• 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.

• 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 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.

• 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.

• Parasites, Hosts and Diseases
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• v.53 no.4
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• pp.431-438
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• 2015

In Trichinella spiralis infection, type 2 helper T (Th2) cell-related and regulatory T ($T_{reg}$) cell-related immune responses are the most important immune events. In order to clarify which Toll-like receptors (TLRs) are closely associated with these responses, we analyzed the expression of mouse TLR genes in the small intestine and muscle tissue during T. spiralis infection. In addition, the expression of several chemokine- and cytokine-encoding genes, which are related to Th2 and $T_{reg}$ cell mediated immune responses, were analyzed in mouse embryonic fibroblasts (MEFs) isolated from myeloid differentiation factor 88 (MyD88)/TIR-associated proteins (TIRAP) and Toll receptor-associated activator of interferons (TRIF) adapter protein deficient and wild type (WT) mice. The results showed significantly increased TLR4 and TLR9 gene expression in the small intestine after 2 weeks of T. spiralis infection. In the muscle, TLR1, TLR2, TLR5, and TLR9 gene expression significantly increased after 4 weeks of infection. Only the expression of the TLR4 and TLR9 genes was significantly elevated in WT MEF cells after treatment with excretory-secretory (ES) proteins. Gene expression for Th2 chemokine genes were highly enhanced by ES proteins in WT MEF cells, while this elevation was slightly reduced in MyD88/$TIRAP^{-/-}$ MEF cells, and quite substantially decreased in $TRIF^{-/-}$ MEF cells. In contrast, IL-10 and $TGF-{\beta}$ expression levels were not elevated in MyD88/$TIRAP^{-/-}$ MEF cells. In conclusion, we suggest that TLR4 and TLR9 might be closely linked to Th2 cell and $T_{reg}$ cell mediated immune responses, although additional data are needed to convincingly prove this observation.

• Biomolecules & Therapeutics
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• v.18 no.4
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• pp.454-462
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• 2010

The present study investigated the neuroprotective effect of Carpinus tschonoskii MAX and its intracellular protective mechanism on 6-hydroxydopamine (6-OHDA)-induced oxidative damage in PC12 cells. We found that pretreatment of PC12 cells with C. tschonoskii extract significantly inhibited the cell death induced by 6-OHDA in a dose dependent manner. C. tschonoskii extract decreased 6-OHDA-induced apoptotic events such as chromatin condensation, DNA fragmentation, the decrease of Bcl-2/Bax ratio, caspase-3 activation and PARP cleavage. C. tschonoskii extract also reduced generation of 6-OHDA-induced reactive oxygen species and nitric oxide. Furthermore, C. tschonoskii extract up-regulated the myocyte enhancer factor 2 D (MEF2D), a critical transcription factor for neuronal survival, and Akt activity, whereas it inhibited the activity of ERK1/2 and JNK. The results suggest that C. tschonoskii extract decreases 6-OHDA-induced oxidative stress and could prevent PC12 cell apoptosis induced by 6-OHDA via the up-regulation of MEF2D and Akt activity, and thus may have application in developing therapeutic agents for Parkinson's disease.

• Molecules and Cells
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• v.28 no.1
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• pp.1-5
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• 2009

Vascular endothelial growth factor (VEGF) is essential for many angiogenic processes both in normal and pathological conditions. However, the signaling pathways involved in VEGF-induced angiogenesis are incompletely understood. The protein kinase D1 (PKD1), a newly described calcium/calmodulin-dependent serine/threonine kinase, has been implicated in cell migration, proliferation and membrane trafficking. Increasing evidence suggests critical roles for PKD1-mediated signaling pathways in endothelial cells, particularly in the regulation of VEGF-induced angiogenesis. Recent studies show that class IIa histone deacetylases (HDACs) are PKD1 substrates and VEGF signal-responsive repressors of myocyte enhancer factor-2 (MEF2) transcriptional activation in endothelial cells. This review provides a guide to PKD1 signaling pathways and the direct downstream targets of PKD1 in VEGF signaling, and suggests important functions of PKD1 in angiogenesis.

• Nutrition Research and Practice
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• v.13 no.2
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• pp.95-104
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• 2019

BACKGROUND/OBJECTIVES: Inflammatory Bowel Disease (IBD) has rapidly escalated in Asia (including Korea) due to increasing westernized diet patterns subsequent to industrialization. Factors associated with endoplasmic reticulum (ER) stress are demonstrated to be one of the major causes of IBD. This study was conducted to investigate the effect of Lycium barbarum (L. barbarum) on ER stress. MATERIALS/METHODS: Mouse embryonic fibroblast (MEF) cell line and polarized Caco-2 human intestinal epithelial cells were treated with crude extract of the L. chinense fruit (LF). Paracellular permeability was measured to examine the effect of tight junction (TJ) integrity. The regulatory pathways of ER stress were evaluated in MEF knockout (KO) cell lines by qPCR for interleukin (IL) 6, IL8 and XBP1 spliced form (XBP1s). Immunoglobulin binding protein (BiP), XBP1s and CCAAT/enhancer-binding homologous protein (CHOP) expressions were measured by RT-PCR. Scanning Ion Conductance Microscopy (SICM) at high resolution was applied to observe morphological changes after treatments. RESULTS: Exposure to LF extract strengthened the TJ, both in the presence and absence of inflammation. In polarized Caco-2 pretreated with LF, induction in the expression of proinflammatory marker IL8 was not significant, whereas ER stress marker XBP1s expression was significantly increased. In wild type (wt) MEF cells, IL6, CHOP and XBP1 spliced form were dose-dependently induced when exposed to $12.5-50{\mu}g/mL$ extract. However, absence of XBP1 or $IRE1{\alpha}$ in MEF cells abolished this effect. CONCLUSION: Results of this study show that LF treatment enhances the barrier function and reduces inflammation and ER stress in an $IRE1{\alpha}$-XBP1-dependent manner. These results suggest the preventive effect of LF on healthy intestine, and the possibility of reducing the degree of inflammatory symptoms in IBD patients.

• Journal of Life Science
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• v.14 no.1
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• pp.82-90
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• 2004

This study was carried out to analysis the composition of fruit body of Morchella esculenta (MEF) to determine the possibility of medical and edible use. The nutritional compositions of MEF were as follows ; The contnt (g%) of crude fat, carbohydrate, crude protein were 3.8, 43.5 and 29.7, respectively. Potassium concentration in MEF was high up to 3558.0 mg% and Ca, Mg, Fe, Na and Zn were followed. There were 23 amino acids in MEF The content of glutamic acid was high up to 1433.0 mg% and leucine, alanine, arginine valine and theronine were followed. Since MEF contains 25 free amino acids, it will be a favorable food stuff. The content of Vitamin A, Vitamin $B_1$, , Vitamin$B_2$, Vitamin $B_6$, Vitamin C, Vitamin $BD_3$, Vitamin E and Vitamin $K_1$, were 2.23 $\mug%$, 0.13 mg%, 0.07 mg%, 0.27 mg%, 0.17 mg%, 52.27 $\mug%$, 5.26 mg% and 3.23 $\mug%$, respectively. MEF will have a good anti-aging effect due to content of Vitamin C and Vitamin E.

• The Korean Journal of Zoology
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• v.28 no.2
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• pp.108-119
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• 1985

Aimed at elucidating the modulation of stress protein gene expression, the effect of environmental stress and pH on the induction of stress protein synthesis has been analyzed using SDS-polyacrylamide gel electrophoresis. Although the general patterns of protein synthesis in MEF and SCK cells are different, stress protein patterns are identical in both cells. Among three stress proteins, the $SP_70$ exhibits an interesting kinetics of induction and decay. The kinetics of $SP_70$ under acidic or normal pH appears to be similar, but the degree of hyperthermia and duration of treatment required for maximum induction are found to be different, being lower temperatures and shorter durations under acidic pH compared to those under normal pH. Inducation of stress protein and the accumulation of mRNA coding for stress proteins are blocked with actinomycin D, indicating the new RNA transcription is required for stress blocked with actinomycin D, indicating that new RNA transcription is required for stress protein induction. Treatment of cycloheximide during the after hyperthermia indicates that no specific protein is required for the induction of stress protein synthesis. Based on our preliminary data, we postulate that induction of stress protein synthesis in MEF and SCK cells is regulated primarily at the level of transcription and that $SP_70$ autoregulates its synthesis and levels of this protein are correlated with the stresseed state of a cell.