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Background & Aims: Cerium oxide nanoparticles (CeO2NPs) have proven to behave as free radical scavengers and/or anti-inflammatory agents. The aim of the study was to determine whether CeO2NPs display hepatoprotective properties in experimental chronic liver disease., Methods: Systemic and hepatic effects of nanoparticles were assessed in CCl4-treated rats receiving CeO2NPs or vehicle twice weekly for two weeks and CCl4 treatment was continued for 8 additional weeks. Thereafter, mean arterial pressure and portal pressure (PP) were assessed and serum samples obtained to measure standard hepatic and renal function tests. Organ and subcellular distribution of NPs were assessed using mass spectrometry (ICP-MS) and transmission electron microscopy. Liver samples were obtained to evaluate steatosis, α-SMA expression, macrophage infiltration, apoptosis and mRNA expression of oxidative stress, inflammatory or vasoactive related genes., Results: Most CeO2NPs were located in the liver and it reduced hepatic steatosis, ameliorated systemic inflammatory biomarkers and improved PP without affecting mean arterial pressure. In addition, a marked reduction in mRNA expression of inflammatory cytokines (TNFα, IL1β, COX-2, iNOS), ET-1 and messengers related to oxidative (Epx, Ncf1, Ncf2) or endoplasmic reticulum (Atf3, Hspa5) stress signaling pathways was observed in the liver of rats receiving CeO2NPs. This was associated with reduced macrophage infiltration and reduced abundance of caspase-3, α-SMA and inflammatory cytokines., Conclusions: CeO2NPs administration to CCl4-treated rats protects against chronic liver injury by reducing liver steatosis and portal hypertension and markedly attenuating the intensity of the inflammatory response, thereby suggesting that CeO2NPs may be of therapeutic value in chronic liver disease., (Copyright © 2015 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Platelet-derived growth factor (PDGF) is the most potent stimulus for proliferation and migration of stellate cells. PDGF receptor β (PDGFRβ) expression is an important phenotypic change in myofibroblastic cells that mediates proliferation and chemotaxis. Here we analyzed the relationship between PDGFRβ expression, hemodynamic deterioration, and fibrosis in CCl(4)-treated rats. Thereafter, we investigated the effects produced by an adenovirus encoding a dominant-negative soluble PDGFRβ (sPDGFRβ) on hemodynamic parameters, PDGFRβ signaling pathway, and fibrosis., Methods: Mean arterial pressure, portal pressure, PDGFRβ mRNA expression, and hepatic collagen were assessed in 6 controls and 21 rats induced to hepatic fibrosis/cirrhosis. Next, 30 fibrotic rats were randomized into three groups receiving iv saline and an adenovirus encoding for sPDGFRβ or β-galactosidase. After 7days, mean arterial pressure, portal pressure, serum sPDGFRβ, and hepatic collagen were measured., Results: CCl(4)-treated animals for 18weeks showed a significantly higher increase in PDGFRβ mRNA compared to those treated for 13weeks and control rats. In CCl(4)-treated rats, the fibrous tissue area ranged from moderate to severe fibrosis. A direct relationship between the degree of fibrosis, hemodynamic changes, and PDGFRβ expression was observed. Fibrotic rats transduced with the adenovirus encoding sPDGFRβ showed increased mean arterial pressure, decreased portal pressure, lower activation of the PDGFRβ signaling pathway, and reduced hepatic collagen than fibrotic rats receiving β-galactosidase or saline., Conclusions: PDGFRβ activation closely correlates with hemodynamic disorders and increased fibrosis in CCl(4)-treated rats. Adenoviral dominant negative soluble PDGFRβ improved fibrosis. As a result, the hemodynamic abnormalities were ameliorated., (Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Our aim was to evaluate a serologic marker (ELF) and two ultrasound-based methods (FibroScan and ARFI), as well as their combinations, in the assessment of liver fibrosis., Methods: One-hundred and forty-six patients (87 liver transplant recipients, 59 non-transplant patients) who underwent liver biopsy were prospectively included. We evaluated the diagnostic accuracy of FibroScan, ARFI, ELF and the combination of ELF with either ARFI or FibroScan. After analyzing in separate transplant and non-transplant patients, the whole cohort was divided into a training set and a validation set., Results: ARFI imaging was successfully performed across the whole cohort, while FibroScan failed in 16 (11%) patients. The three methods showed similar AUROCs and best cut-off values in transplant and non-transplant patients. In the training set, differences between the AUROCs of ARFI, FibroScan and ELF to diagnose F⩾2 (0.879, 0.861, and 0.764, respectively) and cirrhosis (0.936, 0.918, and 0.841) were not statistically significant, although both ultrasound-based methods showed higher accuracy than ELF. The combination of ELF with ARFI or FibroScan increased the negative and positive predictive values of single tests for the diagnosis of F ≥ 2 and cirrhosis. Similar results were obtained when the methods were tested in the validation set., Conclusions: ARFI is as effective as either FibroScan or ELF in the non-invasive assessment of liver fibrosis, and its inclusion in an ultrasound device could facilitate its incorporation into routine clinical practice. The combination of ARFI or FibroScan with ELF may help better identify patients with or without significant fibrosis or cirrhosis., (Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Impairment of kidney function is common in cirrhosis but differential diagnosis remains a challenge. We aimed at assessing the usefulness of neutrophil gelatinase-associated lipocalin (NGAL), a biomarker of tubular damage, in the differential diagnosis of impairment of kidney function in cirrhosis., Methods: Two-hundred and forty-one patients with cirrhosis, 72 without ascites, 85 with ascites, and 84 with impaired kidney function, were studied. Urinary levels of NGAL were measured by ELISA., Results: Patients with impaired kidney function had higher urinary NGAL levels compared to patients with and without ascites. Patients with urinary tract infection (n=25) had higher uNGAL values than non-infected patients. Patients with acute tubular necrosis (ATN) had uNGAL levels markedly higher (417μg/g creatinine (239-2242) median and IQ range) compared to those of patients with pre-renal azotemia due to volume depletion 30 (20-59), chronic kidney disease (CKD) 82 (34-152), and hepatorenal syndrome (HRS) 76 (43-263) μg/g creatinine (p<0.001 for all). Among HRS patients, the highest values were found in HRS-associated with infections, followed by classical (non-associated with active infections) type-1 and type-2 HRS (391 (72-523), 147 (83-263), and 43 (31-74) μg/g creatinine, respectively; p<0.001). Differences in uNGAL levels between classical type 1 HRS and ATN on the one hand and classical type 1 HRS and CKD and pre-renal azotemia on the other were statistically significant (p<0.05)., Conclusions: uNGAL levels may be useful in the differential diagnosis of impairment of kidney function in cirrhosis. Urinary tract infections should be ruled out because they may increase uNGAL excretion., (Copyright © 2012 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background & Aims: Increased activity of the vascular Akt/eNOS signaling pathway is involved in the hemodynamic and renal complications developed by patients and rats with cirrhosis and ascites. This occurs in the setting of impaired Akt/eNOS activity within the cirrhotic liver. Here we assessed the feasibility of selectively inhibiting vascular eNOS without further impairing the intrahepatic activity of this enzyme. Ultimately, we sought to determine whether endothelial transduction of a constitutively inactive mutant of Akt (AA-Akt) improves circulatory function and sodium excretion in cirrhotic rats with ascites., Methods: First, we administered recombinant adenoviruses that encode the β-galactosidase gene (β-gal) to 5 control rats and 5 cirrhotic rats with ascites and analyzed their tissue distribution by chemiluminescence. Next, urine samples were obtained from 18 cirrhotic rats with ascites and then the animal randomly received saline or adenoviruses containing the β-gal or the AA-Akt genes. Following a 24-h urine collection period, hemodynamic studies were performed and tissue samples were obtained to analyze Akt and eNOS expressions., Results: No β-gal activity was detected in the liver of cirrhotic rats compared to that of controls. This was paralleled by increased β-gal activity in other territories such as the thoracic aorta. AA-Akt transduction improved systemic hemodynamics, splanchnic perfusion pressure and renal excretory function in comparison with cirrhotic rats transduced with β-gal adenoviruses or receiving saline. Moreover, the AA-Akt transgene did not modify portal pressure., Conclusions: Inactivation of extrahepatic vascular Akt and the concomitant decrease in nitric oxide expression ameliorate systemic hemodynamics and renal excretory function in experimental cirrhosis., (Copyright © 2010 European Association for the Study of the Liver. Published by Elsevier B.V. All rights reserved.)

Background/aims: Thinning of the vascular wall occurs in conductance vessels of cirrhotic rats. Increased nitric oxide synthase (NOS) activity has been involved in the pathogenesis of this phenomenon. Therefore, we assessed the NO-regulated cell signaling pathways participating in vascular remodeling in cirrhosis., Methods: Aortas were obtained from 15 control and 15 cirrhotic rats. Phosphorylated p38 MAPK and ERK1/2 were used to evaluate the activation of cell MAPK signaling pathways. Extracellular matrix (ECM) turnover was estimated by measuring matrix metalloproteinases (MMPs) activity and protein expression of collagen IV, MMP-2, MMP-9 and tissue inhibitor of MMPs (TIMP)-2. Thereafter, 12 control and 12 cirrhotic rats received Nomega-nitro-L-arginine-methyl-ester or vehicle daily for 11 weeks., Results: Cirrhotic vessels showed a reduction in ERK1/2 phosphorylation, lower MMP activity, decreased MMPs expression and higher collagen IV and TIMP-2 abundance, compared to control rats. Chronic NOS inhibition normalized ERK1/2 phosphorylation and MMPs activity, increased MMPs abundance and decreased TIMP-2 expression in cirrhotic rats., Conclusions: Vascular remodeling in cirrhotic rats is mediated by down-regulation of cell growth and impaired ERK1/2 activation and subsequent imbalance of ECM turnover. These results further stress the importance of vascular NO overactivity in the reduction of vascular wall thickness in cirrhosis.