Nrf2 deficiency causes hepatocyte dedifferentiation and reduced albumin production in an experimental extrahepatic cholestasis model.

The transcription factor Nrf2 modulates the initiation and progression of a number of diseases including liver disorders. We evaluated whether Nrf2 mediates hepatic adaptive responses to cholestasis. Wild-type and Nrf2-null mice were subjected to bile duct ligation (BDL) or a sham operation. As cholestasis progressed to day 15 post-BDL, hepatocytes in the wild-type mice exhibited a tendency to dedifferentiate, indicated by the very weak expression of hepatic progenitor markers: CD133 and tumor necrosis factor-like weak induced apoptosis receptor (Fn14). During the same period, Nrf2 deficiency augmented this tendency, manifested by higher CD133 expression, earlier, stronger, and continuous induction of Fn14 expression, and markedly reduced albumin production. Remarkably, as cholestasis advanced to the late stage (40 days after BDL), hepatocytes in the wild-type mice exhibited a Fn14+ phenotype and strikingly upregulated the expression of deleted in malignant brain tumor 1 (DMBT1), a protein essential for epithelial differentiation during development. In contrast, at this stage, hepatocytes in the Nrf2-null mice entirely inhibited the upregulation of DMBT1 expression, displayed a strong CD133+/Fn14+ phenotype indicative of severe dedifferentiation, and persistently reduced albumin production. We revealed that Nrf2 maintains hepatocytes in the differentiated state potentially via the increased activity of the Nrf2/DMBT1 pathway during cholestasis.

Features of Ductular Reaction in Rats with Extrahepatic Cholestasis.

Ductular reaction develops during liver regeneration, fibrosis, and carcinogenesis. However, the types, stages of formation, and topography of ductular profiles in various pathologies remain insufficiently studied. Using the model of common bile duct occlusion, we showed that the number and topography of ductular profiles are closely related to the duration of biliary obstruction. The ductular profiles can be located inside the portal tract, along the existing bile ducts, and/or intramurally, around the portal vein, periportally, inside the lobules, in the portocaval fibrous connections, in the adventitia of the hepatic veins, in the septs connecting the portal tracts, and also in the "portal plate" of the liver. The ductular profiles can be formed as a result of expansion of existing bile ducts, cholangiocyte proliferation, as well as transdifferentiation of hepatocytes and activation of mesenchymal stem cells.

Hypoplasia of Extrahepatic Biliary Tree and Intrahepatic Cholangiolopathy in Cystic Fibrosis Imperfectly Mimic Biliary Atresia in 4 Infants With Cystic Fibrosis and Kasai Portoenterostomy.

Four male infants with cystic fibrosis and prolonged neonatal jaundice underwent Kasai procedure to relieve biliary obstruction due to apparent biliary atresia. The excised remnants had viscid mucus accumulation in hypoplastic gallbladders and distended peribiliary glands. Main hepatic ducts were narrow and/or malformed. Microscopic differences between the gallbladder and extrahepatic bile ducts in cystic fibrosis and sporadic biliary atresia were unequivocal, despite some histologic overlap; no erosive or fibro-obliterative lesions typical of biliary atresia were seen. Common in liver, biopsies were small duct cholangiopathy with intense focal cholangiolitis and massive accumulation of ceroid pigment within damaged cholangiocytes, and in portal macrophages, portal fibrosis, and unequivocal features of large duct obstruction were inconspicuous compared with biliary atresia. Plugs of bile in small ducts tended to be pale and strongly periodic acid-Schiff-reactive in cystic fibrosis. Distinguishing the liver lesion from that of biliary atresia is challenging but possible. Liver biopsies from 2 additional infants with cystic fibrosis and prolonged jaundice that spontaneously resolved showed a similar small duct cholangiopathy. Small gallbladders and extrahepatic ducts challenge surgical judgment as findings in liver biopsies challenge the pathologist. The decision to perform a Kasai procedure is reasonable when mimicry of biliary atresia is grossly complete. We hypothesize that a disorder of bile volume/flow during development and/or early infancy linked to the CFTR mutation alone or in combination with the stresses of neonatal intensive care causes destructive cholangiolitis and intrahepatic reduction of bile flow with secondary hypoplasia of extrahepatic biliary structures.

Endobiliary radiofrequency ablation for distal extrahepatic cholangiocarcinoma: A clinicopathological study.

BACKGROUND: Most patients with distal extrahepatic cholangiocarcinoma have developed jaundice or cholangitis at the time of initial diagnosis, which can delay surgery. We aim to evaluate the actual EB-RFA ablation volume and validated the clinical feasibility of preoperative endobiliary radiofrequency ablation (EB-RFA) for resectable distal extrahepatic cholangiocarcinoma. METHODS: The medical records of patients who underwent EB-RFA from July 2016 to June 2017 at a single tertiary academic medical center were reviewed. Inclusion criteria were patients with resectable distal extrahepatic cholangiocarcinoma who required preoperative biliary decompression. Clinical outcomes of EB-RFA were reviewed retrospectively and the surgical specimens were reevaluated. RESULTS: Of the eight patients who required a delayed operation, preoperative EB-RFA was successfully performed without serious complications including peritonitis, hemobilia, or perforation. Although curative resection was attempted in all patients, one patient underwent open and closure due to hepatic metastasis. Seven patients underwent curative surgical resection and the histology revealed that median maximal ablation depth was 4.0 mm (range, 1-6) and median effective ablation length (histological ablation length/fluorosocopic ablation length) was 72.0% (range, 42.1-95.3). CONCLUSIONS: EB-RFA partially ablated human cancer tissue and preoperative EB-RFA might be a safe and feasible in patients with distal extrahepatic cholangiocarcinoma who require a delayed operation. Ablation of the target lesion longer than the estimated length by fluoroscopy may improve the efficacy of EB-RFA.

UroVysion Multi-Target Fluorescence in situ Hybridization Assay for the Detection of Malignant Bile Duct Brushing Specimens: A Comparison with Routine Cytology.

OBJECTIVE: Routine bile duct brushing cytology is an important diagnostic tool in the evaluation of bile duct stricture. The purpose of this study was to evaluate the performance of the UroVysion fluorescence in situ hybridization (FISH) assay for the detection of malignant bile duct brushing specimens. STUDY DESIGN: Thirty-five bile duct brushing specimens were included in the study. The FISH assay utilized the commercially available UroVysion probes. The indeterminate cytology results were considered as negative for statistical analysis. RESULTS: Twenty-two of 35 patients were diagnosed as having malignancy based on tissue diagnosis or clinical progression of disease by image assessment. The sensitivity of routine cytology and FISH for the detection of malignancy was 14% (3/22) and 55% (12/22), respectively (p = 0.003). The specificity of routine cytology and FISH was 100% (13/13) and 62% (8/13), respectively (p = 0.025). The false-positive rate for routine cytology and FISH was 0% (0/13) and 38% (5/13), respectively. CONCLUSIONS: Our study shows that FISH is significantly more sensitive than routine cytology for the detection of malignancy in bile duct brushing specimens. However, in our study, the specificity of FISH was poor compared to the excellent specificity of routine cytology. The compromised specificity of FISH may limit its utility in the detection of malignant bile duct brushing specimens.

Prostaglandin E1 Preconditioning Attenuates Liver Ischemia Reperfusion Injury in a Rat Model of Extrahepatic Cholestasis.

The aim of this study is to explore the hepatoprotective effect of intraportal prostaglandin E1 (PGE1) on liver ischemia reperfusion (IR) injury using an extrahepatic cholestatic model, observing oxidative stress markers, proinflammatory factors, apoptotic marker proteins, and an adhesion molecule. The extrahepatic cholestatic model was induced by common bile duct ligation. After seven days, rats were subjected to ischemia by Pringle maneuver for 15 min, followed by 1, 6, or 24 h of reperfusion. Prostaglandin E1 (PGE group) or normal saline (NS group) was continuously infused from 15 min before liver ischemia to 1 h after reperfusion. After reperfusion, histopathological evaluation of the liver was performed, as were measurements of bilirubin, biochemical enzymes, oxidative stress markers (GSH and MDA), proinflammatory factors (MPO, TNF-α, and IL-1ß), apoptotic marker proteins (Bcl-2 and Bax), and the adhesion molecule (ICAM-1). PGE1 pretreatment attenuated IR injury in extrahepatic cholestatic liver probably by suppressing MDA, MPO, TNF-α, IL-1ß, ICAM-1, and Bax levels and improving GSH and Bcl-2 levels. In conclusion, PGE1 protects extrahepatic cholestatic liver from IR injury by improving hepatic microcirculation and reducing oxidative stress damage, intrahepatic neutrophil infiltration, and hepatocyte apoptosis.

[PRINCIPLES OF THE HEPATICO-JEJUNOANASTOMOSIS FORMATION, USING METHOD OF THE SOFT-TISSUES HF-ELECTRIC WELDING IN CLINICAL PRACTICE].

Hepatico-jejunoanastomosis (HJA) was formed in accordance to the high-frequency electric welding method: in 14 patients ­ for the main bile outflow disorders, in 8 of them ­ as a consequence of the periampullar zone malignances, in 6 ­ stricture of a common hepatic duct, HJA earlier formatted, purulent cholangitis, iatrogenic damage of biliary ducts. In all the patients the welded averting one-layered termino-lateral or latero-lateral HJA were formatted. The welded anastomoses have appeared hermetic, sufficiently hard, immediately after the formation and further.

Mutation Profile and Fluorescence In Situ Hybridization Analyses Increase Detection of Malignancies in Biliary Strictures.

BACKGROUND & AIMS: It is a challenge to detect malignancies in biliary strictures. Various sampling methods are available to increase diagnostic yield, but these require additional procedure time and expertise. We evaluated the combined accuracy of fluorescence in situ hybridization (FISH) and polymerase chain reaction-based DNA mutation profiling (MP) of specimens collected using standard brush techniques. METHODS: We performed a prospective study of 107 consecutive patients treated for biliary strictures by endoscopic retrograde cholangiopancreatography from June 2012 through June 2014. We performed routine cytology and FISH analyses on cells collected by standard brush techniques, and analyzed supernatants for point mutations in KRAS and loss-of-heterozygosity mutations in tumor-suppressor genes at 10 loci (MP analysis was performed at Interpace Diagnostics). Strictures were determined to be nonmalignant based on repeat image analysis or laboratory test results 12 months after the procedure. Malignant strictures were identified based on subsequent biopsy or cytology analyses, pathology analyses of samples collected during surgery, or death from biliary malignancy. We determined the sensitivity and specificity with which FISH and MP analyses detected malignancies using the exact binomial test. RESULTS: Our final analysis included 100 patients; 41% had biliary malignancies. Cytology analysis identified patients with malignancies with 32% sensitivity and 100% specificity. Addition of FISH or MP results to cytology results increased the sensitivity of detection to 51% (P < .01) without reducing specificity. The combination of cytology, MP, and FISH analyses detected malignancies with 73% sensitivity (P < .001). FISH identified an additional 9 of the 28 malignancies not detected by cytology analysis, and MP identified an additional 8 malignancies. FISH and MP together identified 17 of the 28 malignancies not detected by cytology analysis. CONCLUSIONS: Addition of FISH and mutation analyses to cytology analysis significantly increased the level of sensitivity with which we detected malignancy in biliary strictures, with 100% specificity. These techniques can be performed using standard brush samples collected during endoscopic retrograde cholangiopancreatography, with mutations detected in free DNA in supernatant fluid of samples. The tests are complementary and therefore should be used sequentially in the diagnostic evaluation of biliary strictures.

[Role of biliary MRI in etiological diagnosis of cholestatic icteruses in Dakar]. / Place de la bili-IRM dans le diagnostic etiologique des icteres cholestatiques à Dakar.

Biliary MRI is a relatively new diagnostic test in the arsenal of exploration techniques in biliopancreatic pathology. This is a reproducible and reliable non invasive technique for direct visualization of biliary and pancreatic ducts. This study aims to evaluate the morphological features of major abnormalities and the role of biliary MRI in the etiological diagnosis of cholestatic icteruses. This is a retrospective study of 17 patients conducted in the Imaging Unit of the University Hospital of Fann and of the Principal hospital of Dakar over a period of 4 years and six months (January 2008 at July 2012). All patients underwent MRI (1.5T) according to the standardized protocols for the explored pathology. Only medical records of patients whose diagnosis was established based on laboratory tests and who underwent biliary MRI and surgical exploration were retained. The study involved 5 women and 12 men with a sex ratio of 2.4. The average age of patients was 58 years, ranging between 35 and 81 years. Klatskin tumors were found in 7 patients with infiltrative form in 71% of cases and exophytic form was found in 28% of cases. Cancers of the gallbladder were found in 28% of cases. Cancers in the head of the pancreas accounted for 28% of cases. Major bile duct lithiasis was detected in 5 patients, choledocholithiasis in 60% of cases and a single lithiasis in 40% of cases. All these lesions were responsible for an expansion of intrahepatic bile duct (IHBD). One case of intra and extrahepatic bile ducts dilatation was found without biliopancreatic cause. Biliary MRI is the test of choice for the exploration of cholestatic icteruses. It should be recommended as first-line examination when residual lithiasis is suspected and as second-line examination after ultrasound, when the latter shows a suspected bile ducts tumoral obstruction. Its association with CT scan is the best combination of screening tests for etiologic diagnosis and pre-operative assessment of tumoral biliary obstructions.

Intracellular autocrine VEGF signaling promotes EBDC cell proliferation, which can be inhibited by Apatinib.

Tumor cells produce vascular endothelial growth factor (VEGF) which can interact with membrane or cytoplasmic VEGF receptors (VEGFRs) to promote cell growth. We aimed to investigate the role of extracellular/intracellular autocrine VEGF signaling and Apatinib, a highly selective VEGFR2 inhibitor, in extrahepatic bile duct cancer (EBDC). We found conditioned medium or recombinant human VEGF treatment promoted EBDC cell proliferation through a phospholipase C-γ1-dependent pathway. This pro-proliferative effect was diminished by VEGF, VEGFR1 or VEGFR2 neutralizing antibodies, but more significantly suppressed by intracellular VEGFR inhibitor. The rhVEGF induced intracellular VEGF signaling by promoting nuclear accumulation of pVEGFR1/2 and enhancing VEGF promoter activity, mRNA and protein expression. Internal VEGFR2 inhibitor Apatinib significantly inhibited intracellular VEGF signaling, suppressed cell proliferation in vitro and delayed xenograft tumor growth in vivo, while anti-VEGF antibody Bevacizumab showed no effect. Clinically, overexpression of pVEGFR1 and pVEGFR2 was significantly correlated with poorer overall survival (P = .007 and P = .020, respectively). In conclusion, the intracellular autocrine VEGF loop plays a predominant role in VEGF-induced cell proliferation. Apatinib is an effective intracellular VEGF pathway blocker that presents a great therapeutic potential in EBDC.

Loss of keratin 19 favours the development of cholestatic liver disease through decreased ductular reaction.

Keratins (K) are cytoprotective proteins and keratin mutations predispose to the development of multiple human diseases. K19 represents the most widely used marker of biliary and hepatic progenitor cells as well as a marker of ductular reaction that constitutes the basic regenerative response to chronic liver injury. In the present study, we investigated the role of K19 in biliary and hepatic progenitor cells and its importance for ductular reaction. K19 wild-type (WT) and knockout (KO) mice were fed: (a) 3,5-diethoxycarbonyl-1,4-dihydrocollidine (DDC); (b) cholic acid (CA); (c) a choline-deficient, ethionine-supplemented (CDE) diet; or (d) were subjected to common bile duct ligation (CBDL). The bile composition, liver damage, bile duct proliferation, oval cell content and biliary fibrosis were analysed. In untreated animals, loss of K19 led to redistribution of the K network in biliary epithelial cells (BECs) but to no obvious biliary phenotype. After DDC feeding, K19 KO mice exhibited (compared to WTs): (a) increased cholestasis; (b) less pronounced ductular reaction with reduced ductular proliferation and fewer oval cells; (c) impaired Notch 2 signalling in BECs; (d) lower biliary fibrosis score and biliary bicarbonate concentration. An attenuated oval cell proliferation in K19 KOs was also found after feeding with the CDE diet. K19 KOs subjected to CBDL displayed lower BEC proliferation, oval cell content and less prominent Notch 2 signal. K19 deficiency did not change the extent of CA- or CBDL-induced liver injury and fibrosis. Our results demonstrate that K19 plays an important role in the ductular reaction and might be of importance in multiple chronic liver disorders that frequently display a ductular reaction.

Gangliocytic Paraganglioma With Atypical Immunohistochemical Features Presenting as Extrahepatic Biliary Obstruction.

Gangliocytic paraganglioma is a rare benign tumor of upper gastrointestinal tract that most commonly involves the second part of duodenum. The tumor is detected incidentally on imaging in most of the cases. However, presentation with extrahepatic biliary obstruction is extremely rare. We recently encountered a 50-year-old male patient who was evaluated for extrahepatic biliary obstruction and was found to have a periampullary mass on imaging. The patient underwent pylorus-preserving pancreaticoduodenectomy along with liver biopsy and hepatoduodenal lymph node dissection. On histopathological examination, a tumor was detected in the periampullary region of duodenum, which was confirmed to be gangliocytic paraganglioma on immunohistochemistry along with atypical histological and immunohistochemical features.

Magnesium protects against bile duct ligation-induced liver injury in male Wistar rats.

The aim of this study was to investigate the effects of magnesium sulfate (MgSO4) on cholestasis-induced hepatic injury after bile duct ligation (BDL) in male Wistar rats. In this study, the effects of 28-day, oral administration of MgSO4 (at doses of 0.01, 0.05, 0.1, and 0.2 g/kg bw) were evaluated in normal and BDL-induced cholestatic rats. The BDL group showed significant increases in serum levels of ALP, ALT, AST, GGT and significant decreases in hepatic SOD and catalase activities. BDL rats also had significant decreases in the serum levels of albumin, bilirubin, total cholesterol, triglycerides, and LDL. Administration of MgSO4 significantly attenuated these changes to nearly normal levels. Administrations of MgSO4 did not change these parameters in normal rats. Histopathological studies further confirmed the protective effects of MgSO4 on cholestasis-induced hepatic injury in the BDL rat model. Taken together, the results of this study suggest that MgSO4 treatment may be beneficial in cholestasis-induced hepatotoxicity.

CCN1 induces hepatic ductular reaction through integrin αvß5-mediated activation of NF-κB.

Liver cholestatic diseases, which stem from diverse etiologies, result in liver toxicity and fibrosis and may progress to cirrhosis and liver failure. We show that CCN1 (also known as CYR61), a matricellular protein that dampens and resolves liver fibrosis, also mediates cholangiocyte proliferation and ductular reaction, which are repair responses to cholestatic injury. In cholangiocytes, CCN1 activated NF-κB through integrin αvß5/αvß3, leading to Jag1 expression, JAG1/NOTCH signaling, and cholangiocyte proliferation. CCN1 also induced Jag1 expression in hepatic stellate cells, whereupon they interacted with hepatic progenitor cells to promote their differentiation into cholangiocytes. Administration of CCN1 protein or soluble JAG1 induced cholangiocyte proliferation in mice, which was blocked by inhibitors of NF-κB or NOTCH signaling. Knock-in mice expressing a CCN1 mutant that is unable to bind αvß5/αvß3 were impaired in ductular reaction, leading to massive hepatic necrosis and mortality after bile duct ligation (BDL), whereas treatment of these mice with soluble JAG1 rescued ductular reaction and reduced hepatic necrosis and mortality. Blockade of integrin αvß5/αvß3, NF-κB, or NOTCH signaling in WT mice also resulted in defective ductular reaction after BDL. These findings demonstrate that CCN1 induces cholangiocyte proliferation and ductular reaction and identify CCN1/αvß5/NF-κB/JAG1 as a critical axis for biliary injury repair.

Cost Efficacy of Metal Stents for Palliation of Extrahepatic Bile Duct Obstruction in a Randomized Controlled Trial.

BACKGROUND & AIMS: Endoscopic stents are placed for palliation of extrahepatic bile duct obstruction. Although self-expandable metal stents (SEMS) remain patent longer than plastic stents, they are more expensive. We aimed to evaluate which type of stent (plastic, uncovered SEMS [uSEMS], or partially covered SEMS [pcSEMS]) is the most effective and we assessed costs. METHODS: We performed a multicenter randomized trial in 219 patients at 18 hospitals in The Netherlands from February 2008 through February 2013. Patients were assigned randomly for placement of a plastic stent (n = 73), uSEMS (n = 75), or pcSEMS (n = 71) during endoscopic retrograde cholangiopancreatography. Patients were followed up for up to 1 year. Researchers were not blinded to groups. The main study end points included functional stent time and costs. RESULTS: The mean functional stent times were 172 days for plastic stents, 288 days for uSEMS, and 299 days for pcSEMS (P < .005 for uSEMS and pcSEMS vs plastic). The initial placement of plastic stents (€1042 or $1106) cost significantly less than placement of SEMS (€1973 or $2094) (P = .001). However, the total cost per patient at the end of the follow-up period did not differ significantly between plastic stents (€7320 or $7770) and SEMS (€6932 or $7356) (P = .61). Furthermore, in patients with short survival times (≤3 mo) or metastatic disease, the total cost per patient did not differ between plastic stents and SEMS. No differences in costs were found between pcSEMS and uSEMS. CONCLUSIONS: Although placement of SEMS (uncovered or partially covered) for palliation of extrahepatic bile duct obstruction initially is more expensive than placement of plastic stents, SEMS have longer functional time. The total costs after 1 year do not differ significantly with stent type. Dutch Clinical Trial Registration no: NTR1361.

Bile acid-induced necrosis in primary human hepatocytes and in patients with obstructive cholestasis.

Accumulation of bile acids is a major mediator of cholestatic liver injury. Recent studies indicate bile acid composition between humans and rodents is dramatically different, as humans have a higher percent of glycine conjugated bile acids and increased chenodeoxycholate content, which increases the hydrophobicity index of bile acids. This increase may lead to direct toxicity that kills hepatocytes, and promotes inflammation. To address this issue, this study assessed how pathophysiological concentrations of bile acids measured in cholestatic patients affected primary human hepatocytes. Individual bile acid levels were determined in serum and bile by UPLC/QTOFMS in patients with extrahepatic cholestasis with, or without, concurrent increases in serum transaminases. Bile acid levels increased in serum of patients with liver injury, while biliary levels decreased, implicating infarction of the biliary tracts. To assess bile acid-induced toxicity in man, primary human hepatocytes were treated with relevant concentrations, derived from patient data, of the model bile acid glycochenodeoxycholic acid (GCDC). Treatment with GCDC resulted in necrosis with no increase in apoptotic parameters. This was recapitulated by treatment with biliary bile acid concentrations, but not serum concentrations. Marked elevations in serum full-length cytokeratin-18, high mobility group box 1 protein (HMGB1), and acetylated HMGB1 confirmed inflammatory necrosis in injured patients; only modest elevations in caspase-cleaved cytokeratin-18 were observed. These data suggest human hepatocytes are more resistant to human-relevant bile acids than rodent hepatocytes, and die through necrosis when exposed to bile acids. These mechanisms of cholestasis in humans are fundamentally different to mechanisms observed in rodent models.

Activation of the renin-angiotensin system stimulates biliary hyperplasia during cholestasis induced by extrahepatic bile duct ligation.

Cholangiocyte proliferation is regulated in a coordinated fashion by many neuroendocrine factors through autocrine and paracrine mechanisms. The renin-angiotensin system (RAS) is known to play a role in the activation of hepatic stellate cells and blocking the RAS attenuates hepatic fibrosis. We investigated the role of the RAS during extrahepatic cholestasis induced by bile duct ligation (BDL). In this study, we used normal and BDL rats that were treated with control, angiotensin II (ANG II), or losartan for 2 wk. In vitro studies were performed in a primary rat cholangiocyte cell line (NRIC). The expression of renin, angiotensin-converting enzyme, angiotensinogen, and angiotensin receptor type 1 was evaluated by immunohistochemistry (IHC), real-time PCR, and FACs and found to be increased in BDL compared with normal rat. The levels of ANG II were evaluated by ELISA and found to be increased in serum and conditioned media of cholangiocytes from BDL compared with normal rats. Treatment with ANG II increased biliary mass and proliferation in both normal and BDL rats. Losartan attenuated BDL-induced biliary proliferation. In vitro, ANG II stimulated NRIC proliferation via increased intracellular cAMP levels and activation of the PKA/ERK/CREB intracellular signaling pathway. ANG II stimulated a significant increase in Sirius red staining and IHC for fibronectin that was blocked by angiotensin receptor blockade. In vitro, ANG II stimulated the gene expression of collagen 1A1, fibronectin 1, and IL-6. These results indicate that cholangiocytes express a local RAS and that ANG II plays an important role in regulating biliary proliferation and fibrosis during extraheptic cholestasis.

A nontumorigenic variant of FGF19 treats cholestatic liver diseases.

Hepatic accumulation of bile acids is central to the pathogenesis of cholestatic liver diseases. Endocrine hormone fibroblast growth factor 19 (FGF19) may reduce hepatic bile acid levels through modulation of bile acid synthesis and prevent subsequent liver damage. However, FGF19 has also been implicated in hepatocellular carcinogenesis, and consequently, the potential risk from prolonged exposure to supraphysiological levels of the hormone represents a major hurdle for developing an FGF19-based therapy. We describe a nontumorigenic FGF19 variant, M70, which regulates bile acid metabolism and, through inhibition of bile acid synthesis and reduction of excess hepatic bile acid accumulation, protects mice from liver injury induced by either extrahepatic or intrahepatic cholestasis. Administration of M70 in healthy human volunteers potently reduces serum levels of 7α-hydroxy-4-cholesten-3-one, a surrogate marker for the hepatic activity of cholesterol 7α-hydroxylase (CYP7A1), the enzyme responsible for catalyzing the first and rate-limiting step in the classical bile acid synthetic pathway. This study provides direct evidence for the regulation of bile acid metabolism by FGF19 pathway in humans. On the basis of these results, the development of nontumorigenic FGF19 variants capable of modulating CYP7A1 expression represents an effective approach for the prevention and treatment of cholestatic liver diseases as well as potentially for other disorders associated with bile acid dysregulation.

Morphological changes in the liver and kidneys of rats subjected to terminal ileum exclusion during obstructive cholestasis.

PURPOSE: To investigate the effects of ileal exclusion on hepatic and renal morphology in extra-hepatic cholestasis. METHODS: Twenty four rats were distributed into three groups. Group 1 (control) underwent laparotomy and laparorrhaphy. The animals in groups 2 and 3 underwent hepatic duct ligature and kept in cholestasis for four weeks. After this period, the rats in groups 2 and 3 underwent internal biliary derivation. In Group 3, the last ten centimeters of the terminal ileum were by passed and excluded. Four weeks later, histological and biochemical analysis were performed in all animals of the three groups. RESULTS: In Group 1, no abnormalities regarding hepatic morphology were observed. All animals from groups 2 and 3 presented hepatic fibrosis. No difference was observed between the two groups. No morphological differences in renal histology could be identified among the three groups. There were differences in AST (p<0.05), ALT (p<0.05), direct bilirubin (p<0.05), ƔGT (p<0.05), urea (p<0.05) and creatinine (p<0.05) in Group 3 compared to control. CONCLUSION: The distal ileum exclusion had no influence upon the hepatic and renal morphological alterations, and biochemical liver and kidney tests have worsened.