213 research outputs found

    YKL-40 Genetic Polymorphisms and the Risk of Liver Disease Progression in Patients with Advanced Fibrosis Due to Chronic Hepatitis C

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    Abstract Background/Aims The aim of this study was to explore the association of a functional YKL-40 promoter polymorphism (rs4950928) with baseline disease stage, response to antiviral therapy, and risk of liver disease progression in a group of patients with chronic hepatitis C (CHC). Methods YKL-40 promoter polymorphisms were determined in 456 HALT-C Trial patients with bridging fibrosis or cirrhosis entering a prerandomization lead-in peginterferon/ribavirin 24-week treatment phase and in 462 patients followed for a mean of 3.8 years after randomization to maintenance peginterferon or observation. RESULTS Mean patient age was 49.5 years, 70.4% were male, and 71.2% were Caucasian. The 17% frequency of the YKL-40 minor allele (T) was similar to that reported in the general population. YKL-40 genotype was associated significantly with baseline serum YKL-40 levels but was not associated with the likelihood of a virological response following 24 to 48 weeks of peginterferon/ribavirin therapy. Serum YKL-40 levels remained significantly lower during follow-up in the randomized TT homozygotes compared to CT heterozygotes and CC homozygotes (p \u3c0.001). Despite this association, YKL-40 genotype was not associated with the risk of clinical or histologic liver disease progression. CONCLUSIONS A reduced frequency of the protective YKL-40 promoter polymorphism was not observed in the HALT-C Trial patient population. The absence of an association between YKL-40 promoter polymorphisms and baseline liver-disease severity as well as with the risk of liver-disease progression over time suggests that this polymorphism is not associated with disease progression in CHC patients with established fibrosis

    Reciprocal Effects of MiR-122 on Expression of Heme Oxygenase-1 and Hepatitis C Virus Genes in Human Hepatocytes

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    Background & Aims Heme oxygenase-1 (HO-1) is an antioxidant defense and key cytoprotective enzyme, which is repressed by Bach1. MicroRNA-122 (miR-122) is specifically expressed and highly abundant in human liver and required for replication of hepatitis C virus (HCV) RNA. This study was to assess whether a specific miR-122 antagomir down-regulates HCV protein replication and up-regulates HO-1. Methods We transfected antagomir of miR-122, 2′-O-methyl-mimic miR-122, or non-specific-control antagomir (NSCA) into wild type Huh-7 cells or Huh-7 stably replicating HCV subgenomic core-NS3 (CNS3 replicon cells), or NS3-5B (9–13 replicon cells). Results Antagomir of miR-122 reduced the abundance of HCV-RNA by 64% in CNS3, and by 84% in 9–13 cells. In contrast, transfection with 2′-O-methlyl-mimic miR-122 increased HCV levels up to 2.5-fold; transfection with NSCA did not change the level of HCV. Antagomir of miR-122 also decreased Bach1 and increased HO-1 mRNA levels in CNS3, 9–13, and WT Huh-7 cells. Increasing HO-1 by silencing Bach1 with 50 nM Bach1-siRNA or by treatment with 5 μM cobalt protoporphyrin or heme (known inducers of HO-1) decreased HCV RNA and protein by 50% in HCV replicon cells. Conclusions Down-regulation of HCV replication using an antagomir targeted to miR-122 is effective, specific, and selective. Increasing HO-1, by silencing the Bach1 gene or by treatment with cobalt protoporphyrin or heme, decreases HCV replication. Thus, miR-122 plays an important role in the regulation of HCV replication and HO-1/Bach1 expression in hepatocytes. Down-regulation of miR-122 and up-regulation of HO-1 may be new strategies for anti-HCV intervention and cytoprotection

    Hepatotoxicity Associated with the Use of Anti-TNF-α Agents

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    Medications to inhibit the actions of tumour necrosis factor alpha have revolutionized the treatment of several pro-inflammatory autoimmune conditions. Despite their many benefits, several serious side effects exist and adverse reactions do occur from these medications. While many of the medications' potential adverse effects were anticipated and recognized in clinical trials prior to drug approval, several more rare adverse reactions were recorded in the literature as the popularity, availability and distribution of these medications grew. Of these potential adverse reactions, liver injury, although uncommon, has been observed in some patients. As case reports accrued over time and ultimately case series developed, the link became better established between this family of medicines and various patterns of liver injury. Interestingly, it appears that the majority of cases exhibit an autoimmune hepatitis profile both in serological markers of autoimmune liver disease and in classic autoimmune features seen on hepatic histopathology. Despite the growing evidence of this relationship, the pathogenesis of this reaction remains incompletely understood, but it appears to depend on characteristics of the medications and the genetic composition of the patients; it is likely more complicated than a simple medication class effect. Because of this still incomplete understanding and the infrequency of the occurrence, treatments have also been limited, although it is clear that most patients improve with cessation of the offending agent and, in certain cases, glucocorticoid use. However, more needs to be done in the future to unveil the underlying mechanisms of this adverse reaction

    Leukocyte Expression of Heme Oxygenase-1 [hmox1] Varies Inversely with Severity of Tricuspid Regurgitation in Acute Pulmonary Embolism.

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    Objective: Pulmonary embolism (PE) can cause intracardiac hemolysis and increased plasma hemoglobin and arginase-1, which can worsen pulmonary vasoconstriction. We test the hypothesis that patients with PE that causes tricuspid regurgitation (TR), indicative of higher pulmonary arterial pressures, have decreased leukocyte expression of hmox-1 compared with patients with PE and no TR and patients without PE. Design: Prospective, noninterventional study. Patients: Normotensive patients with suspected PE (n=87) who underwent CT pulmonary angiography and transthoracic Doppler-echocardiography. Measurements: Significant TR was defined as a jet velocity > 2.7m/s. Leukocyte expression of hmox-1, haptoglobin, haptoglobin related gene, the haptoglobin receptor, CD163 and cox-2 genes were assessed by quantitative rtPCR, and the hmox-1 promoter was examined for the −413 A→T SNP and GT repeat polymorphisms. Results: Of the 44 (50%) with PE+, 22 had TR+, and their mean pulmonary vascular occlusion (39±32%) did not differ significantly from patients who were TR− (28±26%, P=0.15). Patients with PE+ and TR+ had significantly lower expression of hmox-1 and haptoglobin genes than patients without PE+ and no TR. Expression of hmox-1 varied inversely with TR velocity (r2=0.45, P<0.001) for PE+ (n=22) but not patients without PE. Hmox-1 expression did not vary significantly with genotype. Cox-2 did not differ between groups and had no correlation with TR. Conclusions: Severity of TR varied inversely with hmox-1 expression, suggesting that hmox-1 expression affects pulmonary vascular reactivity after PE

    Tissue-specific expression of ALA synthase-1 and heme oxygenase-1 and their expression in livers of rats chronically exposed to ethanol

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    Abstract5-Aminolevulinic acid synthase-1 (ALAS1) and heme oxygenase-1 (HO-1) are the rate-controlling enzymes for heme biosynthesis and degradation, respectively. Expression of these two genes showed tissue-specific expression pattern at both mRNA and protein levels in selected non-treated rat tissues. In the livers of rats receiving oral ethanol for 10 weeks, ALAS1 mRNA levels were increased by 65%, and the precursor and mature ALAS1 protein levels were increased by 1.8- and 2.3-fold, respectively, while no changes were observed in HO-1 mRNA and protein levels, compared with pair-fed controls. These results provide novel insights into the effects of chronic ethanol consumption on hepatic heme biosynthesis and porphyrias

    MicroRNA-196 represses Bach1 protein and hepatitis C virus gene expression in human hepatoma cells expressing hepatitis C viral proteins

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    Hepatitis C virus (HCV) directly induces oxidative stress and liver injury. Bach1, a zipper (bZip) mammalian transcriptional repressor, negatively regulates heme oxygenase 1 (HMOX1), a key cytoprotective enzyme that has anti-oxidant and anti-inflammatory activities. microRNAs are small non-coding RNAs (~22 nt) that are important regulators of gene expression. Whether and how microRNAs regulate Bach1 or HCV are largely unknown. The aims of this study were to determine whether miR-196 regulates Bach1, HMOX1, and/or HCV gene expression. HCV replicon cell lines (Con1 and 9-13) of the Con1 isolate and J6/JFH1-based HCV cell culture system were used in this study. The effects of miR-196 mimic on Bach1, HMOX1 and HCV RNA and protein levels were measured by qRT-PCR and Western blots, respectively. The Dual Glo™ Luciferase Assay System was used to determine reporter activities. miR-196 mimic significantly down-regulated Bach1 and up-regulated HMOX1 gene expression, and inhibited HCV expression. Dual luciferase reporter assays demonstrated that transfection of miR-196 mimic resulted in a significant decrease in Bach1 3′-UTR-dependent luciferase activity but not in mutant Bach1 3′-UTR-dependent luciferase activity. Moreover, there was no detectable effect of mutant miR-196 on Bach1 3′-UTR-dependent luciferase activity

    Zinc Mesoporphyrin Induces Rapid Proteasomal Degradation of Hepatitis C Nonstructural 5A Protein in Human Hepatoma Cells

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    The nonstructural 5A (NS5A) protein of hepatitis C virus (HCV), plays a critical role in HCV replication and is an attractive target for the therapy of HCV infection. So far, little is known about the post-translational regulation of NS5A protein and its precise role in HCV RNA replication. Our objectives were to elucidate the down-regulation of NS5A protein and HCV RNA replication by zinc mesoporphyrin (ZnMP), and the mechanism by which this process occurs

    Evaluating quality of life tools in North American patients with erythropoietic protoporphyria and X-linked protoporphyria.

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    BackgroundErythropoietic protoporphyria (EPP) and X-linked Protoporphyria (XLP) are rare photodermatoses presenting with severe phototoxicity. Although anecdotally, providers who treat EPP patients acknowledge their life-altering effects, tools that fully capture their impact on quality of life (QoL) are lacking.MethodsAdult patients with EPP/XLP were given four validated QoL tools: the Patient Reported Outcomes Measurement Information System 57 (PROMIS-57), the Hospital Anxiety and Depression Scale (HADS), the Illness Perception Questionnaire Revised (IPQR), and an EPP-Specific tool. All patients received the PROMIS-57 while the HADS, IPQR, and EPP-Specific tools were introduced at a later date. Associations between responses and clinical phenotypes were explored.ResultsTwo hundred and two patients were included; 193 completed PROMIS-57, 104 completed IPQR, 103 completed HADS, and 107 completed the EPP-Specific tool. The IPQR showed that patients strongly believed EPP/XLP had a negative impact on their lives. Mean scores in anxiety and depression domains of both HADS and PROMIS-57 were normal; however, anxiety scores from HADS were borderline/abnormal in 20% of patients. The EPP-Specific tool revealed a decreased QoL in most patients. The PROMIS-57 showed that 21.8% of patients have clinically significant pain interference. Several tool domains correlated with measures of disease severity, most being from the PROMIS-57.ConclusionsImpaired QoL is an important consequence of EPP/XLP. PROMIS-57 was most sensitive in evaluating impaired QoL in EPP/XLP. Further research is needed to compare the effectiveness of it for assessing response to treatment

    Associations of gender and a proxy of female menopausal status with histological features of drug‐induced liver injury

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    Background & AimGender and menopause may contribute to type and severity of drug‐induced liver injury (DILI) by influencing host responses to injury. The aim of this study was to assess the associations of gender and female age 50 [a proxy of menopause] with histological features of liver injury in 212 adults enrolled in the Drug‐Induced Liver Injury Network (DILIN) registry.MethodsAll participants had a causality score of at least ‘probable’, a liver biopsy within 30 days of DILI onset, and no prior chronic liver disease. Biochemical and histological injury types were classified as hepatocellular or cholestatic/mixed injury. The cohort was divided into three gender/age categories: men (41.0%), women <50 years (27.4%) and women ≥50 years of age (31.6%). Interaction of gender and age category (≥50 or not) was assessed.ResultsHepatocellular injury was more prevalent in women <50 years vs. others (P=.002). After adjusting for biochemical injury types, black race and possible ageing effects, more severe interface hepatitis was noted in biopsies of women <50 years compared to those of men and women ≥50 years (P=.009 and P=.055 respectively). Compared to those of men, biopsies of women showed greater plasma cell infiltration, hepatocyte apoptosis, hepatocyte rosettes and lobular disarray but less iron‐positive hepatocytes and histological cholestasis (P<.05). These associations persisted after excluding cases of amoxicillin/clavulanic acid, anabolic steroids or nitrofurantoin DILI which showed gender‐specific distributions.ConclusionGender and a proxy of menopause were associated with various features of inflammation and injury in DILI.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/139070/1/liv13380.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/139070/2/liv13380_am.pd
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