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International audience; Background and Aims: In liver fibrosis, myofibroblasts derive from HSCs and as yet undefined mesenchymal cells. We aimed to identify portal mesenchymal progenitors of myofibroblasts.Approach and Results: Portal mesenchymal cells were isolated from mouse bilio-vascular tree and analyzed by single-cell RNA-sequencing. Thereby, we uncovered the landscape of portal mesenchymal cells in homeostatic mouse liver. Trajectory analysis enabled inferring a small cell population further defined by surface markers used to isolate it. This population consisted of portal fibroblasts with mesenchymal stem cell features (PMSCs), i.e., high clonogenicity and trilineage differentiation potential, that generated proliferative myofibroblasts, contrasting with nonproliferative HSC-derived myofibroblasts (-MF). Using bulk RNA-sequencing, we built oligogene signatures of the two cell populations that remained discriminant across myofibroblastic differentiation. SLIT2, a prototypical gene of PMSC/PMSC-MF signature, mediated profibrotic and angiogenic effects of these cells, which conditioned medium promoted HSC survival and endothelial cell tubulogenesis. Using PMSC/PMSC-MF 7-gene signature and slit guidance ligand 2 fluorescent in situ hybridization, we showed that PMSCs display a perivascular portal distribution in homeostatic liver and largely expand with fibrosis progression, contributing to the myofibroblast populations that form fibrotic septa, preferentially along neovessels, in murine and human liver disorders, irrespective of etiology. We also unraveled a 6-gene expression signature of HSCs/HSC-MFs that did not vary in these disorders, consistent with their low proliferation rate.Conclusions: PMSCs form a small reservoir of expansive myofibroblasts, which, in interaction with neovessels and HSC-MFs that mainly arise through differentiation from a preexisting pool, underlie the formation of fibrotic septa in all types of liver diseases

Organ homeostasis is maintained by regulated proliferation of distinct cell populations. In mouse liver, cyclin D1-positive hepatocytes in the midlobular zone repopulate the parenchyma at a constant rate to preserve liver homeostasis. The mitogenic cues that underlie this process are unknown. Hepatic stellate cells, the liver’s pericytes, are in close proximity to hepatocytes and have been implicated in supporting hepatocyte proliferation, but their role in liver homeostasis is unknown. Here, we employ a T cell-mediated hepatic stellate cell ablation model to remove nearly all hepatic stellate cells in the murine liver, enabling the unbiased characterization of hepatic stellate cell functions. In the normal murine liver, complete loss of hepatic stellate cells persists for up to 6 weeks and reduces liver mass. Our results show that hepatic stellate cells induce cyclin D1 in midlobular hepatocytes by release of neurotrophin-3 to promote hepatocyte proliferation via tropomyosin receptor kinase B signaling. These findings establish that hepatic stellate cells form the niche for midlobular hepatocytes and reveal a novel hepatocyte growth factor signaling pathway.One-Sentence SummaryHepatic stellate cells provide mitogenic cues for midlobular hepatocyte proliferation and metabolic zonation by secreting neurotrophin-3.

International audience; Autoimmune hepatitis (AIH) is a liver disease characterised by necrotico-inflammatory lesions of hepatocytes, the presence of specific autoantibodies and response to corticosteroid treatment. AIH must be considered in any patient with acute or chronic liver disease. As there is no pathognomonic sign of AIH, the diagnosis is based on a combination of clinical, biological, immunological and histological findings, after excluding other causes of liver disease. The clinical and biological presentation of AIH is variable and AIH can be associated with an autoimmune biliary disease, primary biliary cholangitis or primary sclerosing cholangitis in an overlap syndrome. For these reasons, diagnosis of AIH can be challenging. Even if liver histology remains essential in the diagnosis of AIH, non-invasive tests can be used at different steps of the management of AIH: diagnosis of AIH, notably diagnosis of an overlap syndrome, assessment of severity of AIH, searching for extra-hepatic disease frequently associated to AIH, evaluation of response to therapy, decision of treatment withdrawal. This review aims to provide practical guidelines for the use of non-invasive tests for the diagnosis and the follow-up of AIH. (C) 2021 Published by Elsevier Masson SAS.

Summary Primary sclerosing cholangitis is a chronic cholestatic liver disease, whose pathogenesis remains poorly understood. Several studies have shown that PSC patients harbor an impaired gut microbiota. A recent study confirmed that PSC patients displayed a bacterial dysbiosis, characterized by an increased abundance of three different bacteria: Klebsiella pneumoniae, Proteus mirabilis and Enterococcus gallinarum. This study also provides evidence for a possible mechanism of action of these bacteria: notably the formation of pores in gut epithelium leading to an increased gut permeability and the induction of liver inflammation characterized by an increased proportion of T helper 17 (TH17) cells. For the first time, strong data demonstrate not only an association between gut microbiota and primary sclerosing cholangitis but also a possible causal link.

Chronic liver diseases with different etiologies represent a major public health issue worldwide. Liver fibrosis is the common feature of almost all chronic liver diseases and remains a key determinant of clinical prognosis. Over the last two decades, basic science studies have uncovered molecular mechanisms underlying the pathophysiology of chronic liver diseases, leading to the recent development of new anti-fibrotic drugs. These new drugs target different steps in the pathophysiology of chronic liver injury: metabolism of glucose, lipids and bile acids, apoptosis, inflammation and fibrosis. Many targets are shared between non-alcoholic steatohepatitis (NASH) and cholestatic diseases, explaining why some drugs have been assessed concurrently in both conditions. This review reports the most recent clinical trials designed to treat liver fibrosis, with a special focus on NASH and cholestatic diseases.

International audience; GBCA gadolinium-based contrast agent MR magnetic resonance MRC magnetic resonance cholangiography PSC primary sclerosing cholangitis VCTE vibration controlled transient elastography Dear editor, We read with interest the review written by Mahzar and Russo about non-invasive prognostic tests for primary sclerosing cholangitis (PSC) 1. Although rare, PSC is a serious disease, associated with potentially lethal complications, notably cirrhosis and cholangiocarcinoma 2. Liver transplantation is the only curative treatment for PSC and median transplant-free survival is approximately 12-21 years after diagnosis 3. Identification of prognostic factors is essential for tailoring the follow-up strategies and testing new therapeutic modalities in homogeneous groups of PSC patients. As detailed in this review, over the last twenty years, different teams across the world, including ours, have identified several noninvasive prognostic tests for PSC patients 1. First, our team demonstrated in a large retrospective study that liver stiffness measured by vibration-controlled transient elastography (VCTE) was an independent predictive marker of survival in PSC patients 4. Next, we built 2 magnetic resonance (MR) risk scores (with and without gadolinium-based contrast agent (GBCA) administration) 5 , called Anali scores, and showed that they were able to predict adverse outcome-free survival (defined by survival without liver transplantation or cirrhosis

Portal myofibroblasts (PMF) form a sub-population of highly proliferative and proangiogenic liver myofibroblasts that derive from portal mesenchymal progenitors. Endoplasmic reticulum (ER) stress was previously shown to modulate fibrogenesis, notably in the liver. Our aim was to determine if ER stress occurred in PMF and affected their functions. PMF were obtained after their expansion in vivo from bile duct-ligated (BDL) rats and referred to as BDL PMF. Compared to standard PMF obtained from normal rats, BDL PMF were more myofibroblastic, as assessed by higher alpha-smooth muscle actin expression and collagen 1 production. Their proangiogenic properties were also higher, whereas their proliferative and migratory capacities were lower. CHOP expression was detected in the liver of BDL rats, at the leading edge of portal fibrosis where PMF accumulate. BDL PMF displayed ER dilatation and an overexpression of the PERK pathway downstream targets, Chop, Gadd34 and Trb3, in comparison with standard PMF. In vitro, the induction of ER stress by tunicamycin in standard PMF, caused a decrease in their proliferative and migratory activity, and an increase in their proangiogenic activity, without affecting their myofibroblastic differentiation. Conversely, the treatment of BDL PMF with the PERK inhibitor GSK2656157 reduced ER stress, which caused a decrease in their angiogenic properties, and restored their proliferative and migratory capacity. In conclusion, PMF develop ER stress as they expand with the progression of fibrosis, which further increases their proangiogenic activity, but also inhibits their proliferation and migration. This phenotypic switch may restrict PMF expansion while they support angiogenesis.

Resume La cholestase est definie par un defaut de transport des acides biliaires du foie vers l’intestin. Les tests de cholestase refletent d’une part les lesions des hepatocytes ou des cellules epitheliales biliaires induites par l’accumulation des acides biliaires (enzymes hepatiques) et d’autre part les alterations fonctionnelles de la secretion biliaire (bilirubine, acides biliaires). La ponction biopsie hepatique garde une place dans le diagnostic etiologique d’une cholestase chronique. Les principales maladies cholestatiques chroniques de l’adulte sont la cholangite biliaire primitive (CBP) et la cholangite sclerosante primitive (CSP). Des facteurs pronostiques ont ete identifies. La mesure de la souplesse du foie par elastometrie semble un examen tres prometteur dans la prise en charge de ces maladies. Le traitement medical est base sur l’acide ursodesoxycholique. Cependant, de nouveaux agents anti-cholestatiques, en particulier les agonistes des recepteurs nucleaires, dont l’acide obeticholique et les fibrates, ont fait l’objet d’une evaluation preclinique et clinique prometteuse. Une amelioration de la prise en charge est donc hautement probable a court terme.

Background & Aims Primary sclerosing cholangitis (PSC) has a variable, often progressive, course. Magnetic resonance cholangiography (MRC) is used in the diagnosis of PSC. Magnetic resonance risk scoring systems, called Anali without and with gadolinium, are used to predict disease progression, determined by radiologic factors. We aimed to assess the prognostic value of Anali scores in patients with PSC and validate our findings in a separate cohort. Methods We performed a retrospective study of patients with large-duct PSC (internal cohort, 119 patients in France; external cohort, 119 patients in Canada, Italy, and the United Kingdom). All the first-available MRC results were reviewed by 2 radiologists and the Anali scores were calculated as follows: Anali without gadolinium = (1× dilatation of intrahepatic bile ducts) + (2× dysmorphy) + (1× portal hypertension); Anali with gadolinium = (1× dysmorphy) + (1× parenchymal enhancement heterogeneity). The primary end point was survival without liver transplantation or cirrhosis decompensation. The prognostic value of Anali scores was assessed by Cox regression modeling. Results During a total of 549 patient-years for the internal cohort and 497 patient-years for the external cohort, we recorded 2 and 8 liver transplantations, 4 and 3 liver-related deaths, and 26 and 25 cirrhosis decompensations, respectively. In the univariate analysis, factors associated with survival without liver transplantation or cirrhosis decompensation in the internal cohort were as follows: serum levels of bilirubin, aspartate aminotransferase, alanine aminotransferase, γ-glutamyl transferase, alkaline phosphatase, albumin, and Anali scores. Anali scores without and with gadolinium identified patients' survival without liver transplantation or cirrhosis decompensation with a c-statistic of 0.89 (95% CI, 0.84–0.95) and 0.75 (95% CI, 0.64–0.87), respectively. Independent prognostic factors identified by multivariate analysis were Anali scores and bilirubinemia. The prognostic value of Anali scores was confirmed in the external cohort. Conclusions In internal and external cohorts, we found that Anali scores, determined from MRC, were associated with outcomes of patients with PSC. These scores might be used as prognostic factors.

ObjectivePatients with primary sclerosing cholangitis (PSC) were previously shown to display a bacterial gut dysbiosis but fungal microbiota has never been examined in these patients. The aim of this study was to assess the fungal gut microbiota in patients with PSC.DesignWe analysed the faecal microbiota of patients with PSC and concomitant IBD (n=27), patients with PSC and no IBD (n=22), patients with IBD and no PSC (n=33) and healthy subjects (n=30). Bacterial and fungal composition of the faecal microbiota was determined using 16S and ITS2 sequencing, respectively.ResultsWe found that patients with PSC harboured bacterial dysbiosis characterised by a decreased biodiversity, an altered composition and a decreased correlation network density. These alterations of the microbiota were associated with PSC, independently of IBD status. For the first time, we showed that patients with PSC displayed a fungal gut dysbiosis, characterised by a relative increase in biodiversity and an altered composition. Notably, we observed an increased proportion of Exophiala and a decreased proportion of Saccharomyces cerevisiae. Compared with patients with IBD and healthy subjects, the gut microbiota of patients with PSC exhibited a strong disruption in bacteria-fungi correlation network, suggesting an alteration in the interkingdom crosstalk.ConclusionThis study demonstrates that bacteria and fungi contribute to gut dysbiosis in PSC.

Magnetic resonance (MR) risk scores and liver stiffness (LS) have individually been shown to predict clinical outcomes in primary sclerosing cholangitis (PSC). The aim of this study was to assess their complementary prognostic value.Patients with PSC from 3 European centers with a 3-dimensional MR cholangiography available for central reviewing and a valid LS measurement assessed by vibration-controlled transient elastography by FibroScan performed within a 6-month interval were included in a longitudinal retrospective study. The MR score (Anali) without gadolinium (Gd) was calculated according to the formula: (1 × dilatation of intrahepatic bile ducts) + (2 × dysmorphy) + (1 × portal hypertension). The primary end point was survival without liver transplantation or cirrhosis decompensation. The prognostic values of LS and Anali score without Gd were assessed using Cox proportional hazard models.One hundred sixty-two patients were included. Over a total follow-up of 753 patient-years, 40 patients experienced an adverse outcome (4 liver transplantations, 6 liver-related deaths, and 30 cirrhosis decompensations). LS and Anali score without Gd were significantly correlated (ρ = 0.51, P0.001) and were independently associated with the occurrence of an adverse outcome. Optimal prognostic thresholds were 10.5 kPa for LS and 2 for the Anali score without Gd. Hazard ratios (95% confidence interval) were 2.07 (1.06-4.06) and 3.78 (1.67-8.59), respectively. The use in combination of these 2 thresholds allowed us to separate patients into low-, medium-, and high-risk groups for developing adverse outcomes. The 5-year cumulative rates of adverse outcome in these 3 groups were 8%, 16%, and 38% (P0.001), respectively.The combined use of MRI and vibration-controlled transient elastography permits easy risk stratification of patients with PSC.

International audience; Non-alcoholic fatty liver disease (NAFLD) has become the leading cause of chronic liver disease, exposing to the risk of liver fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). Angio-genesis is a complex process leading to the development of new vessels from pre-existing vessels. Angiogenesis is triggered by hypoxia and inflammation and is driven by the action of proangiogenic cytokines, mainly vascular endothelial growth factor (VEGF). In this review, we focus on liver angiogenesis associated with NAFLD and analyze the evidence of liver angiogenesis in animal models of NAFLD and in NAFLD patients. We also report the data explaining the role of angiogenesis in the progression of NAFLD and discuss the potential of targeting angiogenesis, notably VEGF, to treat NAFLD.

International audience; Background: The aim of this study was to identify predictive criteria of improvement after endoscopic treatment (ET) for severe strictures of extrahepatic bile ducts in patients with primary sclerosing cholangitis (PSC).Methods: PSC patients who had at least one ET for severe stricture were included. Features of magnetic resonance cholangiography (MRC), performed before ET, were evaluated according to a standard model of interpretation, and a radiologic qualitative score of probability of improvement after ET was built. Score 3 (likely) was given in case of severe common bile duct (CBD) stricture with marked dilatation without severe strictures of upstream ducts, Score 1 (unlikely) was given in case of severe multiple strictures of secondary ducts without biliary dilatation and Score 2 (undeterminate) was given to an intermediate pattern. The response to ET was assessed at 2 months (T2-response) from the last ET and at 12 months (T12-response) from inclusion.Results: Thirty-one patients were included. All had severe stricture (reduction ≥ 75% of the diameter) of CBD and 50% had severe stricture of right and/or left hepatic duct (LHD) at MRC before ET. According to the qualitative score, 16 patients had Score 3, 7 had Score 1 and 9 had Score 2. T12-response was obtained in 50% of patients. In univariate analysis, short LHD strictures, bilirubin, transaminases, pruritus and Score 3 were associated with T12-response. Increased bilirubin and transaminases were independent predictive factors of T12-response (HR 24, 95% CI: 3.4–170.4, P = 0.001 and 23.8, 95% CI: 3.4–169.4, P = 0.002, respectively).Conclusion: MRC, together with biochemical features, may contribute to identify the PSC patients who are likely to be improved after ET for severe strictures of extrahepatic bile ducts.

To evaluate the prognostic value of cystic dilatation (CD) of the intrahepatic biliary ducts in patients with primary sclerosing cholangitis (PSC). A single-center cohort of 205 patients with PSC from 2003 to 2016 was analysed. CD was defined by quantitative and qualitative criteria. Radiological and clinical courses were assessed. A Kaplan-Meier analysis was used to estimate cumulative survival without liver transplantation (LT) from the date of PSC diagnosis. A log-rank test was performed to compare survival time of PSC patients with and without CD. A total of 15 (7.3%) PSC patients (12 males) with a median age of 23 years at diagnosis had CD. Five patients had one CD; seven patients had two or three CDs; and three patients had diffuse CD. CDs ranged in small diameter size from 12 to 32 mm. Radiological evolution of CD was markedly variable. However, a radiological worsening of PSC over time was observed in all patients. The clinical course was characterized by the occurrence of complications in most patients. Half of the patients with CD underwent LT at a median time of 40 months from diagnosis of CD and the median survival time from PSC diagnosis was significantly lower than in PSC without CD (10.7 vs. 23.4 years; HR 3.8, 95% confidence interval: 1.7–8.3, p = 0.001). CD in PSC is an unusual condition that mostly affects young patients. It is characterized by a rapid, unfavorable course and constitutes a significant prognostic factor. • Cystic dilatation of the intrahepatic biliary ducts affects young patients with primary sclerosing cholangitis and is characterized by a markedly variable radiological evolution. • Biliary wall inflammation, found in explanted livers, could be a key feature in the pathogenesis of cystic dilatation. • Cystic dilatation of the intrahepatic biliary ducts is characterized by an unfavorable course and constitutes a significant prognostic factor of primary sclerosing cholangitis.

IF 79.258 (2017); International audience; Background : Patients with primary biliary cholangitis who have an inadequate response to therapy with ursodeoxycholic acid are at high risk for disease progression. Fibrates, which are agonists of peroxisome proliferator–activated receptors, in combination with ursodeoxycholic acid, have shown potential benefit in patients with this condition.Methods : In this 24-month, double-blind, placebo-controlled, phase 3 trial, we randomly assigned 100 patients who had had an inadequate response to ursodeoxycholic acid according to the Paris 2 criteria to receive bezafibrate at a daily dose of 400 mg (50 patients), or placebo (50 patients), in addition to continued treatment with ursodeoxycholic acid. The primary outcome was a complete biochemical response, which was defined as normal levels of total bilirubin, alkaline phosphatase, aminotransferases, and albumin, as well as a normal prothrombin index (a derived measure of prothrombin time), at 24 months.Results : The primary outcome occurred in 31% of the patients assigned to bezafibrate and in 0% assigned to placebo (difference, 31 percentage points; 95% confidence interval, 10 to 50; P

Liver fibrosis expanding from portal tracts and vascular remodeling are determinant factors in the progression of liver diseases to cirrhosis. In the present study, we examined the potential contribution of portal myofibroblasts (PMFs) to the vascular changes leading to cirrhosis. The analyses of liver cells based on the transcriptome of rat PMFs, compared to hepatic stellate cell HSC-derived myofibroblasts in culture, identified collagen, type XV, alpha 1 (COL15A1) as a marker of PMFs. Normal liver contained rare COL15A1-immunoreactive cells adjacent to the bile ducts and canals of Hering in the portal area. A marked increase in COL15A1 expression occurred together with that of the endothelial marker, von Willebrand factor, in human and rat liver tissue, at advanced stages of fibrosis caused by either biliary or hepatocellular injury. In cirrhotic liver, COL15A1-expressing PMFs adopted a perivascular distribution outlining vascular capillaries proximal to reactive ductules, within large fibrotic septa. The effect of PMFs on endothelial cells (ECs) was evaluated by in vitro and in vivo angiogenesis assays. PMF-conditioned medium increased the migration and tubulogenesis of liver ECs as well as human umbilical vein ECs and triggered angiogenesis within Matrigel plugs in mice. In coculture, PMFs developed intercellular junctions with ECs and enhanced the formation of vascular structures. PMFs released vascular endothelial growth factor (VEGF)A-containing microparticles, which activated VEGF receptor 2 in ECs and largely mediated their proangiogenic effect. Cholangiocytes potentiated the angiogenic properties of PMFs by increasing VEGFA expression and microparticle shedding in these cells. Conclusion: PMFs are key cells in hepatic vascular remodeling. They signal to ECs through VEGFA-laden microparticles and act as mural cells for newly formed vessels, driving scar progression from portal tracts into the parenchyma. (Hepatology 2015;61:1041–1055)

Microvesicles (MVs) are extracellular vesicles released by virtually all cells, under both physiological and pathological conditions. They contain lipids, proteins, RNAs and microRNAs and act as vectors of information that regulate the function of target cells. This Review provides an overview of the studies assessing circulating MV levels in patients with liver diseases, together with an insight into the mechanisms that could account for these changes. We also present a detailed analysis of the implication of MVs in key processes of liver diseases. MVs have a dual role in fibrosis as certain types of MVs promote fibrolysis by increasing expression of matrix metalloproteinases, whereas others promote fibrosis by stimulating processes such as angiogenesis. MVs probably enhance portal hypertension by contributing to intrahepatic vasoconstriction, splanchnic vasodilation and angiogenesis. As MVs can modulate vascular permeability, vascular tone and angiogenesis, they might contribute to several complications of cirrhosis including hepatic encephalopathy, hepatopulmonary syndrome and hepatorenal syndrome. Several results also suggest that MVs have a role in hepatocellular carcinoma. Although MVs represent promising biomarkers in patients with liver disease, methods of isolation and subsequent analysis must be standardized.

It was with great interest that we read the recent guidelines from the British Society of Gastroenterology on the treatment and management of primary biliary cholangitis (PBC).1 The authors propose a pragmatic drug approach to treat cholestatic pruritus with cholestyramine as first-line and rifampicin as second-line use, followed by naltrexone, sertraline or gabapentin as third-line options, although with concerns regarding tolerability and adverse events. Pruritus is a characteristic, potentially agonising symptom of PBC that remains poorly cared.2 New drug options are definitively needed to relieve patients of this symptom. Bezafibrate, a pan-agonist of peroxisome proliferator-activated receptors, has been suggested to reduce itch intensity in patients with PBC.3 This beneficial effect has recently been confirmed in a placebo-controlled phase III trial Bezafibrate in Combination with Ursodeoxycholic Acid in PBC (BEZURSO).4 The mechanisms by which bezafibrate improves pruritus in PBC remain unknown. As the lysophospholipase autotaxin (ATX) and its product, lysophosphatidic acid, have been identified as potential key players in the pathogenesis of cholestatic pruritus,5 the present post-hoc analysis of the BEZURSO trial aims to investigate the role of ATX in the antipruritic effect of bezafibrate in patients with PBC. All patients met the following criteria at inclusion: (1) PBC diagnosis and (2) …

Myofibroblasts combine the matrix-producing functions of fibroblasts and the contractile properties of smooth muscle cells. They are the main effectors of fibrosis in all tissues and make a major contribution to other aspects of the wound healing response, including regeneration and angiogenesis. They display the de novo expression of α-smooth muscle actin. Myofibroblasts, which are absent from the normal liver, are derived from two major sources: hepatic stellate cells (HSCs) and portal mesenchymal cells in the injured liver. Reliable markers for distinguishing between the two subpopulations at the myofibroblast stage are currently lacking, but there is evidence to suggest that both myofibroblast cell types, each exposed to a particular microenvironment (e.g. hypoxia for HSC-MFs, ductular reaction for portal mesenchymal cell-derived myofibroblasts (PMFs)), expand and exert specialist functions, in scarring and inflammation for PMFs, and in vasoregulation and hepatocellular healing for HSC-MFs. Angiogenesis is a major mechanism by which myofibroblasts contribute to the progression of fibrosis in liver disease. It has been clearly demonstrated that liver fibrosis can regress, and this process involves a deactivation of myofibroblasts, although probably not to a fully quiescent phenotype. This article is part of a Special Issue entitled: Fibrosis: Translation of basic research to human disease.

International audience; Liver sinusoidal endothelial cells (LSECs) are highly specialized endothelial cells representing the interface between blood cells on the one side and hepatocytes and hepatic stellate cells on the other side. LSECs represent a permeable barrier. Indeed, the association of 'fenestrae', absence of diaphragm and lack of basement membrane make them the most permeable endothelial cells of the mammalian body. They also have the highest endocytosis capacity of human cells. In physiological conditions, LSECs regulate hepatic vascular tone contributing to the maintenance of a low portal pressure despite the major changes in hepatic blood flow occurring during digestion. LSECs maintain hepatic stellate cell quiescence, thus inhibiting intrahepatic vasoconstriction and fibrosis development. In pathological conditions, LSECs play a key role in the initiation and progression of chronic liver diseases. Indeed, they become capillarized and lose their protective properties, and they promote angiogenesis and vasoconstriction. LSECs are implicated in liver regeneration following acute liver injury or partial hepatectomy since they renew from LSECs and/or LSEC progenitors, they sense changes in shear stress resulting from surgery, and they interact with platelets and inflammatory cells. LSECs also play a role in hepatocellular carcinoma development and progression, in ageing, and in liver lesions related to inflammation and infection. This review also presents a detailed analysis of the technical aspects relevant for LSEC analysis including the markers these cells express, the available cell lines and the transgenic mouse models. Finally, this review provides an overview of the strategies available for a specific targeting of LSECs.

International audience; Liver fibrogenesis is a dynamic process including quantitative and qualitative changes of the extracellular matrix, of which the most prominent is the deposition of type I collagen. These changes progressively disrupt normal liver architecture and result in cirrhosis formation. In the fibrotic liver, as in all other fibrotic tissues, the extracellular matrix is produced by cells usually characterized by the de novo expression of alpha-smooth muscle actin and known as myofibroblasts. Portal myofibroblasts (PMFs) appear to be critical in pathological angiogenesis, which constantly occurs in advanced liver fibrosis. Whereas the association between angiogenesis and fibrosis during the progression of liver diseases remains to be elucidated, we suggest that collagen-type-XV-alpha1-producing PMFs could provide an important link both by stabilizing newly formed vessels and by forming a scaffold for the deposition of interstitial collagen.

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Magnetic resonance imaging (MRI) with magnetic resonance cholangiography (MRC) has become the radiologic standard of reference for diagnosis of primary sclerosing cholangitis (PSC). However, natural history of radiologic features of PSC is poorly known. In the current study, we aimed at analyzing the course of PSC using three-dimensional (3D) MRC and liver MRI to find predictive radiologic features of progression. PSC patients, followed up in our center, with at least two 3D MRCs performed in at least a 1-year interval, were retrospectively reviewed. We built an interpretation standard model to score precisely bile ducts and liver parenchyma features. The primary endpoint was overall radiologic course, including worsening, improvement, or stabilization. Radiologic features were analyzed by logistic regression. We reviewed 289 MRIs from 64 patients upon a mean radiologic follow-up of 4 years (range, 1-9). Radiologic features worsened in 37 patients (58%) and stabilized in 27 (42%); no patient showed improvement. Multivariate analysis resulted in two MRI progression risk scores, based on the combination of predictive radiologic features (score without gadolinium administration = 1 × dilatation of intrahepatic bile ducts + 2 × dysmorphy + 1 × portal hypertension; score with gadolinium administration = 1 × dysmorphy + 1 × parenchymal enhancement heterogeneity). These scores were associated with radiologic progression, with an area under the curve of 80 and 83% ± 4%. Conclusion: A majority of PSC patients develop radiologic aggravation upon MRI over 4 years. Two simple scores can predict radiologic progression.(Hepatology 2014;58:242–250)

A 79 year-old patient with prostate cancer related Cushing's syndrome was referred to ICU for acute respiratory distress occurring two days after introduction of mifepristone. Pneumocystis jirovecii pneumonia was diagnosed. Despite anti pneumocystis therapy and supportive treatment, the patient died of multiple organ failure. The relationship between mifepristone and Cushing's syndrome and potential implications are discussed. Cushing's syndrome is a classical but rare disease resulting from exposure to excessive concentrations of glucocorticoid. When surgery is not feasible medical therapy should be discussed. A 79 year-old man was admitted to intensive care unit for acute respiratory distress. He had been treated for prostate cancer for 12 years, with radiotherapy and hormonotherapy. The last prostate-specific antigen (PSA) level was (0, 24 ng/ml) while pelvis MRI disclosed irregular prostate consistent with radiotherapy after-effects without any sign of recurrence of malignancy. He was referred 3 months before to the general ward because of depression, severe systemic hypertension, hypokalaemia and diabetes mellitus. Endogenous hypercortisolism was diagnosed. Static and dynamic analysis: (plasma cortisol level at 8 am : 1564 nmol/l (normal

Summary Background & aims In patients with primary sclerosing cholangitis (PSC), ursodeoxycholic acid (UDCA) treatment improves serum liver tests and surrogate markers of prognosis but has no proven effect on survival. Additional therapies are obviously needed. Fibrates, PPAR agonists with anti-cholestatic properties, have a beneficial effect in primary biliary cholangitis. The aim of this study was to evaluate the safety and efficacy of fibrates in PSC patients. Methods Retrospectively, we investigated PSC patients treated with fibrates (fenofibrate 200 mg/day or bezafibrate 400 mg/day) for at least 6 months in addition to UDCA, after an incomplete biochemical response (alkaline phosphatase [ALP] ≥ 1.5 × upper limit of normal) to UDCA. Changes in biochemical parameters and clinical features were assessed. Results Twenty patients were included (fourteen from Paris and six from Barcelona): median age 43.8 years, median liver stiffness 11 kPa (≥ F3). Upon treatment with fibrates (median duration of 1.56 years), liver tests significantly improved, including a reduction of ALP levels by 41% and pruritus significantly decreased. No serious adverse event attributable to fibrates occurred. Discontinuation of fibrates was followed by a clear rebound of ALP. Despite biochemical improvement, liver stiffness significantly increased. Conclusions Combining UDCA with fibrates results in a significant biochemical improvement and pruritus decrease in PSC patients with incomplete response to UDCA. These results provide a rationale for larger and prospectively designed studies to establish the efficacy and safety of fibrates in PSC.