• Title/Summary/Keyword: SiRNA

Search Result 645, Processing Time 0.025 seconds

Gene Expression of the Kidney Mutant in Bombyx mori - Biochemical Analysis of Yolk Protein and Template Activity of RNA in Unfertilized Egg. (가잠 견장형란에 있어서 유전자의 발현기구 - 특히 미수정란을 중심으로 -)

  • No, Si-Gap;Son, Hae-Ryong
    • Journal of Sericultural and Entomological Science
    • /
    • v.28 no.2
    • /
    • pp.15-20
    • /
    • 1986
  • This study was carried out to investigate the elucidation of gene expression in embryo formation of the Kidney mutant, especially yolk proteins in unfertilized eggs and template activity of m-RNA extracted from them. The results were summarized as follow ; There was no recognized qualitative difference in yolk proteins of unferilized eggs between the Kidney mutant and normal. There was not any difference, between Kidney mutant and normal in the molecular species of m-RNA derived from maternal origin with the template activity in vitro.

  • PDF

RNA Interference as a Plausible Anticancer Therapeutic Tool

  • Ramachandran, Puthucode Venkatakrishnan;Ignacimuthu, Savarimuthu
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.13 no.6
    • /
    • pp.2445-2452
    • /
    • 2012
  • RNA interference has created a breakthrough in gene silencing technology and there is now much debate on the successful usage of RNAi based methods in treating a number of debilitating diseases. Cancer is often regarded as a result of mutations in genomic DNA resulting in faulty gene expression. The occurrence of cancer can also be influenced by epigenetic irregularities in the chromatin structure which leads to alterations and mutations in DNA resulting in cancer cell formation. A number of therapeutic approaches have been put forth to treat cancer. Anti cancer therapy often involves chemotherapy targeting all the cells in common, whereby both cancer cells as well as normal cells get affected. Hence RNAi technology has potential to be a better therapeutic agent as it is possible to deactivate molecular targets like specific mutant genes. This review highlights the successful use of RNAi inducers against different types of cancer, thereby paving the way for specific therapeutic medicines.

Kaurenoic acid, a natural substance from traditional herbal medicine, alleviates palmitate induced hepatic lipid accumulation via Nrf2 activation

  • Han, Changwoo
    • The Journal of Korean Medicine
    • /
    • v.41 no.4
    • /
    • pp.64-71
    • /
    • 2020
  • Objectives: This study was done to look into whether Nrf2 take some role in the anti-lipogenic effect of kaurenoic acid in a nonalcoholic fatty liver disease (NAFLD) cellular model. Materials and Methods: We measured the effect of kaurenoic acid on intracellular steatosis and Nrf2 activation. Next, the effect of kaurenoic acid on SREBP-1c and some lipogenic genes in palmitate treated HepG2 cells with or without Nrf2 silencing. Results: The increased SREBP-1c expression was significantly decreased by concomitant kaurenoic acid treatment in non-targeting negative control siRNA transfected HepG2 cells. However, kaurenoic acid did not significantly inhibited increased SREBP-1c level in Nrf2 specific siRNA transfected HepG2 cells Conclusions: Kaurenoic acid has a potential to activate Nrf2, which may suppress SREBP-1c mediated intracellular steatosis in HepG2 cells.

RNA Interference in Infectious Tropical Diseases

  • Kang, Seok-Young;Hong, Young-S.
    • Parasites, Hosts and Diseases
    • /
    • v.46 no.1
    • /
    • pp.1-15
    • /
    • 2008
  • Introduction of double-stranded RNA (dsRNA) into some cells or organisms results in degradation of its homologous mRNA, a process called RNA interference (RNAi). The dsRNAs are processed into short interfering RNAs (siRNAs) that subsequently bind to the RNA-induced silencing complex (RISC), causing degradation of target mRNAs. Because of this sequence-specific ability to silence target genes, RNAi has been extensively used to study gene functions and has the potential to control disease pathogens or vectors. With this promise of RNAi to control pathogens and vectors, this paper reviews the current status of RNAi in protozoans, animal parasitic helminths and disease-transmitting vectors, such as insects. Many pathogens and vectors cause severe parasitic diseases in tropical regions and it is difficult to control once the host has been invaded. Intracellularly, RNAi can be highly effective in impeding parasitic development and proliferation within the host. To fully realize its potential as a means to control tropical diseases, appropriate delivery methods for RNAi should be developed, and possible off-target effects should be minimized for specific gene suppression. RNAi can also be utilized to reduce vector competence to interfere with disease transmission, as genes critical for pathogenesis of tropical diseases are knockdowned via RNAi.

Identification of the Most Accessible Sites to Ribozymes on the Hepatitis C Virus Internal Ribosome Entry Site

  • Ryu, Kyung-Ju;Lee, Seong-Wook
    • BMB Reports
    • /
    • v.36 no.6
    • /
    • pp.538-544
    • /
    • 2003
  • The hepatitis C virus (HCV) is a major causative agent of chronic hepatitis and hepatocellular carcinoma. The development of alternative antiviral therapies is warranted because current treatments for the HCV infection affect only a limited number of patients and lead to significant toxicities. The HCV genome is exclusively present in the RNA form; therefore, ribozyme strategies to target certain HCV sequences have been proposed as anti-HCV treatments. In this study, we determined which regions of the internal ribosome entry site (IRES) of HCV are accessible to ribozymes by employing an RNA mapping strategy that is based on a trans-splicing ribozyme library. We then discovered that the loop regions of the domain IIIb of HCV IRES appeared to be particularly accessible. Moreover, to verify if the target sites that were predicted to be accessible are truly the most accessible, we assessed the ribozyme activities by comparing not only the trans-splicing activities in vitro but also the trans-cleavage activities in cells of several ribozymes that targeted different sites. The ribozyme that could target the most accessible site identified by mapping studies was then the most active with high fidelity in cells as well as in vitro. These results demonstrate that the RNA mapping strategy represents an effective method to determine the accessible regions of target RNAs and have important implications for the development of various antiviral therapies which are based on RNA such as ribozyme, antisense, or siRNA.

Vinyl-Stilbene Inhibits Human Norovirus RNA Replication by Activating Heat-Shock Factor-1

  • Lee, Ahrim;Sung, Jieun;Harmalkar, Dipesh S.;Kang, Hyeseul;Lee, Hwayoung;Lee, Kyeong;Lee, Choongho
    • Biomolecules & Therapeutics
    • /
    • v.30 no.1
    • /
    • pp.64-71
    • /
    • 2022
  • Norovirus (NV) is the most common cause of viral gastroenteritis, with the potential to develop into a fatal disease in those who are immuno-compromised, and effective vaccines and treatments are still non-existent. In this study, we aimed to elucidate the molecular mechanism of the previously identified NV replication inhibitor utilizing a vinyl-stilbene backbone, AC-1858. First, we confirmed the inhibition of the NV RNA replication by a structural analog of AC-1858, AC-2288 with its exclusive cytoplasmic sub-cellular localization. We further validated the induction of one specific host factor, the phosphorylated form of heat shock factor (HSF)-1, and its increased nuclear localization by AC-1858 treatment. Finally, we verified the positive and negative impact of the siRNA-mediated downregulation and lentivirus-mediated overexpression of HSF-1 on NV RNA replication. In conclusion, these data suggest the restrictive role of the host factor HSF-1 in overall viral RNA genome replication during the NV life cycle.

Study on the Structure of 5S rRNA from Pseudomonas alcaligenes by Metallotripeptides (금속펩타이드를 이용한 Pseudomonas alcaligenes의 5S rRNA의 구조 연구)

  • Kim, Hee-Joung;Kim, Si-Wouk;Koh, Moon-Joo
    • Journal of the Korean Chemical Society
    • /
    • v.46 no.1
    • /
    • pp.46-51
    • /
    • 2002
  • The recognition and cleavage of 5S rRNA from P. alcaligenes by metallopeptides to the form $Ni(II){\cdot}Gly$-Gly-His(Arg)COOH and $Cu(II){\cdot}Gly$-Gly-His(Arg)COOH were investigated. The results of RNA cleavage analyses suggest that metallopeptides selectively target the unpaired or unstably paired bases of stem-loop structure of 5S rRNA. The selectivity of metallopeptides was little affected by the species of metal ion, Ni(II) or Cu(II). When the result of cleavage by metallopeptides was compared with that of by metal complexes M(II)CR, the recognition by metallopeptides was more selective and structure specific. The cleavage data by metallopeptides and other metal complexes were used to probe the secondary structure of 5S rRNA from P. alcaligenes.

Chitosan and Its Derivatives for Gene Delivery

  • Lee, Knen-Yong
    • Macromolecular Research
    • /
    • v.15 no.3
    • /
    • pp.195-201
    • /
    • 2007
  • Non-viral vectors, including lipid- or polymer-based systems, have attracted much attention to date as a gene delivery vehicle, due to safety issues with viral vectors. Chitosan, a naturally existing cationic polymer, has shown great potential as a gene delivery carrier, as it has low immunogenicity and toxicity, excellent transcellular transport ability, and is relatively easy to chemically modify. This review summarizes and discusses the general features of chitosan and its applications as a delivery carrier of DNA and RNA.

Targeted Silencing of Inhibitors of Apoptosis Proteins with siRNAs: A Potential Anti-cancer Strategy for Hepatocellular Carcinoma

  • Li, Gang;Chang, Hong;Zhai, Yun-Peng;Xu, Wei
    • Asian Pacific Journal of Cancer Prevention
    • /
    • v.14 no.9
    • /
    • pp.4943-4952
    • /
    • 2013
  • Hepatocellular carcinoma (HCC) is one of the most common malignancies, with a very poor prognosis. Despite significant improvements in diagnosis and treatment in recent years, the long-term therapeutic efficacy is poor, partially due to tumor metastasis, tecurrence, and resistance to chemo-or radio-therapy. Recently, it was found that a major feature of tumors is a combination of unrestrained cell proliferation and impaired apoptosis. There are now 8 recogized members of the IAP-family: NAIP, c-IAP1, c-IAP2, XIAP, Survivin, Bruce, Livin and ILP-2. There proteins all contribute to ingibition of apoptosis, and provide new potential avenues of cancer treatment. As a powerful tool to suppress gene expression in mammalian cells, RNAi species for inhibiting IAP genes cab be directed against cancers. This review will provide a brief introduction to recent developments of the application IAP-siRNA in tumor studies, with the aim of inspiring future treatment of HCC.

Regulatory Effect of 25-hydroxyvitamin $D_3$ on Nitric Oxide Production in Activated Microglia

  • Hur, Jinyoung;Lee, Pyeongjae;Kim, Mi Jung;Cho, Young-Wuk
    • The Korean Journal of Physiology and Pharmacology
    • /
    • v.18 no.5
    • /
    • pp.397-402
    • /
    • 2014
  • Microglia are activated by inflammatory and pathophysiological stimuli in neurodegenerative diseases, and activated microglia induce neuronal damage by releasing cytotoxic factors like nitric oxide (NO). Activated microglia synthesize a significant amount of vitamin $D_3$ in the rat brain, and vitamin $D_3$ has an inhibitory effect on activated microglia. To investigate the possible role of vitamin $D_3$ as a negative regulator of activated microglia, we examined the effect of 25-hydroxyvitamin $D_3$ on NO production of lipopolysaccharide (LPS)-stimulated microglia. Treatment with LPS increased the production of NO in primary cultured and BV2 microglial cells. Treatment with 25-hydroxyvitamin $D_3$ inhibited the generation of NO in LPS-activated primary microglia and BV2 cells. In addition to NO production, expression of 1-${\alpha}$-hydroxylase and the vitamin D receptor (VDR) was also upregulated in LPS-stimulated primary and BV2 microglia. When BV2 cells were transfected with 1-${\alpha}$-hydroxylase siRNA or VDR siRNA, the inhibitory effect of 25-hydroxyvitamin $D_3$ on activated BV2 cells was suppressed. 25-Hydroxyvitamin $D_3$ also inhibited the increased phosphorylation of p38 seen in LPS-activated BV2 cells, and this inhibition was blocked by VDR siRNA. The present study shows that 25-hydroxyvitamin $D_3$ inhibits NO production in LPS-activated microglia through the mediation of LPS-induced 1-${\alpha}$-hydroxylase. This study also shows that the inhibitory effect of 25-hydroxyvitamin $D_3$ on NO production might be exerted by inhibiting LPS-induced phosphorylation of p38 through the mediation of VDR signaling. These results suggest that vitamin $D_3$ might have an important role in the negative regulation of microglial activation.