Cancer-Associated Fibroblasts Induce Proliferation and Therapeutic Resistance to Everolimus in Neuroendocrine Tumors through STAT3 Activation.

INTRODUCTION: Cancer-associated fibroblasts (CAF) have been identified as relevant contributors to cancer progression and drug resistance in many tumors. Although neuroendocrine tumors (NET) are often associated with a strong stromal reaction, no study has addressed whether CAF are involved in progression and therapeutic resistance in NET. The aim of this study was to characterize the role of CAF in NET. METHODS: We established primary CAF cultures derived from NET liver metastases to study the effect on NET cell lines NT-3 and BON. Immunohistochemistry was performed on tissue sections of primary and metastatic NET tissue. RESULTS: Immunohistochemistry identified CAF dispersed in between tumor cells and within fibrotic bands separating tumor cell clusters in NET. Stimulating NET cells with CAF decreased expression of SSTR2 and chromogranin A and induced expression of CXCR4. CAF induced a 2.3-fold increase in proliferation and completely reversed the response to everolimus in NT-3 cells. We identified STAT3 as the main signaling pathway induced by CAF. STAT3 targeting by small interfering RNA knockdown and inhibitors prevented CAF-induced proliferation and restored everolimus responsiveness. STAT3 activation in NET tissue was associated with decreased chromogranin A expression, increased Ki-67 index, and decreased 5-year overall and progression-free survival. CAF directly influence proliferation and therapeutic response in NET cells. CONCLUSION: Identifying STAT3 as the contributing pathway of this so far neglected tumor-stroma interaction has the potential to become a new therapeutic target to halt tumor growth and to restore therapeutic responsiveness in NET.

Blood metabolomics uncovers inflammation-associated mitochondrial dysfunction as a potential mechanism underlying ACLF.

BACKGROUND & AIMS: Acute-on-chronic liver failure (ACLF), which develops in patients with cirrhosis, is characterized by intense systemic inflammation and organ failure(s). Because systemic inflammation is energetically expensive, its metabolic costs may result in organ dysfunction/failure. Therefore, we aimed to analyze the blood metabolome in patients with cirrhosis, with and without ACLF. METHODS: We performed untargeted metabolomics using liquid chromatography coupled to high-resolution mass spectrometry in serum from 650 patients with AD (acute decompensation of cirrhosis, without ACLF), 181 with ACLF, 43 with compensated cirrhosis, and 29 healthy individuals. RESULTS: Of the 137 annotated metabolites identified, 100 were increased in patients with ACLF of any grade, relative to those with AD, and 38 comprised a distinctive blood metabolite fingerprint for ACLF. Among patients with ACLF, the intensity of the fingerprint increased across ACLF grades, and was similar in patients with kidney failure and in those without, indicating that the fingerprint reflected not only decreased kidney excretion but also altered cell metabolism. The higher the ACLF-associated fingerprint intensity, the higher the plasma levels of inflammatory markers, tumor necrosis factor α, soluble CD206, and soluble CD163. ACLF was characterized by intense proteolysis and lipolysis; amino acid catabolism; extra-mitochondrial glucose metabolism through glycolysis, pentose phosphate, and D-glucuronate pathways; depressed mitochondrial ATP-producing fatty acid ß-oxidation; and extra-mitochondrial amino acid metabolism giving rise to metabotoxins. CONCLUSIONS: In ACLF, intense systemic inflammation is associated with blood metabolite accumulation and profound alterations in major metabolic pathways, in particular inhibition of mitochondrial energy production, which may contribute to the development of organ failures. LAY SUMMARY: Acute-on-chronic liver failure (ACLF), which develops in patients with cirrhosis, is characterized by intense systemic inflammation and organ failure(s). Because systemic inflammation is energetically expensive, its metabolic costs may result in organ dysfunction/failure. We identified a 38-metabolite blood fingerprint specific for ACLF that revealed mitochondrial dysfunction in peripheral organs. This may contribute to organ failures.

Orchestration of Tryptophan-Kynurenine Pathway, Acute Decompensation, and Acute-on-Chronic Liver Failure in Cirrhosis.

Systemic inflammation (SI) is involved in the pathogenesis of acute decompensation (AD) and acute-on-chronic liver failure (ACLF) in cirrhosis. In other diseases, SI activates tryptophan (Trp) degradation through the kynurenine pathway (KP), giving rise to metabolites that contribute to multiorgan/system damage and immunosuppression. In the current study, we aimed to characterize the KP in patients with cirrhosis, in whom this pathway is poorly known. The serum levels of Trp, key KP metabolites (kynurenine and kynurenic and quinolinic acids), and cytokines (SI markers) were measured at enrollment in 40 healthy subjects, 39 patients with compensated cirrhosis, 342 with AD (no ACLF) and 180 with ACLF, and repeated in 258 patients during the 28-day follow-up. Urine KP metabolites were measured in 50 patients with ACLF. Serum KP activity was normal in compensated cirrhosis, increased in AD and further increased in ACLF, in parallel with SI; it was remarkably higher in ACLF with kidney failure than in ACLF without kidney failure in the absence of differences in urine KP activity and fractional excretion of KP metabolites. The short-term course of AD and ACLF (worsening, improvement, stable) correlated closely with follow-up changes in serum KP activity. Among patients with AD at enrollment, those with the highest baseline KP activity developed ACLF during follow-up. Among patients who had ACLF at enrollment, those with immune suppression and the highest KP activity, both at baseline, developed nosocomial infections during follow-up. Finally, higher baseline KP activity independently predicted mortality in patients with AD and ACLF. Conclusion: Features of KP activation appear in patients with AD, culminate in patients with ACLF, and may be involved in the pathogenesis of ACLF, clinical course, and mortality.

A humanized mouse model of liver fibrosis following expansion of transplanted hepatic stellate cells.

Hepatic stellate cells (HSCs) are major contributors to liver fibrosis, as hepatic injuries may cause their transdifferentiation into myofibroblast-like cells capable of producing excessive extracellular matrix proteins. Also, HSCs can modulate engraftment of transplanted hepatocytes and contribute to liver regeneration. Therefore, understanding the biology of human HSCs (hHSCs) is important, but effective methods have not been available to address their fate in vivo. To investigate whether HSCs could engraft and repopulate the liver, we transplanted GFP-transduced immortalized hHSCs into immunodeficient NOD/SCID mice. Biodistribution analysis with radiolabeled hHSCs showed that after intrasplenic injection, the majority of transplanted cells rapidly translocated to the liver. GFP-immunohistochemistry demonstrated that transplanted hHSCs engrafted alongside hepatic sinusoids. Prior permeabilization of the sinusoidal endothelial layer with monocrotaline enhanced engraftment of hHSCs. Transplanted hHSCs remained engrafted without relevant proliferation in the healthy liver. However, after CCl4 or bile duct ligation-induced liver damage, transplanted hHSCs expanded and contributed to extracellular matrix production, formation of bridging cell-septae and cirrhosis-like hepatic pseudolobules. CCl4-induced injury recruited hHSCs mainly to zone 3, whereas after bile duct ligation, hHSCs were mainly in zone 1 of the liver lobule. Transplanted hHSCs neither transdifferentiated into other cell types nor formed tumors in these settings. In conclusion, a humanized mouse model was generated by transplanting hHSCs, which proliferated during hepatic injury and inflammation, and contributed to liver fibrosis. The ability to repopulate the liver with transplanted hHSCs will be particularly significant for mechanistic studies of cell-cell interactions and fibrogenesis within the liver.

[Management of compensated liver cirrhosis 2018 - Evidence based prophylactic measures]. / Versorgung bei kompensierter Leberzirrhose 2018 ­ Evidenzbasierte prophylaktische Maßnahmen.

In 2015, more than 13 000 people died due to the consequences of liver cirrhosis in Germany. Frequently, relevant liver fibrosis is diagnosed by non-invasive methods (e. g., ultrasound-based measurement of liver stiffness) already in the compensated stage. Following diagnosis of liver fibrosis, a thorough investigation of the underlying chronic liver disease and effective treatment are important to prevent progression to decompensated cirrhosis. Since morbidity and mortality dramatically increase in the decompensated stage (patients may present with jaundice, ascites, hepatic encephalopathy, gastrointestinal bleeding) with an upsurge in 1-year-mortality from 1 - 3.4 % to 20 - 57 %, prophylactic measures to prevent decompensation are indicated. Based on a risk stratification, these measures include propranolol or carvedilol as non-selective betablockers, as well as endoscopic band ligations as primary prophylaxis to prevent variceal bleeding. Because of the high risk for malignant transformation (2 - 8 % per year depending on the underlying etiology), surveillance by liver ultrasound every six months is essential to detect liver cancer in an early stage and to facilitate curative therapy. Currently under debate is the administration of antibiotics to prevent bacterial infections, which commonly trigger acute decompensation. To this regard, studies are not convincing and the risk to induce drug resistance has to be observed. However, health care providers should check the vaccination status and recommend missing vaccinations. The management of compensated liver cirrhosis also includes counseling and potentially also a drug therapy to prevent osteoporosis and muscle wasting. In this review, we will discuss specific prophylactic measures in the management of compensated liver cirrhosis based on the pathophysiological background and central clinical studies. If a patient decompensates despite these prophylactic measures (approximately 15 % of patients with liver cirrhosis per year), liver transplantation has to be discussed as definitive therapy (especially in patients with MELD > 15).

Systemic inflammation in decompensated cirrhosis: Characterization and role in acute-on-chronic liver failure.

UNLABELLED: Acute-on-chronic liver failure (ACLF) in cirrhosis is characterized by acute decompensation (AD), organ failure(s), and high short-term mortality. Recently, we have proposed (systemic inflammation [SI] hypothesis) that ACLF is the expression of an acute exacerbation of the SI already present in decompensated cirrhosis. This study was aimed at testing this hypothesis and included 522 patients with decompensated cirrhosis (237 with ACLF) and 40 healthy subjects. SI was assessed by measuring 29 cytokines and the redox state of circulating albumin (HNA2), a marker of systemic oxidative stress. Systemic circulatory dysfunction (SCD) was estimated by plasma renin (PRC) and copeptin (PCC) concentrations. Measurements were performed at enrollment (baseline) in all patients and sequentially during hospitalization in 255. The main findings of this study were: (1) Patients with AD without ACLF showed very high baseline levels of inflammatory cytokines, HNA2, PRC, and PCC. Patients with ACLF showed significantly higher levels of these markers than those without ACLF; (2) different cytokine profiles were identified according to the type of ACLF precipitating event (active alcoholism/acute alcoholic hepatitis, bacterial infection, and others); (3) severity of SI and frequency and severity of ACLF at enrollment were strongly associated. The course of SI and the course of ACLF (improvement, no change, or worsening) during hospitalization and short-term mortality were also strongly associated; and (4) the strength of association of ACLF with SI was higher than with SCD. CONCLUSION: These data support SI as the primary driver of ACLF in cirrhosis. (Hepatology 2016;64:1249-1264).

Copeptin in acute decompensation of liver cirrhosis: relationship with acute-on-chronic liver failure and short-term survival.

BACKGROUND: Acute-on-chronic liver failure (ACLF) is characterized by the presence of acute decompensation (AD) of cirrhosis, organ failure, and high short-term mortality rates. Hemodynamic dysfunction and activation of endogenous vasoconstrictor systems are thought to contribute to the pathogenesis of ACLF. We explored whether copeptin, a surrogate marker of arginine vasopressin, is a potential marker of outcome in patients admitted for AD or ACLF and whether it might be of additional value to conventional prognostic scoring systems in these patients. METHODS: All 779 patients hospitalized for AD of cirrhosis from the CANONIC database with at least one serum sample available for copeptin measurement were included. Presence of ACLF was defined according to the CLIF-consortium organ failure (CLIF-C OF) score. Serum copeptin was measured in samples collected at days 0-2, 3-7, 8-14, 15-21, and 22-28 when available. Competing-risk regression analysis was applied to evaluate the impact of serum copeptin and laboratory and clinical data on short-term survival. RESULTS: Serum copeptin concentration was found to be significantly higher in patients with ACLF compared with those without ACLF at days 0-2 (33 (14-64) vs. 11 (4-26) pmol/L; p < 0.001). Serum copeptin at admission was shown to be a predictor of mortality independently of MELD and CLIF-C OF scores. Moreover, baseline serum copeptin was found to be predictive of ACLF development within 28 days of follow-up. CONCLUSIONS: ACLF is associated with significantly higher serum copeptin concentrations at hospital admission compared with those with traditional AD. Copeptin is independently associated with short-term survival and ACLF development in patients admitted for AD or ACLF.

High clinical manifestation rate in an imported outbreak of hepatitis E genotype 1 infection in a German group of travellers returning from India.

Background. There are only few reports about travel-associated, imported tropical hepatitis E virus (HEV) genotype 1 infections within Western travellers. We describe the clinical course of a single outbreak of hepatitis E in a German travellers group returning from India and compare the results of two commercial HEV-seroassays. MATERIAL AND METHODS: After identifying hepatitis E in an index patient returning from a journey to India all 24 members of this journey were tested for anti-HEV-IgG and IgM using two commercial seroassays (Wantai and Mikrogen), for HEV-RNA by PCR and HEV-Ag by an antigen-assay (Wantai). RESULTS: 5/24 (21%) individuals were viraemic with viral loads between 580-4,800,000 IU/mL. Bilirubin and ALT levels in these patients ranged from 1.3-14.9 mg/dL (mean 7.3 mg/dL, SD 5.6 mg/dL) and 151-4,820 U/L (mean 1,832U/L, SD 1842U/L), respectively and showed significant correlations with viral loads (r = 0.863, p < 0.001; r = 0.890, p < 0.001). No risk factor for food-borne HEV-transmission was identified. All viraemic patients (5/5) tested positive for anti-HEV-IgG and IgM in the Wantai-assay but only 4/5 in the Mikrogen-assay. Wantai-HEV-antigen-assay was negative in all patients. Six months later all previously viraemic patients tested positive for anti-HEV-IgG and negative for IgM in both assays. However, two non-viremic individuals who initially tested Wantai-IgM-positive stayed positive indicating false positive results. CONCLUSIONS: Despite the exact number of exposed individuals could not be determined HEV genotype 1 infections have a high manifestation rate of more than 20%.The Wantai-antigen-test failed, the Wantai-IgMrapid- test and the Mikrogen-IgM-recomblot showed a better performance but still they cannot replace real-time PCR for diagnosing ongoing HEV-infections.

The influence of PEEP and positioning on central venous pressure and venous hepatic hemodynamics in patients undergoing liver resection.

PURPOSE: In order to assess the occurrence of blood congestion in the liver during liver resection, we aimed to evaluate the influence of a positive-end-expiratory-pressure (PEEP) and positioning of patients on central venous pressure (CVP) and venous hepatic blood flow parameters. We further analyzed correlations between CVP and venous hepatic blood flow parameters. METHODS: In 20 patients scheduled for elective liver resection we measured CVP and quantified venous hepatic hemodynamics by ultrasound assessment of flow-velocity and diameter of the right hepatic vein and the portal vein after equilibration following these maneuvers: M1: 0° supine position, PEEP 0 cmH2O; M2: 0° supine position, PEEP 10 cmH2O; M3: 20° reverse-trendelenburg position; PEEP 10 cmH2O; M4: 20° reverse-trendelenburg position, PEEP 0cmH2O. RESULTS: Changing from supine to reverse-trendelenburg position led to a significant decrease in CVP (M3 5.95 ± 2.06 vs. M1 7.35 ± 2.18 mmHg and M2 8.55 ± 1.79 mmHg). A PEEP of 10 cmH2O and reverse-trendelenburg position led to significant reduction of systolic (VsHV) and diastolic (VdHV) flow-velocities of the right hepatic vein (VsHV M3 19.96 ± 6.47 vs. M1 27.81 ± 11.03 cm s-1;VdHV M3 14.94 ± 6.22 vs. M1 20.15 ± 10.34 cm s-1 and M2 20.19 ± 13.19 cm s-1) whereas no significant changes of flow-velocity occurred in the portal vein. No correlations between CVP and diameters or flow-velocities of the right hepatic and the portal vein were found. CONCLUSIONS: Changes of central venous pressure due to changes of PEEP and positioning were not correlated with changes of venous hepatic blood flow parameters as measured after equilibration. Strategies aiming for low central venous pressure cannot be supported by these results. However, before ruling out low-CVP-strategies during liver resections these results should be confirmed by further studies.

Plasma copeptin as biomarker of disease progression and prognosis in cirrhosis.

BACKGROUND & AIMS: Research on vasopressin (AVP) in cirrhosis and its role in the assessment of prognosis has been hindered by the difficulty of measuring AVP levels accurately. Copeptin, a 39-aminoacid glycopeptide, is released from the neurohypophysis together with AVP. Copeptin could have a role as biomarker of prognosis in cirrhosis as it may reflect circulatory dysfunction. The aim of this study is to investigate the role of copeptin as biomarker of disease progression and prognosis in cirrhosis. METHODS: This prospective study is divided in 2 study protocols including 321 consecutive patients. Plasma copeptin levels were measured in all patients at study inclusion. Protocol 1: to investigate the relationship of copeptin with kidney and circulatory function (56 patients). Protocol 2: to investigate the relationship between copeptin and prognosis, as assessed by the development of complications of cirrhosis or mortality at 3months (265 patients admitted to hospital for complications of cirrhosis). RESULTS: Patients with decompensated cirrhosis showed significantly higher plasma copeptin levels compared to those of patients with compensated cirrhosis. Copeptin levels had a significant positive correlation with model for end-satge liver disease (MELD) score, AVP, endogenous vasoconstrictor systems, and kidney function parameters. Patients developing complications of cirrhosis or mortality had significantly higher plasma copeptin levels compared to those of the remaining patients. Plasma copeptin levels were an independent predictive factor of both the development of complications and mortality at 3months. This was confirmed in a validation series of 120 patients. CONCLUSIONS: Copeptin is a novel biomarker of disease progression and prognosis in cirrhosis. LAY SUMMARY: Copeptin is a fragment of the vasopressin precursor, a hormone that is known to be increased in patients with cirrhosis and that plays a role in the development of complications of the disease. Vasopressin is difficult to measure, but copeptin is a more stable molecule and is easier to measure in blood. Solà and Kerbert and colleagues have shown in a series of 361 patients that copeptin is markedly increased in patients with cirrhosis who develop complications during the following 3months, compared to those patients who do not develop complications. Moreover, copeptin correlates with prognosis.

Clinical Course of acute-on-chronic liver failure syndrome and effects on prognosis.

UNLABELLED: Acute-on-chronic liver failure (ACLF) is characterized by acute decompensation (AD) of cirrhosis, organ failure(s), and high 28-day mortality. We investigated whether assessments of patients at specific time points predicted their need for liver transplantation (LT) or the potential futility of their care. We assessed clinical courses of 388 patients who had ACLF at enrollment, from February through September 2011, or during early (28-day) follow-up of the prospective multicenter European Chronic Liver Failure (CLIF) ACLF in Cirrhosis study. We assessed ACLF grades at different time points to define disease resolution, improvement, worsening, or steady or fluctuating course. ACLF resolved or improved in 49.2%, had a steady or fluctuating course in 30.4%, and worsened in 20.4%. The 28-day transplant-free mortality was low-to-moderate (6%-18%) in patients with nonsevere early course (final no ACLF or ACLF-1) and high-to-very high (42%-92%) in those with severe early course (final ACLF-2 or -3) independently of initial grades. Independent predictors of course severity were CLIF Consortium ACLF score (CLIF-C ACLFs) and presence of liver failure (total bilirubin ≥12 mg/dL) at ACLF diagnosis. Eighty-one percent had their final ACLF grade at 1 week, resulting in accurate prediction of short- (28-day) and mid-term (90-day) mortality by ACLF grade at 3-7 days. Among patients that underwent early LT, 75% survived for at least 1 year. Among patients with ≥4 organ failures, or CLIF-C ACLFs >64 at days 3-7 days, and did not undergo LT, mortality was 100% by 28 days. CONCLUSIONS: Assessment of ACLF patients at 3-7 days of the syndrome provides a tool to define the emergency of LT and a rational basis for intensive care discontinuation owing to futility.

Infections complicating severe alcoholic hepatitis: Enterococcus species represent the most frequently identified pathogen.

BACKGROUND: Patients with acute alcoholic steatohepatitis are at a high risk for infections. To date, neither disease-specific pathogen patterns, nor typical sites of infection, nor antibiotic treatment strategies have been established for AH. AIMS: To characterize incidence of infections, pathogen spectrum, sites of infection, and related mortality of patients with AH under steroid therapy. METHODS: We retrospectively analyzed clinical data of 73 patients with severe alcoholic hepatitis (MELD ≥ 20). RESULTS: Infections were detected in 45 patients (73%). Patients who developed an infection after initiation of corticosteroid therapy had a higher 6-month mortality than patients without onset of infection after initiation of corticosteroid treatment (44% versus 24%, p = 0.116). The pathogen identified most frequently was Enterococcus species. DISCUSSION: Infections frequently complicate severe alcoholic hepatitis and affect survival. The high rate of Enterococcus infections suggests that commonly used antibiotics, such as cephalosporins and quinolones, may represent an ineffective choice of empiric antibiotic treatment for complicated AH.

High Rate of Cardiac Abnormalities in a Postmortem Analysis of Patients Suffering From Liver Cirrhosis.

BACKGROUND: Cirrhotic cardiomyopathy is a recently defined cardiac disorder in patients with end-stage liver disease. The frequency and exact manifestations of cardiac changes in liver cirrhosis is unknown. GOALS: We aim to describe cardiac changes in a large autopsy study of patients with liver cirrhosis. STUDY: Postmortem data from 895 individuals with liver cirrhosis of different origin autopsied from 1995 to 2010 were analyzed. A total of 236 patients were excluded, mostly due to an advanced age above 70 years. The remaining 659 patients were assigned to 4 subgroups according to the etiology of cirrhosis: alcoholic cirrhosis (57.4%), nonalcoholic steatohepatitis (4.2%), viral hepatitis (9.3%), and cryptogenic cirrhosis (29.1%). Predefined clinical and cardiac parameters were assessed in these groups and compared by univariate and multivariate analyses to an age-matched and sex-matched control group including 40 deceased patients without evidence of chronic liver disease. RESULTS: A critical heart weight (24%, P=0.024), hypertrophy of the right ventricle (24%, P<0.001), and dilatation of the right ventricle (36%, P=0.040) were significantly more frequent in the cirrhosis group compared with noncirrhotic controls. Cirrhosis patients had a greater risk for high-grade coronary sclerosis (30%, P=0.019). The etiology of cirrhosis was independently associated with hypertrophy and dilatation of the right ventricle, with nonalcoholic steatohepatitis patients being at the highest risk. CONCLUSION: Our results demonstrate a high rate of right-ventricular abnormalities and coronary sclerosis in individuals suffering from liver cirrhosis regardless of the etiology of cirrhosis.

Preoperative TIPS and in-hospital mortality in patients with cirrhosis undergoing surgery.

Background & Aims: Cirrhosis is associated with an increased surgical morbidity and mortality. Portal hypertension and the surgery type have been established as critical determinants of postoperative outcome. We aim to evaluate the hypothesis that preoperative transjugular intrahepatic portosystemic shunt (TIPS) placement in patients with cirrhosis is associated with a lower incidence of in-house mortality/liver transplantation (LT) after surgery. Methods: A retrospective database search for the years 2010-2020 was carried out. We identified 64 patients with cirrhosis who underwent surgery within 3 months after TIPS placement and 131 patients with cirrhosis who underwent surgery without it (controls). Operations were categorised into low-risk and high-risk procedures. The primary endpoint was in-house mortality/LT. We analysed the influence of high-risk surgery, preoperative TIPS placement, age, sex, baseline creatinine, presence of ascites, Chronic Liver Failure Consortium Acute Decompensation (CLIF-C AD), American Society of Anesthesiologists (ASA), and model for end-stage liver disease (MELD) scores on in-house mortality/LT by multivariable Cox proportional hazards regression. Results: In both the TIPS and the control cohort, most patients presented with a Child-Pugh B stage (37/64, 58% vs. 70/131, 53%) at the time of surgery, but the median MELD score was higher in the TIPS cohort (14 vs. 11 points). Low-risk and high-risk procedures amounted to 47% and 53% in both cohorts. The incidence of in-house mortality/LT was lower in the TIPS cohort (12/64, 19% vs. 52/131, 40%), also when further subdivided into low-risk (0/30, 0% vs. 10/61, 16%) and high-risk surgery (12/34, 35% vs. 42/70, 60%). Preoperative TIPS placement was associated with a lower rate for postoperative in-house mortality/LT (hazard ratio 0.44, 95% CI 0.19-1.00) on multivariable analysis. Conclusions: A preoperative TIPS might be associated with reduced postoperative in-house mortality in selected patients with cirrhosis. Impact and implications: Patients with cirrhosis are at risk for more complications and a higher mortality after surgical procedures. A transjugular intrahepatic portosystemic shunt (TIPS) is used to treat complications of cirrhosis, but it is unclear if it also helps to lower the risk of surgery. This study takes a look at complications and mortality of patients undergoing surgery with or without a TIPS, and we found that patients with a TIPS develop less complications and have an improved survival. Therefore, a preoperative TIPS should be considered in selected patients, especially if indicated by ascites.

Myeloperoxidase attracts neutrophils by physical forces.

Recruitment of polymorphonuclear neutrophils (PMNs) remains a paramount prerequisite in innate immune defense and a critical cofounder in inflammatory vascular disease. Neutrophil recruitment comprises a cascade of concerted events allowing for capture, adhesion and extravasation of the leukocyte. Whereas PMN rolling, binding, and diapedesis are well characterized, receptor-mediated processes, mechanisms attenuating the electrostatic repulsion between the negatively charged glycocalyx of leukocyte and endothelium remain poorly understood. We provide evidence for myeloperoxidase (MPO), an abundant PMN-derived heme protein, facilitating PMN recruitment by its positive surface charge. In vitro, MPO evoked highly directed PMN motility, which was solely dependent on electrostatic interactions with the leukocyte's surface. In vivo, PMN recruitment was shown to be MPO-dependent in a model of hepatic ischemia and reperfusion, upon intraportal delivery of MPO and in the cremaster muscle exposed to local inflammation or to intraarterial MPO application. Given MPO's affinity to both the endothelial and the leukocyte's surface, MPO evolves as a mediator of PMN recruitment because of its positive surface charge. This electrostatic MPO effect not only displays a so far unrecognized, catalysis-independent function of the enzyme, but also highlights a principal mechanism of PMN attraction driven by physical forces.

Matrix stiffness modulates proliferation, chemotherapeutic response, and dormancy in hepatocellular carcinoma cells.

UNLABELLED: There is increasing evidence that the physical environment is a critical mediator of tumor behavior. Hepatocellular carcinoma (HCC) develops within an altered biomechanical environment, and increasing matrix stiffness is a strong predictor of HCC development. The aim of this study was to establish whether changes in matrix stiffness, which are characteristic of inflammation and fibrosis, regulate HCC cell proliferation and chemotherapeutic response. Using an in vitro system of "mechanically tunable" matrix-coated polyacrylamide gels, matrix stiffness was modeled across a pathophysiologically relevant range, corresponding to values encountered in normal and fibrotic livers. Increasing matrix stiffness was found to promote HCC cell proliferation. The proliferative index (assessed by Ki67 staining) of Huh7 and HepG2 cells was 2.7-fold and 12.2-fold higher, respectively, when the cells were cultured on stiff (12 kPa) versus soft (1 kPa) supports. This was associated with stiffness-dependent regulation of basal and hepatocyte growth factor-stimulated mitogenic signaling through extracellular signal-regulated kinase, protein kinase B (PKB/Akt), and signal transducer and activator of transcription 3. ß1-Integrin and focal adhesion kinase were found to modulate stiffness-dependent HCC cell proliferation. Following treatment with cisplatin, we observed reduced apoptosis in HCC cells cultured on stiff versus soft (physiological) supports. Interestingly, however, surviving cells from soft supports had significantly higher clonogenic capacity than surviving cells from a stiff microenvironment. This was associated with enhanced expression of cancer stem cell markers, including clusters of differentiation 44 (CD44), CD133, c-kit, cysteine-X-cysteine receptor 4, octamer-4 (CXCR4), and NANOG. CONCLUSION: Increasing matrix stiffness promotes proliferation and chemotherapeutic resistance, whereas a soft environment induces reversible cellular dormancy and stem cell characteristics in HCC. This has implications for both the treatment of primary HCC and the prevention of tumor outgrowth from disseminated tumor cells. (HEPATOLOGY 2011;).

CCK1 and CCK2 receptors are expressed on pancreatic stellate cells and induce collagen production.

The gastrointestinal hormone cholecystokinin (CCK) can induce acute pancreatitis in rodents through its action on acinar cells. Treatment with CCK, in combination with other agents, represents the most commonly used model to induce experimental chronic pancreatitis. Pancreatic stellate cells (PSC) are responsible for pancreatic fibrosis and therefore play a predominant role in the genesis of chronic pancreatitis. However, it is not known whether PSC express CCK receptors. Using real time PCR techniques, we demonstrate that CCK1 and CCK2 receptors are expressed on rat PSC. Interestingly both CCK and gastrin significantly induced type I collagen synthesis. Moreover, both inhibit proliferation. These effects are comparable with TGF-ß-stimulated PSC. Furthermore, the natural agonists CCK and gastrin induce activation of pro-fibrogenic pathways Akt, ERK, and Src. Using specific CCK1 and CCK2 receptor (CCK2R) inhibitors, we found that Akt activation is mainly mediated by CCK2R. Akt activation by CCK and gastrin could be inhibited by the PI3K inhibitor wortmannin. Activation of ERK and the downstream target Elk-1 could be inhibited by the MEK inhibitor U0126. These data suggest that CCK and gastrin have direct activating effects on PSC, are able to induce collagen synthesis in these cells, and therefore appear to be important regulators of pancreatic fibrogenesis. Furthermore, similar to TGF-ß, both CCK and gastrin inhibit proliferation in PSC.

Transplanted endothelial cells repopulate the liver endothelium and correct the phenotype of hemophilia A mice.

Transplantation of healthy cells to repair organ damage or replace deficient functions constitutes a major goal of cell therapy. However, the mechanisms by which transplanted cells engraft, proliferate, and function remain unknown. To investigate whether host liver sinusoidal endothelium could be replaced with transplanted liver sinusoidal endothelial cells, we developed an animal model of tissue replacement that utilized a genetic system to identify transplanted cells and induced host-cell perturbations to confer a proliferative advantage to transplanted cells. Under these experimental conditions, transplanted cells engrafted efficiently and proliferated to replace substantial portions of the liver endothelium. Tissue studies demonstrated that transplanted cells became integral to the liver structure and reacquired characteristic endothelial morphology. Characterization of transplanted endothelial cells by membrane markers and studies of cellular function, including synthesis and release of coagulation factor VIII, demonstrated that transplanted cells were functionally intact. Further analysis showed that repopulation of the livers of mice that model hemophilia A with healthy endothelial cells restored plasma factor VIII activity and corrected their bleeding phenotype. Our studies therefore suggest that transplantation of healthy endothelial cells should be considered for cell therapy of relevant disorders and that endothelial reconstitution with transplanted cells may offer an excellent paradigm for defining organ-specific pathophysiological mechanisms.

The transhepatic endotoxin gradient is present despite liver cirrhosis and is attenuated after transjugular portosystemic shunt (TIPS).

BACKGROUND: Translocation of gut-derived bacterial products such as endotoxin is a major problem in liver cirrhosis. METHODS: To assess the hepatic clearance of bacterial products in individuals with cirrhosis, we tested concentrations of Gram-negative bacterial lipopolysaccharide (LPS), LPS-binding protein (LBP), and the precursor of nitric oxide (NO), L-arginine, in a cohort of 8 stable patients with liver cirrhosis before and after elective transjugular portosystemic shunt (TIPS) implantation, including central venous, hepatic venous, and portal venous measurements. RESULTS: Using an adapted LPS assay, we detected high portal venous LPS concentrations (mean 1743 ± 819 pg/mL). High concentrations of LPS were detectable in the central venous blood (931 ± 551 pg/mL), as expected in persons with cirrhosis. The transhepatic LPS gradient was found to be 438 ± 287 pg/mL, and 25 ± 12% of portal LPS was cleared by the cirrhotic liver. After TIPS, central venous LPS concentrations increased in the hepatic and central veins, indicating shunting of LPS with the portal blood through the stent. This paralleled a systemic increase of L-arginine, whereas the NO synthase inhibitor asymmetric dimethylarginine (ADMA) remained unchanged, suggesting that bacterial translocation may contribute to the pathogenesis of circulatory dysfunction post-TIPS. CONCLUSIONS: This study provides quantitative estimates of the role of the liver in the pathophysiology of bacterial translocation. The data indicate that the cirrhotic liver retains the capacity for clearance of bacterial endotoxin from the portal venous blood and that TIPS implantation attenuates this clearance. Thus, increased endotoxin concentrations in the systemic circulation provide a possible link to the increased encephalopathy in TIPS patients.