• Toxicological Research
• /
• v.19 no.4
• /
• pp.325-330
• /
• 2003

The effects of estrogen on apoptosis induced by 2,3,7,8-tetrachlorodibenzo-p-doxin (TCDD) were examined in cultured MCF-7 cells. TCDD stimulated apoptosis and inhibited the expression of bcl-2 gene in MCF-7 cells grown in the media supplemented with 10% fetal bovine serum. However, TCDD failed to induce apoptosis if cells were grown in the media deprived of all estrogen-like compounds. Removal of estrogen-like compounds from the growth media also led to the activation of bcl-2 gene expression in cells treated with TCDD. Combined treatment of estrogen with TCDD abrogated the binding of Aryl hydrocarbon Receptor (AhR)-TCDD complex to Dioxin response element (DRE) of bcl-2 gene leading to the inhibition of bcl-2 gene expression as well as stimulation of apoptosis. The present study suggests that the binding of estrogen receptor (ER)-estrogen complex to the estrogen responsive element (E) interferes with the binding of AhR- TCDD complex to the DRE and inhibits the bcl-2 expression.

• BMB Reports
• /
• v.54 no.5
• /
• pp.272-277
• /
• 2021

RalBP1 associated EPS domain containing 1 (REPS1) is conserved from Drosophila to humans and implicated in the endocytic system. However, an exact role of REPS1 remains largely unknown. Here, we demonstrated that mitogen activated protein kinase kinase (MEK)-p90 ribosomal S6 Kinase (RSK) signaling pathway directly phosphorylated REPS1 at Ser709 upon stimulation by epidermal growth factor (EGF) and amino acid. While REPS2 is known to be involved in the endocytosis of EGF receptor (EGFR), REPS1 knockout (KO) cells did not show any defect in the endocytosis of EGFR. However, in the REPS1 KO cells and the KO cells reconstituted with a non-phosphorylatable REPS1 (REPS1 S709A), the recycling of transferrin receptor (TfR) was attenuated compared to the cells reconstituted with wild type REPS1. Collectively, we suggested that the phosphorylation of REPS1 at S709 by RSK may have a role of the trafficking of TfR.

• BMB Reports
• /
• v.57 no.5
• /
• pp.238-243
• /
• 2024

Bone marrow-derived mesenchymal stem cells (BM-MSCs) can differentiate into endothelial cells in an inflammatory microenvironment. However, the regulatory mechanisms underlying this process are not entirely understood. Here, we found that TIE2 in BM-MSCs was upregulated at the transcriptional level after stimulation with tumor necrosis factor-alpha (TNFα), a major pro-inflammatory cytokine. Additionally, the STAT-binding sequence within the proximal region of TIE2 was necessary for TNFα-induced TIE2 promoter activation. TIE2 and STAT3 knockdown reduced TNFα-induced endothelial tube formation in BM-MSCs. Among the major TNFα-activated MAP kinases (ERK1/2, JNK1/2, and p38 MAPK) in BM-MSCs, only inhibition of the p38 kinase abrogated TNFα-induced TIE2 upregulation by inhibiting the JAK-STAT signaling pathway. These findings suggest that p38 MAP contributes to the endothelial differentiation of BM-MSCs by activating the JAK-STAT-TIE2 signaling axis in the inflammatory microenvironment.

• Molecules and Cells
• /
• v.38 no.6
• /
• pp.548-561
• /
• 2015

By combining conventional single cell analysis with flow cytometry and public database searches with bioinformatics tools, we extended the expression profiling of thymic stromal cotransporter (TSCOT), Slc46A2/Ly110, that was shown to be expressed in bipotent precursor and cortical thymic epithelial cells. Genome scale analysis verified TSCOT expression in thymic tissue- and cell type- specific fashion and is also expressed in some other epithelial tissues including skin and lung. Coexpression profiling with genes, Foxn1 and Hoxa3, revealed the role of TSCOT during the organogenesis. TSCOT expression was detected in all thymic epithelial cells (TECs), but not in the $CD31^+$endothelial cell lineage in fetal thymus. In addition, ABC transporter-dependent side population and Sca-$1^+$ fetal TEC populations both contain TSCOT-expressing cells, indicating TEC stem cells express TSCOT. TSCOT expression was identified as early as in differentiating embryonic stem cells. TSCOT expression is not under the control of Foxn1 since TSCOT is present in the thymic rudiment of nude mice. By searching variations in the expression levels, TSCOT is positively associated with Grhl3 and Irf6. Cytokines such as IL1b, IL22 and IL24 are the potential regulators of the TSCOT expression. Surprisingly, we found TSCOT expression in the lung is diminished in lung cancers, suggesting TSCOT may be involved in the suppression of lung tumor development. Based on these results, a model for TEC differentiation from the stem cells was proposed in context of multiple epithelial organ formation.

• BMB Reports
• /
• v.46 no.11
• /
• pp.527-532
• /
• 2013

Gangliosides are complex glycosphingolipids that are the major component of cytoplasmic cell membranes, and play a role in the control of biological processes. Human mesenchymal stem cells (hMSCs) have received considerable attention as alternative sources of adult stem cells because of their potential to differentiate into multiple cell lineages. In this study, we focus on various functional roles of gangliosides in the differentiation of hMSCs into osteoblasts or neuronal cells. A relationship between gangliosides and epidermal growth factor receptor (EGFR) activation during osteoblastic differentiation of hMSCs was observed, and the gangliosides may play a major role in the regulation of the differentiation. The roles of gangliosides in osteoblast differentiation are dependent on the origin of hMSCs. The reduction of ganglioside biosynthesis inhibited the neuronal differentiation of hMSCs during an early stage of the differentiation process, and the ganglioside expression can be used as a marker for the identification of neuronal differentiation from hMSCs.

• KSBB Journal
• /
• v.27 no.5
• /
• pp.289-294
• /
• 2012

Resveratrol, natural polyphenol in grapes and red wine, is known to have the anti-proliferatory and anti-angiogenic effects in various cancer cells. In this study, we have investigated the effects of resveratrol in HT-29 colon cancer cells. Treatment of resveratrol in different concentrations and time inhibited proliferation of HT-29 colon cancer cells. We explored the effects of resveratrol on HT-29 colon cancer cell motility using a wound healing assay. In the absence of the resveratrol, the HT-29 cells are migrated along the edges of the wound and showed a large-scale migration, whereas dose- and time-dependent inhibition of cell flattening and spreading was observed in the presence of resveratrol. Resveratrol inhibited MMP-9 in a dose- and time-dependent on HT-29 colon cancer cells by Western blotting. In addition, resveratrol increased AMPK activity and decreased COX-2, VASP and VEGF expression. Treatment of compound C inhibited AMPK activity, however, the expression of VASP and COX-2 increased thus, COX-2 and VASP are modulated by AMPK. However treatment of celecoxib could not control AMPK activity but decreased VEGF expression. We suggest that resveratrol inhibits cell proliferation and migration through activation of AMPK and decreased COX-2, VASP and VEGF expression in HT-29 colon cancer cells.

• Molecules and Cells
• /
• v.46 no.12
• /
• pp.746-756
• /
• 2023

A recent study revealed that the loss of Deup1 expression does not affect either centriole amplification or multicilia formation. Therefore, the deuterosome per se is not a platform for amplification of centrioles. In this study, we examine whether gain-of-function of Deup1 affects the development of multiciliated ependymal cells. Our time-lapse study reveals that deuterosomes with an average diameter of 300 nm have two different fates during ependymal differentiation. In the first instance, deuterosomes are scattered and gradually disappear as cells become multiciliated. In the second instance, deuterosomes self-organize into a larger aggregate, called a deuterosome cluster (DC). Unlike scattered deuterosomes, DCs possess centriole components primarily within their large structure. A characteristic of DC-containing cells is that they tend to become primary ciliated rather than multiciliated. Our in utero electroporation study shows that DCs in ependymal tissue are mostly observed at early postnatal stages, but are scarce at late postnatal stages, suggesting the presence of DC antagonists within the differentiating cells. Importantly, from our bead flow assay, ectopic expression of Deup1 significantly impairs cerebrospinal fluid flow. Furthermore, we show that expression of mouse Deup1 in Xenopus embryos has an inhibitory effect on differentiation of multiciliated cells in the epidermis. Taken together, we conclude that the DC formation of Deup1 in multiciliated cells inhibits production of multiple centrioles.

• Journal of Microbiology and Biotechnology
• /
• v.11 no.3
• /
• pp.482-490
• /
• 2001

The gene for glycoprotein B (gB2) of HSV-2-strain G was subcloned, sequenced, recombinated into the lacZ-HcNPV, expressed in insect cells, and compared with the homologous gene of other HSV-2 strains. The ORF of the gB2 gene was 2,715 bp. The overall nucleotide sequence homology of te gB2 gene compared ith that of the two previously reported HSV-2 strains appeared to be over 98%. A recombinant virus named Baculo-gB2 protein in insect cells. The recombination was confirmed by a PCR and the expression was demonstrated by radio immunoprecipitation. Insect cells infected with the Baculo-gB2 virus synthesized and processed gB2 with approximately 120 kDa in the cells, and then secreted it into the culture media, where it reacted with a nomoclonal antibody to gB2. The gB2 polypeptide contained two main hydrophobic regions (a signal sequence from 1 to 23 amino acid residues, and a membrane anchor sequence from aa 745 to 798), eight N-glycosylation sites evenly distributed, and was rich in alanine (11.2%). Antibodies to this recombinant protein that were raised in mice recognized the viral gB2 and neutralized the infectivity of the HSV-2 in vitro. There results show that the gB2 protein was successfully porduced in insect cells and could be used to raise a protective neutralizing antibody. Accordingly, this particular recombinant protein may be useful in the development of a subunit vaccine.

• Korean Journal of Microbiology
• /
• v.53 no.3
• /
• pp.193-199
• /
• 2017

This study was aimed to evaluate the antimicrobial activity of Penicillium purpurogenum ED76 on several clinically important microorganisms. The endophytic fungus P. purpurogenum ED76 was previously isolated from Swietenia macrophylla leaf. The antimicrobial efficacy of P. purpurogenum ED76 dichloromethane extract was determined via disc diffusion and broth microdilution assay. A kill curve study was conducted and the morphology of extract treated bacterial cells were viewed under scanning electron microscope. The dichloromethane extract showed significant inhibitory activity on 4 test bacteria and 2 test yeasts. The minimal inhibitory concentration of the extract ranged from 125 to $1,000{\mu}g/ml$, which indicates the different susceptibility levels of the test microorganisms to the fungal extract. The kill curve study has revealed a concentration-dependent inhibition for all test microorganisms. With the increase of the extract concentration, the microbial growth was significantly reduced. The scanning electron micrograph of dichloromethane extract-treated Staphylococcus aureus cells showed the total damage of the cells. The cell wall invagination of the bacterial cells also indicates the loss of cellular materials and metabolic activity. The gas chromatography mass spectrometry analysis of the extract also showed that the major compound was stigmasterol, which constitutes 45.30% of the total area. The dichloromethane extract of P. purpurogenum ED76 exhibited significant inhibitory activity on several clinically important bacteria and yeasts. The study proposed a possible mode of action that the extract cause significant damage to the morphology of S. aureus cells.

• Journal of Plant Biotechnology
• /
• v.46 no.3
• /
• pp.217-227
• /
• 2019

Production of therapeutic monoclonal antibodies (mAbs) using a plant platform has been considered an alternative to the mammalian cell-based production system. A plant-derived mAb CO17-1AK ($mAb^P$ COK) can specifically bind to various types of cancer cell lines. The target protein of $mAb^P$ COK is the epithelial cell adhesion molecule (EpCAM) highly expressed in human epithelial cancer cells, including breast and colorectal cancer cells. It has been hypothesized that its overexpression supports tumor growth and metastasis. A ganglioside is extended well beyond the surfaces of the various cell membranes and has roles in cell growth, inflammation, differentiation, and carcinogenesis. However, the regulation of EpCAM gene expression in breast cancers and the role of gangliosides in oncogenesis are unclear. Here, the purpose of this study was to determine the effects of $mAb^P$ COK on human breast cancer cell proliferation, apoptosis, and ganglioside expression patterns. Our results show that treatment with $mAb^P$ COK suppressed the growth of breast cancer cells and induced apoptotic cell death. It also upregulated the expression of metastasis-related gangliosides in breast cancer cells. Thus, treatment with $mAb^P$ COK may have chemo-preventive therapeutic effects against human breast cancer.