Many others have used various carcinogenic regimens to study the origin

of oval cell proliferation in rats, assuming that such proliferation is a precursor to development of HCC, but without actually following the treated rats to determine whether any cancers subsequently develop.37-40 selleckchem However, after rapid proliferation, most oval cells, including those involved in bile-duct proliferation, are either lost by apoptosis or differentiate into mature liver cells41-43 or duct-like cells.44, 45 Thus, oval cells are part of a normal response to liver injury, producing progeny to replace hepatocytes and ducts. It is not known where the critical step occurs in this process that results in induction of cancers. However, shared marker phenotypes PLX-4720 manufacturer between oval cells and HCCs identified by monoclonal antibodies to cells in the liver lineage support the concept that oval cells could give rise to both HCC

and CCA.14, 46, 47 Our marker studies using EpCAM, HNF6, and C-Met (Supporting Information Fig. 5) are not definitive but are consistent with an oval cell–to–duct cell lineage in development of CAA. Bile ducts, oval cells, CF, and CAA are all EpCAM-positive, whereas hepatocytes are not. In human liver cancer, EpCAM expression defines HCCs with stem cell features.48 C-Met is known check details to be positive in mucin-producing cholangiocarcinomas.22 The unexpected finding is that oval cells

and bile duct cells in CF are positive for HNF6, but CAAs are negative. HNF6 is a transcription factor proposed to drive cholangiocyte differentiation.49 Thus, there appears to be a loss of this ductal phenotype with malignant transformation. Although a direct comparison of our results to the human liver is not possible, it is likely that there is a decrease of functional liver stem cells in humans with aging. The major confounding factor is that there is no generally accepted marker for putative stem cells in the adult human liver. In fact, the adult human liver stem cell is functionally defined as “facultative”. That is, such cells are not identifiable in normal liver, but there are cells in the liver that respond to injury.50 OV 6 has been proposed as a marker for “transitional hepatocytes” that may serve this function.51 It has also been proposed that stem cells are located in the canals of Hering.52 There is a decrease in the number of biliary cells expressing the putative liver stem cell marker CD133 from 96.3% at 3 years of age to 59% in the adult.53 Additional Supporting Information may be found in the online version of this article.

Significantly higher levels of AFP, AST, ALT, and lower levels of albumin were observed in the false positive group than in the true negative group (P = 0.04 to

P < 0.001). Of 43 HCC recurrences, 16 were categorized as true positive and 27 as false negative. The false negative AFP group had smaller size of recurrence and lower level of alkaline phosphatase (P = 0.04–0.01) as compared to the true positive group (Table 3). Among the positive AFP results, the true positive Mdm2 inhibitor AFP from tumor recurrence had significantly higher AFP levels than those with false positive AFP results (median = 372 vs 39.8 ng/mL and first to third quartile = 171–2261 ng/mL vs 30–102 ng/mL, respectively; P < 0.001). Of 103 treated HCCs with no recurrence, 56 had normal ALT levels (< 40 U/L) and 47 had abnormal ALT levels (≥ 40 U/L). The abnormal ALT group had significantly higher AFP levels and false selleck chemical positive rates than the normal ALT group (median AFP of 9 ng/mL vs 3.3 ng/mL and false positive rates of 31.9% vs 5.4%, respectively; P ≤ 0.001, Table 4). Of the 43 recurrent HCCs, 25 had abnormal ALT and 18 had normal ALT values. No significant difference between AFP levels and false negative rates between the abnormal and normal ALT group was observed (P = 0.85–0.59).

Among the 120 HCCs occurring in viral-related liver disease which included 85 cases of HCV, 31 cases of HBV, and four cases selleck inhibitor of HBV/HCV co-infection, higher percentages of cases with active viral activity were observed in the abnormal ALT group than in the normal ALT group (P < 0.001,

Table 5). The other 26 HCC occurring in non-viral-related liver diseases had no significant difference in Child-Pugh classification between the normal and abnormal ALT groups. With pretreatment and recurrence AFP cutoff of ≥ 20 ng/mL for both AFP-producing HCC and positive recurrence, the sensitivity of AFP in detecting recurrence in overall, non-AFP-producing, and AFP-producing HCC cases were 37.2%, 12%, and 72.2%, respectively. Corresponding specificity of detection were 82.5%, 98.4%, and 56.4%, respectively. The accuracies of these three groups were 69.2%, 74.2%, and 61.4%, respectively. Using our modified cutoff criteria in cases with elevated ALT (Table 1), the accuracy of AFP in detecting HCC recurrence in the AFP-producing HCC group increased from 61.4% to 79.6% (cutoff AFP ≥ 50 ng/mL if abnormal ALT) and to 89.2% (cutoff AFP ≥ 100 ng/mL if abnormal ALT). The diagnostic performance of AFP with various cutoff values is shown in Table 6. Among tumor markers for HCC surveillance, AFP, lectin-bound AFP and Des-gamma carboxy-prothrombin have been investigated for the detection performance.

15 We previously reported that induction of ER stress (with glucosamine treatment) http://www.selleckchem.com/products/Adriamycin.html leads to misfolding of newly synthesized apoB in the ER and the elimination of apoB via proteasomal and nonproteasomal mechanisms.16 ApoB stability showed a strong inverse correlation with the expression of glucose-regulated protein 78 (GRP78), a key marker of ER stress.16 GRP78 overexpression induced rapid degradation of newly synthesized apoB.16 In line with these observations, Ginsberg

and colleagues showed that treatment of McA-RH7777 cells with oleate at a high concentration (1.2 mM) or for a long period of time (16 hours) induced ER stress and up-regulated GRP78.17 Interestingly, GRP78 has been implicated in not only ERAD induction but also stress-induced autophagy.18 In this report, we present evidence implicating autophagy in ER stress–induced degradation of misfolded apoB. Under ER stress, apoB autophagy appears to be protein kinase R–like ER kinase (PERK)-dependent and is more pronounced in primary hepatocytes compared to established cell lines. Our data suggest that autophagy may be a physiologically important mechanism for the degradation Y-27632 of misfolded apoB under ER stress conditions.

apoB, apolipoprotein B; ALLN, N-acetyl-leucinyl-leucinyl-norleucinal; ATF, activating transcription factor; eIFα, α-subunit of eukaryotic translational initiation factor 2; ER, endoplasmic reticulum; ERAD, ER-associated degradation; GFP, green fluorescent protein; GLS, glucosamine; IRE1, inositol requirement 1; LC3, microtubule-associated protein 1 light chain 3; PAGE, polyacrylamide gel electrophoresis; PBA, 4-phenyl butyric acid; PBS, phosphate-buffered saline; PERK, protein kinase R–like endoplasmic reticulum kinase; RT-PCR, reverse transcription polymerase chain reaction;

SDS, sodium dodecyl sulfate; TM, tunicamycin; VLDL, very low density lipoprotein; WT, wild type; Xbp1, x-box binding protein 1. McA-RH7777 and HepG2 cells were purchased from ATCC (Manassas, selleck products VA). The cells were maintained in Dulbecco’s modified Eagle’s medium (DMEM; Life Technologies, Inc.) containing 20% or 10% fetal bovine serum, respectively. Isolation of primary hepatocytes from rat or hamster was described previously.19 The cells (5 × 105) were seeded in six-well plates 4 hours before the experiments, and 1 μg GFP-LC3 (green fluorescent protein–microtubule-associated protein 1 light chain 3) complementary DNA (cDNA)20 alone, or in addition to 1 μg WT PERK cDNA or kinase inactive mutant PERK (MPERK) cDNA,21 were cotransfected into the cells, using Lipofectamine 2000 (Life Technologies, Grand Island, NY) according to the manufacturer’s protocol.

Only a subset of HDV carriers is reported to benefit from interferon-α (including peginterferon) treatment, the only approved anti-HDV therapy. Currently, there are no drugs in use to directly target HDV, and a number of anti-HBV drugs do not block HDV infection.1, 2, 5-8 In Europe, HDV-induced disease is frequent among immigrants from regions of higher HDV endemicity. HDV remains a serious problem in Vietnam, Iran, Pakistan, India, Tajikistan, Mongolia, Tunisia, Brazil, and other South American countries.1, 6, 9 Despite reports suggesting that chronic carriers of HBV/HDV have a 3-fold increased risk of HCC, and develop HCC ≈14 years earlier than

carriers of HBV only, there is no consensus opinion on the relationship between HDV infection and liver cancer. The molecular SB203580 datasheet basis of HDV pathogenesis is poorly understood and the role of HDV in HCC induction/development has yet to be elucidated.1, 5, 6, 10-13 To advance our understanding of the mechanism of HDV infection and its relation to liver Selumetinib in vitro carcinogenesis, we determined whether HDV could infect in vivo the cells of hepadnavirus-induced HCCs. To accomplish this goal, we used woodchucks (Marmota monax) chronically infected with woodchuck hepatitis virus (WHV), a hepadnavirus that is closely related to HBV. The WHV carrier woodchucks are

a very valuable surrogate animal model to study HBV infection, hepadnavirus-induced HCC, and to test anti-HBV and anti-HCC drugs. Although chronic HBV carrier chimpanzees and wildtype HBV full genome this website transgenic mice do not develop HCCs, 100% of chronic WHV carrier woodchucks develop HCCs usually within 12-36 months postinfection.4, 14 Furthermore, in the laboratory HDV can be coated with WHV envelope proteins, because the HDV-binding site is conserved within the orthohepadnavirus subfamily. Therefore, numerous in vivo studies on HDV infection were conducted using WHV carrier woodchucks superinfected with HDV.1, 2, 7 For HDV, a putative entry receptor

(the receptors for WHV and HBV are currently not identified) and the host range are defined by the origin of the hepadnavirus (i.e., HBV or WHV) envelope proteins forming the virion’s coat. For this reason, HDV is often used as a tool to study the mechanism of hepadnavirus attachment and entry.1, 2 Unlike previous studies, we for the first time have superinfected WHV carriers with WHV-enveloped HDV (wHDV) during the late stage of chronic WHV infection, when WHV-induced HCCs were already developed. Three out of three HDV-negative WHV carriers with formed HCCs were successfully superinfected with wHDV. All HCCs harvested upon the completion of the experiment were infected with wHDV.

In iron overload FDA-approved Drug Library cost disorders, such as HFE-related hereditary hemochromatosis, hepatic iron stores increase over time, with iron depositing predominantly in hepatocytes.[2, 3] Although hepatocytes comprise a major part of the iron storage system, exactly how these cells take up iron, particularly during iron overload, is not well understood. Under normal circumstances,

hepatocytes in the liver can acquire iron from the plasma iron-transport protein, transferrin.[4] It is generally assumed that the uptake of transferrin-bound iron (TBI) by the liver involves the transferrin receptor (TfR)1 endocytosis pathway.[5] In this model, transferrin carrying up to two atoms of ferric iron (Fe3+) binds to TfR1 at the hepatocyte cell surface, initiating the internalization of the transferrin/TfR1 complex into endosomes. Subsequent endosomal acidification causes transferrin to release its Fe3+, which is then reduced to Fe2+ and transported into the cytosol by divalent metal-ion transporter-1 (DMT1). DMT1 was first identified as a transmembrane iron-transport protein by Gunshin et al.[6] in 1997. Iron transport by Sirolimus DMT1

was demonstrated to be maximal at pH 5.5, and its expression was markedly induced in iron-deficient rat duodenum, suggesting that it functions in intestinal iron absorption. A common missense mutation in DMT1 was later found in the mk mouse and Belgrade rat,[7] two animal models characterized by impaired iron absorption, reduced iron assimilation by developing erythroid cells, and anemia. Given that erythroid precursor cells exclusively take up iron from transferrin,[8] it was proposed that DMT1 participates in TBI uptake.[7] Formal proof that DMT1 plays a role in intestinal iron absorption and developing erythroid cells was provided by studies of mice in which DMT1 was inactivated in intestinal epithelial cells (Dmt1int/int) and globally (Dmt1−/−).[9] Because DMT1 is also expressed

in the liver, it is often cited that DMT1 plays a role in hepatocyte iron metabolism,[5, 10-17] either through the uptake of TBI or non-transferrin-bound iron (NTBI), which appears in plasma during iron overload.[18] However, no studies have directly tested the in vivo role of hepatocyte DMT1 in selleck inhibitor liver iron metabolism. Therefore, we examined mice with the Dmt1 gene selectively inactivated in hepatocytes (Dmt1liv/liv) and evaluated their hepatic, as well as systemic, iron status. To determine whether DMT1 is required for hepatic iron accumulation during iron overload, we crossed Dmt1liv/liv mice with two genetic models of iron overload: Hfe knockout (KO) (Hfe−/−) mice[3] and hypotransferrinemic (Trfhpx/hpx) mice.[19] Using Dmt1liv/liv mice, we also directly assessed the requirement for DMT1 in hepatic uptake of TBI and NTBI. Additionally, we examined the effect of iron deficiency on hepatic TBI uptake and iron status in Dmt1liv/liv mice.

Studies of IL28B genotype in the setting of liver transplantation in HCV infection have shown that both donor and recipient IL28B genotypes have a significant effect on treatment outcomes.52 Although it is tempting to imagine a simple, tissue-specific mechanism for the IL28B effect on treatment response, these results collectively suggest an influence of IL28B genotype from both hepatic and extrahepatic tissues. Among the agents in development for treatment of HCV

is the pegylated formulation of human IFN-λ1, which has shown antiviral activity both in cellular models and in vivo and is currently in phase II clinical trials.21-23 Given the influence of host genetic variation in the IFN-λ pathway on treatment response, recombinant IFN-λ products represent Talazoparib concentration a promising avenue in the future of HCV therapeutics and may also provide valuable information regarding the mechanism of the IL28B genetic effect. “
“Autoimmune Selleck MK1775 hepatitis (AIH), like many

autoimmune diseases, is most prevalent in young women. The immunological basis of this age and sex susceptibility bias was investigated in a murine model of AIH. Xenoimmunization of 7-week-old female C57BL/6 mice resulted in more severe AIH with higher levels of liver inflammation, serum alanine aminotransferase, specific T-cell cytotoxicity, and autoantibody than younger and older females. Vaccinated males developed selleck inhibitor minimal liver inflammation and higher percentages of CD4+CD25+FoxP3+ regulatory T cell in peripheral blood mononuclear cells, spleen, and liver than females. Regulatory T cells (Tregs) were virtually absent in liver-lymphocytes infiltrates of females. Castration of C57BL/6 mice, with or without 17β-estradiol supplementation, did not modify susceptibility in males, nor Treg numbers, suggesting minimal contribution of testosterone and estradiol to autoimmune hepatitis

(AIH) susceptibility. Xenoimmunized Aire(+/0) mouse displayed similar AIH susceptibility, sex bias, and Tregs numbers as C57BL/6 mice, suggesting that susceptibility in females is not the result of less stringent thymic central tolerance. Autoreactive B cell response against formiminotransferase-cyclodeaminase correlated with disease activity, possibly linking B-cell autoreactivity and AIH pathogenesis. Conclusion: Peripheral tolerance and development of regulatory T cells after self-mimicking antigen exposure, and not sexual hormone nor central tolerance, are the main factors for susceptibility to AIH in females. HEPATOLOGY 2010 Prevalence of most autoimmune diseases shows a striking sex difference, with women being affected more often than men.1, 2 The ratio of female patients to male ranges from 20:1 in Sjögren’s syndrome, to 3:2 in multiple sclerosis.2 Less frequently, the ratio approaches 1:1, as in ulcerative colitis and diabetes.

The aggregate findings suggest that Notch signaling interfaces with fibrogenic signals that are transduced by TGF-β and the Hh pathway in multipotent liver progenitor cells. This is particularly intriguing because both TGF-β and Hh signaling promote epithelial-to-mesenchymal transitions in developing embryos,[34] and Hh has been proven to stimulate epithelial-to-mesenchymal–like transitions in both adult HSCs and progenitor cells.[8,

35] Having confirmed that DAPT performed as anticipated in Notch-responsive liver progenitor cells, we evaluated its actions in HSCs. For these studies, primary murine HSCs were cultured for 4 days to induce MF transdifferentiation and then treated with DAPT for an additional 3 days. As in 603B cells (Fig. 4), MFs/HSCs showed DAPT-inhibited expression of Notch-2, Jagged-1, and several Notch target

gene (Hey1, XL184 cost Hey2, and HeyL) mRNAs (Fig. http://www.selleckchem.com/products/pf-06463922.html 5A). IHC confirmed that mRNA suppression was accompanied by decreased protein expression (Fig. 5E). Blocking Notch signaling in MFs/HSCs also repressed typical MF-associated genes (α-SMA, collagen, and TGF-β) and Hh target genes that are known to be expressed by MFs/HSCs (Gli2, Ptc, and Sonic Hedgehog [Shh]; Fig. 5B). In contrast, mRNA levels of various epithelial genes (bone morphogenic protein-7, desmoplakin, E-cadherin, AFP, HNF-4α, and Krt19) and Q-HSC markers (peroxisome proliferator-activated receptor gamma [PPAR-γ] and GFAP) were up-regulated (Fig. 5C). Immunocytochemistry confirmed the DAPT-induced reversion of MFs/HSCs to a more quiescent phenotype, showing decreased staining for α-SMA and Ki67 (proliferation marker) and increased Oil Red O staining, indicative of neutral lipid accumulation (Fig. 5F). Interestingly, when Notch signaling was inhibited and MFs/HSCs reverted to a more quiescent phenotype, mRNA expression of delta-like 1 homolog, a Notch-related gene that marks liver progenitors,[36] and mRNAs

encoding other progenitor cell markers (e.g., Nanog, octamer-binding transcription factor 4 [Oct4], and FN14) were down-regulated (Fig. 5D). selleck chemicals llc Thus, Notch signaling is activated during culture-induced primary MF/HSC transdifferentiation, and this permits the cells to acquire a more mesenchymal phenotype with progenitor-like features. This process parallels activation-associated induction of Hh signaling and might be regulated by cross-talk between the Notch and Hh pathways, because HSCs require Hh signaling to become MFs.[8, 31] To further examine possible cross-talk between Notch and Hh signaling, the two Notch-responsive cell types (603B and primary MFs/HSCs) were treated with an Hh-signaling antagonist (GDC-0449). GDC-0449 directly interacts with and inhibits the Hh coreceptor, Smoothened.[37] Earlier work has proven that GDC-0449 recapitulates the effect of Smoothened gene knockdown in MFs/HSCs, with both approaches inhibiting canonical Hh signaling, thereby blocking the nuclear localization and transcriptional activation of Gli DNA-binding proteins.

1A) were observed for up to 139 days post–hydrodynamic injection (PHI; n = 16). The detection of luciferase buy Doxorubicin activity at

48 days PHI indicated selective repopulation of the liver as a result of stable transgene integration into the mouse genome mediated by SB transposition (Supporting Information Fig. 1B, top). The majority of HBx animal livers displayed no evidence of hyperplasia (88%). However, two HBx animals sacrificed at 74 and 139 days PHI displayed livers with hyperplastic nodules (Supporting Information Fig. 1C). Hyperplastic nodules isolated at 139 days PHI were positive for HBx transcripts by RT-PCR (Fig. 1A). These hyperplastic nodules expressed high levels of alpha-fetoprotein (Afp), a known diagnostic marker for HCC, in comparison with the adjacent normal liver (Fig. 1A). According to semiquantitative RT-PCR analyses, the arbitrary expression levels of Afp with respect to β-actin (Actb) were 0.31 ± 0.13 and 0.96 ± 0.042 (means and standard deviations) in normal livers and hyperplastic nodules, respectively (P = 0.0076;

Fig. 1B). In order to visualize the selective hepatocyte repopulation process, control mice injected with Gfp alone (Supporting Information Fig. 1A) were observed for up to 113 days PHI (n = 4). The detection of luciferase activity at 48 days PHI also indicated selective repopulation of the liver (Supporting Information Fig. 1B, bottom). These Gfp mice were sacrificed at 82 and 113 days PHI (n = 4). Although no hyperplastic nodules were initially detected at

82 days PHI (n = 2), a single Gfp-negative nodule was detected at 113 days PHI (n = 2). Viewed with fluorescent imaging, the Gfp expression pattern Y-27632 solubility dmso confirmed that the liver repopulation process occurred uniformly (Supporting Information Fig. selleck chemicals 1D). Importantly, control mice coinjected with an empty vector and shp53 (empty/shp53; Supporting Information Fig. 1A) were negative for hyperplasia up to 139 days (n = 9). Interestingly, Ki67 staining did not show a significant increase in the mitotic index for Gfp animals (data not shown). However, there were higher levels of Ki67 staining in HBx animals (Fig. 2B). The liver weight percentage of HBx mice was significantly higher than that of Gfp mice (P < 0.01) and empty/shp53 controls (P < 0.001; Fig. 3B), and this indicates that HBx may have a proliferative effect on hepatocytes. Mice injected with HBx alone had high levels of Ctnnb1 expression by IHC, and this was mainly localized in the cellular membrane of repopulated hepatocytes (Fig. 4). Livers of HBx mice had hardly detectable levels of phosphorylated v-akt murine thymoma viral oncogene homolog 1 (pAkt; Fig. 5) and displayed more CD45 staining cells by IHC in comparison with control Gfp animals (Supporting Information Fig. 4). Interestingly, ALT levels among HBx, empty/shp53, and Gfp representative animals were not significantly different (Table 1). Mice injected with HBx and shp53 (HBx/shp53; Supporting Information Fig.

In this survey, however, it was also demonstrated that most children had an iron deficit without anemia and that 2/3 ca. of children with iron deficiency or anemia were not infected by H. pylori, signifying that other factors may play a role in the development of anemia. Muhsen et al. [60] stressed the importance of establishing the CagA status of patients which lacks in most surveys. They found low ferritin levels, respectively, in 14.5% and 8.6% of H. pylori infected and uninfected Israeli Arab children. Despite the fact that low ferritin levels were

mostly detected in CagA-positive Rucaparib in vitro subjects, it should be considered that the infection by strains expressing CagA enhances the risk of developing peptic ulceration and reduces the levels of gastric ascorbic acid. Both conditions

which may concur to cause iron-deficiency anemia through gastrointestinal blood loss and insufficient dietary iron absorption, thus complicating the question even more. A condition that may lead to a chronic idiopathic iron deficiency is represented by autoimmune atrophic gastritis, which has been shown to be responsible for refractory iron-deficiency anemia in over 20% of patients with no evidence of gastrointestinal blood loss [55]. Such a disease is considered a possible outcome of a long lasting H. pylori infection. Infected subjects, in fact, have circulating antibodies to the H+,K+-ATPase of the gastric parietal cells [61]. H. pylori infection is a condition in which autoimmunity is exalted; we therefore aligned the amino acid sequence of catalase, an enzyme abundantly expressed find more by erythrocytes, with peptides MAPK Inhibitor Library clinical trial expressed by H. pylori J99, to see whether mechanisms of molecular mimicry could account, at least partially, for the development of anemia in infected individuals. We found a linear homology with numerous bacterial proteins, the widest of which was with the bacterial catalase. In conclusion, to better define the role of H. pylori infection in iron-deficiency anemia, as well as its pathogenic mechanisms, we need larger controlled trials, the definition of the CagA status and exclusion of all the other causes of anemia, including the presence of autoantibodies to erythrocytes.

The possible role of H. pylori infection in the development of ITP is a subject of extensive investigation. Systematic reviews of past literature [62,63] showed an overall platelet response in more than 50% of the patients successfully treated for the infection and increased response rates in countries with a high prevalence of H. pylori infection in background populations, i.e. in patients with less severe degrees of thrombocytopenia and in those with shorter disease duration. In the meta-analysis performed by Arnold et al. [63], the cumulative sample size of cases was 282 patients with ITP (pooling 11 studies, eight from Japan), 205 of whom were H. pylori positive and 77 patients H. pylori negative. All patients underwent eradication treatment.

Results: There were 34 patients with NCPF (M:F 1:1.8) and 30 patients with EHPVO (M: F ratio 1.6:1). The mean age was 24.9 yrs and

41.2 yrs respectively. During follow up, 20 out of 34 and 16 out of 30 patients with NCPF and EHPVO respectively had no progression PD-0332991 research buy of disease. 14 patients with NCPF progressed to cirrhosis over a mean period of 5.21 years. Eight patients developed ascites and required diuretics. 14 patients with EHPVO progressed to NCPF over the mean period of 8.6 years, 12 patients further progressed to cirrhosis over a mean period of 5.1 years. Overall 40% of patients with EHPVO progressed to cirrhosis over a mean period of 13.7 years. Conclusion: INCPH is a spectrum wherein EHPVO progresses to NCPF and further to cirrhosis over a period of 13.7 years at least in a proportion of patients. Conversely, identifying these changes may suggest to the clinicians the need to work-up a patient for portal hypertension. Key Word(s): 1. INCPH; 2. NCPF; 3. EHPVO; 4. Cirrhosis; Presenting Author: WEI HOU Additional Authors: CHENYANG DAI, HANGYU PEI, BTK inhibitor purchase WUKUI CAO, YUQIANG MI, JIMING YANG, WEI LU

Corresponding Author: WEI HOU Affiliations: Tianjin Second People’s Hospital and Tianjin Institute of Hepatology Objective: The aim of this study was to investigate the characteristics of tyrosine-methionine-aspartate-aspartate (YMDD) mutation and analyze the codon usage pattern of YMDD variants in patients with lamivudine (LAM)-resistant chronic hepatitis B (CHB). Methods: 514 CHB inpatients and outpatients from our hospital with confirmed genotypic resistance to LAM were enrolled in this study between Jan 2008 and Oct 2012. The YMDD motif of these HBV isolates were analyzed selleck chemicals using a pyrosequencing method. Results: The baseline YMDD mutation patterns were as follows: rtM204I (298, 57.98%), rtM204V (168, 32.68%), and rtM204I+ rtM204V (48, 9.34%). For rtM204I mutation (I = AAT, ATC or ATA), I/ATT (84.78%) >I/ATC (8.97%) >I/ATA (6.25%). Most of the I/ATC (90.91%), I/ATT (70.34%) and I/ATA (65.21%) variants were completely mutated. For rtM204V mutation (V = GTG, GTT, GTA or GTC), V/GTG

(80.54%) >V/GTT (16.79%) >V/GTA (1.53%) >V/GTC (1.14%). More than half of V/GTG (53.55%) variants were completely mutated. However, V/GTA (100%), V/GTT (90.91%) and V/GTC (66.67%) variants were always mixed with M/ATG wide-type isolates. Conclusion: We firstly show the synonymous codon usage pattern of YMDD variants in HBV isolates. The synonymous codons of YMDD variants are not chosen equally and randomly. I/ATT and V/GTG are predominant for rtM204I and rtM204V mutation, respectively. A further investigation of the mutation pressure with translation selection on codon usage might shed a new light on understanding the evolutionary trends of HBV and host adaptive response, which might assist control this disease. Key Word(s): 1. chronic hepatitis B; 2. lamivudine; 3. YMDD; 4.