microRNA-29b prevents liver fibrosis by attenuating hepatic stellate cell activation and inducing apoptosis through targeting PI3K/AKT pathway

microRNA-29b (miR-29b) is known to be associated with TGF-β-mediated fibrosis, but the mechanistic action of miR-29b in liver fibrosis remains unclear and is warranted for investigation. We found that miR-29b was significantly downregulated in human and mice fibrotic liver tissues and in primary activated HSCs. miR-29b downregulation was directly mediated by Smad3 through binding to the promoter of miR-29b in hepatic stellate cell (HSC) line LX1, whilst miR-29b could in turn suppress Smad3 expression. miR-29b transduction in the liver of mice prevented CCl4 induced-fibrogenesis, concomitant with decreased expression of α-SMA, collagen I and TIMP-1. Ectopic expression of miR-29b in activated HSCs (LX-1, HSC-T6) inhibited cell viability and colony formation, and caused cell cycle arrest in G1 phase by downregulating cyclin D1 and p21cip1. Further, miR-29b induced apoptosis in HSCs mediated by caspase-9 and PARP. miR-29b inhibited its downstream effectors of PIK3R1 and AKT3 through direct targeting their 3'UTR regions. Moreover, knockdown of PIK3R1 or AKT3 suppressed α-SMA and collagen I and induced apoptosis in both HSCs and in mice. In conclusion, miR-29b prevents liver fibrogenesis by inhibiting HSC activation and inducing HSC apoptosis through inhibiting PI3K/AKT pathway. These results provide novel mechanistic insights for the anti-fibrotic effect of miR-29b.published_or_final_versio

Diagnosis of Gastric Cancer by Serum Proteomic Fingerprinting

Background & Aims Accurate serum biomarkers for gastric cancer currently are lacking. We attempted to identify potential diagnostic serum markers for gastric cancer with the use of the surface-enhanced laser desorption/ionization ProteinChip technology. Methods The study was divided into 3 phases: (1) discovery of potential diagnostic markers using sera of gastric cancer patients and controls, (2) development of a diagnostic model, and (3) independent validation of the diagnostic model using a different cohort of gastric cancer and control patients. The serum proteins/peptides were analyzed with 2 types of ProteinChip arrays, IMAC30 arrays loaded with copper (II) ion and CM10 (weak cation exchange) arrays. Results In the discovery set, peak intensities of 31 surface-enhanced laser desorption/ionization proteomic features were significantly higher in gastric cancer patients. The tumor-specific nature of 6 proteomic features with the mass/charge (m/z) values of 5098, 8592, 8610, 11,468, 11,804, and 50,140 was verified by their lower peak intensities in postoperative sera. After excluding the sodium adduct peak (8610 m/z) of the 8592 m/z protein, the peak intensities of the tumor-specific proteomic features were used to develop a linear regression model for calculating a diagnostic index. The area under the receiver operating characteristic curve of the corresponding diagnostic index was 0.92 (95% confidence interval, 0.85-0.99) in the independent validation set. At a specificity of 95%, the sensitivity for gastric cancer detection was 83%. Conclusions A unique serum proteomic fingerprint can be detected in the sera of gastric cancer patients, which may be useful in the noninvasive diagnosis of gastric cancer. © 2006 American Gastroenterological Association Institute.link_to_subscribed_fulltex

Lipoprotein lipase activator ameliorates the severity of dietary steatohepatitis

Dietary model of steatohepatitis was established by feeding mice a methionine choline deficient (MCD) diet. Mice on MCD or control diet for 3 weeks were treated with or without NO-1886, a newly synthetic lipoprotein lipase (LPL) activator. In a separate experiment, NO-1886 was given after pre-treatment with 3 weeks of MCD diet. NO-1886 significantly reduced MCD-induced inflammation by repressing levels of hepatic lipid peroxides and pro-inflammatory tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6), and cyclooxygenase-2 (COX-2). In addition, NO-1886 dampened hepatic steatosis via accelerating fatty acid oxidation caused by enhanced expression of PPARα, cytochrome P450-10 (Cyp4a10), and Acyl-CoA oxidase (ACO). It failed to regulate genes of fatty acid uptake and synthesis pathways. In conclusion, NO-1886 ameliorated and induced regression of experimental steatohepatitis via increasing endogenous LPL activation resulting in suppression on pro-inflammatory factors and reduction of hepatic fatty acids. These findings indicate that NO-1886 is a potential therapeutic agent for steatohepatitis. © 2007 Elsevier Inc. All rights reserved.link_to_subscribed_fulltex

CXC chemokine receptor 3 promotes steatohepatitis in mice through mediating inflammatory cytokines, macrophages and autophagy

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H. pylori genotypes and cytokine gene polymorphisms influence the development of gastric intestinal metaplasia in a chinese population

BACKGROUND: Cytokine gene polymorphisms and Helicobacter pylori (HP) genotypes have been linked to gastric cancer development in Western countries. We determined the role of host cytokine polymorphisms and bacterial virulent factors in the development of gastric intestinal metaplasia (IM) in a Chinese population with a high background gastric cancer incidence. METHODS: Three hundred two HP-infected noncancer individuals living in Shandong province of China with available DNA were studied. Polymorphisms in different loci of inflammatory cytokines Interleukin IL-1B, IL-1RN, Interleukin IL-8, IL-10, IL-18, tumor necrosis factor-A (TNF-A), and Transforming growth factor (TGF-B), were determined by allelic discriminating TaqMan polymerase chain reaction (PCR) or a variable number of tandem repeats. Presence of HP virulence factors in cagA, vacA, and babA2 were determined by PCR. Baseline gastric biopsies were assessed for the presence of IM. RESULTS: Among HP-infected subjects, carriers of the IL-1B-511 T allele were associated with a modestly greater prevalence of IM (adjusted OR 2.0, 95% CI 1.0-3.7). There was no association between the presence of IM and polymorphisms in other inflammatory cytokines. Although most subjects from this region harbored the virulent HP strains, carriage of the vacA m1 strain was associated with a significantly higher prevalence of IM (adjusted OR 1.8, 1.1-3.0). The presence of both host (IL-1B-511 T) and HP (vacA m1) genotypes further increased the risk of IM (OR 5.7, 2.0-16) when compared with individuals with the low-risk genotype. CONCLUSION: The carriage of proinflammatory IL-1B-511 and HP vacA m1 genotypes was associated with the development of gastric IM in the Chinese. © 2006 by Am. Coll. of Gastroenterology.link_to_subscribed_fulltex

High serum interleukin-6 level predicts future hepatocellular carcinoma development in patients with chronic hepatitis B

Increased interleukin-6 (IL-6) production is implicated in the pathogenesis of hepatocellular carcinoma (HCC) in animal models. Although previous studies showed that HCC patients had higher serum IL-6 level at the time of diagnosis, it is unclear if the cytokine contributes to the development of HCC or is just a reaction to cancer. To address this question, we performed a nested case-control study. Consecutive chronic hepatitis B patients were recruited from 1997 to 2000 and followed till 2008. Profiling of 27 cytokines, chemokines and growth factors was performed at baseline, date of peak alanine aminotransferase (ALT) level and the last visit. Thirty-seven patients developed HCC at a median follow-up of 62 months (interquartile range: 41-110). Serum IL-6 was higher in patients with HCC than controls both during peak ALT and at the last visit (both p = 0.02). Patients with IL-6 above 7 pg/ml during peak ALT had increased risk of HCC or death (adjusted hazard ratio 3.0; 95% confidence interval 1.2, 7.8; p = 0.02). The sensitivity, specificity, positive and negative predictive values of this cutoff to predict future HCC development were 70%, 73%, 72% and 71%, respectively. Combination of IL-6 and AFP improved the sensitivity in diagnosing HCC or predicting future HCC development. In conclusion, high serum IL-6 level predates the development of HCC in chronic hepatitis B patients, and has moderate accuracy in predicting future cancer. This may assist clinicians in selecting high-risk patients for HCC surveillance program. © 2009 UICC.link_to_subscribed_fulltex

Effect of celecoxib on experimental liver fibrosis in rat

Background/Aim: Cyclooxugenase-2 (COX-2), an inducible enzyme that catalyzes prostaglandin synthesis, has been implicated in a number of hepatic stellate cell (HSC) functions. In the current study, we assessed the in vivo effect of celecoxib, a COX-2-selective inhibitor, in experimental liver fibrosis in rats. Methods: Male Sprague-Dawley rats received experimental treatments for 5 weeks. Serum alanine transminase at the time of sacrifice was measured. Quantitative assessment of liver fibrosis was performed by computerized morphometry. Expression of COX-2, α smooth muscle actin and connective tissue growth factor (CTGF) was evaluated by immunohistochemistry. Real-time quantitative PCR was used to determine the expression of genes associated with fibrogenesis and extracellular matrix degradation. Results: Liver fibrosis was significantly worse in rats that received both carbon tetrachloride (CCl4) and celecoxib, compared with rats that received CCI4 and gavage of water (P=0.037). There was also more HSC activation, and upregulation of collagen α1(I), heat-shock protein 47, αB crystallin, matrix metalloproteinase (MMP)-2, MMP-9 and tissue inhibitor of MMP (TIMP)-2. The expression of TIMP-1 and CTGF was not significantly different between the two groups. The pro-fibrogenic effect of celecoxib in toxin-induced liver fibrosis in rats was further confirmed in thioacetamide model of liver injury. Conclusions: Celecoxib potentiates experimental liver fibrosis; further studies are warranted to investigate the potential pro-fibrogenic effect of celecoxib in other animal models of liver fibrosis and in patients with chronic hepatitis. Copyright © Blackwell Munksgaard 2005.link_to_subscribed_fulltex

High serum interleukin-6 level predicts future hepatocellular carcinoma development in patients with chronic hepatitis B

Increased interleukin-6 (IL-6) production is implicated in the pathogenesis of hepatocellular carcinoma (HCC) in animal models. Although previous studies showed that HCC patients had higher serum IL-6 level at the time of diagnosis, it is unclear if the cytokine contributes to the development of HCC or is just a reaction to cancer. To address this question, we performed a nested case-control study. Consecutive chronic hepatitis B patients were recruited from 1997 to 2000 and followed till 2008. Profiling of 27 cytokines, chemokines and growth factors was performed at baseline, date of peak alanine aminotransferase (ALT) level and the last visit. Thirty-seven patients developed HCC at a median follow-up of 62 months (interquartile range: 41-110). Serum IL-6 was higher in patients with HCC than controls both during peak ALT and at the last visit (both p = 0.02). Patients with IL-6 above 7 pg/ml during peak ALT had increased risk of HCC or death (adjusted hazard ratio 3.0; 95% confidence interval 1.2, 7.8; p = 0.02). The sensitivity, specificity, positive and negative predictive values of this cutoff to predict future HCC development were 70%, 73%, 72% and 71%, respectively. Combination of IL-6 and AFP improved the sensitivity in diagnosing HCC or predicting future HCC development. In conclusion, high serum IL-6 level predates the development of HCC in chronic hepatitis B patients, and has moderate accuracy in predicting future cancer. This may assist clinicians in selecting high-risk patients for HCC surveillance program. © 2009 UICC.link_to_subscribed_fulltex

Expression of a cyclo-oxygenase-2 transgene in murine liver causes hepatitis

Background: It has been proved that cyclo-oxygenase-2 (COX-2) is rapidly induced by inflammatory mediators. However, it is not known whether overexpression of COX-2 in the liver is sufficient to promote activation or secretion of inflammatory factors leading to hepatitis. Aim: To investigate the role forced expression of COX-2 in liver by using inducible COX-2 transgenic (TG) mice. Methods: TG mice that overexpress the human COX-2 gene in the liver using the liver-specific transthyretin promoter and non-TG littermates were derived and fed the normal diet for up to 12 months. Hepatic prostaglandin E 2 (PGE 2) content was determined using enzyme immunoassay, nuclear factor kappaB (NF-κB) activation by electrophoretic mobility shift assays, apoptosis by terminal deoxynucleotidyl transferase-mediated dUTP-digoxigenin nick end labelling and proliferation by Ki-67 immunohistochemistry. Results: COX-2 TG mice exhibited strongly increased COX-2 and PGE 2, elevated serum alanine aminotransferase level and histological hepatitis. Hepatic COX-2 expression in the TG mice resulted in activation of NF-κB and inflammatory cytokine cascade, with a marked expression of the proinflammatory cytokines tumour necrosis factor (TNF)-α (9.4-fold), interleukin (IL)-6 (4.4-fold), IL-1β (3.6-fold), and of the anti-inflammatory cytokine IL-10 (4.4-fold) and chemokine macrophage inflammatory protein-2 (3.2-fold). The inflammatory response of the COX-2 TG mice was associated with infiltration macrophages and lymphocytes, increased cell proliferation and high rates of cell apoptosis. Administration of the COX-2 inhibitor celecoxib in TG mice restored liver histology to normal. Conclusion: Enhanced COX-2 expression in hepatocytes is sufficient to induce hepatitis by activating NF-κB, stimulating the secretion of proinflammatory cytokines, recruiting macrophage and altering cell kinetics. Inhibition of COX-2 represents a mechanism-based chemopreventive approach to hepatitis.link_to_subscribed_fulltex

CXCL10 plays a key role as an inflammatory mediator and a non-invasive biomarker of non-alcoholic steatohepatitis

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