• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.398-405
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• 2002

Bifidobacteria have been previously shown to stimulate the immune functions and cytokine production in macrophages and T-lymphocytes. Accordingly, the RAW 264.7 murine macrophage cell line was used to assess the effects of Bifidobacterium on the proliferation and cytoskeleton reorganization of the cells. Cytokine production after exposure to Bifidobacterium was also monitored in both whole cells and cell-free extracts. When RAW 264.7 cells were cultured for 24 h in the presence of heat-killed Bifidobacterium bifidum BGN4, the proliferation of macrophages was slowed down in a dose-dependent manner and cell differentiation was observed by staining with the actin-specific fluorescent dye, rhodamin-conjugated phalloidin. Although EL-4 cells, a T-cell line, stimulated RAW 264.7 cells to produce TNF-${\alpha}$ and IL-6, the stimulatory activity of B. bifidum BGN4 decreased as the EL-4 cell number increased. When disrupted and fractionated BGN4 was used, the whole cell fraction was more effective than the other fractions for the TNF-${\alpha}$ production. In contrast, the cell-free extract exhibited the highest IL-6 production level among the fractions, which was evident even at a $1{\mu}g/ml$ concentration. The current results demonstrate that Bifidobacterium induced differentiation of the macrophages from the fast proliferative stage and that the cytokine production was differentially induced by the whole cells and cell-free extracts. The in vitro approaches employed herein are expected to be useful in further characterization of the effects of bifidobacteria with regards to gastrointestinal and systemic immunity.

• Molecules and Cells
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• v.41 no.5
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• pp.436-443
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• 2018

The actin cytoskeleton plays a key role in the entry of mitosis as well as in cytokinesis. In a previous study, we showed that actin disruption delays mitotic entry at G2/M by sustained activation of extracellular signal-related kinase 1/2 (ERK1/2) in primary cells but not in transformed cancer cell lines. Here, we examined the mechanism of cell cycle delay at G2/M by actin dysfunction in IMR-90 normal human fibroblasts. We observed that de-polymerization of actin with cytochalasin D (CD) constitutively activated ribosomal S6 kinase (RSK) and induced inhibitory phosphorylation of Cdc2 (Tyr 15) in IMR-90 cells. In the presence of an actin defect in IMR-90 cells, activating phosphorylation of Wee1 kinase (Ser 642) and inhibitory phosphorylation of Cdc25C (Ser 216) was also maintained. However, when kinase-dead RSK (DN-RSK) was overexpressed, we observed sustained activation of ERK1/2, but no delay in the G2/M transition, demonstrating that RSK functions downstream of ERK in cell cycle delay by actin dysfunction. In DN-RSK overexpressing IMR-90 cells treated with CD, phosphorylation of Cdc25C (Ser 216) was blocked and phosphorylation of Cdc2 (Tyr 15) was decreased, but the phosphorylation of Wee1 (Ser 642) was maintained, demonstrating that RSK directly controls phosphorylation of Cdc25C (Ser 216), but not the activity of Wee1. These results strongly suggest that actin dysfunction in primary cells activates ERK1/2 to inhibit Cdc2, delaying the cell cycle at G2/M by activating downstream RSK, which phosphorylates and blocks Cdc25C, and by directly activating Wee1.

• Journal of Ginseng Research
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• v.40 no.3
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• pp.278-284
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• 2016

Background: The ginsenoside Rb1 (Rb1) is the most abundant compound in the root of Panax ginseng. Recent studies have shown that Rb1 has a neuroprotective effect. However, the mechanisms underlying this effect are still unknown. Methods: We used stable isotope labeling with amino acids in cell culture, combined with quantitative mass spectrometry, to explore a potential protective mechanism of Rb1 in ${\beta}$-amyloid-treated neuronal cells. Results: A total of 1,231 proteins were commonly identified from three replicate experiments. Among these, 40 proteins were significantly changed in response to Rb1 pretreatment in ${\beta}$-amyloid-treated neuronal cells. Analysis of the functional enrichments and protein interactions of altered proteins revealed that actin cytoskeleton proteins might be linked to the regulatory mechanisms of Rb1. The CAP1, CAPZB, TOMM40, and DSTN proteins showed potential as molecular target proteins for the functional contribution of Rb1 in Alzheimer's disease (AD). Conclusion: Our proteomic data may provide new insights into the protective mechanisms of Rb1 in AD.

• Journal of Animal Reproduction and Biotechnology
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• v.37 no.4
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• pp.231-238
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• 2022

Reactive oxygen species (ROS) production and F-actin cytoskeleton dynamics play important roles in the survival rate of blastocysts after the vitrified-warming process. However, the protective effects of Mito-TEMPO against cryo-injury and viability through F-actin aggregation and mitochondrial-specific ROS production in vitrificated-warmed bovine embryos have not been investigated. The aims of the present study were to: (1) determine the effects of Mito-TEMPO on embryonic developmental competence and quality by F-actin stabilization during in vitro culturing (IVC), and (2) confirm the effects of Mito-TEMPO through F-actin structure on the cryotolerance of vitrification-warming in Mito-TEMPO exposed in vitro production (IVP) of bovine blastocysts. Bovine zygotes were cultured with 0.1 μM Mito-TEMPO treatment for 2 days of IVC. Mito-TEMPO (0.1 μM) exposed bovine embryos slightly improved in blastocyst developmental rates compared to the non-treated group. Moreover, the viability of vitrified-warmed blastocysts from Mito-TEMPO treated embryos significantly increased (p < 0.05, non-treated group: 66.7 ± 3.2% vs Mito-TEMPO treated group: 79.2 ± 5.9%; re-expanded at 24 hours). Mito-TEMPO exposed embryos strengthened the F-actin structure and arrangement in the blastocyst after vitrification-warming. Furthermore, the addition of Mito-TEMPO into the IVC medium enhanced embryonic survival and quality through F-actin stabilization after the vitrification-warming procedure. Overall, our results suggest that supplementing the culture with 0.1 μM Mito-TEMPO improves the embryonic quality and cryo-survival of IVP bovine blastocysts.

• Journal of the Korean Society for Nondestructive Testing
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• v.32 no.3
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• pp.263-268
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• 2012

It is important to know the mechanism of cell membrane fluctuation because it can be readout for the nanomechanical interaction between cytoskeleton and plasma membrane. Traditional techniques, however, have drawbacks such as probe contact with the cell surface, complicate analysis, and limit spatial and temporal resolution. In this study, we developed a new system for non-contact measurement of nano-scale localized-cell surface dynamics using modified-scanning ion-conductance microscopy. With 2 nm resolution, we determined that endothelial cells have local membrane fluctuations of ~20 nm, actin depolymerization causes increase in fluctuation amplitude, and ATP depletion abolishes all membrane fluctuations.

• Mass Spectrometry Letters
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• v.11 no.2
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• pp.25-29
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• 2020

Pseudopodia are dynamic actin cytoskeleton-based membrane protrusions of cells that enable directional cell migration. Pseudopodia of cancer cells play key roles in cancer metastasis. Recent studies using pseudopodial subcellular fractionation methodologies combined with mass spectrometry-based proteomic profiling have provided insight into the pseudopodiome that control the protrusions of invasive metastatic cancer cells. This review highlights how to characterize the protein composition of pseudopodia and develop strategies to identify biomarkers or drug candidates that target reduction or prevention of metastatic cancer.

• Childhood Kidney Diseases
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• v.23 no.2
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• pp.86-92
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• 2019

Steroid-resistant nephrotic syndrome (SRNS) has long been a challenge for clinicians due to its poor responsiveness to immunosuppressants, and rapid progression to end-stage renal disease. Identifying a monogenic cause for SRNS may lead to a better understanding of podocyte structure and function in the glomerular filtration barrier. This review focuses on genes associated with slit diaphragm, actin cytoskeleton, transcription factors, nucleus, glomerular basement membrane, mitochondria, and other proteins that affect podocyte biology.

• Microbiology and Biotechnology Letters
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• v.37 no.4
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• pp.316-321
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• 2009

We have isolated Chondromyces crocatus KYC2823 in pure culture and five other strains in mixed culture with companion bacteria from Korean soil samples. The strain KYC2823, which was isolated from the soil sample collected in Cheongdo-gun, Gyeongsangbuk-do, showed typical characteristics of C. crocatus, including the shape of fruiting bodies and production of a peculiar odor. In addition, the 16S rDNA sequence was 99.8% identical to that of the strain Cm c5, the proposed neotype strain of C. crocatus. Cloning and sequence analysis of the polyketide biosynthetic genes from KYC2823 by performing PCR have revealed that this strain has biosynthetic gene clusters for ajudazols (inhibitors of electron transport systems) and chondramides (substances affecting the function of the actin cytoskeleton), and biosynthetic genes for other polyketide compounds that have not been cloned yet.

• Molecules and Cells
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• v.43 no.4
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• pp.340-349
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• 2020

Oleoylethanolamide (OEA), a bioactive lipid in bone, is known as an endogenous ligand for G protein-coupled receptor 119 (GPR119). Here, we explored the effects of OEA on osteoclast differentiation, function, and survival. While OEA inhibits osteoclast resorptive function by disrupting actin cytoskeleton, it does not affect receptor activator of nuclear factor-κB ligand (RANKL)-induced osteoclast differentiation. OEA attenuates osteoclast spreading, blocks actin ring formation, and eventually impairs bone resorption. Mechanistically, OEA inhibits Rac activation in response to macrophage colony-stimulating factor (M-CSF), but not RANKL. Furthermore, the OEA-mediated cytoskeletal disorganization is abrogated by GPR119 knockdown using small hairpin RNA (shRNA), indicating that GPR119 is pivotal for osteoclast cytoskeletal organization. In addition, OEA induces apoptosis in both control and GPR119 shRNA-transduced osteoclasts, suggesting that GPR119 is not required for osteoclast apoptosis. Collectively, our findings reveal that OEA has inhibitory effects on osteoclast function and survival of mature osteoclasts via GPR119-dependent and GPR119-independent pathways, respectively.

• Genomics & Informatics
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• v.16 no.3
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• pp.59-64
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• 2018

Although pork quality traits are important commercially, genome-wide association studies (GWASs) have not well considered Landrace and Yorkshire pigs worldwide. Landrace and Yorkshire pigs are important pork-providing breeds. Although quantitative trait loci of pigs are well-developed, significant genes in GWASs of pigs in Korea must be studied. Through a GWAS using the PLINK program, study of the significant genes in Korean pigs was performed. We conducted a GWAS and surveyed the gene ontology (GO) terms associated with the backfat thickness (BF) trait of these pigs. We included the breed information (Yorkshire and Landrace pigs) as a covariate. The significant genes after false discovery rate (<0.01) correction were AFG1L, SCAI, RIMS1, and SPDEF. The major GO terms for the top 5% of genes were related to neuronal genes, cell morphogenesis and actin cytoskeleton organization. The neuronal genes were previously reported as being associated with backfat thickness. However, the genes in our results were novel, and they included ZNF280D, BAIAP2, LRTM2, GABRA5, PCDH15, HERC1, DTNBP1, SLIT2, TRAPPC9, NGFR, APBB2, RBPJ, and ABL2. These novel genes might have roles in important cellular and physiological functions related to BF accumulation. The genes related to cell morphogenesis were NOX4, MKLN1, ZNF280D, BAIAP2, DNAAF1, LRTM2, PCDH15, NGFR, RBPJ, MYH9, APBB2, DTNBP1, TRIM62, and SLIT2. The genes that belonged to actin cytoskeleton organization were MKLN1, BAIAP2, PCDH15, BCAS3, MYH9, DTNBP1, ABL2, ADD2, and SLIT2.