• Toxicological Research
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• v.17
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• pp.97-104
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• 2001

Three types of proteases (MEF-1, MEF-2 and MEF-3) were purified from the egg cases of Ten-odera sinensis using ammonium sulfate fractionation, gel filtration on Bio-Gel P-60 and affinity chromatography on DEAE Affi-Gel blue gel. The proteases were assessed homogeneous by SDS-polyacrylamide gel electrophoresis and have molecular weight of 31,500, 32,900 and 35,600 Da, respectively. The N-terminal regions of the primary structure were compared and they were found to be different each other. MEFs readily digested the $A\alpha$ - and B$\beta$-chains of fibrinogen and more slowly the ${\gamma}$-chain. The action of the enzymes resulted in extensive hydrolysis of fibrinogen and fibrin, releasing a variety of fibrinopeptides. MEF-1 was inactivated by Cu$^{2+}$ and Zn$^{2+}$ and inhibited by PMSF and chymostatin. MEF-2 was inhibited by PMSF, TLCK. soybean trypsin inhibitor. MEF-3 was only inhibited by PMSF and chymostatin. Antiplasmin was not sensitive to MEF-1 but antithrombin III inhibited the enzymatic activity qf MEF-1. MEF-2 specifically bound to anti plasmin Among the chromogenic protease substrates, the most sensitive one to the hydrolysis of MEFs was benzoyl-Phe-Val-Arg-p-nitroanilide with maximal activity at pH 7.0 and 3$0^{\circ}C$. MEF-1 preferentially cleaved the oxidized B-chain of insulin between Leu15 and Tyr16. In contrast, MEF-2 specifically cleaved the peptide bond between Arg23 and Gly24. D-dimer concentrations increased on incubation of cross-linked fibrin with MEF-1, indicating the enzyme has a strong fibrinolytic activity.ity.

• Journal of Periodontal and Implant Science
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• v.40 no.1
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• pp.39-44
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• 2010

Purpose: Bone tissues for clinical application can be improved by studies on osteoblast differentiation. Runx2 is known to be an important transcription factor for osteoblast differentiation. However, bone morphogenetic protein (BMP)-2 treatment to stimulate Runx2 is not sufficient to acquire enough bone formation in osteoblasts. Therefore, it is necessary to find other regulatory factors which can improve the transcriptional activity of Runx2. The erythroblast transformation-specific (ETS) transcription factor family is reported to be involved in various aspects of cellular proliferation and differentiation. Methods: We have noticed that the promoters of osteoblast differentiation markers such as alkaline phosphatase (Alp), osteopontin (Opn), and osteocalcin (Oc) contain Ets binding sequences which are also close to Runx2 binding elements. Luciferase assays were performed to measure the promoter activities of these osteoblast differentiation markers after the transfection of Runx2, myeloid Elf-1-like factor (MEF), and Runxs+MEF. Reverse-transcription polymerase chain reaction was also done to check the mRNA levels of Opn after Runx2 and MEF transfection into rat osteoblast (ROS) cells. Results: We have found that MEF, an Ets transcription factor, increased the transcriptional activities of Alp, Opn, and Oc. The addition of Runx2 resulted in the 2- to 6-fold increase of the activities. This means that these two transcription factors have a synergistic effect on the osteoblast differentiation markers. Furthermore, early introduction of these two Runx2 and MEF factors significantly elevated the expression of the Opn mRNA levels in ROS cells. We also showed that Runx2 and MEF proteins physically interact with each other. Conclusions: Runx2 interacts with MEF proteins and binds to the promoters of the osteoblast markers such as Opn nearby MEF to increase its transcriptional activity. Our results also imply that osteoblast differentiation and bone formation can be increased by activating MEF to elicit the synergistic effect of Runx2 and MEF.

• Radiation Oncology Journal
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• v.33 no.3
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• pp.256-260
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• 2015

Purpose: Mefenamic acid (MEF) as a non-steroidal anti-inflammatory drug is used as a medication for relieving of pain and inflammation. Radiation-induced inflammation process is involved in DNA damage and cell death. In this study, the radioprotective effect of MEF was investigated against genotoxicity induced by ionizing radiation in human blood lymphocytes. Materials and Methods: Peripheral blood samples were collected from human volunteers and incubated with MEF at different concentrations (5, 10, 50, or $100{\mu}M$) for two hours. The whole blood was exposed to ionizing radiation at a dose 1.5 Gy. Lymphocytes were cultured with mitogenic stimulation to determine the micronuclei in cytokinesis blocked binucleated lymphocyte. Results: A significant decreasing in the frequency of micronuclei was observed in human lymphocytes irradiated with MEF as compared to irradiated lymphocytes without MEF. The maximum decreasing in frequency of micronuclei was observed at $100{\mu}M$ of MEF (38% decrease), providing maximal protection against ionizing radiation. Conclusion: The radioprotective effect of MEF is probably related to anti-inflammatory property of MEF on human lymphocytes.

• Molecules and Cells
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• v.39 no.4
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• pp.292-298
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• 2016

Aquaporin 1 (AQP1) is expressed in most microvasculature endothelial cells and forms water channels that play major roles in a variety of physiologic processes. This study aimed to delineate the transcriptional regulation of AQP1 by Mef2c in endothelial cells. Mef2c cooperated with Sp1 to activate human AQP1 transcription by binding to its proximal promoter in human umbilical cord vein endothelial cells (HUVEC). Over-expression of Mef2c, Sp1, or Mef2c/Sp1 increased HUVEC migration and tube-forming ability, which can be abolished AQP1 knockdown. These data indicate that AQP1 is a direct target of Mef2c in regulating angiogenesis and vasculogenesis of endothelial cells.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2010.05a
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• pp.149-150
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• 2010

• The Journal of Korean Medicine
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• v.27 no.3 s.67
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• pp.26-37
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• 2006

Determination and differentiation of cells in the skeletal muscle lineage is positively regulated by cell-cell contact. Differentiation proteins proposed to mediate this effect include both classical MyoD and MEF members; potential interactions between the promyogenic activities of these classes of protein, however, are unknown. We show here that MyoD and MEF, two promyogenic family members that relate to each other in a cis fashion, form interactions with MyoD and MEF. These proteins contain myosin-heavy chainsand are enriched at sites of cell-cell contact between myoblasts. Therefore, in differentiation of MyoD and MEF from Chungsimyeonjaeum interact dependently, suggesting that the interactions occur in a cis fashion; consistent with this conclusion, MyoD-mediated differentiation is required for myoblasts to occur by Chungsimyeonjaeum. Inhibition in myoblasts of a MyoD by Staurosporine in its ability to associate with MEF interferes with differentiation as assessed by morphological and transcription levels, suggesting that this interaction is functionally important in myogenesis. Also, some of the differentiation-mediated proteins that are required for myogenesis seem to be based on interdependent activities of the promyogenic classical smad-subfamily.

• International Journal of Oral Biology
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• v.38 no.2
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• pp.61-65
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• 2013

Erythromycin is a macrolide antibiotic and inhibits bacterial protein synthesis by stimulating the dissociation of the peptidyl-tRNA molecule from the ribosomes during elongation. The use of macrolides has increased dramatically over the last few years and has led to an increase in bacterial resistance to these antibiotics. Bacterial resistance to erythromycin is generally conferred by the ribosome methylation and/or transport (efflux) protein genes. Among the identified erythromycin-resistant genes, erm(B) (erythromycin methylation) and mef(A) (macrolide efflux) are generally detectable in erythromycin-resistant streptococcal species. The distribution of these genes in oral streptococcal isolates has been reported in studies from other countries but has not been previously examined in a Korean study. We here examined by PCR the presence of erm(B) and mef(A) in oral streptococci isolated from Korean dental plaques. Among the 57 erythromycin-resistant strains tested, 64.9% harbored erm(B) whereas 40.4% were positive for mef(A). Eleven isolates had both the erm(B) and mef(A) genes. Twenty six isolates had only erm(B) and 12 isolates had only mef(A). Eight of the 57 strains examined were negative for both genes.

• Development and Reproduction
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• v.19 no.3
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• pp.119-126
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• 2015

The suitable feeder cell layer is important for culture of embryonic stem (ES) cells. In this study, we investigated the effect of two kinds of the feeder cell, MEF cells and STO cells, layer to mouse ES (mES) cell culture for maintenance of stemness. We compare the colony formations, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins of D3 cell colonies cultured on MEF feeder cell layer (D3/MEF) or STO cell layers (D3/STO) compared to feeder free condition (D3/-) as a control group. Although there were no differences to colony formations and AP activities, interestingly, the transcripts level of pluripotency marker genes, Pou5f1 and Nanog were highly expressed in D3/MEF (79 and 93) than D3/STO (61and 77) or D3/- (65 and 81). Also, pluripotency marker proteins, NANOG and SOX-2, were more synthesized in D3/MEF ($72.8{\pm}7.69$ and $81.2{\pm}3.56$) than D3/STO ($32.0{\pm}4.30$ and $56.0{\pm}4.90$) or D3/- ($55.0{\pm}4.64$ and $62.0{\pm}6.20$). These results suggest that MEF feeder cell layer is more suitable to mES cell culture.

• The Journal of Korean Obstetrics and Gynecology
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• v.23 no.3
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• pp.26-37
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• 2010

Purpose: This experiment is designed to find out anti-oxidant effects of Samultang-Gami which was composed of Rehmanniae Radix(RR), Angelicae Gigantis Radix, Cnidii Rhizoma(CR), Paeoniae Radix(PR), Cortex Moutan Radicis, Hedyotis Diffusa(HD) and Caesalpinia Sappan on MEF cells. Methods: In vitro antioxidant effects were measured by MTT assay, DPPH assay, cell cycle analysis, AnnexinV-FITC/PI assay and DAPI staining using MEF cells treated with various concentrations of 70% ethanol extract of Samultang-Gami. Results: 1. In the scavenging for DPPH radical, the each treated groups of PR, CR and HD showed positive effects. RR and CR increased the viability of oxidative damaged MEF cells in a dose-dependent manner. 2. 70% ethanol extract of Samultang-Gami was shown best antioxidative effect in the concentration of $0.5mg/m{\ell}$. 3. The treatment of Samultang-Gami in oxidative damaged MEF cells didn't have any effect on cell cycle restoration. but it could lower late apoptosis rate a little and be observed the protection of nucleus. Conclusion: It can be concluded that Samultang-Gami, RR and CR have antioxidant effects on MEF cells.

• The Journal of Internal Korean Medicine
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• v.28 no.2
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• pp.333-345
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• 2007

Determination and differentiation of cells in the skeletal muscle lineage is positively regulated by cell-cell contact. differentiation proteins proposed to mediate this effect include both classical MyoD and MEF members : potential interactions between the promyogenic activities of these classes of protein, however, are unknown. We show here that MyoD and MEF, two promyogenic family members that determine to each other in a cis fashion, form ineraction with MyoD- and MEF. These proteins contain myosin heavy chains and are enriched at sites of cell-cell contact between myoblasts, Therefore, In differentiation of MyoD MEF from CST (Chungsimyeonjatang) interact dependently, suggesting that the interactions occur in a cis fashio : consistent with this conclusion, MyoD-mediated differentiation is required for myoblast to occur by CST. Inhibition in myoblasts of a MyoD by STP in its ability to associate with MEF interferes with differentiation as assessed by morphological and transcription level, suggesting that this interaction is functionally important in myogenesis. Also, some of the differentiation-mediated proteins that are required for myogenesis seem to be based on interdependent activities of promyogenic classical SMAD-subfamilly.