• The Korean Journal of Physiology and Pharmacology
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• 제17권2호
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• pp.157-162
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• 2013

Insulin-like growth factor binding proteins (IGFBPs) are important components of insulin growth factor (IGF) signaling pathways. One of the binding proteins, IGFBP-5, enhances the actions of IGF-1, which include the enhanced proliferation of smooth muscle cells. In the present study, we examined the expression and the biological effects of IGFBP-5 in vascular smooth muscle cells (VSMCs) from spontaneously hypertensive rats (SHR) and Wistar Kyoto rats (WKY). The levels of IGFBP-5 mRNA and protein were found to be higher in the VSMC from SHR than in those from WKY. Treatment with recombinant IGFBP-5-stimulated VSMC proliferation in WKY to the levels observed in SHR. In the VSMCs of WKY, incubation with angiotensin (Ang) II or IGF-1 dose dependently increased IGFBP-5 protein levels. Transfection with IGFBP-5 siRNA reduced VSMC proliferation in SHR to the levels exhibited in WKY. In addition, recombinant IGFBP-5 significantly up-regulated ERK1/2 phosphorylation in the VSMCs of WKY as much as those of SHR. Concurrent treatment with the MEK1/2 inhibitors, PD98059 or U0126 completely inhibited recombinant IGFBP-5-induced VSMC proliferation in WKY, while concurrent treatment with the phosphatidylinositol-3 kinase inhibitor, LY294002, had no effect. Furthermore, knockdown with IGFBP-5 siRNA inhibited ERK1/2 phosphorylation in VSMC of SHR. These results suggest that IGFBP-5 plays a role in the regulation of VSMC proliferation via ERK1/2 MAPK signaling in hypertensive rats.

• 한국수산과학회지
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• 제47권5호
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• pp.527-536
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• 2014

An ethanolic extract from Myagropsis yendoi was fractionated using several solvents. Among these, an ethyl acetate fraction (Myagropsis yendoi ethyl acetate fraction: MYE) showed the highest anti-inflammatory activity based on inhibition of lipopolysaccharides (LPS)-induced nitric oxide (NO) production in RAW 264.7 cells. We thus investigated the molecular mechanisms underlying MYE's inhibitory effects. Pretreatment of cells with up to $30{\mu}g/mL$ of MYE significantly inhibited NO production and inducible nitric oxide synthase expression in a dose-dependent manner (P<0.05). Similarly, MYE markedly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-$1{\beta}$, IL-6, and tumor necrosis factor (TNF)-${\alpha}$, as well as their mRNA levels. While the nuclear translocation of nuclear factor-kappa B (NF-${\kappa}B$) was strongly suppressed by MYE, the activation of a nuclear factor erythroid 2-related factor (Nrf2) was increased. Moreover, MYE significantly reduced the phosphorylation of JNK, p38 MAPK, and phosphatidylinositol 3-kinase/Akt in LPS-stimulated cells. These results indicate that MYE contains anti-inflammatory compounds, and that it might be used as a dietary supplement for the prevention of inflammatory diseases.

• 한국수산과학회지
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• 제54권2호
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• pp.152-161
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• 2021

Eisenia bicyclis is known to have secondary metabolites exhibiting various biological activities. In a preliminary study, the n-hexane fraction obtained from the ethanolic extract of E. bicyclis showed higher anti-inflammatory activity than the ethyl acetate and butyl alcohol fractions based on the inhibition of lipopolysaccharide (LPS)-stimulated nitric oxide (NO) production in RAW 264.7 cells. Using this fraction (E. bicyclis hexane fraction, EHF), we investigated the molecular mechanisms underlying its anti-inflammatory effect in LPS-stimulated RAW 264.7 cells. Pretreatment of the cells with up to 50 ㎍/mL EHF significantly inhibited NO and prostaglandin E₂ production as well as their responsible enzyme proteins and mRNAs, in a dose-dependent manner (P<0.05). Similarly, EHF markedly reduced the production of pro-inflammatory cytokines, such as interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α as well as their mRNA levels. Nuclear translocation of nuclear factor-kappa B (NF-κB) was strongly suppressed by EHF treatment. EHF significantly reduced the phosphorylation of mitogen-activated protein kinases and phosphatidylinositol 3-kinase/Akt in LPS-stimulated cells. Moreover, EHF reduced ear edema in phorbol myristate acetate (PMA)-induced mice. These results indicate that EHF contains potent anti-inflammatory compounds, which may be used as a dietary supplement for the prevention of inflammatory diseases.

• Journal of Veterinary Science
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• 제23권6호
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• pp.90.01-90.13
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• 2022

Background: Insulin regulates glucose homeostasis and has important effects on metabolism, cell growth, and differentiation. Depending on the cell type and physiological context, insulin signal has specific pathways and biological outcomes in different tissues and cells. For studying the signal pathway of insulin on glycolipid metabolism in porcine embryonic fibroblast (PEF), we used high-throughput sequencing to monitor gene expression patterns regulated by insulin. Objectives: The goal of our research was to see how insulin affected glucose and lipid metabolism in PEFs. Methods: We cultured the PEFs with the addition of insulin and sampled them at 0, 48, and 72 h for RNA-Seq analysis in triplicate for each time point. Results: At 48 and 72 h, 801 and 1,176 genes were differentially expressed, respectively. Of these, 272 up-regulated genes and 264 down-regulated genes were common to both time points. Gene Ontology analysis was used to annotate the functions of the differentially expressed genes (DEGs), the biological processes related to lipid metabolism and cell cycle were dominant. And the DEGs were significantly enriched in interleukin-17 signaling pathway, phosphatidylinositol-3-kinase-protein kinase B signaling pathway, pyruvate metabolism, and others pathways related to lipid metabolism by Kyoto Encyclopedia of Genes and Genomes enrichment analysis. Conclusions: These results elucidate the transcriptomic response to insulin in PEF. The genes and pathways involved in the transcriptome mechanisms provide useful information for further research into the complicated molecular processes of insulin in PEF.

• Radiation Oncology Journal
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• 제17권4호
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• pp.299-306
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• 1999

목 적 : Ataxia-Telangiectasia (AT) 증은 여러 가지 유전적 결함을 갖는 질병으로 방사선 민감도가 비정상적으로 상승되어 있는 것이 특징이다 AT 환자에서 공통적으로 존재하는 ATM 유전자는 현재까지 방사선 신호전달에 관여하는 것으로 알려진 Pl-3 kinase와 유사한 구조임이 알려져 ATM이 방사선 신호전달경로에 중요한 작용을 할 것으로 추정하게 되었다. 본 연구에서는 AT 세포와 정상세포에 PKCI를 과발현 시킴으로써 방사선 신호전달에 관여하는 PKC를 억제하여 이것이 방사선 민감도에 미치는 영향을 관찰하고, 방사선에 의해 유도되는 early response gene인 c-fos transcription의 차이를 측정하여 ATM과 PKCI에 의한 신호전달이 c-fos 유전자 전사에 미치는 영향을 분석하고자 하였다. 대상 및 방법 : PKCI expression vector를 작제한 후 정상세포인 LM217과 AT세포인 AT5BIVA에 transfection 시킨 후 plasmid의 genomic DNA에 결합된 것은 polymerase chain reaction (PCR) 방법으로 확인하였고 PKCI의 mRNA 발현 여부는 northern blotting으로 확인하였다. 방사선 민감도는 아포토시스로 측정하였으며 PKCI가 과발현된 각 세포주에 5 Gy의 방사선을 조사한 후 48시간에 세포를 모아 TUNEL방법으로 아포토시스 세포의 수를 측정하였다. c-fos 유전자의 전사는 reporter 유전자로 c-fos CAT plsmid를 $\beta$-gal expression vector와 같이 각 세포주에 transfection 시키고 36시간이 지난 후 CAT assay를 하여 activity를 측정하고 동시에 $\beta$-gal assay를 시행하여 transfection 효율을 보정해 주었다. PKCI, Ras의 영향을 보기 위하여는 PKCI, Ras expression vector와 c-fos CAT plasmid를 cotransfection하고 CAT activity로 측정 하였다. 결 과 : 이 실험의 결과 LM과 AT 세포에서 PKCI가 방사선 민감도에 미치는 영향과 c-fos 전사에 미치는 영향을 처음으로 보여주었다. PKCI의 과발현이 LM 세포에서는 방사선 민감도를 증가시켰지만 AT세포에서는 오히려 약간 감소시키는 작용을 나타내었다. c-fos 전사는 AT 세포에서 LM 세포에 비하여 70배 낮게 나타났는데 PKCI가 과발현 됨으로써 LM 에서는 c-fos의 전사가 감소되었지만 AT 세포에서는 영향이 없었다. Ras 단백으로 c-fos를 유도시키고 여기에 PKCI 발현 백터를 contransfection 하면 LM세포에서는 induction 이 감소되었지만 AT 세포에서는 영향이 없었다. 즉 LM과 AT 세포에서의 PKCI에 의한 반응의 차이는 Ras와 관련된 signal transduction pathway라는 것을 알 수 있었다. 결 론 : PKCI는 정상세포에서는 방사선에 의한 세포 손상을 증가시키지만 AT 세포에서는 별 영향을 보이지 않는 것을 알 수 있었으며, 두 세포간의 이러한 차이는 c-fos proto-oncogene의 전사차이로 설명할 수 있겠다. 이러한 차이가 AT 세포의 방사선 민감도의 한 원인일 것으로 생각된다.

• 대한임상검사과학회지
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• 제49권2호
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• pp.99-107
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• 2017

진균 속에 속하는 종인 Cordyceps는 중국의 전통약제로서, 그 유효성분인 cordycepin이 혈소판 응집에 관여한다는 보고가 있지만 phosphoprotein 조절에 관련된 연구는 미흡하다. 본 연구에서는, cordycepin이 fibrinogen binding에 관여한다고 알려진 PI3k/Akt와 $TXA_2$ 분비 및 과립방출에 관여한다고 알려진 p38와 같은 phosphoprotein의 인산화를 어떻게 조절하며 혈소판응집을 억제시키는지 규명하고자 하였다. 그 결과, cordycepin가 $261.1{\mu}M$의 $IC_{50}$으로 collagen이 유도한 혈소판 응집을 강력하게 억제하였고, PI3K와 Akt의 인산화를 감소시키며 ${\alpha}IIb/{\beta}_3$에 대한 fibrinogen 결합을 농도의존적으로 억제하였다. 또한, cordycepin은 collagen이 촉진시킨 p38의 인산화를 억제함으로써, 과립방출의 지표인 ATP 과 serotonin의 방출을 억제하였고 COX-1과 TXAS의 활성 및 $PLC-{\gamma}_2$ 인산화에 대한 영향없이 $TXA_2$ 생성량을 감소시켰다. 따라서, cordycepin은 PI3K/Akt, p38와 같은 phosphoprotein의 인산화를 억제함으로써 혈소판 응집억제를 나타내는 항혈전 치료 및 예방약물로서 유용한 가치가 있다고 여겨진다.

• 한국식품영양과학회지
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• 제32권3호
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• pp.428-436
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• 2003

Carotenoids는 항암 효과가 있는 것으로 알려져 있으나 각각의 carotenoids가 대장암에 미치는 영향에 대해서는 명확하게 밝혀진 바가 없다. 본 연구에서는 4가지 종류의 carotenoids가 인간의 대장에서 유래한 암세포인 HT-29 세포의 증식에 미치는 영향을 조사하였다. $\alpha$-carotene, $\beta$-carotene, lutein lycopene을 농도를 달리 하여 세포 배양액 에 첨가하여 살아있는 세포의 수를 측정한 결과 $\beta$-carotene는 세포의 증식을 다소 증가시키는 반면 $\alpha$-carotene, lutein, lcopene은 세포의 증식을 감소하였다. 세포의 증식을 억제한 carotenoids 중에서 lycopene이 그 효과가 가장 컸다. ErbB receptor family는 세포의 증식을 촉진하고 대장암에서 그 발현이 증가된 것으로 보고되었기 때문에 lycopene이 heregulin-ErbB3 signaling을 억제하는지를 조사하였다. Lycopene는 ErbB2 단백질을 감소하였고 ErbB3 단백질의 변화를 초래하였다. Heregulin을 첨가하여 인산화를 유도한 경우 ErbB3의 인산화, ErbB3와 p85의 결합, Akt 인산화가 lycopene에 의해 억제되었다. 이 결과들은 carotenoids 중 lycopene이 대장암 세포 증식 억제 효과가 가장 크고, 대장암 세포의 DNA 합성을 억제하고 apoptosis를 유도하는 lycopene효과의 일부는 Erb-B3와 Akt의 인산화 감소에 기인하는 것임을 나타낸다.

• 한국식품영양과학회지
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• 제45권6호
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• pp.835-842
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• 2016

PI3K/Akt 신호계는 세포 생존의 조절에 필수적인 경로로 대부분 암세포에서 활성이 증대되어 있다. 본 연구에서는 동충하초의 주요 생리활성 물질인 cordycepin에 의한 AGS 인체 위암 세포의 apoptosis 유도에 미치는 PI3K/Akt 신호계의 역할을 조사하였다. 본 연구의 결과에 의하면 cordycepin의 처리 농도의 증가에 따라 AGS 세포의 생존율은 억제되었으며, 이는 apoptosis 유도와 밀접한 관계가 있음을 핵의 형태적 변화와 flow cytometry 분석을 통하여 확인 하였다. 이러한 cordycepin의 apoptosis 유도 효과는 PI3K/Akt 신호계의 활성 저하와 연관성이 있었으며, 세포독성을 나타내지 않는 범위의 PI3K/Akt 신호계 저해제인 LY294002를 cordycepin과 동시 처리하였을 경우, cordycepin에 의한 apoptosis 유발을 더욱 증대시켰다. 그리고 cordycepin에 대한 LY294002의 apoptosis 유발 증대는 caspases (caspase-3, -8 및 -9)의 활성 증가와 poly(ADP-ribose) polymerase 단백질의 분해 증가를 촉진했다. 또한 cordycepin이 처리된 AGS 세포에서 LY294002는 apoptosis 유도에 관여하는 Bax의 발현을 증가시켰고 apoptosis 억제에 관여하는 Bcl-2의 발현은 감소시켰으며, 이는 미토콘드리아 기능 손상과 미토콘드리아에서 세포질로의 cytochrome c 유리를 증대시켰다. 따라서 PI3K/Akt 신호계의 활성 차단은 cordycepin의 항암 활성을 더욱 상승시켰으며, 이는 미토콘드리아 기능 손상과 caspase의 활성 증대를 통하여 이루어짐을 알 수 있었다.

• Asian Pacific Journal of Cancer Prevention
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• 제16권7호
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• pp.2645-2651
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• 2015

Background: The phosphatidylinositol 3'-kinase/Akt (PI3K/Akt) pathway is a key regulator for HER2-overexpressing breast cancer, but data about whether activation of PI3K/Akt is associated with poor prognosis and resistance to trastuzumab therapy is controversial. In this study we investigated predictive and prognostic significance of expression of p27, Akt, PTEN and PI3K, which are components of the PI3K/Akt signaling pathway, in HER2-positive metastatic breast cancer (MBC), retrospectively. Materials and Methods: Fifty-four HER2-positive MBC patients who had received first-line trastuzumab-based therapy were recruited for the study group. All of the patient's breast tissue samples were examined for p27 and Akt expression. In addition, twenty-five patients with sufficient amount of tumor tissue were also examined for PTEN and PI3K expression. p27, Akt, PTEN and PI3K were evaluated by immunohistochemistry and their relationship with patient demographic features, tumor characteristics, response to trastuzumab-based treatment and survival outcomes were analyzed. Results: p27, Akt, PTEN and PI3K were positive in 25.9%, 70.4%, 24% and 96% of the cases, respectively. Nomne were significantly associated with response to trastuzumab and time to progression (TTP). A trend toward statistical significance for longer overall survival (OS) was found for PTEN-positive patients (p=0.058); there was no significant relationship between the other immunohistochemical variables and OS. When we analyzed groups regarding co-expression, the PTEN-negative/Akt-negative group had a significantly lower objective response rate (ORR) (20% vs 80%, p=0.023) and the PTEN-negative/p27-negative and PTEN-negative/Akt-negative groups had significantly lower median OS compared to other patients (26.4 months vs 76.1 months, p=0.005 and 25.6 months vs 52.0 months, p=0.007, respectively). Conclusions: p27, Akt, PTEN and PI3K expression is not statistically significantly associated with ORR, TTP and OS, individually. However, the combined evaluation of p27, Akt and PTEN could be helpful to predict the response to trastuzumab-based therapy and prognosis in HER2-positive MBC.

• Biomolecules & Therapeutics
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• 제22권3호
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• pp.184-192
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• 2014

${\beta}$-lapachone is a naturally occurring quinone that selectively induces apoptotic cell death in a variety of human cancer cells in vitro and in vivo; however, its mechanism of action needs to be further elaborated. In this study, we investigated the effects of ${\beta}$-lapachone on the induction of apoptosis in human gastric carcinoma AGS cells. ${\beta}$-lapachone significantly inhibited cellular proliferation, and some typical apoptotic characteristics such as chromatin condensation and an increase in the population of sub-G1 hypodiploid cells were observed in ${\beta}$-lapachone-treated AGS cells. Treatment with ${\beta}$-lapachone caused mitochondrial transmembrane potential dissipation, stimulated the mitochondria-mediated intrinsic apoptotic pathway, as indicated by caspase-9 activation, cytochrome c release, Bcl-2 downregulation and Bax upregulation, as well as death receptor-mediated extrinsic apoptotic pathway, as indicated by activation of caspase-8 and truncation of Bid. This process was accompanied by activation of caspase-3 and concomitant with cleavage of poly(ADP-ribose) polymerase. The general caspase inhibitor, z-VAD-fmk, significantly abolished ${\beta}$-lapachone-induced cell death and inhibited growth. Further analysis demonstrated that the induction of apoptosis by ${\beta}$-lapachone was accompanied by inactivation of the phosphatidylinositol 3-kinase (PI3K)/Akt signaling pathway. The PI3K inhibitor LY29004 significantly increased ${\beta}$-lapachone-induced apoptosis and growth inhibition. Taken together, these findings indicate that the apoptotic activity of ${\beta}$-lapachone is probably regulated by a caspase-dependent cascade through activation of both intrinsic and extrinsic signaling pathways, and that inhibition of the PI3K/Akt signaling may contribute to ${\beta}$-lapachone-mediated AGS cell growth inhibition and apoptosis induction.