• Title/Summary/Keyword: HEK293 cells

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Wide Spectrum of Inhibitory Effects of Sertraline on Cardiac Ion Channels

  • Lee, Hyang-Ae;Kim, Ki-Suk;Hyun, Sung-Ae;Park, Sung-Gurl;Kim, Sung-Joon
    • The Korean Journal of Physiology and Pharmacology
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    • v.16 no.5
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    • pp.327-332
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    • 2012
  • Sertraline is a commonly used antidepressant of the selective serotonin reuptake inhibitors (SSRIs) class. In these experiments, we have used the whole cell patch clamp technique to examine the effects of sertraline on the major cardiac ion channels expressed in HEK293 cells and the native voltage-gated $Ca^{2+}$ channels in rat ventricular myocytes. According to the results, sertraline is a potent blocker of cardiac $K^+$ channels, such as hERG, $I_{Ks}$ and $I_{K1}$. The rank order of inhibitory potency was hERG > $I_{K1}$ > $I_{Ks}$ with $IC_{50}$ values of 0.7, 10.5, and 15.2 ${\mu}M$, respectively. In addition to $K^+$ channels, sertraline also inhibited $I_{Na}$ and $I_{Ca}$, and the $IC_{50}$ values are 6.1 and 2.6 ${\mu}M$, respectively. Modification of these ion channels by sertraline could induce changes of the cardiac action potential duration and QT interval, and might result in cardiac arrhythmia.

Anticancer Activity of Ultrasonified Extracts from Seawater-based Culture of the Microalga Spirulina platensis (해수배양 Spirulina platensis 초음파 추출물의 항암효과)

  • Kim, Hyou-Sung;Kim, Cheol-Hee;Kwon, Min-Chul;Song, Young-Kyu;Cho, Jung-Hwan;Gwak, Hyeong-Geun;Hwang, Bo-Young;Kim, Jin-Chul;Lee, Hyeon-Yong
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.39 no.4
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    • pp.318-325
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    • 2006
  • Ultrasonified extracts from seawater-based cultures of the microalga Spiyulina platensis were obtained using water and ethanol at 60 and 100$^{\circ}C$. The yield of the aqueous fraction of S. platensis extracted using ultrasonification was about 33.46%. The cytotoxicity against HEK293 and inhibition ratios of the cancer cell lines A549, AGS, MCF7, and Hep3B were measured using the sulforhodamine-B (SRB) assay. The cytotoxicity of all extracts at 1.0 mg/mL was below 26%. The cytotoxicity of the ultrasonified extracts from the seawater-based culture of the microalga Spirulina platensis was about 4% less than that of Spirulina platensis without ultrasonification. The inhibition ratio of cancer cell growth was approximately 80% for 1.0 mg/mL extracts. The inhibitory effect on cancer cell growth was greater for seawater containing ultrasonified Spirulina platensis extracts than for extracts without ultrasonification. The differentiation ratio of HL-60 cells was 160.9%. Densitometric analysis of Bcl-2 revealed that the ultrasonified extracts had greater anticancer activity than the extracts without ultrasonification.

Interaction between the p75 neurotrophin receptor and a novel adaptor protein

  • Lee, Yun-Hee;Yu, Ji-Hee;Cho, Jung-Sun;Park, Han-Jeong;Lee, Seung-Pyo;Paik, Ki-Suk;Chang, Mi-Sook
    • International Journal of Oral Biology
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    • v.33 no.2
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    • pp.71-76
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    • 2008
  • The neurotrophin plays an important role in the development, differentiation and survival of the nervous system in vertebrates. It exerts its cellular effects through two different receptors, the Trk receptor tyrosine kinase neurotrophin receptor and the p75 neurotrophin receptor, a member of the tumor necrosis factor receptor superfamily. Trk and p75 neurotrophin receptors utilize specific target proteins to transmit signals into the cell. An ankyrin-rich membrane spanning protein (ARMS) was identified as a new p75 interacting protein and serves as a novel downstream target of p75 neurotrophin receptor. We sought to delineate the interaction between p75 and ARMS by deletion constructs of p75 and green fluorescent protein (GFP)-tagged ARMS. We examined the interaction between these two proteins after overexpressing them in HEK-293 cells. Using both Western blot analysis and immunocytochemistry followed by confocal laser scanning microscopy, we found out that the intracellular domain of the p75 neurotrophin receptor was important for the interaction with ARMS. The results from this study suggest that ARMS may play an important role for mediating the signals from p75 neurotrophin receptor into the cell.

Promoter demethylation mediates the expression of ZNF645, a novel cancer/testis gene

  • Bai, Gang;Liu, Yunqiang;Zhang, Hao;Su, Dan;Tao, Dachang;Yang, Yuan;Ma, Yongxin;Zhang, Sizhong
    • BMB Reports
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    • v.43 no.6
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    • pp.400-406
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    • 2010
  • Cancer/testis (CT) antigens exhibit highly tissue-restricted expression and are considered promising targets for cancer vaccines. Here we identified a novel CT gene ZNF645 which restrictively expresses in normal human testes and lung cancer patients (68.3%). To investigate the promoter methylation status of ZNF645, we carried out bisulfite genomic sequencing and found that the CpG island in its promoter was heavily methylated in normal lung tissues without the expression of ZNF645, whereas there was high demethylation in normal human testes and lung carcinoma tissues with its expression. Also ZNF645 could be remarkably activated in A549 and HEK293T cells treated by DNA demethylation agent 5'-aza-2'-deoxycytidine. And the dual luciferase assay revealed that the promoter activity of the ZNF645 was inhibited by methylation of the CpG island region. Therefore, we proposed that ZNF645 is a CT gene and activated in human testis and lung cancers by demethylation of its promoter region.

Characterization and Transcriptional Activity of a Vitamin D Receptor Ortholog in the Ascidian Halocynthia roretzi (멍게(Halocynthia roretzi) 비타민 D 수용체 상동체 동정 및 전사활성)

  • Lee, Jung Hwan;Sohn, Young Chang
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.48 no.6
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    • pp.913-919
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    • 2015
  • In vertebrates, the vitamin D receptor (VDR), a member of the nuclear receptor superfamily, binds the biologically active ligand $1{\alpha},25-(OH)_2$-vitamin $D_3$ (1,25 $D_3$). Nearly all vertebrates, including Agnatha, possess a VDR with high ligand selectivity for 1,25 $D_3$ and related metabolites. Although a putative ancestral VDR gene is present in the genome of the chordate invertebrate Ciona intestinalis, the functional characteristics of marine invertebrate VDR are still obscure. To elucidate the ascidian Halocynthia roretzi VDR (HrVDR), we cloned full-length HrVDR cDNA and investigated the transcriptional activity of HrVDR in HEK293 cells. HrVDR consists of 1,680 nucleotides (559 amino acids [aa]), including a short N-terminal region (A/B domain; 26 aa), DNA-binding domain (C domain; 72 aa), hinge region (D domain; 272 aa), and C-terminal ligand-binding domain (E domain; 161 aa). The amino acid sequence identity of HrVDR was greatest to that of C. intestinalis VDR (56%). In the luciferase reporter assays, the transcriptional activity of HrVDR was not significantly increased by 1,25 $D_3$, whereas the farnesoid X receptor agonist GW4064 increased the transactivation of HrVDR. These results suggest the presence of a novel ligand for and a distinct ligand-binding domain in ascidian VDR.

Transcriptional Activity of an Estrogen Receptor β Subtype in the Medaka Oryzias dancena

  • Maeng, Sejung;Yoon, Sung Woo;Kim, Eun Jeong;Nam, Yoon Kwon;Sohn, Young Chang
    • Development and Reproduction
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    • v.23 no.4
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    • pp.333-344
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    • 2019
  • In vertebrate reproductive system, estrogen receptor (ER) plays a pivotal role in mediation of estrogenic signaling pathways. In the present study, we report the cDNA cloning, expression analysis, and transcriptional activity of ERβ1 subtype from medaka Oryzias dancena. The deduced O. dancena ERβ1 (odERβ1; 519 amino acids) contained six characteristic A/B to E/F domains with very short activation function 2 region (called AF2). A phylogenetic analysis indicated that odERβ1 was highly conserved among teleost ERβ1 subgroup. A conventional RT-PCR revealed that the odERβ1 transcripts were widely distributed in the multiple tissues, the ovary, brain, gill, intestine, kidney, and muscle. Further, the relatively higher odERβ1 expressions in the ovary and brain were clearly reproduced in RT-qPCR assay. When HA-fused odERβ1 expression vector was transfected into HEK293 cells, an immunoreactivity for odERβ1 was mainly detected in the nucleus part. Finally, an estrogen responsive element driven luciferase reporter assays demonstrated that the transcriptional activity of odERβ1 significantly increased by estradiol-17β (E2) in a dose dependent manner (p<0.05). However, fold-activation of odERβ1 in the presence of E2 was markedly weak, when it compared with those of O. latipes ERβ1. Taken together, these data suggest that odERβ1 represents a functional variant of teleost ERβ subtype and provides a basic tool allowing future studies examining the function of F domain of ERβ1 subtype and expanding our knowledge of ERβ evolution.

Functional characterization of $P_{2X}/P_{2Y}$ receptor in isolated swine renal artery

  • Kim, Joo-heon;Jeon, Je-cheol;Lee, Sang-kil;Lee, Su-jin;Lee, Younggeon;Won, Jinyoung;Kang, Jae seon;Hong, Yonggeun
    • Korean Journal of Veterinary Research
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    • v.47 no.4
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    • pp.371-378
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    • 2007
  • To understand the role of $PM_{2X}/P_{2Y}$ receptor in cortex region of kidney and renal artery, molecular and functional analysis of $PM_{2X}/P_{2Y}$ receptor by pharmacophysiological skill in conventional swine tissues were performed. In functional analysis of $P_{2Y}$ receptor for vascular relaxation, 2-methylthio adenosine triphosphate, a strong agonist of $P_{2Y}$ receptor, induced relaxation of noradrenaline (NA)-precontracted renal artery in a dose-dependent manner. Strikingly, relaxative effect of ATP, 2-msATP, agonists of $P_{2Y}$ receptor, abolished by treatment of reactive blue 2, a putative $P_{2Y}$ receptor antagonist. In contrast, no significant differences of gene encoding $PM_{2X}/P_{2Y}$ and protein expression in immortalized suprachiasmatic nucleus from brain, primary isolated vascular smooth muscle cells from renal artery of pigs and HEK293 from human embryonic kidney under with/without adenosine triphosphate were observed. Taken together, the relationship between molecular and functional characteristic of $PM_{2X}/P_{2Y}$ receptors in conventional pig should be considered that they are another important factor which regulate the kidney function in swine. Based on this study, we propose the purinergic receptor as well as adrenergic and cholinergic receptors is an essential component of the renal homeostasis.

Ginsenoside Rg1 from Panax ginseng enhances myoblast differentiation and myotube growth

  • Go, Ga-Yeon;Lee, Sang-Jin;Jo, Ayoung;Lee, Jaecheol;Seo, Dong-Wan;Kang, Jong-Sun;Kim, Si-Kwan;Kim, Su-Nam;Kim, Yong Kee;Bae, Gyu-Un
    • Journal of Ginseng Research
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    • v.41 no.4
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    • pp.608-614
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    • 2017
  • Background: Ginsenoside Rg1 belongs to protopanaxatriol-type ginsenosides and has diverse pharmacological activities. In this report, we investigated whether Rg1 could upregulate muscular stem cell differentiation and muscle growth. Methods: C2C12 myoblasts, MyoD-transfected 10T1/2 embryonic fibroblasts, and HEK293T cells were treated with Rg1 and differentiated for 2 d, subjected to immunoblotting, immunocytochemistry, or immunoprecipitation. Results: Rg1 activated promyogenic kinases, p38MAPK (mitogen-activated protein kinase) and Akt signaling, that in turn promote the heterodimerization with MyoD and E proteins, resulting in enhancing myogenic differentiation. Through the activation of Akt/mammalian target of rapamycin pathway, Rg1 induced myotube growth and prevented dexamethasone-induced myotube atrophy. Furthermore, Rg1 increased MyoD-dependent myogenic conversion of fibroblast. Conclusion: Rg1 upregulates promyogenic kinases, especially Akt, resulting in improvement of myoblast differentiation and myotube growth.

Korean Red Ginseng extract and ginsenoside Rg3 have anti-pruritic effects on chloroquine-induced itch by inhibition of MrgprA3/TRPA1-mediated pathway

  • Lee, Wook-Joo;Kim, Young-Sik;Shim, Won-Sik
    • Journal of Ginseng Research
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    • v.42 no.4
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    • pp.470-475
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    • 2018
  • Background: It was previously found that Korean Red Ginseng water extract (KRGE) inhibits the histamine-induced itch signaling pathway in peripheral sensory neurons. Thus, in the present study, we investigated whether KRGE inhibited another distinctive itch pathway induced by chloroquine (CQ); a representative histamine-independent pathway mediated by MrgprA3 and TRPA1. Methods: Intracellular calcium changes were measured by the calcium imaging technique in the HEK293T cells transfected with both MrgprA3 and TRPA1 ("MrgprA3/TRPA1"), and in primary culture of mouse dorsal root ganglia (DRGs). Mouse scratching behavior tests were performed to verify proposed antipruritic effects of KRGE and ginsenoside Rg3. Results: CQ-induced $Ca^{2+}$ influx was strongly inhibited by KRGE ($10{\mu}g/mL$) in MrgprA3/TRPA1, and notably ginsenoside Rg3 dose-dependently suppressed CQ-induced $Ca^{2+}$ influx in MrgprA3/TRPA1. Moreover, both KRGE ($10{\mu}g/mL$) and Rg3 ($100{\mu}M$) suppressed CQ-induced $Ca^{2+}$ influx in primary culture of mouse DRGs, indicating that the inhibitory effect of KRGE was functional in peripheral sensory neurons. In vivo tests revealed that not only KRGE (100 mg) suppressed CQ-induced scratching in mice [bouts of scratching: $274.0{\pm}51.47$ (control) vs. $104.7{\pm}17.39$ (KRGE)], but also Rg3 (1.5 mg) oral administration significantly reduced CQ-induced scratching as well [bouts of scratching: $216.8{\pm}33.73$ (control) vs.$115.7{\pm}20.94$ (Rg3)]. Conclusion: The present study verified that KRGE and Rg3 have a strong antipruritic effect against CQ-induced itch. Thus, KRGE is as a promising antipruritic agent that blocks both histamine-dependent and -independent itch at peripheral sensory neuronal levels.

AKT-targeted anti-inflammatory activity of Panax ginseng calyx ethanolic extract

  • Han, Sang Yun;Kim, Juewon;Kim, Eunji;Kim, Su Hwan;Seo, Dae Bang;Kim, Jong-Hoon;Shin, Song Seok;Cho, Jae Youl
    • Journal of Ginseng Research
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    • v.42 no.4
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    • pp.496-503
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    • 2018
  • Background: Korean ginseng (Panax ginseng) plays an anti-inflammatory role in a variety of inflammatory diseases such as gastritis, hepatitis, and colitis. However, inflammation-regulatory activity of the calyx of the P. ginseng berry has not been thoroughly evaluated. To understand whether the calyx portion of the P. ginseng berry is able to ameliorate inflammatory processes, an ethanolic extract of P. ginseng berry calyx (Pg-C-EE) was prepared, and lipopolysaccharide-activated macrophages and HEK293 cells transfected with inflammation-regulatory proteins were used to test the anti-inflammatory action of Pg-C-EE. Methods: The ginsenoside contents of Pg-C-EE were analyzed by HPLC. Suppressive activity of Pg-C-EE on NO production, inflammatory gene expression, transcriptional activation, and inflammation signaling events were examined using the Griess assay, reverse transcription-polymerization chain reaction, luciferase activity reporter gene assay, and immunoblotting analysis. Results: Pg-C-EE reduced NO production and diminished mRNA expression of inflammatory genes such as cyclooxygenase-2, inducible NO synthase, and tumor necrosis factor-${\alpha}$ in a dose-dependent manner. This extract suppressed luciferase activity induced only by nuclear factor-${\kappa}B$. Interestingly, immunoblotting analysis results demonstrated that Pg-C-EE reduced the activities of protein kinase B (AKT)1 and AKT2. Conclusion: These results suggest that Pg-C-EE may have nuclear-factor-${\kappa}B$-targeted anti-inflammatory properties through suppression of AKT. The calyx of the P. ginseng berry is an underused part of the ginseng plant, and development of calyx-derived extracts may be useful for treatment of inflammatory diseases.