• Proceedings of the Korean Society of Applied Pharmacology
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• 1994.04a
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• pp.178-178
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• 1994

Hepatitis B Virus (HBV) is a DNA virus with a 3.2kb partially double-stranded genome. The life cycle of the virus involves a reverse transcription of the greater than genome length 3.5kb mRNA. This pegenomic RNA contains all the genetic information encoded by the virus and functions as an intermediate in viral replication. Tumor suppressor p53 has previously been shown to interact with the X-gene product of the HBV, which led us to hypothesize that p53 may act as a negative regulator of HBV replication and the role of the X-gene product is to overcome the p53-mediated restriction. As a first step to prove the above hypothesis, we tested whether p53 represses the propagation of HBV in in vitro replication system. By transient cotransfection of the plasmid containing a complete copy of the HBV genome and/or the plasmid encoding p53, we found that the replication of HBV is specifically blocked by wild-type p53. The levels of HBV DNA, HBs Ag and HBc/e Ag secreted in cell culture media were dramatically reduced upon coexpresion of wild-type p53 but not by the coexpression of the mutants of p53 (G154V and R273L). Furthermore, levels of RNAs originated from HBV genome were repressed more than 10 fold by the cotransfection of the p53 encoding plasmid. These results clearly states that p53 is a nesative regulator of the HBV replication. Next, to addresss the mechanism by which p53 represses the HBV replication, we performed the transient transfection experiments employing the pregenomic/core promoter-CAT(Chloramphenicol Acetyl Transferase) construct as a reporter. Cotransfection of wild-type p53 but not the mutant p53 expression plasmids repressed the CAT activity more than 8 fold. Integrating the above results, we propose that p53 represses the replication of HBV specifically by the down-regulation of the pregenomic/core promoter, which results in the reduced DNA synthesis of HBV. Currently, the mechanism by which HBV overcomes the observed p53-mediated restriction of replication is tinder investigation.

• BMB Reports
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• v.48 no.2
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• pp.115-120
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• 2015

Tight junction protein 1 (TJP1), a component of tight junction, has been reported to play a role in protein networks as an adaptor protein, and TJP1 expression is altered during tumor development. Here, we found that TJP1 expression was increased at the RNA and protein levels in TGF-${\beta}$-stimulated lung cancer cells, A549. SB431542, a type-I TGF-${\beta}$ receptor inhibitor, as well as SB203580, a p38 kinase inhibitor, significantly abrogated the effect of TGF-${\beta}$ on TJP1 expression. Diphenyleneiodonium, an NADPH oxidase inhibitor, also attenuated TJP1 expression in response to TGF-${\beta}$ in lung cancer cells. When TJP1 expression was reduced by shRNA lentiviral particles in A549 cells (A549-sh TJP1), wound healing was much lower than in cells infected with control viral particles. Taken together, these data suggest that TGF-${\beta}$ enhances TJP1 expression, which may play a role beyond structural support in tight junctions during cancer development.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.300.2-301
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• 2002

HCV is transmitted via various plasma-derived medicinal products. The transmission of HCV could. however, be prevented by screening plasma pools with NAT and validating HCV viral clearance during the manufacturing of plasma derivatives, Although various screening methods including commercial kits are available. it is yet to develop an analytical method to detect HCV in both plasma and plasma derivatives. The objective of this study was to develop a reliable in house method for reliable for the HCV RNA detection from plasma and plasma derivatives. (omitted)

• Journal of Ginseng Research
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• v.28 no.4
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• pp.173-182
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• 2004

We have shown that long-term intake of Korean red ginseng (KRG) delays disease progression in HIV-I infected patients. In the present study to investigate whether this slow progression was associated with protective human leukocyte antigen (HLA) alleles as well as with KRG-intake, we have performed clinical analysis of 31 HIV-1 infected patients who have been living for more than 10 years without any antiretroviral therapy. Average amount of KRG-intake over $130\;{\pm}16$ months was $4,797\;{\pm}4,921\;g$ and the annual decrease in CD4 T cell (AD) was $30\;{\pm}29{\mu}L$. We observed significant correlations among amount of KRG-intake, AD(r=-0.53, P < 0.01), and plasma HIV-1 RNA copy (r=-0.35, P < 0.05), along with a significant correlation between KRG-intake and HLA score AD(r=-0.49, P < 0.01), whereas there was no significant correlation between HLA score and AD or viral load. When the 31 patients were divided into 2 groups based on the amount of KRG-intake, the $AD(14/{\mu}L)$ in the 16 patients who had taken higher amounts of KRG was significantly less than that $(49/{\mu}L)$ in the 15 patients with a little or no KRG-intake (P < 0.01). These data indicate that KRG-intake sig­nificantly slows CD4 T cell depletion in HIV-1 infected patients.

• Bulletin of the Korean Chemical Society
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• v.34 no.3
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• pp.735-742
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• 2013

Peptide nucleic acids (PNAs) that bind to complementary nucleic acid sequences with extraordinarily high affinity and sequence specificity can be used as antisense oligonucleotides against microRNAs, namely antagomir PNAs. However, methods for efficient cellular delivery must be developed for effective use of PNAs as therapeutic agents. Here, we demonstrate that antagomir PNAs can be delivered to hepatic cells by complementary DNA oligonucleotide and cationic liposomes containing galactosylated ceramide and a novel cationic lipid, DMKE (O,O'-dimyristyl-N-lysyl glutamate), through glycoprotein-mediated endocytosis. An antagomir PNA was designed to target miR-122, which is required for translation of the hepatitis C virus (HCV) genome in hepatocytes, and was hybridized to a DNA oligonucleotide for complexation with cationic liposome. The PNA-DNA hybrid molecules were efficiently internalized into hepatic cells by complexing with the galactosylated cationic liposome in vitro. Galactosylation of liposome significantly enhanced both lipoplex cell binding and PNA delivery to the hepatic cells. After 4-h incubation with galactosylated lipoplexes, PNAs were efficiently delivered into hepatic cells and HCV genome translation was suppressed more than 70% through sequestration of miR-122 in cytoplasm. PNAs were readily released from the PNA-DNA hybrid in the low pH environment of the endosome. The present study indicates that transfection of PNA-DNA hybrid molecules using galactosylated cationic liposomes can be used as an efficient non-viral carrier for antagomir PNAs targeted to hepatocytes.

• The Plant Pathology Journal
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• v.19 no.3
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• pp.171-176
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• 2003

The complete nucleotide sequences of the genomic RNAs of Soybean mosaic virus strains GS (SMV-G5) and G7H (SMV-G7H) were determined and compared with sequences of other SMV strains. Each viral RNA was determined to be 9588 nucleotides in length excluding the poly (A) tail and contained an open reading frame to encode a polyprotein subsequently processed into up to ten proteins by proteolytic cleavage. Com-parison of the amino acid sequences with those of other SMV strains showed high percentage of amino acid sequence homology with the same genome organization. The nucleotide and the deduced amino acid sequences between SMV-G5 and SMV-G7H were greater than 99% identity. When compared with those of other SMV strains in a phylogenetic analysis of the nucleotide and deduced amino acid sequences, they formed a distinct virus clade showing over 97％ amino acid identity, but were more distantly related to the other potyvirus (44.1-69.6% identity). Interestingly, SMV G7H strain caused a severe mosaic or necrosis symptom in soybean cultivars including Jinpum-1, Jinpum-2, and Sodam, whereas, no symptom was observed in SMV-G5 inoculation. Complete nucleotide sequences of these strains will give clues for determining symptom determinant(s) in future research.

• Clinical and Experimental Pediatrics
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• v.57 no.3
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• pp.117-124
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• 2014

Purpose: Administration of antiretroviral drugs to mothers and infants significantly decreases mother-to-child human immunodeficiency virus (HIV) transmission; cesarean sections and discouraging breastfeeding further decreases this risk. The present study confirmed the HIV status of babies born to mothers infected with HIV and describes the characteristics of babies and mothers who received preventive treatment. Methods: This study retrospectively analyzed medical records of nine infants and their mothers positive for HIV who gave birth at Korea University Ansan Hospital, between June 1, 2003, and May 31, 2013. Maternal parameters, including HIV diagnosis date, CD4+ count, and HIV ribonucleic acid (RNA) copy number, were analyzed. Infant growth and development, HIV RNA copy number, and HIV antigen/antibody test results were analyzed. Results: Eight HIV-positive mothers delivered nine babies; all the infants received antiretroviral therapy. Three (37.5%) and five mothers (62.5%) were administered single- and multidrug therapy, respectively. Intravenous zidovudine was administered to four infants (50%) at birth. Breastfeeding was discouraged for all the infants. All the infants were negative for HIV, although two were lost to follow-up. Third trimester maternal viral copy numbers were less than 1,000 copies/mL with a median CD4+ count of $325{\mu}L$ ($92-729{\mu}L$). Among the nine infants, two were preterm (22.2%) and three had low birth weights (33.3%). Conclusion: This study concludes that prophylactic antiretroviral therapy, scheduled cesarean section, and prohibition of breastfeeding considerably decrease mother-to-child HIV transmission. Because the number of infants infected via mother-to-child transmission may be increasing, studies in additional regions using more variables are necessary.

• The Plant Pathology Journal
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• v.29 no.3
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• pp.274-284
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• 2013

The incidence of Broad bean wilt virus 2 (BBWV2) on red pepper was investigated using the samples obtained from 24 areas of 8 provinces in Korea. Two hundred and five samples (79%) out of 260 collected samples were found to be infected with BBWV2. While the single infection rate of BBWV2 was 21.5%, the co-infection rate of BBWV2 with Cucumber mosaic virus, Pepper mottle virus, Pepper mild mottle virus and/or Potato virus Y was 78.5%. To characterize the genetic diversity of BBWV2 Korean isolates, 7 isolates were fully sequenced and analyzed. Phylogenetic analyses revealed that BBWV2 isolates could be divided largely into two groups as Group I and Group II. Based on the partial sequence analyses, 153 selected BBWV2 isolates were subgrouped into GS-I (21.6%), GS-II (3.9%) and GS-III (56.9%). BBWV2 GS-III, which was predominant in Korea, appears to be a new combination between Group I RNA-1 and Group II RNA-2. Viral disease incidence of BBWV2 on red pepper was under 2% before 2004. However, the incidence was increased abruptly to 41.3% in 2005, 58.2% in 2006 and 79% in 2007. These rapid increases might be related with the emergence of new combinations between BBWV2 groups.

• Journal of fish pathology
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• v.9 no.2
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• pp.177-183
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• 1996

A new RNA virus isolated from abnormally swimming behavior has caused mortalities in salmonid fish (Oh et al., 1995 a), A reverse transcriptase (RTase) activity of the virus was determined by using poly r(A) : oligo d(T) as templete : primer. This RTase activity was associated with virus particles of buoyant density of 1.16 g/ml. The virus particles in sucrose fractions were enveloped and were about 85 nm diameter with central electron-dense core. The brain and kidney samples of artificially infected fish showed RTase activity. Virus particle associated proteins about 120, 80, 65, 61, 48, 42, 35, 30, 25, 19, and 15 kDa were observed when examined by polyacrylamide gel electrophoresis analysis. This study showed the presence of a new retrovirus in salmonid fish, which tentatively called RVS (Retrovirus of salmonid).

• Journal of Pharmaceutical Investigation
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• v.40 no.6
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• pp.357-362
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• 2010

To enhance therapeutic effects of insulin-sensitizing adipokine, ADN gene and potent agonists, rosiglitazone for the $PPAR{\gamma}$, cationic liposomes as non-viral vectors were formulated. The particle size and zeta potential of drug loaded and unloaded cationic liposomes were investigated. The complex formation between cationic liposomes and negatively charged plasmid DNA was confirmed and the protection from DNase was observed. In vitro transfection was investigated in HepG2, HeLa, and HEK293 cells by mRNA expression of ADN. Encapsulation efficacy of rosiglitazone-loaded liposomes was determined by UV detection. Particle sizes of cationic liposomes were in the range of 110-170 nm and those of rosiglitazone-loaded cationic liposomes were in the range of 130-180 nm, respectively. Gel retardation of complexes indicated that the complex was formed at weight ratios of cationic lipid to plasmid DNA higher than 20:1. Both complexes protected plasmid DNA from DNase either drug free or drug loading. Encapsulation efficiency of rosiglitazone-loaded emulsion was increased by drug dose. The mRNA expression levels of ADN were dose-dependently increased in cells transfected with plasmid DNA. Therefore, cationic liposomes could be potential co-delivery system for drug and gene.