• Bulletin of the Korean Chemical Society
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• v.26 no.12
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• pp.2033-2037
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• 2005

In vitro selection was used to isolate $Mg^{2+}$-dependent self-cleaving ribozymes with cis-cleavage activity from a pre-tRNA library having 40-mer random sequences attached to 5'-end of E. coli $tRNA^{Phe}$. After 8 rounds of SELEX (Systematic Evolution of Ligands by Exponential Enrichment), RNA molecules which can self-cleave at the high concentration of $Mg^{2+}$ were isolated. The selected ribozymes can carry out the self-cleavage reaction in the presence of 100 mM $Mg^{2+}$ but not in 10 mM $Mg^{2+}$. The cleavage sites of the ribozymes are located at +3 and +4 of $tRNA^{Phe}$, compared with +1 position of 5'-end cleavage site of pre-tRNA by RNase P. New RNA constructs deprived of its D stem-loop, anticodon stem-loop, variable loop and T stem-loop, respectively showed the cleavage specificity identical to a ribozyme having the intact tRNA structure. Also, the new ribozyme fused with both a ribozyme and $tRNA^{Leu}$ showed the cleavage activities at the various sites within its sequences, different from two sites of position +3 and +4 observed in the ribozyme with $tRNA^{Phe}$. Our results suggest that the selected ribozyme is not structural-specific for tRNA.

• Biomedical Science Letters
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• v.29 no.4
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• pp.231-241
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• 2023

Messenger RNA (mRNA)-based vaccines and treatments have recently emerged as a promising strategy. Naked mRNA presents various limitations for direct delivery. Therefore, in this paper, Lipid Nanoparticles (LNPs) were utilized for the delivery of mRNA. Lipid nanoparticle (LNP) mRNA systems are highly effective as vaccines, but their efficacy for pulmonary delivery has not yet been fully established. Additionally, research on effective delivery systems and administration methods for vaccines is required to resolve the stability and degradation issues associated with naked mRNA delivery. This study aimed to determine mRNA delivery efficiency via the inhalation of a lipid nanoparticle (LNP) formulation designed specifically for pulmonary delivery. To this purpose, we built a library of seven LNP configurations with different lipid molar and N/P ratios and evaluated their encapsulation efficiency using gel retardation assay. Among the tested LNPs, LNP1, LNP2-2, and LNP3-2 demonstrated high transfection efficiency in vitro based on FACS analyses luciferase assays, and intracellular accumulation tests. The mRNA delivery efficiencies of the selected LNPs after inhalation and intravenous injection were compared and evaluated. LNP2-2 showed the highest mRNA expression in healthy mouse lungs when aerosolized and was found to be non-toxic. These results indicate that LNP2-2 is a promising carrier for lung mRNA delivery via inhalation.

• The Korean Journal of Zoology
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• v.39 no.1
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• pp.115-121
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• 1996

To investigate gestational profiles in gene expression of placental lactogen I fpL4), PL-lI and Pit-1, RNA samples were extracted from the placentas of pregnant day 12 to 20 at 2 day intervals. Northern blots showed changes in gene expression of PL4, - 11 and Pit-i. Sizes of PL-l and -II mRNA were changed and amounts of PL-I, -H and Pit-1 mRNA increased during progress of gestation. To examine the effect of estrogen on the gene expression of PL-I, -Il and Pit-1, pregnant female rats were ovariectomized (OVX) and daily injected with estradiol (OVX + E). OVX markedly lowered the amount of PL4 and 41 mRNA, and shifted niRNA size from 1 kb to i 3 kb in PL-l mRNA and 0.6 kb to i kb in PL-ll mRNA, respectively. OVX had no effect on the mRNA size of Pit-1, but markedly attenuated Pit-1 mRNA level. Estrogen injection reversed the effect of OVX on the size-shift but not on the amount of PL4 and -Il mRNA. Replacement of E partially recovered OVX-induced inhibition of Pit-i mRNA level. Present results suggest that estrogen may play a pivotal role on the gene expression of PL-l and -Il such as alternative RNA splicing and/or polyadenylation, and Pit-1 may be involved in the gene expression of PL-l and 41 by estrogen.

• Microbiology and Biotechnology Letters
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• v.8 no.1
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• pp.9-18
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• 1980

During an extensive screening tests of yeasts for their RNA formation, it was found that Cryptococcus laurentii had especially high RNA content and high dry cell weight, when hydrolyzate of sliced and dried sweet potatoes was used as a carbon source. Growth conditions of this strain were examined, and the most desirable results were obtained at 48 hours of cultivation on a reciprocal shaker at 3$0^{\circ}C$ with initial pH 6.0. Under the above conditions, the RNA content and yield of dry cells were investigated using various media compositions. Ammonium sulfate 0.40%, peptone 0.6 ％, and yeast extract 0.4% were appeared to be favorable as a nitrogen sources. The optimum concentrations of K $H_2$P $O_4$, M $n^{++}$, C $O^{++}$ were 0.05 ％, 0.1 ％, and 0.001 ％, respectively. Ca-pantothenate, 400$\mu\textrm{g}$/$m\ell$, showed relatively favorable effects as a growth factor. The maximum RNA content obtained in this study was 16.8 ％ of the total dry cell weight.t.t.

• Microbiology and Biotechnology Letters
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• v.30 no.1
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• pp.68-72
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• 2002

To obtain a yeast mutant with high RNA content and high growth rate, Saccharomyces cerevisiae MTY62 was mutated with ethylmethane sulfonate. Among the selected mutants that were sensitive to the high concentration of KCl, M40-10 strain was finally selected due to its rapid cell growth and high RNA content in the tube and baffled-flask cultures. In the batch culture of M40-10 mutant, the maximum specific growth rate ($\mu_{max}$) of $0.38 h^{-1}$ , RNA concentration of 3210 mg-RNA/1, and RNA content of 183 mg-RNA/g-DCW were obtained, which were 23%, 15%, and 12% increased levels, respectively, compared to those of MTY62 parent strain. The intermittent fed-batch culture of M40-10 strain resulted in the maximum cell concentration of 35.6 g-DCW/1, RNA concentration of 5677 mg/1, and RNA content of 160 mg-RNA/g-DCW. Through the constant fed-batch culture, the maximum cell concentration of 46.4 g-DCW/1, RNA concentration of 6270 mg-RNA/1, and RNA content of 135 mg-RNA/g-DCW were obtained. At the 20 h culture time in the fed-batch cultures of M40-10 strain, the cell and RNA concentrations were increased by 30% and 10%, respectively, over the parent strain MTY62. In addition, it was also found that the accumulated RNA within the mutant cell was not degraded until the end of fed-batch cultivation, indicating that the M40-10 cell is a mutant with weak acidic RNase activity.y.

• Genomics & Informatics
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• v.19 no.2
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• pp.17.1-17.13
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• 2021

Breast cancer is one of the leading causes of cancer in women all over the world and accounts for ~25% of newly observed cancers in women. Epigenetic modifications influence differential expression of genes through non-coding RNA and play a crucial role in cancer regulation. In the present study, epigenetic regulation of gene expression by in-silico analysis of histone modifications using chromatin immunoprecipitation sequencing (ChIP-Seq) has been carried out. Histone modification data of H3K4me3 from one normal-like and four breast cancer cell lines were used to predict miRNA expression at the promoter level. Predicted miRNA promoters (based on ChIP-Seq) were used as a probe to identify gene targets. Five triple-negative breast cancer (TNBC)-specific miRNAs (miR153-1, miR4767, miR4487, miR6720, and miR-LET7I) were identified and corresponding 13 gene targets were predicted. Eight miRNA promoter peaks were predicted to be differentially expressed in at least three breast cancer cell lines (miR4512, miR6791, miR330, miR3180-3, miR6080, miR5787, miR6733, and miR3613). A total of 44 gene targets were identified based on the 3'-untranslated regions of downregulated mRNA genes that contain putative binding targets to these eight miRNAs. These include 17 and 15 genes in luminal-A type and TNBC respectively, that have been reported to be associated with breast cancer regulation. Of the remaining 12 genes, seven (A4GALT, C2ORF74, HRCT1, ZC4H2, ZNF512, ZNF655, and ZNF608) show similar relative expression profiles in large patient samples and other breast cancer cell lines thereby giving insight into predicted role of H3K4me3 mediated gene regulation via the miRNA-mRNA axis.

• Korean Journal of Microbiology
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• v.45 no.4
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• pp.300-305
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• 2009

We constructed the deletion mutants of fission yeast Schizosaccharomyces pombe spNab2 gene that is homologous to poly(A)-binding protein NAB2 in budding yeast Saccharomyces cerevisiae, which plays crucial roles in mRNA 3' end formation and mRNA export from nucleus into the cytoplasm. A null mutant in an $h^+$/ $h^+$ diploid strain was constructed by replacing the spNab2-coding region with an $ura4^+$ gene using one-step gene disruption method. Tetrad analysis showed that the spNab2 is not essential for vegetative growth and mRNA export. However, over-expression of spNab2 cause the severe growth defects and intensive accumulation of poly(A) RNA in the nucleus. Also, the spNab2-GFP fusions were localized mainly in the nucleus. These results suggest that spNab2 is also involved in mRNA export out of the nucleus.

• The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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• v.21 no.3
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• pp.69-81
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• 2008

Objective : The purpose of this study was find out the anti-allergic effects of SESHINGO on the allergic rhinitis. Methods : Cell viability was evaluated by the MTT assay. Cells were treated with the indicated concentration of SSG. $TNF-\alpha$ concentration was measured from cell supernatants using ELISA method. IL-4 concentration was measured from cell supernatants using ELISA method.$IFN-\gamma$ concentration was measured from cell supernatants using ELISA method. Total RNA was isolated, $TNF-\alpha$ and IL-4 mRNA expression was detected by RT-PCR analysis Total RNA was isolated, COX-1, COX-2 mRNA was analyzed by RT-PCR analysis. Results : 1. $\beta$-hexosaminidase release in RBL-2H3 cells were decresed by SESHINGO attentively. 2. Secreting ration of $TNF-\alpha$was restrained in RBL-2H3 cells by SESHINGO attentively. 3. Secreting ration of IL-4 was restrained in RBL-2H3 cells by SESHINGO attentively 4. Revelation of $TNF-\alpha$ mRNA was decresed in RBL-2H3 cells as concetration. 5. Revelation of.IL-4 mRNA was decresed in RBL-2H3 cells as concetration. 6. Revelation of COX-2 mRNA was decresed in RBL-2H3 cells. Conclusion : According to above results, to evaluate the effect of SSG on the anti-allergic effects.

• BMB Reports
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• v.50 no.4
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• pp.160-161
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• 2017

Proper maintenance of biological components is crucial for longevity and healthy aging. Although the role of homeostatic maintenance systems for DNA and protein in longevity is established, it remains largely unknown for RNA. In our recent work, we show that nonsense-mediated mRNA decay (NMD) promotes longevity in the roundworm C. elegans by enhancing RNA quality control. We find that the activity of NMD decreases during aging, raising the possibility that RNA quality declines in old animals. We then show that key components of NMD complex are required for prolonged lifespan in C. elegans. In addition, animals with reduced insulin/insulin-like growth factor-1 (IGF-1) signaling (IIS), a representative longevity model, display increased NMD activity. Thus, up-regulation of NMD appears to play crucial roles in longevity conferred by reduced IIS via enhancing mRNA quality control. As both IIS and NMD pathways are evolutionarily conserved, mammals including humans may be equipped with similar RNA quality control systems to achieve longevity.

• Genomics & Informatics
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• v.13 no.4
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• pp.94-101
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• 2015

tRNA-derived RNA fragments (tRFs) are an emerging class of non-coding RNAs (ncRNAs). A growing number of reports have shown that tRFs are not random degradation products but are functional ncRNAs made of specific tRNA cleavage. They play regulatory roles in several biological contexts such as cancer, innate immunity, stress responses, and neurological disorders. In this review, we summarize the biogenesis and functions of tRFs.