Primary splenic angiosarcoma: a case series of a rare oncological entity and diagnostic challenge.

BACKGROUND AND PURPOSE: Primary angiosarcoma of the spleen (PAS), an exceptionally rare and aggressive neoplasm with high metastatic risk (70%-85%), is frequently diagnosed in an advanced or metastatic stage. It presents diagnostic challenges due to its nonspecific symptomatology and resemblance to benign vascular lesions in various imaging modalities. PATIENTS AND METHODS: This case series aims to clarify the diagnostic difficulties by comparing imaging characteristics (CT-scan, MRI, and [18F]FDG-PET/CT) as well as pathological findings of three PAS cases diagnosed in different stages of the diseases (localized, metastatic, and metastatic with organ failure). Furthermore, a brief review on diagnostic and therapeutic features is included. RESULTS AND INTERPRETATION: We suggest [18F]FDG-PET/CT as a differentiating tool between benign and malignant splenic lesions and propose a flowchart of a diagnostic algorithm for PAS. For treatment, we advocate for early splenectomy and when systemic therapy is warranted, paclitaxel emerges as a viable first-line option. While it is crucial to acknowledge that further trial data is required to evaluate the efficacy of emerging treatment regimens, designing and conducting trials for PAS is challenging given its scarcity and aggressive behavior. Therefore case reporting remains important.

Viral clade is associated with severity of symptomatic genotype 3 hepatitis E virus infections in Belgium, 2010-2018.

BACKGROUND & AIMS: HEV genotype (gt) 3 infections are prevalent in high-income countries and display a wide spectrum of clinical presentations. Host - but not viral - factors are reported to be associated with worse clinical outcomes. METHODS: Demographic, clinical, and biochemical data laboratory-confirmed HEV infections (by PCR and/or a combination of IgM and IgG serology) at the Belgian National Reference Centre between January 2010 and June 2018 were collected using standardised case report forms. Genotyping was based on HEV open reading frame 2 sequences. Serum CXCL10 levels were measured by a magnetic bead-based assay. H&E staining was performed on liver biopsies. RESULTS: A total of 274 HEV-infected individuals were included. Subtype assignment was possible for 179/218 viraemic cases, confirming gt3 as dominant with an almost equal representation of clades abchijklm and efg. An increased hospitalisation rate and higher peak serum levels of alanine aminotransferase, bilirubin, and alkaline phosphatase were found in clade efg-infected individuals in univariate analyses. In multivariable analyses, clade efg infections remained more strongly associated with severe disease presentation than any of the previously identified host risk factors, being associated with a 2.1-fold higher risk of hospitalisation (95% CI 1.1-4.4, p = 0.034) and a 68.2% higher peak of bilirubin levels (95% CI 13.3-149.9, p = 0.010), independently of other factors included in the model. In addition, acute clade efg infections were characterised by higher serum CXCL10 levels (p = 0.0005) and a more pronounced liver necro-inflammatory activity (p = 0.022). CONCLUSIONS: In symptomatic HEV gt3 infections, clade efg is associated with a more severe disease presentation, higher serum CXCL10 levels, and liver necro-inflammatory activity, irrespective of known host risk factors. CLINICAL TRIAL REGISTRATION: The protocol was submitted to clinicaltrials.gov (NCT04670419). IMPACT AND IMPLICATIONS: HEV genotype (gt) 3 infections display a wide spectrum of clinical presentations currently ascribed to host factors. Here we examined the role of viral factors on liver disease outcomes by combining viral phylogeny with clinical, biochemical, cytokine, and histological data from 274 Belgian adults infected with HEV presenting between 2010 and 2018. HEV gt 3 clade efg infections were associated with a more severe disease presentation, higher serum CXCL10 levels and liver necro-inflammatory activity, irrespective of known host risk factors. HEV gt3 clade-dependent clinical outcomes call for broad HEV gt3 subtyping in clinical practice and research to help identify those at higher risk for worse outcomes and to further unravel underlying virus-host interactions.

Best Practices and Progress in Precision-Cut Liver Slice Cultures.

Thirty-five years ago, precision-cut liver slices (PCLS) were described as a promising tool and were expected to become the standard in vitro model to study liver disease as they tick off all characteristics of a good in vitro model. In contrast to most in vitro models, PCLS retain the complex 3D liver structures found in vivo, including cell-cell and cell-matrix interactions, and therefore should constitute the most reliable tool to model and to investigate pathways underlying chronic liver disease in vitro. Nevertheless, the biggest disadvantage of the model is the initiation of a procedure-induced fibrotic response. In this review, we describe the parameters and potential of PCLS cultures and discuss whether the initially described limitations and pitfalls have been overcome. We summarize the latest advances in PCLS research and critically evaluate PCLS use and progress since its invention in 1985.

Somatostatin as Inflow Modulator in Liver-transplant Recipients With Severe Portal Hypertension: A Randomized Trial.

OBJECTIVE: To investigate the safety and efficacy of somatostatin as liver inflow modulator in patients with end-stage liver disease (ESLD) and clinically significant portal hypertension (CSPH) undergoing liver transplantation (LT) (ClinicalTrials.gov number,01290172). BACKGROUND: In LT, portal hyperperfusion can severely impair graft function and survival, mainly in cases of partial LT. METHODS: Thirty-three patients undergoing LT for ESLD and CSPH were randomized double-blindly to receive somatostatin or placebo (2:1). The study drug was administered intraoperatively as 5-mL bolus (somatostatin: 500 µg), followed by a 2.5 mL/h infusion (somatostatin: 250 µg/h) for 5 days. Hepatic and systemic hemodynamics were measured, along with liver function tests and clinical outcomes. The ischemia-reperfusion injury (IRI) was analyzed through histological and protein expression analysis. RESULTS: Twenty-nine patients (18 receiving somatostatin, 11 placebo) were included in the final analysis. Ten patients responded to somatostatin bolus, with a significant decrease in hepatic venous portal gradient (HVPG) and portal flow of -28.3% and -29.1%, respectively. At graft reperfusion, HVPG was lower in patients receiving somatostatin (-81.7% vs -58.8%; P = 0.0084), whereas no difference was observed in the portal flow (P = 0.4185). Somatostatin infusion counteracted the decrease in arterial flow (-10% vs -45%; P = 0.0431). There was no difference between the groups in the severity of IRI, incidence of adverse events, long-term complications, graft, and patient survival. CONCLUSIONS: Somatostatin infusion during LT in patients with CSPH is safe, reduces the HVPG, and preserves the arterial inflow to the graft. This study establishes the efficacy of somatostatin as a liver inflow modulator.

Treatment of Advanced Hepatocellular Carcinoma with Somatostatin Analogues: A Review of the Literature.

Hepatocellular carcinoma, one of the most dreaded complications of cirrhosis, is a frequent cancer with high mortality. Early primary liver cancer can be treated by surgery or ablation techniques, but advanced hepatocellular carcinoma remains a challenge for clinicians. Most of these patients have underlying cirrhosis, which complicates or even precludes treatment. Therefore, efficacious treatments without major side effects are welcomed. Initial results of treatment of advanced hepatocellular carcinoma with somatostatin analogues were promising, but subsequent trials have resulted in conflicting outcomes. This might be explained by different patient populations, differences in dosage and type of treatment and differences in somatostatin receptor expression in the tumor or surrounding tissue. It has been shown that the expression of somatostatin receptors in the tumor might be of importance to select patients who could benefit from treatment with somatostatin analogues. Moreover, somatostatin receptor expression in hepatocellular carcinoma has been shown to correlate with recurrence, prognosis, and survival. In this review, we will summarize the available data on treatment of primary liver cancer with somatostatin analogues and analyze the current knowledge of somatostatin receptor expression in hepatocellular carcinoma and its possible clinical impact.

Prospects in non-invasive assessment of liver fibrosis: Liquid biopsy as the future gold standard?

Liver fibrosis is the result of persistent liver injury, and is characterized by sustained scar formation and disruption of the normal liver architecture. The extent of fibrosis is considered as an important prognostic factor for the patient outcome, as an absence of (early) treatment can lead to the development of liver cirrhosis and hepatocellular carcinoma. Till date, the most sensitive and specific way for the diagnosis and staging of liver fibrosis remains liver biopsy, an invasive diagnostic tool, which is associated with high costs and discomfort for the patient. Over time, non-invasive scoring systems have been developed, of which the measurements of serum markers and liver stiffness are validated for use in the clinic. These tools lack however the sensitivity and specificity to detect small changes in the progression or regression of both early and late stages of fibrosis. Novel non-invasive diagnostic markers with the potential to overcome these limitations have been developed, but often lack validation in large patient cohorts. In this review, we will summarize novel trends in non-invasive markers of liver fibrosis development and will discuss their (dis-)advantages for use in the clinic.

Intensive Enteral Nutrition Is Ineffective for Patients With Severe Alcoholic Hepatitis Treated With Corticosteroids.

BACKGROUND & AIMS: Severe alcoholic hepatitis (AH) is a life-threatening disease for which adequate oral nutritional support is recommended. We performed a randomized controlled trial to determine whether the combination of corticosteroid and intensive enteral nutrition therapy is more effective than corticosteroid therapy alone in patients with severe AH. METHODS: We enrolled 136 heavy consumers of alcohol (age, 18-75 y) with recent onset of jaundice and biopsy-proven severe AH in our study, performed at 18 hospitals in Belgium and 2 in France, from February 2010 through February 2013. Subjects were assigned randomly (1:1) to groups that received either intensive enteral nutrition plus methylprednisolone or conventional nutrition plus methylprednisolone (controls). In the intensive enteral nutrition group, enteral nutrition was given via feeding tube for 14 days. The primary end point was patient survival for 6 months. RESULTS: In an intention-to-treat analysis, we found no significant difference between groups in 6-month cumulative mortality: 44.4% of patients died in the intensive enteral nutrition group (95% confidence interval [CI], 32.2%-55.9%) and 52.1% of controls died (95% CI, 39.4%-63.4%) (P = .406). The enteral feeding tube was withdrawn prematurely from 48.5% of patients, and serious adverse events considered to be related to enteral nutrition occurred in 5 patients. Regardless of group, a greater proportion of patients with a daily calorie intake less than 21.5 kcal/kg/day died (65.8%; 95% CI, 48.8-78.4) than patients with a higher intake of calories (33.1%; 95% CI, 23.1%-43.4%) (P < .001). CONCLUSIONS: In a randomized trial of patients with severe AH treated with corticosteroids, we found that intensive enteral nutrition was difficult to implement and did not increase survival. However, low daily energy intake was associated with greater mortality, so adequate nutritional intake should be a main goal for treatment. ClinicalTrials.gov number: NCT01801332.

The Hippo pathway effector YAP controls mouse hepatic stellate cell activation.

BACKGROUND & AIMS: Hepatic stellate cell activation is a wound-healing response to liver injury. However, continued activation of stellate cells during chronic liver damage causes excessive matrix deposition and the formation of pathological scar tissue leading to fibrosis and ultimately cirrhosis. The importance of sustained stellate cell activation for this pathological process is well recognized, and several signalling pathways that can promote stellate cell activation have been identified, such as the TGFß-, PDGF-, and LPS-dependent pathways. However, the mechanisms that trigger and drive the early steps in activation are not well understood. METHODS AND RESULTS: We identified the Hippo pathway and its effector YAP as a key pathway that controls stellate cell activation. YAP is a transcriptional co-activator and we found that it drives the earliest changes in gene expression during stellate cell activation. Activation of stellate cells in vivo by CCl4 administration to mice or activation in vitro caused rapid activation of YAP as revealed by its nuclear translocation and by the induction of YAP target genes. YAP was also activated in stellate cells of human fibrotic livers as evidenced by its nuclear localization. Importantly, knockdown of YAP expression or pharmacological inhibition of YAP prevented hepatic stellate cell activation in vitro and pharmacological inhibition of YAP impeded fibrogenesis in mice. CONCLUSIONS: YAP activation is a critical driver of hepatic stellate cell activation and inhibition of YAP presents a novel approach for the treatment of liver fibrosis.

Human iPSC-derived liver co-culture spheroids to model liver fibrosis.

The lack of adequate humanin vitromodels that recapitulate the cellular composition and response of the human liver to injury hampers the development of anti-fibrotic drugs. The goal of this study was to develop a human spheroid culture model to study liver fibrosis by using induced pluripotent stem cell (iPSC)-derived liver cells. iPSCs were independently differentiated towards hepatoblasts (iHepatoblasts), hepatic stellate cells (iHSCs), endothelial cells (iECs) and macrophages (iMΦ), before assembly into free floating spheroids by culturing cells in 96-well U-bottom plates and orbital shaking for up to 21 days to allow further maturation. Through transcriptome analysis, we show further maturation of iECs and iMΦ, the differentiation of the iHepatoblasts towards hepatocyte-like cells (iHeps) and the inactivation of the iHSCs by the end of the 3D culture. Moreover, these cultures display a similar expression of cell-specific marker genes (CYP3A4, PDGFRß, CD31andCD68) and sensitivity to hepatotoxicity as spheroids made using freshly isolated primary human liver cells. Furthermore, we show the functionality of the iHeps and the iHSCs by mimicking liver fibrosis through iHep-induced iHSC activation, using acetaminophen. In conclusion, we have established a reproducible human iPSC-derived liver culture model that can be used to mimic fibrosisin vitroas a replacement of primary human liver derived 3D models. The model can be used to investigate pathways involved in fibrosis development and to identify new targets for chronic liver disease therapy.

Orphan receptor GPR176 in hepatic stellate cells exerts a profibrotic role in chronic liver disease.

Background & Aims: Chronic liver disease (CLD) remains a global health issue associated with a significant disease burden. Liver fibrosis, a hallmark of CLD, is characterised by the activation of hepatic stellate cells (HSCs) that gain profibrotic characteristics including increased production of extracellular matrix protein. Currently, no antifibrotic therapies are available clinically, in part because of the lack of HSC-specific drug targets. Here, we aimed to identify HSC-specific membrane proteins that can serve as targets for antifibrotic drug development. Methods: Small interfering RNA-mediated knockdown of GPR176 was used to assess the in vitro function of GPR176 in HSCs and in precision cut liver slices (PCLS). The in vivo role of GPR176 was assessed using the carbon tetrachloride (CCl4) and common bile duct ligation (BDL) models in wild-type and GPR176 knockout mice. GPR176 in human CLD was assessed by immunohistochemistry of diseased human livers and RNA expression analysis in human primary HSCs and transcriptomic data sets. Results: We identified Gpr176, an orphan G-protein coupled receptor, as an HSC-enriched activation associated gene. In vitro, Gpr176 is strongly induced upon culture-induced and hepatocyte-damage-induced activation of primary HSCs. Knockdown of GPR176 in primary mouse HSCs or PCLS cultures resulted in reduced fibrogenic characteristics. Absence of GPR176 did not influence liver homeostasis, but Gpr176-/- mice developed less severe fibrosis in CCl4 and BDL fibrosis models. In humans, GPR176 expression was correlated with in vitro HSC activation and with fibrosis stage in patients with CLD. Conclusions: GPR176 is a functional protein during liver fibrosis and reducing its activity attenuates fibrogenesis. These results highlight the potential of GPR176 as an HSC-specific antifibrotic candidate to treat CLD. Impact and implications: The lack of effective antifibrotic drugs is partly attributed to the insufficient knowledge about the mechanisms involved in the development of liver fibrosis. We demonstrate that the G-protein coupled receptor GPR176 contributes to fibrosis development. Since GPR176 is specifically expressed on the membrane of activated hepatic stellate cells and is linked with fibrosis progression in humans, it opens new avenues for the development of targeted interventions.

Parenteral Nutrition, Sepsis, Acute Heart Failure and Hepatotoxic Drugs Are Related to Liver Test Disturbances in Critically Ill Patients.

BACKGROUND: Parenteral nutrition (PN) is often associated with liver dysfunction in the ICU, although other factors such as sepsis, acute heart failure (AHF), and hepatotoxic drugs can be equally present. The relative impact of PN on liver dysfunction in critically ill patients is largely unknown. METHODS: We recorded the presence of pre-existing liver disturbances, AHF, sepsis, daily PN volume, and commonly used hepatotoxic drugs in adult ICU patients, together with daily aspartate aminotransferase (AST), alanine aminotransferase (ALT), gamma-glutamyltransferase (GGT), alkalic phosphatase (AP), total bilirubin (TB), and INR values in patients with three or more PN treatment days. A linear mixed-effects model was used to assess the relative contribution of each liver parameter. Nutritional adequacy was defined as intake/needs. RESULTS: We included 224 ICU patients with PN treatment lasting more than 3 days between 1 January 2017 and 31 December 2019. For AST, pre-existing liver disturbances (+180% ± 11%) and the presence of AHF (+75% ± 14%) were the main predictors of deterioration, whereas PN volume caused only a limited increase of 14% ± 1%/L. Similar results were observed for ALT. GGT, INR, and TB are mainly influenced by the presence of sepsis/septic shock and pre-existing liver disturbances, with no impact of PN or hepatotoxic drugs. Carbohydrate intake exceeded recommendations, and protein and lipid intake were insufficient in this study cohort. CONCLUSIONS: Liver test disturbances in ICU patients on PN are multifactorial, with sepsis and AHF having the highest influence, with only limited impact from PN and hepatotoxic drugs. Feeding adequacy can be improved.

Fascin, a novel marker of human hepatic stellate cells, may regulate their proliferation, migration, and collagen gene expression through the FAK-PI3K-Akt pathway.

Fascin is a component of actin bundles and may regulate various cellular events. The expression and function of fascin in human hepatic stellate cells (HSCs) has remained largely uncharacterized. Fascin expression in human liver tissue was studied using immunohistochemistry. To identify cells expressing fascin, double immunofluorescent staining with vimentin, α-smooth muscle actin (α-SMA), or fibulin-2 was performed and analyzed with confocal microscopy. In culture experiments, fascin expression and the phosphorylation of focal adhesion kinase (FAK) and Akt in LX-2 cells, a cell line of human HSCs, were investigated using western blot. Specific siRNAs were used to reduce the expression of fascin in LX-2 cells. Proliferation and migration were assayed with a CyQuant assay kit and a Matrigel-coated culture insert system, respectively. Levels of matrix metalloproteinase (MMP)-2 and collagen mRNAs were examined using quantitative RT-PCR. Immunohistochemistry revealed the expression of fascin along sinusoids and overlapping with vimentin and α-SMA in both non-fibrotic and fibrotic liver tissue, but it was almost absent in periportal myofibroblastic cells and did not colocalize with fibulin-2, a marker of portal myofibroblasts. In addition, fascin immunoreactivity was almost undetectable in septa of fibrotic human liver tissue. The expression of fascin in LX-2 cells was confirmed using western blot. Two different specific siRNAs against fascin significantly reduced the number of viable LX-2 cells to 65% compared with control cultures and downregulated the mRNAs levels of types I and III collagen and MMP-2 to 62%, 65%, and 70% of control levels, respectively. This condition also reduced the migration activity of LX-2 cells to 46% of control cells and the phosphorylation level of both FAK and Akt. Fascin may be an excellent novel marker of human HSCs that distinguishes HSCs from periportal myofibroblasts. Fascin may regulate functions of human HSCs through the FAK-phosphoinositide 3-kinase-Akt pathway.

Inhibition of placental growth factor activity reduces the severity of fibrosis, inflammation, and portal hypertension in cirrhotic mice.

UNLABELLED: Placental growth factor (PlGF) is associated selectively with pathological angiogenesis, and PlGF blockade does not affect the healthy vasculature. Anti-PlGF is therefore currently being clinically evaluated for the treatment of cancer patients. In cirrhosis, hepatic fibrogenesis is accompanied by extensive angiogenesis. In this paper, we evaluated the pathophysiological role of PlGF and the therapeutic potential of anti-PlGF in liver cirrhosis. PlGF was significantly up-regulated in the CCl(4) -induced rodent model of liver cirrhosis as well as in cirrhotic patients. Compared with wild-type animals, cirrhotic PlGF(-/-) mice showed a significant reduction in angiogenesis, arteriogenesis, inflammation, fibrosis, and portal hypertension. Importantly, pharmacological inhibition with anti-PlGF antibodies yielded similar results as genetic loss of PlGF. Notably, PlGF treatment of activated hepatic stellate cells induced sustained extracellular signal-regulated kinase 1/2 phosphorylation, as well as chemotaxis and proliferation, indicating a previously unrecognized profibrogenic role of PlGF. CONCLUSION: PlGF is a disease-candidate gene in liver cirrhosis, and inhibition of PlGF offers a therapeutic alternative with an attractive safety profile.

Step-up approach in emphysematous hepatitis: A case report.

BACKGROUND: Emphysematous hepatitis (EH) is a rare, rapidly progressive fulminant gas-forming infection of the liver parenchyma. It is often fatal and mostly affects diabetes patients. CASE SUMMARY: We report a case of EH successfully managed by a step-up approach consisting of aggressive hemodynamic support, intravenous antibiotics, and percutaneous drainage, ultimately followed by laparoscopic deroofing. Of 11 documented cases worldwide, only 1 of the patients survived, treated by urgent laparotomy and surgical debridement. CONCLUSION: EH is a life-threatening infection. Its high mortality rate makes timely diagnosis essential, in order to navigate treatment accordingly.

Improved Precision-Cut Liver Slice Cultures for Testing Drug-Induced Liver Fibrosis.

In vitro models of human liver disease often fail to mimic the complex 3D structures and cellular organizations found in vivo. Precision cut liver slices (PCLS) retain the complex physiological architecture of the native liver and therefore could be an exceptional in vitro liver model. However, the production of PCLS induces a spontaneous culture-induced fibrogenic reaction, limiting the application of PCLS to anti-fibrotic compounds. Our aim was to improve PCLS cultures to allow compound-induced fibrosis induction. Hepatotoxicity in PCLS cultures was analyzed by lactate dehydrogenase leakage and albumin secretion, while fibrogenesis was analyzed by qRT-PCR and western blot for hepatic stellate cell (HSC) activation markers and collagen 6 secretion by enzyme-linked immunosorbent assays (ELISA). We demonstrate that supplementation of 3 mm mouse PCLS cultures with valproate strongly reduces fibrosis and improves cell viability in our PCLS cultures for up to 5 days. Fibrogenesis can still be induced both directly and indirectly through exposure to TGFß and the hepatotoxin acetaminophen, respectively. Finally, human PCLS cultures showed similar but less robust results. In conclusion, we optimized PCLS cultures to allow for drug-induced liver fibrosis modeling.

Modelling fatty liver disease with mouse liver-derived multicellular spheroids.

Chronic liver disease can lead to liver fibrosis and ultimately cirrhosis, which is a significant health burden and a major cause of death worldwide. Reliable in vitro models are lacking and thus mono-cultures of cell lines are still used to study liver disease and evaluate candidate anti-fibrotic drugs. We established functional multicellular liver spheroid (MCLS) cultures using primary mouse hepatocytes, hepatic stellate cells, liver sinusoidal endothelial cells and Kupffer cells. Cell-aggregation and spheroid formation was enhanced with 96-well U-bottom plates generating over ±700 spheroids from one mouse. Extensive characterization showed that MCLS cultures contain functional hepatocytes, quiescent stellate cells, fenestrated sinusoidal endothelium and responsive Kupffer cells that can be maintained for 17 days. MCLS cultures display a fibrotic response upon chronic exposure to acetaminophen, and present steatosis and fibrosis when challenged with free fatty acid and lipopolysaccharides, reminiscent of non-alcoholic fatty liver disease (NAFLD) stages. Treatment of MCLS cultures with potential anti-NAFLD drugs such as Elafibranor, Lanifibranor, Pioglitazone and Obeticholic acid shows that all can inhibit steatosis, but only Elafibranor and especially Lanifibranor inhibit fibrosis. Therefore, primary mouse MCLS cultures can be used to model acute and chronic liver disease and are suitable for the assessment of anti-NAFLD drugs.

Distinct roles for non-muscle myosin II isoforms in mouse hepatic stellate cells.

BACKGROUND & AIMS: Upon liver injury, hepatic stellate cells (HSCs) undergo dramatic morphological and functional changes including migration and contraction. In the present study, we investigated the role of myosin II isoforms in the development of the contractile phenotype of mouse HSCs, which are considered therapeutic targets to decrease portal hypertension and fibrosis. METHODS: We characterized the expression of myosin IIA and IIB in primary mouse HSCs and addressed their function by gene knock-down using isoform-specific siRNAs. RESULTS: We found that myosin IIA and IIB are differentially expressed and localized and have clearly different functions in HSCs. Myosin IIA is mainly located in the subcortical area of quiescent HSCs and at α-SMA-containing stress fibres after activation, while myosin IIB is located in the cytoplasm and at the edge of protrusions of quiescent HSCs, at stress fibres of activated cells, and at the leading edge of lamellipodia. Knock-down of myosin IIA in HSCs influences cell size and shape, results in the disruption of stress fibres and in a decrease of focal adhesions, and inhibits contractility and intra-cellular Ca(2+) release but increases cell migration. Myosin IIB contributes to the extension of lamellipodia and cell spreading but has no direct role in stress fibres and focal adhesion formation, contraction, or intra-cellular Ca(2+) signalling. CONCLUSIONS: In mouse HSCs, myosin IIA and IIB clearly fulfil distinct roles. Our results provide an insight into the contractile machinery of HSCs, that could be important in the search for new molecules to treat portal hypertension.

The quest for liver progenitor cells: a practical point of view.

Many chronic liver diseases can lead to hepatic dysfunction with organ failure. At present, orthotopic liver transplantation represents the benchmark therapy of terminal liver disease. However this practice is limited by shortage of donor grafts, the need for lifelong immunosuppression and very demanding state-of-the-art surgery. For this reason, new therapies have been developed to restore liver function, primarily in the form of hepatocyte transplantation and artificial liver support devices. While already offered in very specialized centers, both of these modalities still remain experimental. Recently, liver progenitor cells have shown great promise for cell therapy, and consequently they have attracted a lot of attention as an alternative or supportive tool for liver transplantation. These liver progenitor cells are quiescent in the healthy liver and become activated in certain liver diseases in which the regenerative capacity of mature hepatocytes and/or cholangiocytes is impaired. Although reports describing liver progenitor cells are numerous, they have not led to a consensus on the identity of the liver progenitor cell. In this review, we will discuss some of the characteristics of these cells and the different ways that have been used to obtain these from rodents. We will also highlight the challenges that researchers are facing in their quest to identify and use liver progenitor cells.

An Unexpected Cause of Recurrent Jaundice after Resolution of Acute Hepatitis E.

In this report, we describe a rare case of liver enzyme disturbance caused by myeloid sarcoma of the gallbladder and biliary tract. A 63-year-old man with progressive chronic myeloid leukemia presented with acute hepatitis. Viral serology revealed an infection with hepatitis E virus. The liver enzymes and bilirubin improved gradually under treatment with ribavirin, but there was a flair up shortly after. Imaging including CT and echo-endoscopy showed a thickened infiltrated gallbladder wall and dilated bile ducts, suspected for myeloid sarcoma. Biopsy of an atypical skin lesion, present at the same time, confirmed the diagnosis of acute extramedullary leukemia. After induction chemotherapy, hematological improvement was seen together with a decrease of bilirubin and liver enzymes and a normalization of the bile ducts and gallbladder on imaging. However, three months later, myeloid leukemia progressed again, and the patient deceased.