• BMB Reports
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• 제52권3호
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• pp.163-164
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• 2019

The ribosomal synthesis of proteins in the eukaryotic cytosol has always been thought to start from the unformylated N-terminal (Nt) methionine (Met). In contrast, in virtually all nascent proteins in bacteria and eukaryotic organelles, such as mitochondria and chloroplasts, Nt-formyl-methionine (fMet) is the first building block of ribosomal synthesis. Through extensive approaches, including mass spectrometric analyses of the N-termini of proteins and molecular genetic techniques with an affinity-purified antibody for Nt-formylation, we investigated whether Nt-formylated proteins could also be produced and have their own metabolic fate in the cytosol of a eukaryote, such as yeast Saccharomyces cerevisiae. We discovered that Nt-formylated proteins could be generated in the cytosol by yeast mitochondrial formyltransferase (Fmt1). These Nt-formylated proteins were massively upregulated in the stationary phase or upon starvation for specific amino acids and were crucial for the adaptation to specific stresses. The stress-activated kinase Gcn2 was strictly required for the upregulation of Nt-formylated proteins by regulating the activity of Fmt1 and its retention in the cytosol. We also found that the Nt-fMet residues of Nt-formylated proteins could be distinct N-terminal degradation signals, termed fMet/N-degrons, and that Psh1 E3 ubiquitin ligase mediated the selective destruction of Nt-formylated proteins as the recognition component of a novel eukaryotic fMet/N-end rule pathway, termed fMet/N-recognin.

• BMB Reports
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• 제55권2호
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• pp.104-109
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• 2022

Skeletal myogenesis is essential to keep muscle mass and integrity, and impaired myogenesis is closely related to the etiology of muscle wasting. Recently, miR-141-3p has been shown to be induced under various conditions associated with muscle wasting, such as aging, oxidative stress, and mitochondrial dysfunction. However, the functional significance and mechanism of miR-141-3p in myogenic differentiation have not been explored to date. In this study, we investigated the roles of miR-141-3p on CFL2 expression, proliferation, and myogenic differentiation in C2C12 myoblasts. MiR-141-3p appeared to target the 3'UTR of CFL2 directly and suppressed the expression of CFL2, an essential factor for actin filament (F-actin) dynamics. Transfection of miR-141-3p mimic in myoblasts increased F-actin formation and augmented nuclear Yes-associated protein (YAP), a key component of mechanotransduction. Furthermore, miR-141-3p mimic increased myoblast proliferation and promoted cell cycle progression throughout the S and G2/M phases. Consequently, miR-141-3p mimic led to significant suppressions of myogenic factors expression, such as MyoD, MyoG, and MyHC, and hindered the myogenic differentiation of myoblasts. Thus, this study reveals the crucial role of miR-141-3p in myogenic differentiation via CFL2-YAP-mediated mechanotransduction and provides implications of miRNA-mediated myogenic regulation in skeletal muscle homeostasis.

• Journal of Ginseng Research
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• 제48권1호
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• pp.12-19
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• 2024

Skeletal muscle (SM) is the largest organ of the body and is largely responsible for the metabolism required to maintain body functions. Furthermore, the maintenance of SM is dependent on the activation of muscle satellite (stem) cells (MSCs) and the subsequent proliferation and fusion of differentiating myoblasts into mature myofibers (myogenesis). Natural compounds are being used as therapeutic options to promote SM regeneration during aging, muscle atrophy, sarcopenia, cachexia, or obesity. In particular, ginseng-derived compounds have been utilized in these contexts, though ginsenoside Rg1 is mostly used for SM mass management. These compounds primarily function by activating the Akt/mTOR signaling pathway, upregulating myogenin and MyoD to induce muscle hypertrophy, downregulating atrophic factors (atrogin1, muscle ring-finger protein-1, myostatin, and mitochondrial reactive oxygen species production), and suppressing the expressions of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) in cachexia. Ginsenoside compounds are also used for obesity management, and their anti-obesity effects are attributed to peroxisome proliferator activated receptor gamma (PPARγ) inhibition, AMPK activation, glucose transporter type 4 (GLUT4) translocation, and increased phosphorylations of insulin resistance (IR), insulin receptor substrate-1 (IRS-1), and Akt. This review was undertaken to provide an overview of the use of ginseng-related compounds for the management of SM-related disorders.

• 한국임상수의학회지
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• 제25권3호
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• pp.152-158
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• 2008

We investigated the changes of protein in chronic MI which was occurred with long-term ischemia, without reperfusion. Sprague Dawley (SD) rats were divided into the sham group and the experimental groups (MI groups). The sham group was treated only thoracotomy without ligation for left main descending artery (LMDA) of left coronary artery (LCA), and the experimental groups (MI7d, ligation of LMDA for 7 days and MI30d, ligation of LMDA for 30 days) were conducted an artificial chronic MI. The change of proteins according to passage of times was compared and analyzed on first and second dimension (1 and 2D) sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis. Among total 46 spots expressed differentially in the sham group versus MI7d and MI30d groups on 2D gel, we selected proteins that the volume of spot was increased in the MI7d and MI30d groups compared with the sham group. After that, the proteins were identified through liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis. In result, we could obtain many proteins as follows; albumin, glucose regulated protein 58 KDa, similar to tripartite motif protein 50, ubiquinol-cytochrome c reductase core protein II, sarcomeric mitochondrial creatine kinase, ATP synthetase alpha chain (mitochondrial precursor) and creatine kinase. In conclusion, we suggest many changed proteins shown at chronic ischemia after artificial MI and consider that these proteins play an important role in the function of heart after MI.

• Biomolecules & Therapeutics
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• 제29권6호
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• pp.685-696
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• 2021

In this study, we investigated the inhibitory effect of 5-aminolevulinic acid (ALA), a heme precursor, on inflammatory and oxidative stress activated by lipopolysaccharide (LPS) in RAW 264.7 macrophages by estimating nitric oxide (NO), prostaglandin E2 (PGE2), cytokines, and reactive oxygen species (ROS). We also evaluated the molecular mechanisms through analysis of the expression of their regulatory genes, and further evaluated the anti-inflammatory and antioxidant efficacy of ALA against LPS in the zebrafish model. Our results indicated that ALA treatment significantly attenuated the LPS-induced release of pro-inflammatory mediators including NO and PGE2, which was associated with decreased inducible NO synthase and cyclooxygenase-2 expression. ALA also inhibited the LPS-induced expression of pro-inflammatory cytokines, such as tumor necrosis factor (TNF)-α, interleukin (IL)-1β, and IL-6, reducing their extracellular secretion. Additionally, ALA abolished ROS generation, improved the mitochondrial mass, and enhanced the expression of heme oxygenase-1 (HO-1) and the activation of nuclear translocation of nuclear factor-E2-related factor 2 (Nrf2) in LPS-stimulated RAW 264.7 macrophages. However, zinc protoporphyrin, a specific inhibitor of HO-1, reversed the ALA-mediated inhibition of pro-inflammatory cytokines production and activation of mitochondrial function in LPS-treated RAW 264.7 macrophages. Furthermore, ALA significantly abolished the expression of LPS-induced pro-inflammatory mediators and cytokines, and showed strong protective effects against NO and ROS production in zebrafish larvae. In conclusion, our findings suggest that ALA exerts LPS-induced anti-inflammatory and antioxidant effects by upregulating the Nrf2/HO-1 signaling pathway, and that ALA can be a potential functional agent to prevent inflammatory and oxidative damage.

• 대한유전성대사질환학회지
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• 제3권1호
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• pp.86-93
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• 2003

Background : The SCL began screening of newborns and high risk group blood spots with tandem mass spectrometry (MS/MS) in April 2001. Our goal was to determine approximate prevalence of metabolic disorders, optimization of decision criteria for estimation of preventive effect with early diagnosis. This report describes the ongoing effort to identify more than 30 metabolic disorders by MS/MS in South Korea. Methods : Blood spot was collected from day 2 to 30 (mostly from day 2 to 10) after birth for newborn. Blood spot of high risk group was from the pediatric patients in NICU, developmental delay, mental retardation, strong family history of metabolic disorders. One punch (3.2 mm ID) of dried blood spots was extracted with $150{\mu}L$ of methanol containing isotopically labelled amino acids (AA) and acylcarnitines (AC) internal standards. Butanolic HCl was added and incubated at $65^{\circ}C$ for 15 min. The butylated extract was introduced into the inlet of MS/MS. Neutral loss of m/z 102 and parent ion mode of m/z 85 were set for the analyses of AA and AC, respectively. Diagnosis was confirmed by repeating acylcarnitine profile, urine organic acid and plasma amino acid analysis, direct enzyme assay, or molecular testing. Results : Approximately 31,000 neonates and children were screened and the estimated prevalence (newborn/high risk group), sensitivity, specificity and recall rate amounted to 1:2384/1:2066, 96.55%, 99.98%, and 0.73%, respectively. Confirmed 28 (0.09%) multiple metabolic disorders (newborn/high risk) were as follows; 13 amino acid disorders [classical PKU (3/4), BH4 deficient-hyperphenylalaninemia (0/1), Citrullinemia (1/0), Homocystinuria (0/2), Hypermethioninemia (0/1), Tyrosinemia (1/0)], 8 organic acidurias [Propionic aciduria (2/1), Methylmalonic aciduria (0/1), Isovaleric aciduria (1/1), 3-methylcrotonylglycineuria (1/0), Glutaric aciduria type1 (1/0)], 7 fatty acid oxidation disorders [LCHAD def. (2/2), Mitochondrial TFP def. (0/1), VLCAD def. (1/0), LC3KT def. (0/1). Conclnsion : The relatively normal development of 10 patients with metabolic disorders among newborns (except for the expired) demonstrates the usefulness of newborn screening by MS/MS for early diagnosis and medical intervention. However, close coordination between the MS/MS screening laboratory and the metabolic clinic/biochmical geneticists is needed to determine proper decision of screening parameters, confirmation diagnosis, follow-up scheme and additional tests.

• 대한의생명과학회지
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• 제18권3호
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• pp.227-236
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• 2012

Previous study showed that swimming improved obesity but was not through $PPAR{\alpha}$ activation in liver and skeletal muscle in high fat diet-fed female mice with functioning ovaries as an animal model of obese premenopausal women. Thus, this study was aimed at investigation of the effects of swimming on the promotion of health and its molecular mechanism in adipose tissue of high fat diet-fed female mice. Eight-week-old female C57BL/6J mice were randomly divided into two groups (a non-swim control group and a swim group, n=8/group). Mice in the swim group swam for 2 h daily for 6 weeks in water bath with temperature of $35{\pm}1^{\circ}C$. All the animals received high fat diet (45% kcal fat) for 6 weeks. Reverse transcription-polymerase chain reaction was used to elucidate the molecular mechanism. Female mice subjected to swimming had significantly decreased body weight gain and white adipose tissue mass compared with the female control mice. Histological studies illustrated that swimming decreases the hepatic lipid accumulation. As expected, swimming did not affect the expression of mRNA levels of peroxisome proliferator-activated receptor (PPAR) ${\alpha}$ and $PPAR{\alpha}$ target genes responsible for mitochondrial fatty acid ${\beta}$-oxidation, such as carnitine palmitoyltransgerase-1 and medium chain acyl-CoA dehydrogenase in the white adipose tissue. However, mice that underwent 6-weeks of swimming exercise had decreased the mRNA expression of lipogenic genes, such as sterol regulatory element-binding proteins-1C and fatty acid synthase in comparison to sedentary control mice, with decreased $PPAR{\gamma}$ target genes involved in adipocyte-specific marker genes, such as adipocyte fatty acid binding protein and leptin in the white adipose tissue. These results suggest that swimming can effectively prevent obesity induced by high fat diet-fed, in part through down-regulation of adipogenesis and lipogenesis in white adipose tissue of female obese mice. Moreover, these results suggest that swimming maybe contributing the promotion of health through regulation of adipogenesis and lipogenesis in overweight premenopausal women.

• 한국조리학회지
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• 제23권1호
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• pp.66-78
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• 2017

"Sarcopenia", sarcopenia is an old age syndrome, and used to describe the reduction of skeletal muscle. Initially, it was thought that sarcopenia was only a senile disease characterized by degeneration of muscle tissue. However, its cause is widely regarded as multifactorial, with neurological decline, hormonal changes, inflammatory pathway activation, declines in activity, chronic illness, fatty infiltration, and poor nutrition, all shown to be contributing factors. Skeletal muscle mass can be measured by a variety of methods, currently, the commonly used methods are dual-energy X-ray scanning (DXA), computer tomography (CT), magnetic resonance imaging (MRI), etc. Muscular skeletal disorders can also be assessed by measuring appendicular skeletal muscle (ASM), particularly muscle tissue content. At the same time, sarcopenia refers to skeletal muscle cell denervation, mitochondrial dysfunction, inflammation, hormone synthesis and secretion changes and a series of consequences caused by the above process and is a progressive loss of skeletal muscle syndrome, which can lead to the decrease of muscle strength, physical and functional disorders, and increase the risk of death. Sarcopenia is mainly associated with the aging process, but also related to other causes such as severe malnutrition, neurodegenerative diseases, and disuse and endocrine diseases associated with muscular dystrophy, and it is the comprehensive results of multi-factors, so it is difficult to define that sarcopenia is caused by a specific disease. With the aging problem of the population, the incidence of this disease is increasingly common, and seriously affects the quality of the life of the elderly. This paper reviews the etiology and pathogenesis of myopathy, screening methods and diagnosis, the influence of eating habits, etc, and hopes to provide reference for the diagnosis and treatment of this disease. At present, adequate nutrition and targeted exercise remain the gold standard for the therapy of sarcopenia.

• Journal of Ecology and Environment
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• 제44권3호
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• pp.185-195
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• 2020

Background: The flathead grey mullet Mugil cephalus has the widest distribution among mugilid species. Recent studies based on mitochondrial DNA sequences showed that the species comprises at least 14 different groups, three of which occur in the northwest Pacific. We analyzed the otolith microchemistry of M. cephalus at several locations in Korea to improve understanding of migration pattern and population origin. Results: We collected 123 sagittal otoliths from seven locations and determined their concentrations of eight elements (⁷Li, ²⁴Mg, ⁵⁵Mn, ⁵⁷Fe, ⁶⁰Ni, ⁶³Cu, ⁸⁸Sr, and ¹³⁸Ba) using laser ablation inductively coupled plasma mass spectrometry. Mean otolith elemental ratios differed significantly among the locations. The Sr:Ca, Fe:Ca, and Ba:Ca ratios were significantly higher than others, and useful chemical signatures for investigating the habitat use of M. cephalus populations. We identified five diverse and complicated migration patterns using the otolith data that we collected: estuarine resident (type I), freshwater migrant (type II), estuarine migrant (type III), seawater resident (type IV), and seawater migrant (type V). A canonical discriminant analysis plot revealed separation of two groups (type II in the Yellow Sea vs. other types in remaining locations). Two locations on Jeju Island, despite their close proximity, had fish with quite different migration patterns, corroborating previous molecular studies that distinguished two groups of fishes. Conclusion: We successfully showed that the migration patterns of the Korean mullet varied by location. Only fish from the western sector of Jeju had a unique migration pattern, which is likely confined population in this area. Among the eight otolith elements measured, the Sr:Ca ratio was found to be the best indicator of migration pattern and population origin.

• Journal of Korean Neurosurgical Society
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• 제59권6호
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• pp.544-550
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• 2016

Objective : Cerebral endothelial cells have unique biological features and are fascinating candidate cells for stroke therapy. Methods : In order to understand the molecular mechanisms of human cerebral endothelial cell (hCMEC/D3) transplantation in a rat stroke model, we performed proteomic analysis using 2-dimensional electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Protein expression was confirmed by quantitative real-time PCR and Western blot. Results : Several protein spots were identified by gel electrophoresis in the sham, cerebral ischemia (CI), and CI with hCMEC/D3 treatment cerebral ischemia with cell transplantation (CT) groups, and we identified 14 differentially expressed proteins in the CT group. Proteins involved in mitochondrial dysfunction (paraplegin matrix AAA peptidase subunit, SPG7), neuroinflammation (peroxiredoxin 6, PRDX6), and neuronal death (zinc finger protein 90, ZFP90) were markedly reduced in the CT group compared with the CI group. The expression of chloride intracellular channel 4 proteins involved in post-ischemic vasculogenesis was significantly decreased in the CI group but comparable to sham in the CT group. Conclusion : These results contribute to our understanding of the early phase processes that follow cerebral endothelial cell treatment in CI. Moreover, some of the identified proteins may present promising new targets for stroke therapy.