• Development and Reproduction
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• v.22 no.3
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• pp.235-244
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• 2018

We investigate the effect of endoplasmic reticulum (ER) stress inhibitor treatment during parthenogenetic activation of oocytes on the ER stress generation, apoptosis, and in vitro development of parthenogenetic porcine embryos. Porcine in vitro matured oocytes were activated by 1) electric stimulus (E) or 2) $E+10{\mu}M$ Ca-ionophore (A23187) treatment (EC). Oocytes were then treated by ER stress inhibitors such as salubrinal (200 nM) and tauroursodeoxychloic acid (TUDCA, $100{\mu}M$) for 3 h prior to in vitro culture. Parthenogenetic embryos were sampled to analyze ER stress and apoptosis at the 1-cell and blastocyst stages. The x-box binding protein 1 (Xbp1) mRNA and ER stress-associated genes were analyzed by RT-PCR or RT-qPCR. Apoptotic gene expression was analyzed by RT-PCR. At the 1-cell stage, although no difference was observed in Xbp1 splicing among treatments, BiP transcription level in the E group was significantly reduced by salubrinal treatment, and GRP94 and ATF4 transcription levels in EC group were significantly reduced by all treatments (p<0.05) compared to control. In the EC group, both apoptotic genes were reduced by ER stress inhibitor treatments compared to control (p<0.05) except Caspase-3 gene by TUDCA treatment. These results suggest that the treatment of ER stress inhibitor during parthenogenetic activation can reduce ER stress, and thereby reduce apoptosis and promote in vitro development of porcine parthenogenetic embryos.

• The Korean Journal of Physiology and Pharmacology
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• v.18 no.3
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• pp.211-216
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• 2014

Endoplasmic reticulum (ER) stress, unfolded protein response (UPR), and mitochondrial biogenesis were assessed following varying intensities of exercise training. The animals were randomly assigned to receive either low- (LIT, n=7) or high intensity training (HIT, n=7), or were assigned to a control group (n=7). Over 5 weeks, the animals in the LIT were exercised on a treadmill with a $10^{\circ}$ incline for 60 min at a speed of 20 m/min group, and in the HIT group at a speed of 34 m/min for 5 days a week. No statistically significant differences were found in the body weight, plasma triglyceride, and total cholesterol levels across the three groups, but fasting glucose and insulin levels were significantly lower in the exercise-trained groups. Additionally, no statistically significant differences were observed in the levels of PERK phosphorylation in skeletal muscles between the three groups. However, compared to the control and LIT groups, the level of BiP was lower in the HIT group. Compared to the control group, the levels of ATF4 in skeletal muscles and CHOP were significantly lower in the HIT group. The HIT group also showed increased PGC-$1{\alpha}$ mRNA expression in comparison with the control group. Furthermore, both of the trained groups showed higher levels of mitochondrial UCP3 than the control group. In summary, we found that a 5-week high-intensity exercise training routine resulted in increased mitochondrial biogenesis and decreased ER stress and apoptotic signaling in the skeletal muscle tissue of rats.

• Asian-Australasian Journal of Animal Sciences
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• v.20 no.12
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• pp.1827-1831
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• 2007

Effects of daidzein on expression of mRNAs of gonadotropin receptors (FSHR, LHR) and P450 aromatase (P450arom) were evaluated in ovarian follicles of white silky fowls. The hens were 13 months old in the post-peak period of egg laying and were randomly allocated as control and daidzein-treated groups, with daidzein supplemented to the basal diet at 10 mg/kg for 7 consecutive weeks. The mRNA expression of related genes was measured by semi-quantitative RT-PCR in the granulosa layers of the preovulatory follicle (PRF: F1, F2 ...) and follicular layers of the small yellow follicle (SYF), large white follicle (LWF) and atretic follicle (ATF). Results showed that daidzein supplementation significantly increased the number of SYF and LWF (p<0.05). The relative abundance of the FSHR mRNA decreased in the granulosa layers from F3 to F1, but LHR mRNA displayed opposite developmental changes. P450arom mRNA was highest in the SYF, but was very low in the granulosa layers after follicles finished selection. Treatment with daidzein resulted in increased mRNA expression of FSHR in F3 granulosa layer, LHR in granulosa layers of F3 to F1 and P450arom in LWF (p<0.05). These results indicated that dietary supplementation of daidzein up-regulated mRNA expression of gonadotropin receptors and P450arom to improve the development of preovulatory follicles in white silky fowls after the peak-laying period.

• Molecules and Cells
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• v.41 no.5
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• pp.401-412
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• 2018

Oxymatrine (OMT) often used in treatment for chronic hepatitis B virus infection in clinic. However, OMT-induced liver injury has been reported. In this study, we aim to investigate the possible mechanism of OMT-induced hepatotoxicity in human normal liver cells (L02). Exposed cells to OMT, the cell viability was decreased and apoptosis rate increased, the intracellular markers of oxidative stress were changed. Simultaneously, OMT altered apoptotic related proteins levels, including Bcl-2, Bax and pro-caspase-8/-9/-3. In addition, OMT enhanced the protein levels of endoplasmic reticulum (ER) stress makers (GRP78/Bip, CHOP, and cleaved-Caspase-4) and phosphorylation of c-Jun N-terminal kinase (p-JNK), as well as the mRNA levels of GRP78/Bip, CHOP, caspase-4, and ER stress sensors (IREI, ATF6, and PERK). Pre-treatment with Z-VAD-fmk, JNK inhibitor SP600125 and N-acetyl-l-cysteine (NAC), a ROS scavenger, partly improved the survival rates and restored OMT-induced cellular damage, and reduced caspase-3 cleavage. SP600125 or NAC reduced OMT-induced p-JNK and NAC significantly lowered caspase-4. Furthermore, 4-PBA, the ER stress inhibitor, weakened inhibitory effect of OMT on cells, on the contrary, TM worsen. 4-PBA also reduced the levels of p-JNK and cleaved-caspase-3 proteins. Therefore, OMT-induced injury in L02 cells was related to ROS mediated p-JNK and ER stress induction. Antioxidant, by inhibition of p-JNK or ER stress, may be a feasible method to alleviate OMT-induced liver injury.

• BMB Reports
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• v.36 no.3
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• pp.326-331
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• 2003

The fission yeast cells that contained the cloned glutathione synthetase (GS) gene showed 1.4-fold higher glutathione (GSB) content and 1.9-fold higher GS activity than the cells without the cloned GS gene. Interestingly, $\gamma$-glutamylcysteine synthetase activity increased 2.1-fold in the S. pombe cells that contained the cloned GS gene. The S. pombe cells that harbored the multi copy-number plasmid pRGS49 (containing the cloned GS gene) showed a higher level of survival on solid media with cadmium chloride (1 mM) or mercuric chloride ($10\;{\mu}M$) than the cells that harbored the YEp357R vector. The 506 bp upstream sequence from the translational initiation point and N-terminal8 amino acid-coding region were fused into the promoteriess $\beta$-galactosidase gene of the shuttle vector YEp367R to generate the fusion plasmid pUGS39. Synthesis of $\beta$-galactosidase from the fusion plasmid pUGS39 was significantly enhanced by cadmium chloride and NO-generating S-nitroso-N-acetylpenicillamine (SNAP) and sodium nitroprusside (SN). It was also induced by L-buthionine-(S,R)-sulfoximine, a specific inhibitor of $\gamma$-glutamylcysteine synthetase (GCS). We also found that the expression of the S. pombe GS gene is regulated by the Atf1-Spc1-Wis1 signal pathway.

• International Journal of Oral Biology
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• v.41 no.2
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• pp.53-62
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• 2016

In the present study, we evaluated the effect of CGM on osteogenic differentiation of cultured osteoblasts, and determined whether combination treatment with LLLT had synergistic effects on osteogenic differentiation. The results indicated that CGM promoted proliferation, differentiation, and mineralization of osteoblasts at the threshold concentration of $10{\mu}g/ml$; whereas, CGM showed cytotoxic properties at concentrations above $100{\mu}g/ml$. ALP activity and mineralization were increased at concentrations above $10{\mu}g/ml$. CGM in concentrations up to $10{\mu}g/ml$ also increased the expression of osteoblast-activated factors including type I collagen, BMP-2, RUNX2, and Osterix. The CGM ($50{\mu}g/ml$) and LLLT (80 mW for 15 sec) combination treatment group showed the highest proliferation levels, ALP activity, and mineralization ratios. The combination treatment also increased the levels of phosphorylated forms of p38, ATF2, PKD, ERK, and JNK. In addition, the osteoblast differentiation factors including type I collagen, BMP-2, RUNX2, and Osterix protein levels were clearly increased in the combination treatment group. These results suggested that the combination treatment of CGM and LLLT has synergistic effects on the differentiation and mineralization of osteoblastic cells.

• YAKHAK HOEJI
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• v.60 no.3
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• pp.128-134
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• 2016

L1 cell adhesion molecule (L1CAM) is a cell surface molecule to initiate a variety of cellular responses through interacting with other cell adhesion molecules in a homophilic or heterophilic manner. Although its expression was found to be upregulated in some tumor cells, including cholangiocarcinomas, and ovarian cancers, and many studies have investigated the role of L1CAM in these cancers, its role in inflammatory responses has been poorly understood. In this study, we explored the role of L1CAM in macrophage-mediated inflammatory responses. L1CAM significantly suppressed the production of nitric oxide (NO), but induced cell proliferation in RAW264.7 cells. L1CAM expression was detectable, but its expression was markedly decreased by lipopolysaccharide (LPS) in RAW264.7 cells. In addition, the expression of pro-inflammatory genes, such as tumor necrosis factor (TNF)-${\alpha}$, cyclooxygenase (COX)-2, and inducible nitric oxide synthase (iNOS) induced by LPS was dramatically suppressed by L1CAM in RAW264.7 cells. L1CAM inhibited the transcriptional activities of NF-${\kappa}B$ and AP-1 while its cytoplasmic domain deletion form, $L1{\Delta}CD$ did not suppressed their activities in RAW264.7 cells. Moreover, L1CAM suppressed nuclear translocation of p65 and p50 as well as c-Jun, c-Fos and p-ATF2 which are transcription factors of NF-${\kappa}B$ and AP-1, respectively. In conclusion, L1CAM suppressed inflammatory responses in macrophages through inhibiting NF-${\kappa}B$ and AP-1 pathways.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.3 no.3
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• pp.569-577
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• 1999

A wideband RF receiver for satellite mobile communications system was fabricated and evaluated of performance in low noise amplifier and high gain amplifier. The low noise amplifier used to the resistive decoupling and self-bias circuits. The low noise amplifier is fabricated with both the RF circuits and the self-bias circuits. Using a INA-03184, the high gain amplifier consists of matched amplifier type. The active bias circuitry can be used to provide temperature stability without requiring the large voltage drop or relatively high-dissipated power needed with a bias stabilized resistor. The bandpass filter was used to reduce a spurious level. As a result, the characteristics of the receiver implemented here show more than 55 dB in gain, 50.83 dBc in a spurious level and less than 1.8 : 1 in input and output voltage standing wave ratio(VSWR), especially the carrier to noise ratio is a 43.15 dB/Hz at a 1 KHz from 1537.5 MHz.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.4
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• pp.886-893
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• 2004

In this paper, active resonator oscillator using active band pass filter with gain, active resonator with negative resistance using transistor(agilent ATF-34143) is designed and fabricated. Proposed active resonator oscillator for local oscillator in ISM band(5.8GHz) is designed with 5.5 GHz oscillation frequency. Designed active resonator oscillator implemented on the substrate which has the relative dielectric constant of 3.38, the height of 0.508mm, and metal thickness of 0.018mm. Active resonator oscillators using active band pass filter with gain show the oscillation frequency of 5.6GHz with the output power of -2dBm and phase noise of -81dBc/Hz at the offset frequency of 100kHz. Active resonator oscillators active resonator with negative resistance show the oscillation frequency of 5.6, 5.8GHz with the output power of -4dBm and phase noise of -91dBc/Hz at the offset frequency of 100kHz.

• Composites Research
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• v.35 no.3
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• pp.161-174
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• 2022

SiC fiber-reinforced SiC matrix composite is a promising accident-tolerant fuel cladding material to improve the safety of light water nuclear reactors. Compared to the current zirconium alloy fuel cladding as well as metallic accident-tolerant fuel cladding, SiC composite fuel cladding has exceptional accident-tolerance such as excellent structural integrity and extremely low corrosion rate during severe accident of light water nuclear reactors, which reduces reactor core temperature and delays core degradation processes. In this paper, we introduce the concept, technical issues, and properties of SiC composite accident-tolerant fuel cladding during operation and accident scenarios of light water nuclear reactors.