Cholangiopathy and Biliary Fibrosis in Cyp2c70-Deficient Mice Are Fully Reversed by Ursodeoxycholic Acid.

BACKGROUND AND AIMS: Bile acids (BAs) aid intestinal fat absorption and exert systemic actions by receptor-mediated signaling. BA receptors have been identified as drug targets for liver diseases. Yet, differences in BA metabolism between humans and mice hamper translation of pre-clinical outcomes. Cyp2c70-ablation in mice prevents synthesis of mouse/rat-specific muricholic acids (MCAs), but potential (patho)physiological consequences of their absence are unknown. We therefore assessed age- and gender-dependent effects of Cyp2c70-deficiency in mice. METHODS: The consequences of Cyp2c70-deficiency were assessed in male and female mice at different ages. RESULTS: Cyp2c70-/- mice were devoid of MCAs and showed high abundances of chenodeoxycholic and lithocholic acids. Cyp2c70-deficiency profoundly impacted microbiome composition. Bile flow and biliary BA secretion were normal in Cyp2c70-/- mice of both sexes. Yet, the pathophysiological consequences of Cyp2c70-deficiency differed considerably between sexes. Three-week old male Cyp2c70-/- mice showed high plasma BAs and transaminases, which spontaneously decreased thereafter to near-normal levels. Only mild ductular reactions were observed in male Cyp2c70-/- mice up to 8 months of age. In female Cyp2c70-/- mice, plasma BAs and transaminases remained substantially elevated with age, gut barrier function was impaired and bridging fibrosis was observed at advanced age. Addition of 0.1% ursodeoxycholic acid to the diet fully normalized hepatic and intestinal functions in female Cyp2c70-/- mice. CONCLUSION: Cyp2c70-/- mice show transient neonatal cholestasis and develop cholangiopathic features that progress to bridging fibrosis in females only. These consequences of Cyp2c70-deficiency are restored by treatment with UDCA, indicating a role of BA hydrophobicity in disease development.

Aging and the Biological Response to Liver Injury.

Interest in understanding the aging process has recently risen in the scientific community. Aging, commonly defined as the functional decline in the function of organs and tissues, is indeed the major risk factor for the development of many chronic diseases, such as cardiovascular diseases, pathologies of nervous system, or cancer. To date, the influence of aging in the pathophysiology of liver and biliary diseases is not fully understood. Although liver cells have a high regenerative capacity, hepatocytes and cholangiocytes undergo extensive molecular changes in response to aging. Following time-dependent damage induced by aging, liver cells initially activate compensatory mechanisms that, if hyperstimulated, may lead to the decline of regenerative capacity and the development of pathologies. A deeper understanding of molecular aging has undoubtedly the potential to improve the clinical management of patients, possibly unveiling new pathways for selective drug treatment.

Possible application of melatonin treatment in human diseases of the biliary tract.

Melatonin was discovered in 1958 by Aaron Lerner. Its name comes from the ability of melatonin to change the shape of amphibian melanophores from stellate to roundish. Starting from the 1980s, the role of melatonin in the regulation of mammalian circadian and seasonal clocks has been elucidated. Presently, several other effects have been identified in different organs. For example, the beneficial effects of melatonin in models of liver damage have been described. This review gives first a general background on experimental and clinical data on the use of melatonin in liver damage. The second part of the review focuses on the findings related to the role of melatonin in biliary functions, suggesting a possible use of melatonin therapy in human diseases of the biliary tree.

Cell Interactions in Biliary Diseases: Clues from Pathophysiology and Repair Mechanisms to Foster Early Assessment.

In modern hepatology, diseases of the biliary epithelium, currently termed cholangiopathies, represent one of the main gaps in knowledge, both on experimental and clinical grounds, though they started to draw attention since the late 80s [...].

Metabolic derangements and reduced survival of bile-extracted Asiatic black bears (Ursus thibetanus).

BACKGROUND: Across China and Southeast Asia, an estimated 17,000 bears are currently farmed for bile, primarily for traditional medicines. Depending on country, bile is extracted daily via transabdominal gallbladder fistulas, indwelling catheters, or needle aspiration. Despite claims that bears do not develop adverse effects from bile extraction, health issues identified in bears removed from bile farms include bile-extraction site infections, abdominal hernias, peritonitis, cholecystitis, hepatic neoplasia, cardiac disease, skeletal abnormalities, and abnormal behaviors. We present a comprehensive assessment of the effects of bile farming by comparing serum biochemical and hematological values of bears from farms that were bile-extracted (BE) and bears from farms not bile-extracted (FNE) with bears from non-farm captive (ZOO) and free-range (FR) environments. We hypothesized BE bears would have significant laboratory abnormalities compared to all non-extracted bear groups. We also hypothesized BE bears would have reduced long-term survival compared to FNE bears despite removal from farms. RESULTS: BE bears exhibited the highest values and greatest variation (on a population level) in laboratory parameters compared to all non-extracted bear groups particularly for alanine transaminase, gamma glutamyltransferase (GGT), total bilirubin (TBIL), alkaline phosphatase (ALKP), blood urea nitrogen, creatinine (CREA), and total white blood cell count. Significant differences were detected between bear groups when accounting for season, sex, and/or age. BE bears exhibited greater mean serum GGT compared to all non-extracted bear groups, and the odds of having elevated TBIL were 7.3 times greater for BE bears, consistent with hepatobiliary disease. Biochemical parameter elevations in BE bears persisted up to 14 years post-rescue, consistent with long-term effects of bile-extraction. BE bears that arrived with elevated CREA and ALKP had median survival times of 1 and 4 years respectively, and regardless of laboratory abnormalities, BE bears had significantly shorter survival times compared to FNE bears. CONCLUSIONS: Our results provide strong evidence that bile extraction practices not only represent a temporary constraint for bears' welfare, but confer distinct long-term adverse health consequences. Routine laboratory panels may be insensitive to detect the extent of underlying illness in BE bears as these bears have significantly reduced survival regardless of biochemical assessment compared to FNE bears.

Secretin/secretin receptor signaling mediates biliary damage and liver fibrosis in early-stage primary biliary cholangitis.

Primary biliary cholangitis (PBC) primarily targets cholangiocytes and is characterized by liver fibrosis and biliary proliferation. Activation of the secretin (Sct)/secretin receptor (SR) axis, expressed only by cholangiocytes, increases biliary proliferation, liver fibrosis, and bicarbonate secretion. We evaluated the effectiveness of SR antagonist treatment for early-stage PBC. Male and female dominant-negative TGF-ß receptor II (dnTGF-ßRII) (model of PBC) and wild-type mice at 12 wk of age were treated with saline or the SR antagonist, Sec 5-27, for 1 wk. dnTGF-ßRII mice expressed features of early-stage PBC along with enhanced Sct/SR axis activation and Sct secretion. dnTGF-ßRII mice had increased biliary proliferation or senescence, inflammation, and liver fibrosis. In dnTGF-ßRII mice, there was increased microRNA-125b/TGF-ß1/TGF-ß receptor 1/VEGF-A signaling. Human early-stage PBC patients had an increase in hepatobiliary Sct and SR expression and serum Sct levels. Increased biliary Sct/SR signaling promotes biliary and hepatic damage during early-stage PBC.-Kennedy, L., Francis, H., Invernizzi, P., Venter, J., Wu, N., Carbone, M., Gershwin, M. E., Bernuzzi, F., Franchitto, A., Alvaro, D., Marzioni, M., Onori, P., Gaudio, E., Sybenga, A., Fabris, L., Meng, F., Glaser, S., Alpini, G. Secretin/secretin receptor signaling mediates biliary damage and liver fibrosis in early-stage primary biliary cholangitis.

Preliminary results from the use of intraoperative real-time biliary oxygen monitoring in liver transplantation.

BACKGROUND AND AIMS: Biliary anastomosis is a frequent area of complications after liver transplantation (LT) and a potential area of "microangiopathy". The concept of a "marginal bile duct" is unexplored. The main aim was to make a preliminary evaluation of the utility of an innovative real-time oxygen microtension (pO2mt) testing device for the assessment of bile duct viability during LT and to correlate these pO2mt values with microvascular tissue quality by histopathology and outcomes. PATIENTS AND METHODS: Observational prospective cohort study with 23 patients. Oxygen microtension measurements were made placing a micropO2 probe in different areas of recipient and donor's bile duct intraoperative. RESULTS: Mean pO2mt in the graft bile duct at the level of the anastomosis 103.82 (31-157) mm Hg, being 121.52 (55-174) mm Hg 1.5 cm proximal to the hilar plate (P < 0.001). Mean pO2mt in the recipient's bile duct was 117.87 (62-185) mm Hg, while a value of 137.30 (81-198) mm Hg was observed 1.5 cm distal to the anastomosis (P < 0.001). Cystic duct resection (12 cases) was also related with higher pO2mt values at anastomosis [117.8 (93-157) vs 88.54 (31-124) mm Hg] and distal to anastomosis [135.6 (111-174) vs 106.2 (55-133) mm Hg; P < 0.001]. Patients with 1-, 3-, and 12-month biliary complications had significantly lower pO2mt in the intraoperative measurements. CONCLUSION: Our preliminary results show that distal borders of donor and recipient bile ducts may be low-vascularized areas. Tissue pO2mt is significantly higher in areas close to the hilar plate and to the duodenum in donor and recipient's sides, respectively. Bile duct injury and biliary complications are associated with worse tissue pO2mt.

Contribution of Resident Stem Cells to Liver and Biliary Tree Regeneration in Human Diseases.

Two distinct stem/progenitor cell populations of biliary origin have been identified in the adult liver and biliary tree. Hepatic Stem/progenitor Cells (HpSCs) are bipotent progenitor cells located within the canals of Hering and can be differentiated into mature hepatocytes and cholangiocytes; Biliary Tree Stem/progenitor Cells (BTSCs) are multipotent stem cells located within the peribiliary glands of large intrahepatic and extrahepatic bile ducts and able to differentiate into hepatic and pancreatic lineages. HpSCs and BTSCs are endowed in a specialized niche constituted by supporting cells and extracellular matrix compounds. The actual contribution of these stem cell niches to liver and biliary tree homeostatic regeneration is marginal; this is due to the high replicative capabilities and plasticity of mature parenchymal cells (i.e., hepatocytes and cholangiocytes). However, the study of human liver and biliary diseases disclosed how these stem cell niches are involved in the regenerative response after extensive and/or chronic injuries, with the activation of specific signaling pathways. The present review summarizes the contribution of stem/progenitor cell niches in human liver diseases, underlining mechanisms of activation and clinical implications, including fibrogenesis and disease progression.

Dilemma of elevated CA 19-9 in biliary pathology.

Carbohydrate antigen 19-9 (CA 19-9) is a tumor marker which has been extensively evaluated and widely utilized primarily in diagnosing and prognosticating pancreaticobiliary malignancies. Levels may be significantly influenced and elevated in cases of benign biliary conditions however, especially in obstructive jaundice, thereby posing difficulty in distinguishing between benign and malignant cholestasis. A myriad of studies have focused on elucidating proper use and interpretation of CA 19-9 in pancreatic cancer as well as in the setting of cholestasis. These studies have demonstrated that many factors influence CA 19-9 values and various methods for interpreting CA 19-9 in obstructive jaundice have been proposed. With improvements in diagnostic imaging, advancements in endoscopic modalities, and likelihood that management will not change based on the results of the test, clinicians should be cautious when ordering CA 19-9 and consider the reasons for measuring the tumor marker.

Lysyl oxidase-like protein 2 (LOXL2) modulates barrier function in cholangiocytes in cholestasis.

BACKGROUND & AIMS: The lysyl oxidase-like protein 2 (LOXL2) promotes stabilization of the extracellular matrix, chemotaxis, cell growth and cell mobility. We aimed to (i) identify stimuli of LOXL2 in cholangiopathies, (ii) characterize the effects of LOXL2 on biliary epithelial cells' (BECs) barrier function, (iii) compare LOXL2 expression in primary sclerosing cholangitis (PSC), primary biliary cholangitis, and disease controls, and (iv) to determine LOXL2 expression and its cellular sources in four mouse models of cholangiopathies. METHODS: Cultured murine BECs were challenged with well-known triggers of cellular senescence, hypoxia, phospholipid-deficient Abcb4-/- mouse bile and chenodeoxycholic acid and investigated for LOXL2, SNAIL1 and E-cadherin expression and transepithelial electrical resistance with and without LOX-inhibition. In vivo, LOXL2 expression was studied in PSC livers, and controls and mouse models. We compared LOXL2 serum levels in patients with PSC, secondary SC, primary biliary cholangitis, and controls. RESULTS: Cellular senescence, hypoxia, Abcb4-/- bile and chenodeoxycholic acid induced LOXL2 and SNAIL1 expression, repressed E-cadherin expression, and significantly reduced transepithelial electrical resistance in BECs. Notably, all of the pathological changes could be recovered via pharmacological LOX-inhibition. Mouse models showed induced LOXL2 expression in the portal region and in association with ductular reaction. LOXL2 serum levels were significantly elevated in patients with cholangiopathies. In PSC, LOXL2 expression was located to characteristic periductal onion skin-type fibrosis, ductular reaction, Kupffer cells, and fibrotic septa. Importantly, in PSC, LOXL2 overexpression was paralleled by E-cadherin loss in BECs from medium-sized bile ducts. CONCLUSIONS: Reactive BECs produce LOXL2, resulting in increased tight junction permeability, which can be ameliorated by pharmacological LOX-inhibition in vitro. Reactive BECs, portal myofibroblasts, and Kupffer cells are the main sources of LOXL2 in cholangiopathies. LAY SUMMARY: In this study, we investigate the role of lysyl oxidase-like protein 2 (LOXL2), an enzyme pivotal in the development of organ fibrosis, in the pathogenesis of cholangiopathies (diseases of bile ducts), such as primary sclerosing cholangitis. We found LOXL2 to be expressed in association with bile duct epithelial injury and uncovered mechanisms for its upregulation and the subsequent effects in vitro and in vivo. Our findings support testing of anti-LOXL2 treatment strategies for patients with primary sclerosing cholangitis.

A newborn with combined pituitary hormone deficiency developing shock and sludge.

A male neonate was born at 41 weeks of gestation with a birth weight of 3320 g. Artificial respiratory management was required due to respiratory disturbance 1 h after birth, and subsequently catecholamine-refractory low cardiac output-induced shock occurred. Severe combined pituitary hormone deficiency (CPHD) was considered based on the presence of his respiratory disturbance, hypoglycemia and micropenis. After hydrocortisone (HDC) administration, circulatory dynamics rapidly improved. Brain magnetic resonance imaging (MRI) showed aplasia of the anterior pituitary gland and ectopic posterior gland. γ-Glutamyltranspeptidase (γ-GTP) increased from day 10 after birth and direct bilirubin increased from day 18. On ultrasonography, sludge filling the common bile duct and gall bladder was observed. After initiating treatment with both ursodeoxycholic acid and recombinant human growth hormone (rhGH), cholestasis improved and the sludge disappeared at 3 months after birth. In newborns with CPHD, severe central adrenal insufficiency might induce cardiogenic shock after birth. Early diagnosis and intervention are necessary.

Curcumin in Hepatobiliary Disease: Pharmacotherapeutic Properties and Emerging Potential Clinical Applications.

Curcumin, an aromatic phytoextract from the turmeric (Curcuma longa) rhizome, has been used for centuries for a variety of purposes, not the least of which is medicinal. A growing body of evidence suggests that curcumin has a broad range of potentially therapeutic pharmacological properties, including anti-inflammatory, anti-fibrotic, and anti-neoplastic effects, among others. Clinical applications of curcumin have been hampered by quality control concerns and limited oral bioavailability, although novel formulations appear to have largely overcome these issues. Recent in vitro and in vivo studies have found that curcumin's cytoprotective and other biological activities may play a role in an array of benign and malignant hepatobiliary conditions, including but not limited to non-alcoholic fatty liver disease, cholestatic liver disease (e.g. primary sclerosing cholangitis), and cholangiocarcinoma. Here we provide an overview of fundamental principles, recent discoveries, and potential clinical hepatobiliary applications of this pleiotropic phytocompound.

The roles of Toll-like receptor 4 in the pathogenesis of pathogen-associated biliary fibrosis caused by Clonorchis sinensis.

Pathogen-associated biliary fibrosis (PABF) is a type of liver fibrosis characterized by injuries of cholangiocytes and extra cellular matrix (ECM) deposition around bile ducts caused by various bacteria, fungi, virus and parasites. Recent studies show that TLR4 plays an important role in several other types of liver fibrosis, but the mechanism of TLR4 in PABF is yet really unclear. In the present study, a PABF mouse model was established by a trematode infection-Clonorchis sinensis which dwells in the bile ducts and causes severe biliary fibrosis of mice. The results showed that the levels of collagen depositions, α-SMA and hydroxyproline (Hyp) contents in TLR4 mut mice infected by C. sinensis were significantly lower than in those of TLR4 wild ones. Furthermore, we found that the activation of TGF-ß signaling was impaired in the TLR4 mut mice, compared with wild mice when they were challenged to the same dose of C. sinensis metacercariae. Moreover, the mice with TLR4 mutation showed a decreased activation of hepatic stellate cells indicated by the expression of α-SMA, when compared with TLR4 wild mice. These data demonstrate that TLR4 contributes to PABF caused by C. sinensis and TLR4 signaling may be a potential medical target for treatment of PABF.

New Advances in the Molecular Mechanisms Driving Biliary Fibrosis and Emerging Molecular Targets.

Persistent exposure of biliary epithelial cells (i.e., cholangiocytes) to diverse factors such as disordered immunity, genetic alterations, ischemia, toxic compounds and/or infectious agents leads to a chronic portal inflammatory response which eventually progresses to biliary fibrosis. This stage is characterized by increased production and deposition of scar-forming extracellular matrix proteins (ECM), in particular fibrillar collagen types I and III, but including other ECM constituents such as elastin and fibrillin-1, both components of elastic fibers. The major cellular mediators responsible for collagen deposition are activated hepatic stellate cells (HSCs) and to a lesser extent, portal myofibroblasts, which are activated by soluble inflammatory mediators (i.e., cytokines, growth factors) and extracellular matrix components. Unless the underlying cause of biliary injury can be effectively treated, these processes may ultimately lead to decompensated cirrhosis and can also provide ideal microenvironments for the development and growth of primary tumors. Recent evidence indicates that fibrosis is a dynamic and potentially reversible process. As the curative options for most chronic biliary diseases remain limited to transplantation, there is an urgent need to clarify the molecular pathways involved in the development of biliary fibrosis and identify new therapeutic targets. In this review we describe the cellular and molecular regulators that orchestrate the cholangiocyte /myofibroblast cross-talk and identify the signaling processes that are most promising for therapeutic targeting.

[The volatile fatty acids in children with dysfunction of biliary tract].

The volatile fatty acids are metabolites of bacteria reflecting condition and disbiotic alterations of microflora of gastrointestinal tract. The study was carried out to determine qualitatively volatile fatty acids in saliva of children with dysfunction of biliary tract and healthy ones. The indices of volatile fatty acids were analyzed in 46 children aged 7-17 years and with dysfunction of biliary tract. The comparison group included 34 healthy children aged from 7 to 17 years. The gas-liquid chromatography was applied to qualitatively detect acetic, butyric, isovaleric acids (volatile fatty acids). The automatedgas chromatograph "Crystal deluxe 4000" with capillary column "HP-FFAP" and flame ionizing detector was used. The study established decreasing of anaerobic index, increasing of acetic, propionic acids and sum of volatile fatty acids in saliva of children of main group as opposed to children of comparison group. The possible role of bacterial metabolites and bacteria in pathogenesis of dysfunction of biliary tract in children. The description is made of one of possible mechanisms of increasing of volatile fatty acids in saliva under dysfunction of biliary tract. The integral indices of volatile fatty acids of saliva are the new additional criteria for diagnostic of dysfunction of biliary tract in children.

Proliferative index facilitates distinction between benign biliary lesions and intrahepatic cholangiocarcinoma.

Differentiation between benign and malignant lesions of the hepatic biliary tree may pose a diagnostic problem because well-differentiated intrahepatic cholangiocarcinoma may mimic biliary hamartoma, bile duct adenoma, or parenchymal extinction. We evaluated Ki-67 proliferative index and p53 status by immunohistochemical staining to aid in exclusion of cholangiocarcinoma. Fourteen biliary hamartomas, 21 bile duct adenomas, and 11 livers with parenchymal extinction were compared with 26 intrahepatic cholangiocarcinomas (16 well-differentiated and 10 moderately or poorly differentiated tumors). We found an increased proliferative index in intrahepatic cholangiocarcinomas compared with benign biliary lesions (average 23.0% in cholangiocarcinoma versus 1.4% in all benign biliary lesions, n = 26 versus n = 46, P < .001). No difference in average proliferative index was observed between well-differentiated and moderately/poorly differentiated cholangiocarcinomas (average 22.7% versus 23.3%, n = 16 versus n = 10, P = .92). Average proliferation indices of benign biliary lesions were uniformly low (biliary hamartoma, 1.2%; bile duct adenoma, 2%; parenchymal extinction, 0.5%). Most cholangiocarcinomas (23/26; 88.5%), but none of the benign lesions (0/46; 0%), had proliferative indices greater than 10%. Strong nuclear p53 immunohistochemical staining was only seen in cholangiocarcinomas (9/26; 34.6%) and not in benign biliary lesions (0/46; 0%), although many of the benign lesions showed weak to moderate staining. Immunohistochemical staining for Ki-67 facilitates distinction between benign and malignant lesions of the intrahepatic biliary tree, whereas p53 immunohistochemical staining is less helpful.

Etiology, Diagnosis, and Management of Bilomas: A Current Update.

A biloma is a well-demarcated collection of bile outside the biliary tree. Traumatic and iatrogenic injuries, most commonly secondary to cholecystectomy, are the usual causes. Although bilomas are relatively uncommon, this pathologic entity may lead to significant morbidity and mortality if not promptly diagnosed and properly managed. As clinical signs and symptoms of bilomas are often nonspecific and laboratory values may be unremarkable, imaging modalities including ultrasound, computed tomography, magnetic resonance imaging, and hepatobiliary cholescintigraphy play a crucial role in the diagnosis of this condition. It is paramount that interventional radiologists not only be well versed in the management of bilomas but also be knowledgeable in the diagnosis as well as key imaging findings that dictate the interventional management. The purpose of this article is to review the etiology, pathophysiology, and clinical presentation of bilomas to primarily focus on the relevant multimodal imaging findings and the minimally invasive management options.

[Characteristics of Leydig cells in the newborn posterity of female rats with chronic injury of the hepatobiliary system of various genesis].

Morphological and functional features of interstitial endocrine cells (Leydig cells) in the posterity of female rats with experimental liver injury of various genesis in the neonatal period were analized. Found that in experimental rats are a reduction in the number of Leydig cells, the ratio between active and inactive endocrinocytes and as a consequence, reduction of its cell activity index.

Bile acid signaling through farnesoid X and TGR5 receptors in hepatobiliary and intestinal diseases.

BACKGROUND: The well-known functions of bile acids (BAs) are the emulsification and absorption of lipophilic xenobiotics. However, the emerging evidences in the past decade showed that BAs act as signaling molecules that not only autoregulate their own metabolism and enterohepatic recirculation, but also as important regulators of integrative metabolism by activating nuclear and membrane-bound G protein-coupled receptors. The present review was to get insight into the role of maintenance of BA homeostasis and BA signaling pathways in development and management of hepatobiliary and intestinal diseases. DATA SOURCES: Detailed and comprehensive search of PubMed and Scopus databases was carried out for original and review articles. RESULTS: Disturbances in BA homeostasis contribute to the development of several hepatobiliary and intestinal disorders, such as non-alcoholic fatty liver disease, liver cirrhosis, cholesterol gallstone disease, intestinal diseases and both hepatocellular and colorectal carcinoma. CONCLUSION: Further efforts made in order to advance the understanding of sophisticated BA signaling network may be promising in developing novel therapeutic strategies related not only to hepatobiliary and gastrointestinal but also systemic diseases.