• Korean Journal of Medicinal Crop Science
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• v.15 no.5
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• pp.311-314
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• 2007

Vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) are the most important angiogenic molecules associated with tumor-induced neovascularization. This study was carried out to investigate inhibitory effect of extracts from root of Rehmannia glutinosa LIBOSCHITZ (Rehmannia Radix and Rehmannia Radix Preparata) on endothelial cell proliferation. The methanol extracts from the medicinal herb were fractionated into n-hexane, ethyl acetate, n-butanol and aqueous fractions. Among the four fractions, the n-butanol fraction from R. Radix on exhibited highly effective inhibition (${\approx}79%$ inhibition) on the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ and then ethyl acetate fraction from R. Radix (${\approx}45%$ inhibition) at the concentration of $100\;{\mu}g/ml$. The n-butanol fraction efficiently blocked the VEGF- and bFGF-induced HUVEC proliferation in a dose-dependent manner, but did not affect the growth of HT1080 human fibrosarcoma cells. The n-butanol fraction more efficiently blocked the binding of KDR/Flk-1-Fc to immobilized $VEGF_{165}$ and VEGF- and bFGF-induced human umbilical vein endothelial cell proliferation than the fraction from R. Radix Preparata. Our results suggest that Rehmannia Radix may be used as a candidate for developing anti-angiogenic agent.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.79-85
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• 2008

Some studies of dandelion have been carried out on bioactivities, however, no comparative analysis on antioxidant and cytotoxic activities in the Korean dandelion (T. coreanum NAKAI.; KD) and dandelion (T. officinale WEB.) have been reported. In this study, the extracts of KD and dandelion analyzed relative phenolic contents and free radical scavenging, antioxidant enzyme and cytotoxic activities. The extract of Korean dandelion leaves (KDL) exhibited a higher phenolics content ($368{\pm}11.5\;mg/l00\;g$) and a strong free radical scavenging activity ($RC_{50}$value;87.89 ug/ml) than other parts and BHT (120.12 ug/ml), synthetic antioxidant. At ascorbate peroxidase (APX) activity, the dandelion root (DR) had a greater (38.8 U/mg protein) antioxidant enzyme compare to the dandelion leaves (12.2 U/mg protein). The catalase (CAT) and superoxide dismutase (SOD) followed higher enzyme activity in Korean dandelion root (KDR) than other parts. In a cytotoxic activity against human cancer cell, the extracts of KDR was found to be active against Calu-6, HCT-116, and SNU-601 cell lines, with $IC_{50}$ values of 522.34, 532.74 and 614.85 ug/ml, respectively. These results suggest that KD and dandelion would be an alternative antioxidant source, based on natural plant resources.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.237-239
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• 2006

Nowadays the core control systems are made by multiple redundancy strategy. There are analog excitation systems which have been operating during more than twenty years. This project is aim to retrofit nuclear power plants, also improves the reliance, safety, faculty of nuclear generator excitation system.

• The Journal of Korean Society for Radiation Therapy
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• v.14 no.1
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• pp.165-174
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• 2002

Vascular endothelial growth factor (VEGF) has been identified as a peptide growth factor specific for vascular endothelial cells. In this study, we examined the effect of VEGF on radiation induced apoptosis and receptor/second messenger signal transduction pathway for VEGF effect in human umbilical vein endothelial cells (HUVECs). VEGF was found to protect HUVECs against the lethal effects of ionizing radiation by inhibiting the apoptosis induced in these cells by radiation exposure. VEGF (1-30 ng/ml) dose dependently inhibited apoptosis by irradiation. Pre-treatment with Flt-1 and Flk-l/KDR receptor blocked the VEGF-in duced antiapoptotic effect. Phosphatidylinositol 3'-kinase (PI3-kinase) specific inhibitor, Wortman in and LY294002, blocked the VEGF-induced antiapoptotic effect. These data suggest that VEGF may play an important role in survival of HUVECs due to the prevention of apoptotic cell death caused by some stresses such as ionizing radiation.

• BMB Reports
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• v.54 no.9
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• pp.464-469
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• 2021

Cardiomyocyte differentiation occurs through complex and finely regulated processes including cardiac lineage commitment and maturation from pluripotent stem cells (PSCs). To gain some insight into the genome-wide characteristics of cardiac lineage commitment, we performed transcriptome analysis on both mouse embryonic stem cells (mESCs) and human induced PSCs (hiPSCs) at specific stages of cardiomyocyte differentiation. Specifically, the gene expression profiles and the protein-protein interaction networks of the mESC-derived platelet-derived growth factor receptor-alpha (PDGFRα)⁺ cardiac lineage-committed cells (CLCs) and hiPSC-derived kinase insert domain receptor (KDR)⁺ and PDGFRα⁺ cardiac progenitor cells (CPCs) at cardiac lineage commitment were compared with those of mesodermal cells and differentiated cardiomyocytes. Gene Ontology and Kyoto Encyclopedia of Genes and Genomes pathway analyses revealed that the genes significantly upregulated at cardiac lineage commitment were associated with responses to organic substances and external stimuli, extracellular and myocardial contractile components, receptor binding, gated channel activity, PI3K-AKT signaling, and cardiac hypertrophy and dilation pathways. Protein-protein interaction network analysis revealed that the expression levels of genes that regulate cardiac maturation, heart contraction, and calcium handling showed a consistent increase during cardiac differentiation; however, the expression levels of genes that regulate cell differentiation and multicellular organism development decreased at the cardiac maturation stage following lineage commitment. Additionally, we identified for the first time the protein-protein interaction network connecting cardiac development, the immune system, and metabolism during cardiac lineage commitment in both mESC-derived PDGFRα⁺ CLCs and hiPSC-derived KDR⁺PDGFRα⁺ CPCs. These findings shed light on the regulation of cardiac lineage commitment and the pathogenesis of cardiometabolic diseases.

• Bulletin of the Korean Chemical Society
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• v.33 no.5
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• pp.1571-1576
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• 2012

A diarylurea compound 1 possessing pyrrolo[3,2-$c$]pyridine nucleus was designed and synthesized with structure similarity to Sorafenib. Compound 1 was tested over 60-cancer cell line panel at a single dose concentration of 10 ${\mu}M$ and showed high activity. It was further tested in a five-dose mode to determine its $IC_{50}$, TGI, and $LC_{50}$ values over the 60 cell lines. Compound 1 showed high potency and good efficacy, and was accordingly tested at a single dose concentration of 10 ${\mu}M$ over a panel of 40 kinases. At this concentration, it completely inhibited the enzymatic activities of a number of oncogenic kinases, including ABL, ALK, c-RAF, FLT3, KDR, and TrkB. The target compound was subsequently tested over these 6 kinases in 10-dose testing mode in order to determine its $IC_{50}$ values.

• Natural Product Sciences
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• v.27 no.2
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• pp.134-139
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• 2021

A new cipadesin limonoid, i.e. 3-epi-cipadonoid C (1), and a new tirucallane triterpene, i.e. hispidol B 3-palmitate (3), have been isolated from the seeds and fruit peels extract of Sandoricum koetjape, respectively. Along with these compounds the known limonoid, cipaferen G (2), and two pentacyclic triterpenes, bryonolic (4) and bryononic (5) acids, were also isolated. The strucrures of the new compounds were elucidated by the analysis of NMR and mass spectral data. Compounds 1 - 5 were evaluated as the inhibitor of receptor tyrosine kinases (EGFR, Epidermal Growth Factor Receptor; HER2, HER4, Human Epidermal growth factor Receptor 2, -4; IGFR, Insulin-like Growth Factor Receptor; InsR, Insulin Receptor; KDR, Kinase insert Domain Receptor; PDGFRα, and PDGFRβ, Platelet-Derived Growth Factor Receptor-α and -β). The results showed only 1 and 3 that have weak activity against InsR.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.4
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• pp.366-379
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• 2017

In this study, we performed a systematic review and meta-analysis to identify the effects of exercise on endothelial progenitor cells (EPCs) in patients with cardiovascular disease (CVD). We conducted database searches (Cochrane Library, PubMed, EMBASE, ScienceDirect, CINAHL, Scopus, KoreaMed, KISS, RISS, KMBASE) for the effect of exercise on cardiovascular disease, using heart disease, coronary artery disease, heart failure, cardiovascular disease, exercise, motor activity, rehabilitation, and endothelial progenitor cells as the keywords. Of the 539 studies identified, 9 met the inclusion and exclusion criteria. Comprehensive Meta-Analysis version 2.0 was used to analyze the effect size and the publication bias was checked with a funnel plot. Exercise was found to improve the VEGF (vascular endothelial growth factor), CD34+KDR+, and endothelial function, assessed via FMD (flow-mediated dilation), in the exercise vs. control groups, viz. 2.008 (95% CI 0.204-3.812), 1.399 (95% CI 0.310-2.489), and 1.881 (95% CI 0.848-2.914), respectively. Exercise improved the VEGF, number of EPCs, and endothelial function in the CVD patients. Considering the increasing prevalence and mortality rates for cardiovascular disease in Korea, the findings of this study that analyzed the effects of exercise on EPCs might provide guidelines for planning exercise interventions for patients with CVD.

• Molecules and Cells
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• v.25 no.4
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• pp.487-493
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• 2008

HoxB4 has been shown to enhance hematopoietic engraftment by hematopoietic stem cells (HSC) from differentiating mouse embryonic stem cell (mESC) cultures. Here we examined the effect of ectopic expression of HoxB4 in differentiated human embryonic stem cells (hESCs). Stable HoxB4-expressing hESCs were established by lentiviral transduction, and the forced expression of HoxB4 did not affect stem cell features. HoxB4-expressing hESC-derived CD34+ cells generated higher numbers of erythroid and blast-like colonies than controls. The number of CD34+ cells increased but CD45+ and KDR+ cell numbers were not significantly affected. When the hESC derived CD34+ cells were transplanted into $NOD/SCID{\beta}2m-/-$ mice, the ectopic expression of HoxB4 did not alter their repopulating capacity. Our findings show that overexpression of HoxB4 in differentiating hESCs increases hematopoietic colony formation and hematopoietic cell formation in vitro, but does not affect in vivo repopulation in adult mice hosts.

• Natural Product Sciences
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• v.26 no.4
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• pp.345-350
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• 2020

In recent years, tyrosine kinases (TKs) have been the target to combat cancers, and most of the developed inhibitors are of synthetic origin. Natural compounds that have the properties as the TK's inhibitors are very limited. This paper described the isolation of a new dammarane triterpene from the tree bark of Sandoricum koetjape, along with three known related dammaranes from the damar resin of Shorea javanica, as well as their inhibitory properties against eight receptor TKs (RTKs: EGFR, HER2, HER4, IGF1R, InsR, KDR, PDGFRα, and PDGFRβ). Based on the NMR and mass spectral data the new compound was identified as (12β,20S)-12,20-dihydroxy-3,4-seco-dammaran-4,24-dien-3-oic acid (12β-hydroxydammarenolic acid) (1), while the three known compounds were identified as (20S)-20-hydroxy-3,4-seco-dammaran-4,24-dien-3-oic acid (dammarenolic acid) (2), (3β,20S)-3,20-dihydroxydammaran-24-ene (3), and (20S)-3-oxo-20-hydroxydammaran-24-ene (4). The tyrosine kinase assay of the four compounds resulted only 1 and 2 at concentration of 10 μM that had weak activity against EGFR and InsR, with their % inhibitory were 30%, 27% (1), 45%, and 32% (2), respectively. The results suggested that the presence of a linear carboxylic acid group in both compounds could be of significance to the inhibitory properties against the two RTKs.