• The Korean Journal of Physiology and Pharmacology
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• v.11 no.5
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• pp.227-231
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• 2007

The classic type of transient receptor potential channel(TRPC) is a molecular candidate for $Ca^{2+}$-permeable cation channel in mammalian cells. TRPC5 is rapidly desensitized after activation by G protein-coupled receptor. Herein we report the effect of dimethyl sulfoxide(DMSO) on the desensitization of TRPC5. TRPC5 was initially activated by muscarinic stimulation with $50{\mu}M$ carbachol(CCh) and then decayed rapidly even in the presence of CCh(desensitization). DMSO in the pipette solution slowed the rate of this desensitization. Under the control conditions, TRPC5 current spontaneously declined to $6{\pm}1%$ of the initial peak amplitude 60 sec after CCh application and to $1{\pm}0.5%$ after 120 sec. But, in the presence of 0.01%, 0.1% and 1% DMSO, TRPC5 current spontaneously declined to $55{\pm}2%,\;68{\pm}1%\;and\;100{\pm}0.2%$ of the initial peak amplitude 60 sec after CCh application and to $38{\pm}2%,\;61{\pm}1%\;and\;100{\pm}1%$ after 120 see, respectively. The results suggest that DMSO can internally attenuate the desensitization of TRPC5 current through unknown mechanisms that remain to be elucidated.

• Biomedical Science Letters
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• v.17 no.1
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• pp.89-93
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• 2011

Asthma is an inflammatory airway disease and is characterized by the releases of inflammatory mediators including chemokines. They are mainly associated with the recruitment, activation and dysregulation of specific inflammatory cells, especially neutrophils in neutrophilic asthma. CC chemokines bind to CC chemokine receptors (CCRs) in the surface of their target cells. The aims of this study are to examine the CCR expression in neutrophils of bronchoalveolar lavage fluid (BALF) of asthmatic patients and to determine the alternation of migration and apoptosis of neutrophils by the BALF. We demonstrate that CCR3 strongly expresses in BALF neutrophils of asthmatic patients as compared to other CCRs and increases during apoptosis of the BALF neutrophils. The migration of asthmatic blood neutrophils increases in response to asthmatic BALF as compared to BALF of normal volunteer. In addition, asthmatic BALF includes the higher levels of IL-8 protein than normal BALF and it has no effect on apoptosis of asthmatic blood neutrophils. Taken together, our results indicate that CCR3 expression may be associated with unknown function of asthmatic BALF neutrophils and BALF may be involved in the recruitment of neutrophils into the airway, but not in the neutrophils apoptosis.

• BMB Reports
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• v.41 no.12
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• pp.858-862
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• 2008

Membrane-type 1 matrix metalloproteinase (MT1-MMP) is a zinc-dependent proteinase found in cholesterol-rich lipid rafts on the plasma membrane. MT1-MMP hydrolyzes extracellular matrix (ECM) proteins, activates pro-matrix metalloproteinase-2 (proMMP-2) and plays an important role in ECM remodeling, cancer cell migration and metastasis. The role of caveolin-1, an integral protein of caveolae, in the activation of MT1-MMP remains largely unknown. Here, we show that the expression of caveolin-1 attenuates the activation of proMMP-2, reduces proteolytic cleavage of ECM and inhibits cell migration. We utilized the cytoplasmic tail domain deletion (${\Delta}CT$) or the E240A mutant of MT1-MMP. Co-expression of caveolin-1 with the wild-type or the ${\Delta}CT$ MT1-MMP decreased the proMMP-2 activation and inhibited collagen degradation and cell migration. Caveolin-1 had no effect on the catalytically inert E240A MT1-MMP. Our findings suggest that caveolin-1 is essential in the down-regulation of MT1-MMP activity by promoting internalization from the cell surface.

• BMB Reports
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• v.46 no.4
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• pp.219-224
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• 2013

The cell-fate specification of the anchor cell (AC) and a ventral uterine precursor cell (VU) in Caenorhabditis elegans is initiated by a stochastic interaction between LIN-12/Notch receptor and LAG-2/Delta ligand in two neighboring Z1.ppp and Z4.aaa cells. Both cells express lin-12 and lag-2 before specification, and a small difference in LIN-12 activity leads to the exclusive expressions of lin-12 in VU and lag-2 in the AC, through a feedback mechanism of unknown nature. Here we show that the expression pattern of lag-1/CSL, a transcriptional repressor itself that turns into an activator upon binding of the intracellular domain of Notch, overlaps with that of lin-12. Site-directed mutagenesis of LAG-1 binding sites in lag-1 maintains its expression in the AC, and eliminates it in the VU. Thus, AC/VU cell-fate specification appears to involve direct regulation of lag-1 expression by the LAG-1 protein, activating its transcription in VU cells, but repressing it in the AC.

• Molecules and Cells
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• v.41 no.8
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• pp.753-761
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• 2018

Tumor necrosis factor receptor-associated factor 6 (TRAF6) is identified as a signaling adaptor protein that regulates bone metabolism, immunity, and the development of several tissues. Therefore, its functions are closely associated with multiple diseases. TRAF6 is also involved in the regulation of hematopoiesis under steady-state conditions, but the role of TRAF6 in modulating hematopoietic stem and progenitor cells (HSPCs) during the developmental stages remains unknown. Here, we report that the deletion of TRAF6 in hematopoietic lineage cells resulted in the upregulation of HSPCs in the fetal liver at the prenatal period. However, in the early postnatal period, deletion of TRAF6 drastically diminished HSPCs in the bone marrow (BM), with severe defects in BM development and extramedullary hematopoiesis in the spleen being identified. In the analysis of adult HSPCs in a BM reconstitution setting, TRAF6 played no significant role in HSPC homeostasis, albeit it affected the development of T cells. Taken together, our results suggest that the role of TRAF6 in regulating HSPCs is altered in a spatial and temporal manner during the developmental course of mice.

• Proceedings of the Korean Society of Embryo Transfer Conference
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• 1998.05a
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• pp.12-28
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• 1998

The technology of creating transgenic animals has a potential value in improving productivity and disease resistance of animals, gene therapy, drug pharming and production of model animals for certain diseases. Up to date, fairly low success rate of production of transgenic animals and a pronounced variability with respect to the expression of transgenes have been much observed. The mechanisms how to integrate the injected genes with a certain part of the genomes are unknown yet. Many techniques in gene transfer, beside microinjection, have been introduced and explored thus to improve the production efficiency of transgenic animals. In this article, the methods and efficiency of gene-transfer techniques, the detection and preselection of transgenes in embryos by PCR- and GFP-screenings and cloning of preselected transgenic embryos by nuclear transplantation are described and discussed. Some experimental results showed that the early screening and selection of integration of the injected gene with embryonic genome by polymerase chain reaction(PCR) and green fluorecence protein(GFP) were promising methods. Further, the application of nuclear transplantation technology to cloning and multiplication of the positively integrated genes in the cleaving embryos and embryonic cells will be beneficially used for the mass production of transgenic embryos and consequently improving the production efficiency in transgenic animals.

• The Korean Journal of Physiology and Pharmacology
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• v.22 no.3
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• pp.343-348
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• 2018

Recent human genetic studies have shown that $G{\beta}5$ is related to various clinical symptoms, such as sinus bradycardia, cognitive disability, and attention deficit hyperactivity disorder. Although the calcium signaling cascade is closely associated with a heterotrimeric G-protein, the function of $G{\beta}5$ in calcium signaling and its relevance to clinical symptoms remain unknown. In this study, we investigated the in vitro changes of store-operated calcium entry (SOCE) with exogenous expression of $G{\beta}5$. The cells expressing $G{\beta}5$ had enhanced SOCE after depletion of calcium ion inside the endoplasmic reticulum. $G{\beta}5$ also augmented Stim1- and Orai1-dependent SOCE. An ORAI1 loss-of-function mutant did not show inhibition of $G{\beta}5$-induced SOCE, and a STIM1-ERM truncation mutant showed no enhancement of SOCE. These results suggested a novel role of GNB5 and Stim1, and provided insight into the regulatory mechanism of SOCE.

• Molecules and Cells
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• v.38 no.1
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• pp.58-64
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• 2015

Activating transcription factor-3 (ATF3) acts as a negative regulator of cytokine production during Gram-negative bacterial infection. A recent study reported that ATF3 provides protection from Streptococcus pneumoniae infection by activating cytokines. However, the mechanism by which S. pneumoniae induces ATF3 after infection is still unknown. In this study, we show that ATF3 was upregulated via Toll-like receptor (TLR) pathways in response to S. pneumoniae infection in vitro. Induction was mediated by TLR4 and TLR2, which are in the TLR family. The expression of ATF3 was induced by pneumolysin (PLY), a potent pneumococcal virulence factor, via the TLR4 pathway. Furthermore, ATF3 induction is mediated by p38 mitogen-activated protein kinase (MAPK) and c-Jun N-terminal kinase (JNK). Thus, this study reveals a potential role of PLY in modulating ATF3 expression, which is required for the regulation of immune responses against pneumococcal infection in macrophages.

• Korean Journal of Bronchoesophagology
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• v.4 no.1
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• pp.85-90
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• 1998

The role of the ECP(Eosinophilic cationic protein) is still unknown in the allergic rhinitis. In bronchial asthma, ECP can induce the exposure of the neuropeptidergic nerve to environments destroying the bronchial mucosa, aggravating the bronchial hypersensitivity and delay the mucociliary clearance. In the clinical aspect, we can (md that patients with perennial allergic rhinitis sometimes have sinusitis. The purpose of this article is to evaluate whether mucosal damage by ECP can play a role to develop the sinusitis by delaying the mucociliary clearance, and relationship between long symptom duration of allergic rhinitis and mucociliary clearance. In 32 perennial allergic rhinitis patients, we elucidated there is correlation among ECP presence, mucociliary clearance, sinusitis, and symptom durations. The obtained results were as follows : 1. ECP appeared in all mucosa of each specimen. 2. Mean mucociliary clearance time is 6 mins. 12 sec. in allergic patients with sinusitis, 6 mins. 36 sec in allergic patients without sinusitis. 3. n out of 32 cases have mucosal destruction. 4. Symptom duration is not correlated with the development of sinusitis. This study suggests that ECP may destroy the mucosa in allergic rhinitis and the mucociliary clearance of allergic rhinitis is not related to sinusitis and symptom dotation. Therefore development of sinusitis in allergic rhinitis seems not to be caused by delaying of mucociliary clearance due to mucosal destruction, but by some other factors.

• Parasites, Hosts and Diseases
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• v.59 no.5
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• pp.501-505
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• 2021

The pathogenic free-living amoeba Naegleria fowleri causes primary amoebic meningoencephalitis, a fatal infection, by penetrating the nasal mucosa and migrating to the brain via the olfactory nerves. N. fowleri can induce host cell death via lytic necrosis. Similar to phosphorylation, O-linked β-N-acetylglucosamine (O-GlcNAc) glycosylation (O-GlcNAcylation) is involved in various cell-signaling processes, including apoptosis and proliferation, with O-GlcNAc addition and removal regulated by O-GlcNAc transferase and O-GlcNAcase (OGA), respectively. However, the detailed mechanism of host cell death induced by N. fowleri is unknown. In this study, we investigated whether N. fowleri can induce the modulation of O-GlcNAcylated proteins during cell death in Jurkat T cells. Co-incubation with live N. fowleri trophozoites increased DNA fragmentation. In addition, incubation with N. fowleri induced a dramatic reduction in O-GlcNAcylated protein levels in 30 min. Moreover, pretreatment of Jurkat T cells with the OGA inhibitor PUGNAc prevented N. fowleri-induced O-deGlcNAcylation and DNA fragmentation. These results suggest that O-deGlcNAcylation is an important signaling process that occurs during Jurkat T cell death induced by N. fowleri.