more information
Search within Results:

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author (up) Chen, X.; Qian, Y.; Yan, F.; Tu, J.; Yang, X.; Xing, Y.; Chen, Z. file  url
openurl 
  Title 5'-triphosphate-siRNA activates RIG-I-dependent type I interferon production and enhances inhibition of hepatitis B virus replication in HepG2.2.15 cells Type Journal Article
  Year 2013 Publication European Journal of Pharmacology Abbreviated Journal Eur J Pharmacol  
  Volume 721 Issue 1-3 Pages 86-95  
  Keywords Base Sequence; DEAD-box RNA Helicases/*metabolism; DNA Replication/genetics; Hep G2 Cells; Hepatitis B Antigens/genetics/metabolism; Hepatitis B virus/*genetics/*physiology; Humans; Immunity, Innate; Interferon Type I/*biosynthesis/genetics; Polyphosphates/*chemistry; RNA Interference; RNA, Messenger/genetics; RNA, Small Interfering/chemistry/*genetics; Transcription, Genetic/genetics; Virus Replication/*genetics; 3-(4,5)-dimethylthiahiazol-2-y1)-2,5-diphenytetrazolium bromide; 3p-siRNA; 5â²-Triphosphated siRNA; 5â²-triphosphated siRNA; BF-siRNA; Ciap; Elisa; Hbv; HBV e antigen; HBV s antigen; HBeAg; HBsAg; Hcc; HepG2.2.15 cells; Hepatitis B virus; Ifn; Ifnî±/β; Mtt; NC-siRNA; Od; Prr; Rig-I; RNA interference; RNAi; Rt-Pcr; Tlr; bifunctional siRNA; calf intestine alkaline phosphatase; double strand DNA; double strand RNA; dsDNA; dsRNA; enzyme-linked immunosorbent assay; hepatitis B virus; hepatocellular carcinoma; interferon; negative control siRNA; optical density; pathogen-recognition receptor; retinoic acid-inducible gene I; reverse transcription PCR; siRNA; single strand RNA; small interfering RNA; ssRNA; toll-like receptor  
  Abstract Hepatitis B virus (HBV) infection often results in acute or chronic viral hepatitis and other liver diseases including cirrhosis and hepatocellular carcinoma. Current therapies for HBV usually have severe side effects and can cause development of drug-resistant mutants. An alternative and safe immunotherapeutic approach for HBV infection is urgently needed for effective anti-HBV therapy. In this study, we propose a new strategy for anti-HBV therapy that activates type-I interferon (IFN) antiviral innate immunity through stimulating pattern-recognition receptors with RNA interference (RNAi) using a 5'-end triphosphate-modified small interfering RNA (3p-siRNA). We designed and generated a 3p-siRNA targeting overlapping region of S gene and P gene of the HBV genome at the 5'-end of pregenomic HBV RNA. Our results demonstrated that 3p-siRNA induced a RIG-I-dependent antiviral type-I IFN response when transfected into HepG2.2.15 cells that support HBV replication. The 3p-siRNA significantly inhibited HBsAg and HBeAg secretion from HepG2.2.15 cells in a RIG-I-dependent manner, and the antiviral effect of 3p-siRNA was superior to that of siRNA. Furthermore, 3p-siRNA had more pronounced inhibition effects on the replication of HBV DNA and the transcription of mRNA than that of siRNA. Finally, 3p-siRNA displayed antiviral activity with long-term suppression of HBV replication. In conclusion, our findings suggest that 3p-siRNA could act as a powerful bifunctional antiviral molecule with potential for developing a promising therapeutic against chronic HBV infection.  
  Call Number Serial 1013  
Permanent link to this record
 

 
Author (up) Marimani, M.D.; Ely, A.; Buff, M.C.R.; Bernhardt, S.; Engels, J.W.; Arbuthnot, P. file  url
openurl 
  Title Inhibition of hepatitis B virus replication in cultured cells and in vivo using 2'-O-guanidinopropyl modified siRNAs Type Journal Article
  Year 2013 Publication Bioorganic & Medicinal Chemistry Abbreviated Journal Bioorg Med Chem  
  Volume 21 Issue 20 Pages 6145-6155  
  Keywords Animals; Cell Line, Tumor; Cells, Cultured; Guanidines/chemistry/*pharmacology; Hepatitis B virus/drug effects/genetics/*physiology; Humans; Mice; Organophosphorus Compounds/chemistry/pharmacology; RNA Interference; RNA, Small Interfering/genetics/*pharmacology; Transfection; Virus Replication/*drug effects/genetics; 2â²-O-Guanidinopropyl; Hbv; RNAi; siRNAs  
  Abstract Silencing hepatitis B virus (HBV) gene expression with exogenous activators of the RNA interference (RNAi) pathway has shown promise as a new mode of treating infection with the virus. However, optimizing efficacy, specificity, pharmacokinetics and stability of RNAi activators remains a priority before clinical application of this promising therapeutic approach is realised. Chemical modification of synthetic short interfering RNAs (siRNAs) provides the means to address these goals. This study aimed to assess the benefits of incorporating nucleotides with 2'-O-guanidinopropyl (GP) modifications into siRNAs that target HBV. Single GP residues were incorporated at nucleotide positions from 2 to 21 of the antisense strand of a previously characterised effective antiHBV siRNA. When tested in cultured cells, siRNAs with GP moieties at selected positions improved silencing efficacy. Stability of chemically modified siRNAs in 80% serum was moderately improved and better silencing effects were observed without evidence for toxicity or induction of an interferon response. Moreover, partially complementary target sequences were less susceptible to silencing by siRNAs with GP residues located in the seed region. Hydrodynamic co-injection of siRNAs with a replication-competent HBV plasmid resulted in highly effective knock down of markers of viral replication in mice. Evidence for improved efficacy, reduced off target effects and good silencing in vivo indicate that GP-modifications of siRNAs may be used to enhance their therapeutic utility.  
  Call Number Serial 1014  
Permanent link to this record
 

 
Author (up) Thongthae, N.; Payungporn, S.; Poovorawan, Y.; T-Thienprasert, N.P. file  url
openurl 
  Title A rational study for identification of highly effective siRNAs against hepatitis B virus Type Journal Article
  Year 2014 Publication Experimental and Molecular Pathology Abbreviated Journal Exp Mol Pathol  
  Volume 97 Issue 1 Pages 120-127  
  Keywords 2',5'-Oligoadenylate Synthetase/genetics; Algorithms; Base Sequence; Gene Expression Regulation; Hep G2 Cells/virology; Hepatitis B virus/*genetics; Humans; Luciferases/genetics/metabolism; Molecular Sequence Data; NF-kappa B/genetics; Promoter Regions, Genetic; RNA, Small Interfering/chemistry/*genetics; Regulatory Sequences, Nucleic Acid; STAT1 Transcription Factor/genetics; Thermodynamics; Effective siRNAs; Hbv Pre; Hepatitis B virus; RNA interference; siRNA predicting program  
  Abstract RNA interference (RNAi) is a powerful gene knockdown technique used for study gene function. It also potentially provides effective agents for inhibiting infectious and genetic diseases. Most of RNAi studies employ a single siRNA designing program and then require large-scale screening experiments to identify functional siRNAs. In this study, we demonstrate that an assembly of results generated from different siRNA designing programs could provide clusters of predicting sites that aided selection of potent siRNAs. Based on the clusters, three siRNA target sites were selected on a conserved RNA region of hepatitis B virus (HBV), known as HBV post-transcriptional regulatory element (HBV PRE) at nucleotide positions 1317-1337, 1357-1377 and 1644-1664. All three chosen siRNAs driven by H1 promoter were highly effective and could drastically decrease expression of HBV transcripts (core, surface and X) and surface protein without induction of interferon response and cell cytotoxicity in liver cancer cell line (HepG2). Based on prediction of secondary structures, the silencing effects of siRNAs were less effective against a loop sequence of the mRNA target with hairpin structure. In summary, we demonstrate an effectual approach for identification of functional siRNAs. Moreover, highly potent siRNAs identified here may serve as novel agents for development of nucleic acid-based HBV therapy.  
  Call Number Serial 1012  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations: