• 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.

• Journal of the Korea Convergence Society
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• v.12 no.8
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• pp.179-186
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• 2021

Among the Covid-19 vaccine platforms, mRNA-platform vaccines are summarized qualitatively in this paper. Manufacturing mRNA vaccines consist of serial processes; the preparation process of DNA template, the transcription of mRNA, nanoemulsion process, and the fill and finish unit combined with formulation stages. It is noticeable that major players are collaborated for producing mRNA vaccines. In particular, the nanoemulsion process is recognized to the key process requiring formulated lipid materials to protect modified mRNA until they arrive in intracellular cytosol. It is known that the nanoemulsion process adapts well-designed microfluidic devices. We expect that the nanoemulsion process will stimulate pharmaceutical industries to develop diverse applications.

• 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.33 no.2
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• pp.183-190
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• 1990

The present study exarnines the physiological alteradons in prolactin (PRL) messenger ribonucleic acid (mRNA) and serum PRL levels during the rat estrous cycle and the effed of naloxone, an endogenous oploid peptide receptor antagonist, on PRL gene expression during the rat estrous cycle. Adult female rats exhibiting at least two consecutive 4-day estrous cycles were used in this study. A single injection of naloxone (2mg/kg b.w.) or saline was given sc 30 mm prior to decapitation. Animals were sacrificed at 10:00 h of each stage of the estrous cycle, and at 2-h intervals from 10:00 h to 20:00 h during the proestrus. PRL mRNA and serum PRL levels were determined by a RNA-blot hybridization with the rat PRL cDNA probe and by a PRL radjoimmunoassay, respectively. PRL mRNA and serum PRL levels were not dramatically altered in the morning of each stage of diestrus I, II and proestrus, and naloxone failed to modify the two parameters. During estrus naloxone clearly suppressed serum PRL levels, but it was unable to modify PRL mRNA levels. A more detailed examination of the proestrus stage revealed that PRL mRNA and serum PRL levels were fluctuated as a function of time: PRL mRNA levels reached a maximum level at 12:00 h and gradually decreased until 18:00 h. PRL mRNA levels then rose at 20:00 h. No difference of PRL mRNA levels between the control and naloxone-treated groups was observed. Changes in serum PRL levek during proestrus were conversely related to changes in PRL mRNA: serum PRL levels were low from 10:00 h to 14:00 h, then increased and reached a maximum level at 16:00-18:00 h. Following then, serum PRL levels were decreased. Naloxone was effective in suppressing the charaderistic afternoon surge of PRL from 16:00 h to 20:00 h. These data clearly showed that alterations in PRL mRNA levels were conversely correlated with changes mn serum PRL levels on proestrus, indicating a differential regulation of PRL gene expression and secretion.

• Molecules and Cells
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• v.37 no.1
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• pp.1-8
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• 2014

Mammalian-cell messenger RNAs (mRNAs) are generated in the nucleus from precursor RNAs (pre-mRNAs, which often contain one or more introns) that are complexed with an array of incompletely inventoried proteins. During their biogenesis, pre-mRNAs and their derivative mRNAs are subject to extensive cis-modifications. These modifications promote the binding of distinct polypeptides that mediate a diverse array of functions needed for mRNA metabolism, including nuclear export, inspection by the nonsense-mediated mRNA decay (NMD) quality-control machinery, and synthesis of the encoded protein product. Ribonucleoprotein complex (RNP) remodeling through the loss and gain of protein constituents before and after pre-mRNA splicing, during mRNA export, and within the cytoplasm facilitates NMD, ensuring integrity of the transcriptome. Here we review the mRNP rearrangements that culminate in detection and elimination of faulty transcripts by mammalian-cell NMD.

• Molecules and Cells
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• v.46 no.11
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• pp.664-671
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• 2023

The proper maintenance of mRNA quality that is regulated by diverse surveillance pathways is essential for cellular homeostasis and is highly conserved among eukaryotes. Here, we review findings regarding the role of mRNA quality control in the aging and longevity of Caenorhabditis elegans, an outstanding model for aging research. We discuss the recently discovered functions of the proper regulation of nonsense-mediated mRNA decay, ribosome-associated quality control, and mRNA splicing in the aging of C. elegans. We describe how mRNA quality control contributes to longevity conferred by various regimens, including inhibition of insulin/insulin-like growth factor 1 (IGF-1) signaling, dietary restriction, and reduced mechanistic target of rapamycin signaling. This review provides valuable information regarding the relationship between the mRNA quality control and aging in C. elegans, which may lead to insights into healthy longevity in complex organisms, including humans.

• The korean journal of orthodontics
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• v.39 no.4
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• pp.248-256
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• 2009

Objective: The aim of this study was to determine if human PDL cells can produce osteoclastogenic mRNA and examine how compressive stress affects the expression of osteoclastogenic mRNA in human PDL cells. Methods: Human PDL cells were obtained from biscupids extracted for orthodontic treatment. The compressive force was adjusted by increasing the number of cover glasses. PDL cells were subjected to a compressive force of 0.5, 1.0, 2.0, 3.0 or $4.0\;g/cm^2$ for 0.5, 1.5, 6, 24 or 48 hours. Reverse transcription polymerase chain reaction (RT-PCR) analysis was performed to examine levels of M-CSF, IL-$1{\beta}$, RANKL, OPG mRNA expression. Results: Human PDL cells could produce M-CSF mRNA. Human PDL cells under compressive stress showed increased M-CSF, IL-$1{\beta}$ and RANKL mRNAs expression in a force (up to $2\;g/cm^2$) and time-dependent manner. However, OPG mRNA expression was constant regardless of the level and duration of stress. Conclusions: Continuous compressive stress induced the mRNA expression of osteoclastogenic cytokines including M-CSF, RANKL, IL-$1{\beta}$ in PDL cells. Together with an unchanged OPG mRNA level, these results suggest that compressive stress-induced osteoclastogenesis in vivo is partly controlled by M-CSF, RANKL and IL-$1{\beta}$ expression in PDL cells.

• BMB Reports
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• v.47 no.11
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• pp.619-624
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• 2014

Antisense RNA is a type of noncoding RNA (ncRNA) that binds to complementary mRNA sequences and induces gene repression by inhibiting translation or degrading mRNA. Recently, several small ncRNAs (sRNAs) have been identified in Escherichia coli that act as antisense RNA mainly via base pairing with mRNA. The base pairing predominantly leads to gene repression, and in some cases, gene activation. In the current study, we examined how the location of target sites affects sRNA-mediated gene regulation. An efficient antisense RNA expression system was developed, and the effects of antisense RNAs on various target sites in a model mRNA were examined. The target sites of antisense RNAs suppressing gene expression were identified, not only in the translation initiation region (TIR) of mRNA, but also at the junction between the coding region and 3' untranslated region. Surprisingly, an antisense RNA recognizing the upstream region of TIR enhanced gene expression through increasing mRNA stability.

• Korean Journal of Microbiology
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• v.44 no.4
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• pp.271-276
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• 2008

Ribosome stalling by nascent sticky peptide has been reported in several organisms across the kingdom. To test whether small subunit (SSU) rRNA is involved in this phenomenon, we developed a genetic system that utilized the specialized ribosome system to isolate SSU rRNA mutants that enable ribosomes to bypass the SecM-derived sticky peptide in protein synthesis. In this system, CAT-SecM mRNA, which encodes CAT protein containing the sticky peptide derived from SecM, is only translated by specialized ribosomes. These ribosomes were shown to transiently stall on CAT-SecM mRNA followed by the synthesis of the sticky peptide. Expression of specialized ribosomes resulted in the decreased steady-state level of CAT-SecM mRNA, which is consistent with a notion that ribosome stalling induces mRNA degradation. Isolation and characterization of SSU rRNA mutations using this genetic system that are sufficient to circumvent ribosome stalling induced by the SecM-derived sticky peptide will provide evidence of SSU rRNA function in mRNA cleavage.

• The Korean Journal of Pharmacology
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• v.29 no.2
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• pp.237-244
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• 1993

The effect of nicotine on the secretion of $[Met^{5}]-enkephalin$ (ME) in addition to proenkephalin A (proENK) mRNA levels and effects of indomethacin, nordihydroguaiaretic acid (NDGA), and captopril on nicotine-induced responses were studied in bovine adrenal medullary chromaffrin (BAMC) cells. Long-term exposure of BAMC cells to nicotine at a concentration of $10{\mu}M$ significantly increased proENK mRNA level and the secretion of ME into the medium. Treatment of BAMC cells with NDGA (a lipoxygenase inhibitor, $10{\mu}M$), indomethacin (a cycloooxygenase inhibitor) or captopril (an angiotensin converting enzyme inhibitor) alone did not affect ME secretion and proENK mRNA levels. The pretreatment of BAMC cells with NDGA inhibited the increased ME secretion and proENK mRNA level induced by nicotine. However, indomethacin and captopril did not affect nicotine-induced responses. Our results indicate that neuronal regulations of ME secretion and proENK mRNA level induced by nicotine in BAMC cells are in part mediated by a lipoxygenase-but not cyclooxygenase-and endogenous renin-angiotensin pathway.