various neuropathies. We measured Gli1 expression in brain tissues from mice and evaluated how circulating TGFβ1 and canonical hedgehog signalling regulate its activation. Methods Mice were injected with azoxymethane (AOM) to induce liver failure and HE in the presence of Gli1 vivo-morpholinos, the hedgehog inhibitor cyclopamine, Smoothened vivo-morpholinos, a Smoothened agonist, or TGFβ-neutralizing antibodies. Molecular analyses were used to assess Gli1, hedgehog signalling, and TGFβ1 signalling in the liver and brain of AOM mice and HE patients. Results Gli1 expression was increased in brains of AOM mice and in HE patients. Intra-cortical infusion of Gli1 vivo-morpholinos exacerbated the neurologic deficits of AOM mice. Measures to modulate hedgehog signalling had no effect on HE neurological decline. Levels of TGFβ1 increased in the liver and serum of mice following AOM administration. TGFβ neutralizing antibodies slowed neurologic decline following AOM administration without significantly affecting liver damage. TGFβ1 inhibited Gli1 expression via a SMAD3-dependent mechanism. Conversely, inhibiting TGFβ1 increased Gli1 expression. Conclusions Cortical activation of Gli1 protects mice from induction of HE. TGFβ1 suppresses Gli1 in neurons via SMAD3 and promotes the neurologic decline. Strategies to activate Gli1 or inhibit TGFβ1 signalling might be developed to treat patients with HE.

Cholangiocarcinoma is a type of liver cancer arising from the neoplastic transformation of the epithelial cells that line the intraand extrahepatic bile ducts. Symptoms are usually evident only after blockage of the bile duct by the tumor. This is an extremely aggressive tumor, which has very poor prognosis and limited treatment options. Cholangiocarcinoma is relatively resistant to chemotherapy and radiation therapy leaving conventional treatment like surgery as the only option. Therefore, further understanding into the factors that are involved in tumor initiation, promotion and progression is required for designing alternate therapies to combat this devastating disease.

Hepatic Encephalopathy (HE) is a neurological complication of the brain following liver damage that was classically thought of being a functional decline in neuronal activity due to metabolic disturbances. Acute liver failure as well as chronic liver diseases can cause HE, with the progression of HE correlating to the severity of liver damage. Initially there are disturbances in cognition, that then progress to disruptions in motor control, and finally global suppression of neural circuits, which can lead to coma. The first factor identified as a causal link and a treatment point for HE was ammonia. However, recent research has begun to elucidate strong support for other pathological processes in this disorder as well. Due to these varying ideas on the progression of HE, this editorial will discuss why the ammonia hypothesis of HE pathogenesis is supported by current research as well as some strong counterpoints that refute this hypothesis. Ammonia does play a part in HE pathogenesis, the studies conducted clinically and using animal models have demonstrated that other elements must be involved with HE progression to explain pathogenesis not accounted for by ammonia toxicity. As it stands, ammonia seems to play a significant role in chronic liver disease states while playing a small role during acute liver failure and minimal hepatic encephalopathy. Future studies will need to find ways to isolate these pathological processes in various acute and chronic liver damage models to fully identify the pathological effects of ammonia. In conclusion, ammonia does play a role in HE progression but due to its lack of involvement in some aspects of HE progression, there is the need to investigate its interplay with other pathological processes to help develop better therapeutic treatments options for HE.

Background and Aims: Infiltration of neutrophils in the liver contributes to the development of alcoholic liver diseases (ALD). However, the factors that regulate neutrophil infiltration and functions remain unclear. miR-223 is one of the most abundant miRNAs expressed in neutrophils, the purpose of this study is to investigate its role in the pathogenesis of ALD. Methods: The mouse model of chronic-plus-binge ethanol feeding was employed in miR223-/mice and their wild-type controls. Liver injury and inflammation were determined. Results: Real-time PCR analyses demonstrated the expression of miR-223 levels in neutrophils was about 24 fold and 15 fold higher than that in hepatocytes and Kupffer cells/macrophages, respectively. Chronic-plus-binge ethanol feeding markedly increased miR-223 expression in hepatic neutrophils. Compared with wild-type mice, miR223-/mice had higher levels of serum ALT and AST, and greater number of peripheral neutrophils post ethanol feeding. Immunostaining analyses revealed that the numbers of MPO positive neutrophils in the liver were elevated after chronic-plus-binge ethanol feeding with higher levels in miR223-/mice than in wild-type mice. The oxidative reaction as demonstrated by MDA and HNE staining in ethanol-fed miR223-/mice was stronger than ethanol-fed wild-type mice. In consistent with this notion, neutrophils from miR223-/mice produced higher levels of ROS compared with those from wild-type mice. In conclusion, miR223 protects against alcoholic liver injury by suppressing neutrophil infiltration and ROS production; miR223 could be a novel therapeutic target for the treatment of ALD.

Background and Aims: Infiltration of neutrophils in the liver contributes to the development of alcoholic liver diseases (ALD). However, the factors that regulate neutrophil infiltration and functions remain unclear. miR-223 is one of the most abundant miRNAs expressed in neutrophils, the purpose of this study is to investigate its role in the pathogenesis of ALD. Methods: The mouse model of chronic-plus-binge ethanol feeding was employed in miR223-/mice and their wild-type controls. Liver injury and inflammation were determined. Results: Real-time PCR analyses demonstrated the expression of miR-223 levels in neutrophils was about 24 fold and 15 fold higher than that in hepatocytes and Kupffer cells/macrophages, respectively. Chronic-plus-binge ethanol feeding markedly increased miR-223 expression in hepatic neutrophils. Compared with wild-type mice, miR223-/mice had higher levels of serum ALT and AST, and greater number of peripheral neutrophils post ethanol feeding. Immunostaining analyses revealed that the numbers of MPO positive neutrophils in the liver were elevated after chronic-plus-binge ethanol feeding with higher levels in miR223-/mice than in wild-type mice. The oxidative reaction as demonstrated by MDA and HNE staining in ethanol-fed miR223-/mice was stronger than ethanol-fed wild-type mice. In consistent with this notion, neutrophils from miR223-/mice produced higher levels of ROS compared with those from wild-type mice. In conclusion, miR223 protects against alcoholic liver injury by suppressing neutrophil infiltration and ROS production; miR223 could be a novel therapeutic target for the treatment of ALD.

A S L D A b st ra ct s increase in circulating Galanin in the serum. Galanin immunoreactivity was observed in both cholangiocytes and hepatocytes, whereas GalR1 was found predominantly in cholangiocytes. Systemic treatment of rats with M617 increased both CK-19 expression and IBDM in both sham and BDL-treated animals. In vitro, treatment of the mouse cholangiocyte cell line with M617 increased ERK1/2 and RSK-1 activity. There was a concomitant increase in cholangiocyte proliferation after M617 treatment that could be blocked by pretreatment with inhibitors for ERK1/2 and RSK-1. Conclusions: Data presented here demonstrate a direct stimulatory role for Galanin on cholangiocyte proliferation under physiological (sham) and pathological (BDL) conditions via a mechanism involving the activation of ERK1/2 and subsequent phosphorylation of RSK-1. Targeting Galanin or GalR1 may prove a useful strategy to regulate biliary mass during cholestatic liver injury.

Background Acute liver failure is associated with numerous systemic consequences including neurological dysfunction, termed hepatic encephalopathy, which contributes to mortality and is a challenge to manage in the clinic. During hepatic encephalopathy, microglia activation and neuroinflammation occur due to dysregulated cell signaling and an increase of toxic metabolites in the brain. Fractalkine is a chemokine that is expressed primarily in neurons and through signaling with its receptor CX3CR1 on microglia, leads to microglia remaining in a quiescent state. Fractalkine is often suppressed during neuropathies that are characterized by neuroinflammation. However, the expression and subsequent role of fractalkine on microglia activation and the pathogenesis of hepatic encephalopathy due to acute liver failure is unknown. Methods Hepatic encephalopathy was induced in mice via injection of azoxymethane (AOM) or saline for controls. Subsets of these mice were implanted with osmotic minipumps that infused soluble fractalkine or saline into the lateral ventricle of the brain. Neurological decline and the latency to coma were recorded in these mice, and brain, serum, and liver samples were collected. Neurons or microglia were isolated from whole brain samples using immunoprecipitation. Liver damage was assessed using hematoxylin and eosin staining and by measuring serum liver enzyme concentrations. Fractalkine and CX3CR1 expression were assessed by real-time PCR, and proinflammatory cytokine expression was assessed using ELISA assays. Results Following AOM administration, fractalkine expression is suppressed in the cortex and in isolated neurons compared to vehicle-treated mice. CX3CR1 is suppressed in isolated microglia from AOM-treated mice. Soluble fractalkine infusion into the brain significantly reduced neurological decline in AOM-treated mice compared to saline-infused AOM-treated mice. Infusion of soluble fractalkine into AOM-treated mice reduced liver damage, lessened microglia activation, and suppressed expression of chemokine ligand 2, interleukin-6, and tumor necrosis factor alpha compared to saline-infused mice. Conclusions These findings suggest that fractalkine-mediated signaling is suppressed in the brain following the development of hepatic encephalopathy. Supplementation of AOM-treated mice with soluble fractalkine led to improved outcomes, which identifies this pathway as a possible therapeutic target for the management of hepatic encephalopathy following acute liver injury.