• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 145
  • 27
  • 21
  • 20
  • 9
  • 8
  • 6
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • Tagged with
  • 234
  • 234
  • 234
  • 38
  • 34
  • 34
  • 21
  • 20
  • 19
  • 19
  • 17
  • 16
  • 16
  • 15
  • 13
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
131

Inhibiting Hepatitus B virus replication with short hairpin RNA sequences that target the viral X open reading frame

Ely, Abdullah 17 November 2006 (has links)
Student Number : 9903082V - MSc (Med) dissertation - Faculty of Health Sciences / Chronic infection with the hepatitis B virus (HBV) is endemic to sub-Saharan Africa and south-east Asia where it is a major risk factor for the development of cirrhosis and hepatocellular carcinoma (HCC). Currently available therapy is only effective in a small subset of chronic carriers. The development of novel treatment modalities for the management of HBV therefore remains an important global medical objective. Sequence plasticity of the HBV genome is limited by its small size and the overlapping nature of its open reading frames (ORFs). These features make HBV an ideal target for therapy based on nucleic acid hybridization. The use of ribozymes (RNA enzymes) and antisense molecules to inhibit gene expression is well documented. The recent discovery of RNA interference (RNAi) has added to the arsenal of therapy based on nucleic acid hybridization. RNAi is the process whereby short RNA duplexes (called short interfering RNA or siRNA) mediate the sequence-specific post-transcriptional silencing of genes homologous in sequence to the siRNA. siRNA function by guiding a protein complex (RNA Induced Silencing Complex or RISC) to target mRNA for degradation or translational repression. The protein X ORF (HBx ORF) is a conserved region of the HBV genome and is common to all viral transcripts. HBx is required for infection by the virus and plays an important role in the establishment of chronic infections in vivo as well as in the development of HCC. RNAi targeted against the HBx ORF may therefore prove useful as treatment of chronic HBV infection. Plasmid based expression cassettes capable of endogenously generating short hairpin RNA (shRNA) targeted to the HBx ORF were constructed. The shRNA function as substrates for the RNAi machinery and are processed into siRNA. The ability of the expression cassettes to knockdown markers of HBV gene expression was tested in a human hepatoma cell line. A panel of 10 U6 promoter-driven shRNA expression vectors was generated. The U6 promoter (an RNA polymerase III promoter) is normally involved in the transcription of small nuclear RNA and as such is ideal for the generation of shRNA of precisely defined length. Three cytomegalovirus (CMV) promoter-driven shRNA expression cassettes incorporating ribozymes that produce defined hairpin sequences were also generated. The CMV promoter (an RNA polymerase II) promoter is involved in the transcription of large messenger RNA. Two hammerhead ribozymes lying 5’ and 3’ of the shRNA encoding sequence were incorporated into the cassette. Cis-cleavage by the ribozymes releases a shRNA of defined length thereby overcoming the limitations imposed by extraneous sequences from CMV promoter-driven transcription. U6 promoter-driven shRNA expression vectors efficiently knocked down markers of HBV replication in liver cells. The CMV promoter-driven expression vectors were incapable of inhibiting HBV gene expression; however shRNA generated in vitro from these vectors mediated efficient knockdown of HBV replication. shRNA-mediated inhibition of gene expression therefore holds promise as a novel treatment strategy for the management of HBV and other mobile genetic elements.
132

The design and application of a real-time PCR assay to assess rcDNA and cccDNA produced by HBV during infection

Bloom, Kristie Michelle 30 August 2010 (has links)
Chronic hepatitis B virus (HBV) infection is endemic to sub-Saharan Africa, and despite the availability of anti-viral agents, there is currently no cure. This double stranded DNA virus is hepatotropic, and active viral replication results in two genomic equivalents, the relaxed circular DNA (rcDNA) and covalently closed circular DNA (cccDNA). The virion encapsulated rcDNA contains a partially synthesised positive DNA stand and a gap region within the negative strand. After infection of hepatocytes, the rcDNA is repaired in the nucleus to form cccDNA. An important objective of HBV therapy is the elimination of cccDNA, as its persistence within hepatocytes has been attributed to chronic HBV infection. Therefore a reliable assay for this replication intermediate is crucial. The objective of this study was to develop a method based on real-time PCR to detect and quantify HBV cccDNA. PCR primers which flank the rcDNA gap were designed to amplify cccDNA whilst primers flanking the pre-S1 region quantify total HBV DNA. Viral DNA was extracted from HepG2.2.15 cells, along with serum and livers from HBV transgenic mice. According to this assay, cccDNA was readily detectable in transgenic mouse livers, but was present at low concentrations in serum samples. The intrahepatic HBV DNA profile of transgenic mice was found to be 40% cccDNA to 60% rcDNA. In HepG2.2.15 cells, only 2% of HBV DNA was cccDNA whilst the majority was in the form of rcDNA. These results were validated using non-radioactive Southern blothybridisation. Additionally, it was established that although RNAi-based effecters inhibit HBV replication, established cccDNA pools were not eliminated. Real-time PCR provides a convenient platform for HBV cccDNA detection as it allows for the rapid simultaneous amplification and quantification of a specific DNA target through either non-specific or specific DNA detection chemistries. In conclusion, this HBV qPCR assay should enable improved monitoring of patients’ responses to antiviral therapy
133

Příprava nanočástic pro terapii viru žloutenky typu B / Preparation of nanoparticles for hepatitis B viral therapy

Kružíková, Zuzana January 2018 (has links)
Hepatitis B virus (HBV) represents one of the hot topics of current basic and pharmaceutical research. Although an effective vaccine against HBV exists since 1982, the world prevalence of chronic infection is still alarming. The infection can lead to significant liver damage, often resulting in hepatocellular carcinoma. Chronic HBV infection cannot be cured due to the fact that the viral genome persists in the infected hepatocyte hidden from the host immune response as well as from the antiviral treatment. One of the novel approaches aiming for HBV cure suggests that this cccDNA pool could be destroyed using gene editing tools such as CRISPR/Cas9 system. In order to shift this gene editing system to possible medicinal application, CRISPR/Cas9 has to be specifically delivered into the target cell in order to minimize its putative off-target activity. This thesis focuses at first on the design and efficacy testing of new sgRNAs targeting HBV cccDNA and secondly, it describes modular lipid nanoparticles developed specially for delivery of the CRISPR/Cas9 system in the form of RNA. Keywords: hepatitis B virus, CRISPR/Cas9, gene editing, lipid nanoparticles, mRNA delivery, targeted delivery
134

Estudo da distribuição genotípica e de mutações no genoma do vírus da hepatite B, em pacientes co-infectados pelo vírus da hepatite B e HIV, na Casa da AIDS, do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo / Hepatitis B genotype distribution and frequency of resistance mutations in a group of patients co-infected with HIV and hepatitis B virus (HBV) at an AIDS Outpatient Clinic in Sao Paulo

Silva, Adriana Cristina da 12 January 2011 (has links)
O objetivo deste estudo foi avaliar a distribuição genotípica e mutações no genoma do vírus da hepatite B (VHB) em um grupo de pacientes co-infectados pelo VHB e vírus da imunodeficiência humana (HIV). Foram incluídos pacientes AgHBs +/HIV+ , atendidos em um ambulatório de referência para pacientes infectados pelo HIV, na cidade de São Paulo. Para a detecção dos marcadores sorológicos para infecção pelo VHB utilizou-se técnica de ELISA através de kits comerciais. A detecção do DNA-VHB foi realizada através de nested-PCR e sua quantificação foi realizada por COBAS AMPLICOR. De acordo com a literatura, a infecção pelo VHB no Brasil varia de 0,4 a 8,5%. Os genótipos de VHB, as mutações na região do core, BCP, pré-core e na região da polimerase foram determinados por seqüenciamento. Cinqüenta e nove pacientes foram incluídos neste estudo e cinqüenta e seis pacientes relatavam uso prévio de lamivudina ou tenofovir. A presença do DNA-VHB foi detectada em 22 pacientes AgHBs positivos. A identificação dos genótipos foi realizada em 16 pacientes e a distribuição dos genótipos do VHB foi: A (12-75%); G (2-13%), D (1-6%) e F (1-6%). Em 10 dos pacientes com viremia presente para DNA-VHB, foram observadas mutações na região da polimerase (rtL180M + rtM204V, rtV173L + rtL180M + rtM204V) e no gene do envelope (sI195M, sW196L, sI195M/sE164D). Mutações na região do BCP (A1762T, G1764A) e do pré-core (G1896A) foram identificados em quatro pacientes. Em conclusão, entre os pacientes analisados observou-se uma alta prevalência de mutações associadas a resistência à lamivudina e associadas a resistência a anti-HBs. O genótipo G, raramente descrito em nosso meio, foi também observado nesse grupo de pacientes. / The objective of this study was to evaluate the genotype distribution and genomic mutations of hepatitis B virus (HBV) among a group of HIVHBV co-infected patients from an AIDS outpatient clinic in São Paulo. HBV serological markers were detected by commercially available enzyme immunoassay kits. HBV DNA was detected by using an in-house nested PCR and quantified by COBAS AMPLICOR. HBV genotypes, basal core promoter (BCP) / pre-core / core region and surface / polymerase genes mutations were determined by sequencing. Among the 59 patients included in this study, 56 reported previous use of lamivudine or tenofovir. According to the literature HBV infection in Brazil varies from 0,4 to 8,5%. HBV DNA was detected in 16/22 patients and the genotypes distribution was A (n=12, 75%); G (n=2, 13%); D (n=1, 6%), and F (n=1, 6%). In 10 patients with viremia, lamivudine-resistance mutations in the polymerase gene (rtL180M + rtM204V, rtV173L + rtL180M + rtM204V) were found, accompanied by changes in the envelope gene (sI195M, sW196L, and sI195M/sE164D). Mutations in the BCP and pre-core regions were identified in 4 patients. In conclusion, genotype G, rarely seen in Brazil, was observed in this group of patients. A high prevalence of mutations associated with lamivudine-resistance accompanied by mutations associated with anti-HBs resistance was also found among these patients.
135

Molecular studies on hepatitis B virus induced hepatocellular carcinoma by est sequencing and suppression subtractive hybridization.

January 2000 (has links)
Yu Chi Hung. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2000. / Includes bibliographical references (leaves 124-139). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Table of Contents --- p.ii / Abbreviations --- p.iv / Abstract --- p.v / 論文摘要 --- p.vi / Chapter Chapter 1 --- Introduction --- p.1 / Chapter 1.1 --- General introduction / Chapter 1.2 --- HBV and its potential oncogenic properties / Chapter 1.3 --- Aim of the present study / Chapter 1.4 --- Expressed sequence tag (EST) analysis: an approach to reveal gene expression pattern in a specific tissue / Chapter 1.5 --- cDNA subtraction / Chapter Chapter 2 --- Materials and Methods --- p.17 / Chapter 2.1 --- Plating out the adult human normal liver cDNA library / Chapter 2.2 --- PCR amplification of cloned human normal liver cDNA inserts / Chapter 2.3 --- Cycle sequencing of cloned human normal liver cDNA inserts / Chapter 2.4 --- mRNA preparation from the HCC tissue and its surrounding normal counterpart / Chapter 2.5 --- PCR-Select cDNA subtraction / Chapter 2.6 --- Construction of HCC subtracted cDNA library by T/A cloning method / Chapter 2.7 --- PCR amplification of cloned subtracted cDNA / Chapter 2.8 --- Cycle sequencing of cloned subtracted cDNA / Chapter 2.9 --- Sequence analysis / Chapter 2.10 --- Differential hybridization of HCC subtracted clones / Chapter Chapter 3 --- Results --- p.46 / Chapter 3.1 --- The sequencing results of adult human normal liver cDNA clones / Chapter 3.2 --- Categorization of ESTs sequenced from the adult normal liver / Chapter 3.3 --- Adaptor ligation efficiency analysis / Chapter 3.4 --- Primary and secondary PCR Amplification / Chapter 3.5 --- PCR analysis of subtraction efficiency / Chapter 3.6 --- The sequencing results of subtracted HCC cDNA clones / Chapter 3.7 --- Categorization of ESTs sequenced from the subtracted HCC cDNA library / Chapter 3.8 --- Differential hybridization of subtracted cDNA clones / Chapter Chapter 4 --- Discussions --- p.90 / Chapter 4.1 --- Characterization of the ESTs generated from human normal liver cDNA library / Chapter 4.2 --- EST analysis on subtracted HCC cDNA clones / Chapter 4.3 --- Candidate genes differentially expressed in HCC / Appendix A The coordinates of dot blots (in numerical order according to clone numbers) / Appendix B The coordinates of dot blots (in alphabetical order according to putative identity) / References --- p.124
136

Over expression, purification and characterization of hepatitis B virus X protein (HBx) and its interacting partner HBx - interacting protein (XIP).

January 2002 (has links)
by Cheung Yuk Yin. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves xx-xxviii). / Abstracts in English and Chinese. / Acknowledgements --- p.i / Abstract --- p.ii / 摘要 --- p.iii / Table of Content --- p.iv / Abbreviations / for Amino Acids --- p.viii / for Standard Genetic Code --- p.ix / for Units --- p.x / for Prefixes --- p.xi / for Terms commonly used in the report --- p.xii / List of Figures --- p.xiii / List of Tables --- p.xiv / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Epidemiology of Hepatitis B Virus (HBV) --- p.1 / Chapter 1.2 --- Relationship between Hepatitis B Virus and Hepatocellular Carcinoma --- p.2 / Chapter 1.3 --- Brief Description of HBV Genome --- p.2 / Chapter 1.4 --- Possible Roles of HBx in Hepatocellular Carcinoma --- p.4 / Chapter 1.5 --- Novel Interacting Partner of HBx - HBx-lnteracting Protein (XIP) --- p.6 / Chapter 1.6 --- Objective --- p.6 / Chapter Chapter 2 --- Methodology / Chapter 2.1 --- Information of the HBx and XIP Clones --- p.7 / Chapter 2.2 --- "Information of the Expression Vectors (pRSETA, 6xHis-pRSETA and pET8C)" --- p.7 / Chapter 2.3 --- Sub-Cloning of HBx and XIP into Different Vectors --- p.9 / Chapter 2.3.1 --- Design of Primers for Cloning of HBx and XIP into Different Vectors --- p.9 / Chapter 2.3.2 --- Polymerase Chain Reaction (PCR) Protocol --- p.12 / Chapter 2.3.3 --- Enzyme Digestion Reaction Protocol --- p.14 / Chapter 2.3.4 --- Ligation Protocol --- p.16 / Chapter 2.3.5 --- Preparation of Competent Cells --- p.17 / Chapter 2.3.6 --- Transformation --- p.18 / Chapter 2.3.7 --- Gel Extraction Protocol --- p.19 / Chapter 2.3.7.1 --- Life Technologies CONCERT´ёØ Rapid Gel Extraction System --- p.19 / Chapter 2.3.7.2 --- QIAGEN Gel Extraction Kit --- p.20 / Chapter 2.3.8 --- Plasmid Preparation Protocol --- p.22 / Chapter 2.3.8.1 --- Life Technologies CONCERT´ёØ Rapid Plasmid Minipreps --- p.22 / Chapter 2.3.8.2 --- QIAGEN Plasmid Maxi Kit --- p.23 / Chapter 2.4 --- Expression of HBx and XIP in E. coli Strain C41 (DE3) --- p.25 / Chapter 2.4.1 --- Transformation --- p.25 / Chapter 2.4.2 --- Expression of HBx and 6xHis-HBx in E. coli Strain C41 (DE3) --- p.26 / Chapter 2.4.3 --- Expression of XIP in E. coli Strain C41 (DE3) --- p.27 / Chapter 2.5 --- Preparation of Buffers for Chromatography and Circular Dichroism Spectrum Measurement --- p.28 / Chapter 2.6 --- Purification and Refolding of HBx and His-Tagged HBx --- p.28 / Chapter 2.6.1 --- Washing of HBx and His-Tagged HBx Inclusion Bodies --- p.28 / Chapter 2.6.2 --- His-Tagged HBx Purification by Affinity Chromatography --- p.29 / Chapter 2.6.3 --- HBx Purification by Size Exclusion Chromatography --- p.30 / Chapter 2.6.4 --- Refolding of HBx and His-Tagged HBx by Oxidative Dialysis --- p.30 / Chapter 2.7 --- Purification of XIP --- p.33 / Chapter 2.7.1 --- Screening of Chromatographic Conditions for the Purification of XIP --- p.33 / Chapter 2.7.2 --- XIP 1st Step of Purification by Hydrophobic Interaction Chromatography --- p.34 / Chapter 2.7.3 --- XIP 2nd step of Purification by Size Exclusion Chromatography --- p.34 / Chapter 2.8 --- Chemical Denaturation Experiment of HBx and XIP --- p.36 / Chapter 2.8.1 --- Preparation of Urea Buffers for the Chemical Denaturation of HBx --- p.37 / Chapter 2.8.2 --- Preparation of Different GdnHCI Buffer for the Chemical Denaturation of XIP --- p.38 / Chapter 2.8.3 --- Calculation for Chemical Denaturation Experiment --- p.39 / Chapter 2.8.3.1 --- Protein Concentration Calculation --- p.39 / Chapter 2.8.3.2 --- Residual Molar Elipticity Calculation --- p.39 / Chapter 2.8.3.3 --- Free Energy Change (ΔGu) Calculation --- p.40 / Chapter 2.9 --- Two-dimensional Heteronuclear Nuclear Magnetic Resonance (NMR) Experiment --- p.41 / Chapter 2.10 --- Interaction Confirmation between HBx and XIP --- p.42 / Chapter 2.10.1 --- "Transfection of pEGFP, pEGFP-HBx and pEGFP-XIP into HepG2" --- p.42 / Chapter 2.10.2 --- Yeast Two Hybrid System for Confirmation of HBx and XIP Interaction --- p.44 / Chapter 2.10.2.1 --- Preparation of Y187 Competent Cells --- p.44 / Chapter 2.10.2.2 --- Transformation of pGBKT7-HBx and pACT2-XIP into Y187 --- p.45 / Chapter 2.10.2.3 --- β-galactosidase Colony Lift Assay --- p.46 / Chapter Chapter 3 --- "Expression, Purification and Characterization of Hepatitis B Virus X Protein (HBx)" / Chapter 3.1 --- Introduction --- p.47 / Chapter 3.2 --- Construction of Recombinant HBx-pRSETA and 6xHis-HBx-pRSETA Plasmids --- p.48 / Chapter 3.3 --- Expression of 6xHis-HBx in E. coli C41 (DE3) using M9ZB Medium --- p.52 / Chapter 3.4 --- Expression of HBx in E. coli C41 (DE3) using M9ZB Medium --- p.54 / Chapter 3.5 --- Purification and Refolding of 6xHis-HBx Fusion Proteins --- p.56 / Chapter 3.6 --- Purification and Refolding of HBx Proteins --- p.60 / Chapter 3.7 --- Structural Characterization of Refolded HBx --- p.65 / Chapter 3.7.1 --- Introduction --- p.55 / Chapter 3.7.2 --- Experimental Analysis of HBx Secondary Structure --- p.66 / Chapter 3.7.3 --- Chemical Unfolding Experiment of HBx --- p.68 / Chapter 3.8 --- Discussion --- p.70 / Chapter 3.8.1 --- "HBx was Expressed, Purified and Characterized instead of 6xHis-HBx" --- p.71 / Chapter 3.8.2 --- High Concentration of DTT was used to Minimize Formation of HBx Aggregates --- p.72 / Chapter 3.8.3 --- Oxidative Refolding to Ensure Proper Disulfide Bond Formation --- p.73 / Chapter 3.8.4 --- Computational Prediction and Experimental Prediction of Secondary Structure of HBx --- p.75 / Chapter 3.9 --- Concluding Remarks --- p.77 / Chapter Chapter 4 --- "Expression, Purification and Characterization of HBx-lnteracting Protein (XIP)" / Chapter 4.1 --- Introduction --- p.78 / Chapter 4.2 --- Construction of Recombinant XIP-pET8C --- p.78 / Chapter 4.3 --- Expression of XIP in E. coli C41 (DE3) using M9ZB and M9 Mediums --- p.82 / Chapter 4.4 --- Screening of Chromatographic Conditions for the Purification of XIP --- p.83 / Chapter 4.4.1 --- Introduction --- p.83 / Chapter 4.4.2 --- Purification Details --- p.83 / Chapter 4.5 --- Purification of XIP by HiTrap Phenyl HP 5-ml Column --- p.87 / Chapter 4.6 --- Purification of XIP by HiLoad 26/60 Superdex 75 Prep Grade --- p.89 / Chapter 4.7 --- Structural Characterization of XIP --- p.92 / Chapter 4.7.1 --- CD Spectrum --- p.92 / Chapter 4.7.2 --- Chemical Denaturation Experiment of XIP --- p.93 / Chapter 4.7.3 --- Two-Dimensional Heteronuclear Nuclear Magnetic Resonance (NMR) Spectrum of 15N Labeled XIP --- p.95 / Chapter 4.8 --- Discussion --- p.97 / Chapter 4.8.1 --- Purification Method Development --- p.97 / Chapter 4.8.2 --- "Do Different Protein Cosolutes, Protein Stabilizers and Detergents Help XIP to Adopt a Stable Conformation?" --- p.99 / Chapter 4.9 --- Concluding Remarks --- p.101 / Chapter Chapter 5 --- In vivo Studies of HBx and XIP Interactions / Chapter 5.1 --- Investigation of Sub-Cellular Localization of HBx and XIP in Liver Cells --- p.102 / Chapter 5.1.1 --- Introduction --- p.102 / Chapter 5.1.2 --- "Construction of Recombinant HBx-pECFP-C1, HBx-pEGFP-C1, HBx-pEYFP-C1 and XIP-pECFP-C1, XIP-pEGFP-C1, XIP-pEYFP-C1" --- p.103 / Chapter 5.1.3 --- Transfection of pEGFP-C1 HBx and pEGFP-C1 XIP into HepG2 to Find Out HBx and XIP Sub-Cellular Localization --- p.106 / Chapter 5.1.3.1 --- Introduction --- p.107 / Chapter 5.1.3.2 --- Investigation of EGFP Proteins Expression using the Confocal Microscope and the Leica TCS Software --- p.108 / Chapter 5.1.4 --- Discussion and Future Prospects --- p.111 / Chapter 5.2 --- Interaction of HBx and XIP Studied by Yeast Two-Hybrid System --- p.113 / Chapter 5.2.1 --- Introduction --- p.113 / Chapter 5.2.2 --- Construction of Recombinant HBx-pGBKT7 and XIP-pACT2 Plasmids --- p.114 / Chapter 5.2.3 --- Confirmation of HBx and XIP Interaction by Yeast Two-Hybrid System --- p.117 / Chapter 5.2.4 --- Discussion --- p.121 / Chapter Chapter 6 --- Conclusion --- p.123 / Appendix I Sequence of HBx and XIP --- p.I / Chapter II --- Vector Sequences --- p.II / Chapter III --- Vector Maps --- p.VI / Chapter IV --- Electrophoresis Markers --- p.XI / Chapter V --- Agarose Gel Electrophoresis --- p.XII / Chapter VI --- SDS-PAGE Eectrophoresis --- p.XIII / Chapter VII --- Medium for Bacterial Culture --- p.XV / Chapter VIII --- Medium for Cell Culture --- p.XVII / Chapter IX --- Medium for Yeast Culture --- p.XVIII / Chapter X --- Buffers for Yeast Transformation --- p.XIX / Reference --- p.XX
137

Differential early gene expression in HBV X protein (HBx)-mediated hepatocarcinogenesis.

January 2002 (has links)
by Ray, Kit Ng. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 112-121). / Abstracts in English and Chinese. / Abstract --- p.i / Acknowledgments --- p.iv / Abbreviations --- p.x / List of Figures --- p.xii / List of Tables --- p.xiv / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- Hepatitis B Virus (HBV) --- p.1 / Chapter 1.2 --- Hepatitis B Virus X Protein (HBx) --- p.5 / Chapter 1.2.1 --- The Genomic Structure of HBx --- p.5 / Chapter 1.2.2 --- The HBx Protein Structure --- p.6 / Chapter 1.2.3 --- Subcellular Localization of HBx --- p.7 / Chapter 1.2.4 --- Possible Functions of HBx --- p.8 / Chapter 1.3 --- Etiology of Hepatocellular Carcinoma (HCC) --- p.12 / Chapter 1.4 --- Relationship between HCC and HBx --- p.13 / Chapter 1.5 --- Aims of Study --- p.14 / Chapter 1.6 --- The Basis of Tet-On System --- p.15 / Chapter 1.7 --- The Basis of DNA Microarray --- p.18 / Chapter 1.8 --- The Basis of Two-Dimensional Electrophoresis --- p.20 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Construction of a Tet-On HBx Expressing Cell Model --- p.22 / Chapter 2.1.1 --- Cloning of HBx Gene into pTRE2 Vector --- p.22 / Chapter 2.1.1.1 --- PCR of HBx Gene --- p.22 / Chapter 2.1.1.2 --- Purification of the PCR Product --- p.23 / Chapter 2.1.1.3 --- Restriction Enzyme Digestion --- p.23 / Chapter 2.1.1.4 --- Ligation of HBx into pTRE Vector --- p.24 / Chapter 2.1.1.5 --- Transformation of the Ligation Product into Competent Cells --- p.24 / Chapter 2.1.2 --- Preparation of the Plasmid DNA --- p.24 / Chapter 2.1.2.1 --- DNA Sequencing of the Cloned Plasmid DNA --- p.25 / Chapter 2.1.3 --- Cell Culture of AML12 Cell Line --- p.26 / Chapter 2.1.4 --- Transfection of pTet-On Vector into AML12 Cells --- p.26 / Chapter 2.1.5 --- Selection of the Transfected AML12 Cells by G418 --- p.27 / Chapter 2.1.6 --- Single Clone Isolation --- p.27 / Chapter 2.1.6.1 --- Luciferase Assay for Selection of Highly Inducible Clones --- p.28 / Chapter 2.1.7 --- Second Transfection of pTRE-HBx Plasmid --- p.28 / Chapter 2.1.8 --- Selection of the Transfected Cells by Hygromycin --- p.29 / Chapter 2.1.9 --- Second Single Clone Isolation --- p.29 / Chapter 2.1.10 --- Total RNA Isolation --- p.29 / Chapter 2.1.11 --- DNase I Digestion --- p.30 / Chapter 2.1.12 --- First-Strand cDNA Synthesis --- p.31 / Chapter 2.1.13 --- RT-PCR of HBx Gene --- p.31 / Chapter 2.1.14 --- Northern Blotting --- p.32 / Chapter 2.1.15 --- Preparation of the Probe --- p.33 / Chapter 2.1.16 --- Northern Blot Hybridization --- p.33 / Chapter 2.1.17 --- 3H-Thymidine Incorporation Assay --- p.34 / Chapter 2.1.18 --- Analysis of Cell Cycle by Flow Cytometry --- p.35 / Chapter 2.2 --- Microarray Analysis of Differential Gene Expression upon HBx Induction --- p.35 / Chapter 2.2.1 --- Sample Preparation for Microarray Analysis --- p.35 / Chapter 2.2.2 --- Probe Labelling --- p.36 / Chapter 2.2.3 --- Microarray Hybridization --- p.37 / Chapter 2.2.4 --- RT-PCR of the Candidate Genes --- p.38 / Chapter 2.2.5 --- Northern Blot Analysis of the Candidate Genes --- p.39 / Chapter 2.3 --- Two-Dimensional (2D) Gel Electrophoretic Analysis --- p.40 / Chapter 2.3.1 --- Protein Sample Preparation for 2D Gel Electrophoresis --- p.40 / Chapter 2.3.2 --- First-Dimension Isoelectric Focusing (IEF) --- p.40 / Chapter 2.3.3 --- Second-Dimension SDS-PAGE --- p.41 / Chapter 2.3.4 --- Silver Stain of 2D Gel --- p.42 / Chapter 2.3.5 --- Mass Spectroscopic Analysis --- p.43 / Chapter 2.4 --- Subcellular Localization of HBx --- p.44 / Chapter 2.4.1 --- Cloning of HBx into Green Fluorescent Protein (GFP) Expression Vector --- p.44 / Chapter 2.4.2 --- Transfection of GFP-HBx --- p.44 / Chapter 2.4.3 --- Propidium Iodide (PI) Staining --- p.45 / Chapter 2.4.4 --- Mitochondria Staining --- p.45 / Chapter 2.4.5 --- Subcellular Localization Study using Epi-Fluorescent Microscopy --- p.45 / Chapter 2.5 --- Analysis of Mitochondrial Transmembrane Potential --- p.46 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Construction of Tet-On AML12 Cell Line of HBx Gene --- p.47 / Chapter 3.2 --- Characterization of the HBx-Expressing Cell Model --- p.53 / Chapter 3.2.1 --- 3H-Thymidine Proliferation Assay --- p.53 / Chapter 3.2.2 --- Cell Cycle Analysis --- p.55 / Chapter 3.3 --- Microarray Analysis of Differential Gene Expression Pattern upon HBx Induction --- p.57 / Chapter 3.4 --- Northern Blot Analysis and RT-PCR of the Candidate Genes --- p.65 / Chapter 3.5 --- Differential Protein Expression Pattern under HBx Induction --- p.70 / Chapter 3.6 --- Subcellular Localization of HBx --- p.77 / Chapter 3.7 --- Analysis of Mitochondrial Transmembrane Potential --- p.83 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Conditional HBx-Expressing Cell Model --- p.84 / Chapter 4.2 --- The Effects of HBx in Clone X18 --- p.86 / Chapter 4.2.1 --- Proliferative Effect of HBx --- p.86 / Chapter 4.2.2 --- Deregulation of G2/M Checkpoint by HBx --- p.86 / Chapter 4.3 --- Early Differential Gene Expression due to HBx Induction --- p.88 / Chapter 4.4 --- The Relationship of the Potential Candidate Genes and Cancer Development --- p.90 / Chapter 4.5 --- The Protein Expression Pattern due to HBx Induction --- p.93 / Chapter 4.6 --- The Subcellular Localization of HBx --- p.96 / Chapter 4.7 --- The Possible Involvement of HBx in Mitochondrial Transmembrane Potential --- p.98 / Chapter 4.8 --- Conclusions --- p.101 / Chapter 4.9 --- Future Prospects --- p.104 / Appendix --- p.107 / References --- p.112
138

A catalogue of genes expressed in human hepatocellular carcinoma as identified by expressed sequence tag sequencing and molecular cloning and characterization of KIAA0022.

January 2002 (has links)
Au Chi Chuen. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2002. / Includes bibliographical references (leaves 157-169). / Abstracts in English and Chinese. / Acknowledgement --- p.i / Table of Contents --- p.ii / Abstract --- p.v / 論文摘要 --- p.vii / Abbreviations --- p.viii / List of Figures --- p.ix / List of Tables --- p.x / Chapter Chapter 1 --- Introduction / Chapter 1.1 --- General introduction --- p.1 / Chapter 1.2 --- Hepatitis B virus and Hepatocellular carcinoma --- p.3 / Chapter 1.3 --- Pathogenesis of HBV related HCC --- p.6 / Chapter 1.4 --- Current screening test and tumor markers --- p.10 / Chapter 1.5 --- Expressed sequence tag (EST) sequencing --- p.13 / Chapter 1.6 --- Aim of the present study --- p.15 / Chapter 1.7 --- Characterization of KIAA0022 --- p.16 / Chapter Chapter 2 --- Materials and Methods / Chapter 2.1 --- Construction of liver HCC and normal counterpart libraries --- p.19 / Chapter 2.2 --- Plating out the human liver cDNA libraries --- p.19 / Chapter 2.3 --- PCR amplification of clones human liver cancer and the normal counterpart cDNA libraries --- p.21 / Chapter 2.4 --- Cycle sequencing of cloned human liver cancer and the normal counterpart cDNA libraries --- p.21 / Chapter 2.4.1 --- Dye-primer cycle sequencing (Pharmacia) --- p.21 / Chapter 2.4.1.1 --- Using Pharmacia LBKA.L.F. DNA sequencer --- p.21 / Chapter 2.4.1.2 --- Using Li-Cor 4200 Automated DNA sequencer --- p.22 / Chapter 2.4.2 --- Dye-terminator cycle sequencing (Pharmacia) --- p.22 / Chapter 2.5 --- Sequences analysis --- p.23 / Chapter 2.6 --- Cloning of full-length cDNA of KIAA0022 --- p.24 / Chapter 2.6.1 --- Amplification of KIAA0022 gene using PCR --- p.24 / Chapter 2.6.2 --- Purification of the PCR product --- p.25 / Chapter 2.6.3 --- Ligation --- p.25 / Chapter 2.6.4 --- One Shot® TOP 10 Chemical Transformation --- p.25 / Chapter 2.6.5 --- Small-scale preparation of the plasmid DNA --- p.26 / Chapter 2.6.6 --- Large-scale preparation of the plasmid DNA Table of Contents (continued) --- p.26 / Chapter 2.6.7 --- DNA sequencing of the full-length cDNA of KIAA0022 --- p.28 / Chapter 2.7 --- Northern Hybridization --- p.29 / Chapter 2.7.1 --- The Human multiple tissue Northern Blot --- p.29 / Chapter 2.7.2 --- Synthesis of the radiolabeled DNA probe --- p.29 / Chapter 2.7.3 --- Hybridization of the Northern blot --- p.30 / Chapter 2.8 --- Subcellular localization of KIAA0022 by tagging with green fluorescence protein (GFP) --- p.30 / Chapter 2.8.1 --- Amplification and purification of the KIAA0022 gene product --- p.30 / Chapter 2.8.2 --- Restriction enzymes digestion --- p.31 / Chapter 2.8.3 --- DNA ligation --- p.31 / Chapter 2.8.4 --- Preparation of the Escherichia coli competent cells for transformation --- p.31 / Chapter 2.8.5 --- Transformation of the plasmid DNA into competent Escherichia coli cells --- p.32 / Chapter 2.8.6 --- Small-scale preparation of the plasmid DNA --- p.32 / Chapter 2.8.7 --- Large-scale preparation of the plasmid DNA --- p.32 / Chapter 2.8.8 --- DNA sequencing of the cloned plasmid DNA --- p.33 / Chapter 2.8.9 --- Transfection --- p.33 / Chapter 2.8.10 --- Fluorescence microscopy examination --- p.33 / Chapter 2.9 --- Yeast two-hybrid screening assay --- p.34 / Chapter 2.9.1 --- "Cloning of the KIAA0022 gene into the yeast two-hybrid DNA-BD vector, pGBKT7" --- p.34 / Chapter 2.9.2 --- Small-scale transformation of pGBKT7-KIAA0022 plasmid --- p.34 / Chapter 2.9.2.1 --- Preparation of yeast competent cells --- p.34 / Chapter 2.9.2.2 --- Transformation of the pGBKT7-KIAA 0022 plasmid into the yeast strain PJ69-2A --- p.35 / Chapter 2.9.3 --- Screening a pretransformed library by yeast mating --- p.35 / Chapter 2.9.4 --- β -Galactosidase analysis - colony lift filter assay --- p.36 / Chapter 2.9.5 --- Analysis of yeast plasmid inserts using PCR and DNA sequencing --- p.37 / Chapter 2.9.5.1 --- PCR --- p.37 / Chapter 2.9.5.2 --- DNA sequencing --- p.37 / Chapter Chapter 3 --- Results / Chapter 3.1 --- Results of ESTs sequencing in normal counterpart and HCC libraries --- p.38 / Chapter 3.1.1 --- The sequencing results of the normal counterpart cDNA clones --- p.38 / Chapter 3.1.2 --- Sequencing results of the human liver cancer cDNA clones --- p.41 / Chapter 3.1.3 --- The accuracy of the automated sequencing technique --- p.41 / Chapter 3.1.4 --- Catalogue of normal counterpart ESTs --- p.45 / Chapter 3.1.5 --- Catalogue of liver cancer ESTs --- p.47 / Chapter 3.2 --- Identification of genes differentially expressed in HCC using in silico method --- p.115 / Chapter 3.3 --- Sequence analysis of KIAA0022 --- p.121 / Chapter 3.3.1 --- Structural analysis of KIAA0022 --- p.121 / Chapter 3.3.2 --- Homology alignment --- p.122 / Chapter 3.4 --- Tissue distribution and expression profile of KIAA0022 using Northern blot analysis --- p.132 / Chapter 3.5 --- Subcellular localization of the KIAA0022 tagging by green fluorescence protein --- p.134 / Chapter 3.6 --- Yeast two-hybrid screening assay --- p.136 / Chapter Chapter 4 --- Discussion / Chapter 4.1 --- Large-scale partial cDNA sequencing --- p.138 / Chapter 4.2 --- Characterization of ESTs --- p.139 / Chapter 4.3 --- Identification of genes differentially expressed in liver cancer using Poisson probability --- p.143 / Chapter 4.4 --- Characterization of KIAA0022 --- p.154 / Reference --- p.157 / Appendix --- p.170
139

Virus de l’Hépatite B et transcription cellulaire : impact de la protéine HBx et de ses interactions avec les ARNs non-codants / Hepatits B virus and host cell transcription : impact of the HBx protein and its interaction with non coding RNA

Floriot, Océane 18 December 2018 (has links)
Le virus de l'hépatite B (VHB) reste un problème de santé majeur dans le monde malgré la disponibilité du vaccin. Le VHB n’est pas éradiqué par les thérapies actuelles et 240 millions de personnes infectées chroniquement restent à risque de développer une cirrhose du foie et un carcinome hépatocellulaire (CHC).Le VHB est un petit virus hépatotrope doté d'un génome à ADN double brin partiel (ADNrc). Après infection l'ADNrc est converti en ADN épisomal (ADNccc) qui est ensuite organisé en minichromosome viral, qui est le modèle pour la transcription et qui initie la réplication. La protéine de l'hépatite B x (HBx) est recrutée sur l'ADNccc pour initier et maintenir la transcription de l'ADN ccc. HBx cible aussi directement des gènes cellulaires impliqué dans le développement du CHC.Nous avons utilisé une approche ChIP-Seq pour identifier toutes les cibles génomiques de HBx dans les cellules qui répliquent le VHB. Les cibles HBx sont à la fois des gènes codant les protéines et des ARNnc (75 miARN et 34 lncRNA). Nous avons montré que HBx réprimait un sous-ensemble de miARNs qui réguleraient négativement la réplication virale (ex : miR-24) et des miARNs impliqués dans le développement du CHC (ex : miR-21). Parmi les lncARNs ciblés pour HBx, nous avons étudié DLEU2, qui est fortement surexprimé dans l’infection par le VHB et le CHC. Nous avons en outre montré que DLEU2 lie à la fois HBx et l’histone méthyltransférase Ezh2, la sous-unité catalytique du complexe répressif PRC2. L'interaction avec DLEU2 et HBx relie les fonctions Ezh2/PRC2 conduisant à l'activation constitutive d'un sous-ensemble de gènes cibles d'Ezh2 qui sont normalement conservés dans un état réprimé. Nous avons également montré que l’interaction de HBx avec DLEU2 se produisait sur le minichromosome de l’ADNccc où elle stimulait la transcription/réplication du virus. Enfin, nous avons caractérisé par ATAC-Seq les changements d'accessibilité de la chromatine imposés par HBV dans les hépatocytes humains primaires / Hepatitis B virus (HBV) remains a major health problem worldwide despite the availability of the vaccine. No cure is available for the 240 million peoples chronically infected with HBV that are at risk to develop liver cirrhosis and hepatocellular carcinoma (HCC). Viral suppression, achieved by long term treatment with nucleotides analogues (NUCs), impacts on liver fibrosis and prevents liver decompensation but HCC risk is not reduced in the first 5 years of treatment. HBV is a small hepatotropic virus with a partially double strand DNA (rcDNA) genome. After hepatocyte infection the rcDNA is converted into the cccDNA episome that is then organized into a viral minichromosome that is the template for all viral transcripts and initiates replication. The hepatitis B x protein (HBx) is recruited on the cccDNA and is required to launch and maintain cccDNA transcription. HBx has also been shown to directly target cellular genes and this has been related to HCC development.We used a ChIP-Seq approach to determine the full repertoire of HBx genomic targets in HBV replicating cells. HBx targets include both protein coding genes and ncRNA (75 miRNAs and 34 lncRNAs). We showed that HBx represses a subset of miRNAs that would negatively regulate viral replication (i.e. miR-24) and miRNAs involved in HCC development (i.e. miR-21). Among the HBx targeted lncRNAs we focused DLEU2, which is strongly upregulated in HBV infection and HCC. We further showed that DLEU2 binds both HBx the Ezh2 histone methyltransferase, the catalytic subunit of the repressive PRC2 complex. The interaction with DLEU2 and HBx re-wires Ezh2/PRC2 functions leading to the constitutive activation of a subset of Ezh2 target genes that are normally kept in a repressed state. We also showed that HBx interaction with DLEU2 occurs on the cccDNA minichromosome where it boosts HBV transcription/replication. Finally, we characterized by ATAC-Seq HBV imposed changes of chromatin accessibility in primary human hepatocytes
140

Hepatitis B virus, syphilis, and HIV seroprevalence in pregnant women and their male partners from six indigenous populations of the Peruvian Amazon Basin, 2007–2008

Ormaeche, Melvy, Whittembury, Alvaro, Pun, Mónica, Suárez Ognio, Luis 17 July 2014 (has links)
mormaeche@dge.gob.pe / Objective: To assess the seroprevalence of hepatitis B virus (HBV), syphilis, and HIV and associated risk factors in pregnant women and their male partners from six indigenous populations of the Peruvian Amazon Basin. Methods: A cross-sectional study was performed in six indigenous populations from the Peruvian Amazon Basin. Blood samples were obtained and tested for HBV (antibodies to the hepatitis B core antigen (anti-HBc) and hepatitis B surface antigen (HBsAg)), for syphilis (rapid plasma reagin and microhemagglutination assay for Treponema pallidum antibodies), and for HIV (ELISA and indirect immunofluorescence test). A survey was also performed to identify associated risk factors. Results: One thousand two hundred and fifty-one pregnant women and 778 male partners were enrolled in the study. The seroprevalence of anti-HBc in pregnant women was 42.06% (95% confidence interval (CI) 39.28–44.85%) and in their male partners was 54.09% (95% CI 50.32–57.86%). The seroprevalence of HBsAg in pregnant women was 2.11% (95% CI 0.78–3.44%) and in their male partners was 3.98% (95% CI 1.87–6.08%). The seroprevalence of syphilis in pregnant women was 1.60% (95% CI 0.86–2.33%) and in their male partners was 2.44% (95% CI 1.22–3.66%). HIV seroprevalence in pregnant women was 0.16% (95% CI 0.02–0.58%) and in their male partners was 0.29% (95% CI 0.04–1.03%). Sexual risk factors were strongly related to blood markers of syphilis and HBV. Conclusions: Hepatitis B was found to be hyperendemic and strongly related to sexual factors, suggesting an important sexual component in the transmission of the disease in the populations studied. Syphilis was found to have an endemicity in pregnant women above the national level and this may be indicative of high mother-to-child transmission. HIV has started to show its presence in indigenous populations of the Amazon Basin and the results suggest the epidemic is concentrated. / Revisión por pares

Page generated in 0.0667 seconds