• Biomolecules & Therapeutics
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• 제24권2호
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• pp.171-177
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• 2016

Statins, HMG-CoA reductase inhibitors, are known to cause serious muscle injuries (e.g. myopathy, myositis and rhabdomyolysis), and these adverse effects can be rescued by co-administration of coenzyme $Q_{10}$ ($CoQ_{10}$) with statins. The goal of the current research is to assess the efficacy of combined treatment of $CoQ_{10}$ with Atorvastatin for hyperlipidemia induced by high-fat diet in SD rats. 4-week-old Sprague-Dawley male rats were fed normal diet or high-fat diet for 6 weeks. Then, rats were treated with either Statin or Statin with various dosages of $CoQ_{10}$ (30, 90 or 270 mg/kg/day, p.o.) for another 6 weeks. Compared to Statin only treatment, $CoQ_{10}$ supplementation significantly reduced creatine kinase and aspartate aminotransferase levels in serum which are markers for myopathy. Moreover, $CoQ_{10}$ supplementation with Statin further reduced total fat, triglycerides, total cholesterol, and low-density lipoprotein-cholesterol. In contrast, the levels of high-density lipoprotein-cholesterol and $CoQ_{10}$ were increased in the $CoQ_{10}$ co-treated group. These results indicate that $CoQ_{10}$ treatment not only reduces the side effects of Statin, but also has an anti-obesity effect. Therefore an intake of supplementary $CoQ_{10}$ is helpful for solving problem of obese metabolism, so the multiple prescription of $CoQ_{10}$ makes us think a possibility that can be solved in being contiguous to the obesity problem, a sort of disease of the obese metabolism.

• Molecules and Cells
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• 제26권6호
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• pp.611-615
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• 2008

DNA methylation is an epigenetic mechanism for gene silencing. In Arabidopsis, MET1 is the primary DNA methyltransferase that maintains CG DNA methylation. Plants having an overall reduction of MET1 activity, caused by a met1 mutation or a constitutively expressed MET1 antisense gene, display genome hypomethylation, inappropriate gene and transposon transcription, and developmental abnormalities. However, the effect of a transient reduction in MET1 activity caused by inhibiting MET1 expression in a restricted set of cells is not known. For this reason, we generated transgenic plants with a MET1 antisense gene fused to the DEMETER (DME) promoter (DME:MET1 a/s). Here we show that DME is expressed in leaf primordia, lateral root primoridia, in the region distal to the primary root apical meristem, which are regions that include proliferating cells. Endogenous MET1 expression was normal in organs where the DME:MET1 a/s was not expressed. Although DME promoter is active only in a small set of cells, these plants displayed global developmental abnormalities. Moreover, centromeric repeats were hypomethylated. The developmental defects were accumulated by the generations. Thus, not maintaining CG methylation in a small population of proliferating cells flanking the meristems causes global developmental and epigenetic abnormalities that cannot be rescued by restoring MET1 activity. These results suggest that during plant development there is little or no short-term molecular memory for reestablishing certain patterns of CG methylation that are maintained by MET1. Thus, continuous MET1 activity in dividing cells is essential for proper patterns of CG DNA methylation and development.

• 한국발생생물학회지:발생과생식
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• 제5권2호
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• pp.101-106
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• 2001

Insulin과 tumor necrosis factor alpha(TNF-$\alpha$)에 의한 초기 배아 발생의 조절기작을 알아보고자 생쥐의 상실배를 대상으로 이들이 첨가된 배양액에서 형태발생, 세포증식을 조사하고, 포배에서 mitogen activated protein kinase(MAPK, ERK1/2)의 활성 변화에 미치는 영향을 조사하였다. Insulin은 상실배의 체외발생 및 포배내 할구 수를 대조군에 비해 유의하게 증가시켰으며, TNF-$\alpha$는 발생율을 유의하게 감소시켰다. Insulin은 TNF- $\alpha$에 의한 배아 발생율 감소를 완화하였다. TNF-$\alpha$는 농도에 의존적으로 MAPK 활성을 감소시켰으며, insulin은 포배에서 MAPK의 활성을 유의하게 증가시킨 반면 TNF-$\alpha$는 처리농도에 의존적으로 MAPK 활성을 감소시켰다. 50 ng/ml 농도의 TNF-$\alpha$를 전처리한 포배에서는 insulin에 의한 MAPK 활성의 증가가 저해되었다. 이러한 결과로부터 생쥐의 착상전 초기 배아 발생조절에 insulin과 TNF-$\alpha$ 사이에 MAPK를 경유하는 cross talk이 존재함을 확인하였고 insulin은 TNF-$\alpha$ 에 의한 배아의 손상을 억제하는 것으로 사료된다.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2017년도 9th Asian Crop Science Association conference
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• pp.109-109
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• 2017

The core components of ABA-dependent gene expression signaling have been identified in Arabidopsis and rice. This signaling pathway consists of four major components; group A OsbZIPs, SAPKs, subclass A OsPP2Cs and OsPYL/RCARs in rice. These might be able to make thousands of combinations through interaction networks resulting in diverse signaling responses. We tried to characterize those gene functions using transient gene expression for rice protoplasts (TGERP) because it is instantaneous and convenient system. Firstly, in order to monitor the ABA signaling output, we developed reporter system named pRab16A-fLUC which consists of Rab16A promoter of rice and luciferase gene. It responses more rapidly and sensitively to ABA than pABRC3-fLUC that consists of ABRC3 of HVA1 promoter in TGERP. We screened the reporter responses for over-expression of each signaling components from group A OsbZIPs to OsPYL/RCARs with or without ABA in TGERP. OsbZIP46 induced reporter most strongly among OsbZIPs tested in the presence of ABA. SAPKs could activate the OsbZIP46 even in the ABA independence. Subclass A OsPP2C6 and -8 almost completely inhibited the OsbZIP46 activity in the different degree through the SAPK9. Lastly, OsPYL/RCAR2 and -5 rescued the OsbZIP46 activity in the presence of SAPK9 and OsPP2C6 dependent on ABA concentration and expression level. By using TGERP, we could characterize successfully the effects of ABA dependent gene expression signaling components in rice. In conclusion, TGERP represents very useful technology to study systemic functional genomics in rice or other monocots.

• Asian Pacific Journal of Cancer Prevention
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• 제15권8호
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• pp.3817-3823
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• 2014

Background: The MDM2 oncogene, a negative regulator of p53, has a functional polymorphism in the promoter region (SNP309) that is associated with multiple kinds of cancers including non-melanoma skin cancer. SNP309 has been shown to associate with accelerated tumor formation by increasing the affinity of the transcriptional activator Sp1. It remains unknown whether there are other factors involved in the regulation of MDM2 transcription through a trans-regulatory mechanism. Methods: In this study, SNP309 was verified to be associated with overexpression of MDM2 in tumor cells. Bioinformatics predicts that the T to G substitution at SNP309 generates a stronger E2F1 binding site, which was confirmed by ChIP and luciferase assays. Results: E2F1 knockdown downregulates the expression of MDM2, which confirms that E2F1 is a functional upstream regulator. Furthermore, tumor cells with the GG genotype exhibited a higher proliferation rate than TT, correlating with cyclin D1 expression. E2F1 depletion significantly inhibits the proliferation capacity and downregulates cyclin D1 expression, especially in GG genotype skin fibroblasts. Notably, E2F1 siRNA effects could be rescued by cyclin D1 overexpression. Conclusion: Taken together, a novel modulator E2F1 was identified as regulating MDM2 expression dependent on SNP309 and further mediates cyclin D1 expression and tumor cell proliferation. E2F1 might act as an important factor for SNP309 serving as a rate-limiting event in carcinogenesis.

• BMB Reports
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• 제34권6호
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• pp.578-583
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• 2001

As a prototypic Thl vs Th2 cytokine, IFN-$\gamma$ and IL-4 activate distinct STAT proteins, STAT1 and STATE, respectively. In cytokine-producing Jurkat T cells, IL-4 is effectively rescued from cell death that is induced by dexamethasone, but IFN-$\gamma$ failed to do so. Since the Ras/MAPK pathway is known to play an important role in cytokine-induced cell survival, we investigated the mechanism of T cell survival through the analysis of functional cross-talk between Ras/MAPK and distinct STAT proteins that are activated by IL-4 and IFN-$\gamma$. Although IL-4 and IFN-$\gamma$ each induced the activation of STATE and STATI. in Jurkat T cells, respectively, only IL-4 was capable of inducing MAPK. Along with tyrosine kinase inhibitors, MEK/MAPK inhibitors also caused a significant suppression of the IL-4-induced STATE activity. This suggests a positive regulation of STATE by MAPK during IL-4 signal transduction. Furthermore, transfection studies with dominant active (da) vs dominant negative (dn) Ras revealed that daRas, but not dnRas, selectively up-regulated the expression and activity of STATE with a concomitant increase in MAPK activity. These results, therefore, suggest that there is a functional cross-talk between the Ras/MAPK and Jak/STAT6 pathways, which may have a role in the IL-4-induced T cell survival.

• 대한한의학회지
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• 제24권2호
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• pp.179-192
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• 2003

Objectives : Boyanghwanoh-tang (Buyanhaiwu-tang) has been used as a prescription for stroke, senile and vascular dementia, ischemic brain and heart damage in Oriental traditional medicine. However, there is little known about the mechanism by which the water extracts of Boyanghwanoh-tang (Buyanhaiwu-tang) rescue cells fromthese damages, and little is known about the protective mechanisms of Boyanghwanoh-tang (Buyanhaiwu-tang) on oxidative stress in neuronal cells. Therefore, we have investigated the role of Boyanghwanoh-tang (Buyanhaiwu-tang) on serum and glucose deprived apoptosis in PC12 cells. Methods : PC12 Cells have been used extensively as a model for studying the cellular and molecular effects of neuronal cells. The viability of cells was measured by MIT assay. We used DNA fragmentation and caspase 1, 2, 3, 6, 9-likeproteases activation assay. Transcriptional activation of NF-kB was assessed by using electrophoretic mobility shift assay. Results : Boyanghwanoh-tang (Buyanhaiwu-tang) rescued PC12 cells from apoptotic death by serum and glucose deprivation in a dose-dependent manner. The nuclear staining of PC12 cells clearly showed that Boyanghwanoh-tang (Buyanhaiwu-tang) attenuated nuclear condensation and fragmentation, which represent typical neuronal apoptotic characteristics. Boyanghwanoh-tang (Buyanhaiwu-tang) also prevents fragmentation of genomic DNA and activation of caspase 3-like protease in serum and glucose deprived PC12 cells. Furthermore, Boyanghwanoh-tang (Buyanhaiwu-tang) reduced the activation of NF-kB by serum and glucose-deprived apoptosis. Conclusions : These findings suggest that serum and glucose deprivation induces reduced glutathione (GSH) depletion, and consequently, apoptosis through endogenously produced reactive oxygen species in PC12 cells. Also, our data indicated that Boyanghwanoh-tang (Buyanhaiwu-tang) has protective effects against the serum and glucose deprived deaths of PC12 cells, which are mediated by the generation of GSH that, in turn, can reduce oxidative stress caused by reactive oxygen species (ROS) such as hydrogen peroxide.

• 대한한방내과학회지
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• 제29권1호
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• pp.243-257
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• 2008

Myostatin, a negative regulator of myogenesis, is shown to function by controlling the proliferation of myoblasts. In this study we show that myostatin is an inhibitor of myoblast differentiation and that this inhibition is mediated through Smad 3. To determine MyoD expression by Dodamtang treatment, we compared the expression pattern of $C_{2}C_{12}$ mouse myoblasts that constitutively express myostatin with control cells. In vitro, increasing concentrations of Dodamtang reversibly prevented the myogenic blockage of myoblasts by myostatin expression. ELISA assay, Western and confocal analysis indicated that treatment of Dodamtang to the low serum culture media increased the levels of MyoD leading to the inhibition of myogenic differentiation by myostatin. The stable transfection of $C_{2}C_{12}$ myoblasts with myostatin expressing constructs did rescue MyoD-induced myogenic differentiation. Consistent with this, the treatment of Dodamtang rescued the expression of a MyoD in $C_{2}C_{12}$ myoblasts treated with myostatin. Taken together, these results suggest that induction of MyoD by Dodamtang inhibits myostatin activity and expression via SMAD3 resulting in the rescue of the myoblasts to differentiate into myotubes. Thus we propose that myostatin action by Dodamtang plays a critical role in myogenic differentiation and that the muscular hyperplasia and hypertrophy seen in animals that blockage of functional myostatin is because of deregulated proliferation and differentiation of myoblasts.

• Journal of Plant Biotechnology
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• 제43권1호
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• pp.30-36
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• 2016

Brassinosteroids (BRs) are essential plant steroid hormones required for cell elongation, plant growth, development and abiotic and biotic stress tolerance. BRs are recognized by BRI1 receptor kinase that is localized in the plasma membrane, and the BRI1 protein will eventually autophosphorylate in the intracellular domain and transphosphorylate BAK1, which is a co-receptor in Arabidopsis thaliana. However, little is known of the role OsBRI1 receptor kinase plays in Oryza sativa, monocotyledonous plants, compared to that in Arabidopsis thaliana, dicotyledonous plants. As such, we have studied OsBRI1 receptor kinase in vitro and in vivo with recombinant protein and transgenic plants, whose phenotypes were also investigated. A OsBRI1 cytoplasmic domain (CD) recombinant protein was induced in BL21 (DE3) E.coli cells with IPTG, and purified to obtain OsBRI1 recombinant protein. Based on Western blot analysis with phospho-specific pTyr and pThr antibodies, OsBRI1 recombinant protein and OsBRI1-Flag protein were phosphorylated on Threonine residue(s), however, not on Tyrosine residue(s), both in vitro and in vivo. This is particularly intriguing as AtBRI1 protein was phosphorylated on both Ser/Thr and Tyr residues. Also, the OsBRI1 full-length gene was expressed in, and rescued, bri1-5 mutants, such as is seen in normal wild-type plants where AtBRI1-Flag rescues bri1-5 mutant plants. Root growth in seedlings decreased in Ws2, AtBRI1, and 3 independent OsBRI1 transgenic seedlings and had an almost complete lack of response to brassinolide in the bri1-5 mutant. In conclusion, OsBRI1, an orthologous gene of AtBRI1, can mediate normal BR signaling for plant growth and development in Arabidopsis thaliana.

• Journal of Plant Biotechnology
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• 제43권3호
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• pp.376-382
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• 2016

DNA methylation은 무수히 많이 발생하는 생리적 및 병리적 측면의 과정에서 관련 유전자의 발현을 조절함으로써 중추적인 역할을 가지고 있다. 본 연구에서는 NtROS2a가 과발현된 형질전환 벼를 육성하고, 그들의 형태적 측면을 관찰하고 스트레스 내성을 검토하였다. 형질전환 식물체는 WT에 비하여 신초의 신장이 작게 나타났다. 저온 스트레스 처리 하에서 NtROS2a 형질전환 벼는 스트레스로 인한 생육 불량을 보였으나 건조 스트레스 처리 하에서는 WT보다는 높은 비율로 회복하여 생존하는 것을 확인할 수 있었다. 이러한 결과는 NtROS2a 유전자의 과발현으로 인해 벼가 건조 스트레스에 노출되면 내성을 증진시킨 것으로 생각된다.