• Title/Summary/Keyword: Cellular and molecular mechanisms

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Regulatory Effects of WRAP53 on Radiosensitivity of Laryngeal Squamous Cell Carcinoma Cells

  • Qiu, Hui;Zhao, De-Ying;Yuan, Li-Mei;Zhang, Gong;Xie, Cong-Hua
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.7
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    • pp.2975-2979
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    • 2015
  • Background: Telomere length is closely associated with cellular radiosensitivity and WRAP53 is required for telomere addition by telomerase. In this research we assessed radiosensitivity of laryngeal squamous cell carcinoma Hep-2 cell lines after WRAP53 inhibition, and analyzed the molecular mechanisms. Materials and Methods: phWRAP53-siRNA and pNeg-siRNA were constructed and transfected into Hep-2 cells with lipofectamine. Expression of WRAP53 was analyzed by RT-PCR and Western-blottin, radiosensitivity of Hep-2 cells was assessed colony formation assay, and the relative length of telomeres was measured by QPCR. Results: The data revealed that the plasmid of phWRAP53-siRNA was constructed successfully, and the mRNA and protein levels of WRAP53 were both obviously reduced in the Hep-2 cell line transfected with phWRAP53-siRNA. After Hep-2 cells were irradiated with X-rays, the $D_0$ and $SF_2$ were 2.481 and 0.472, respectively, in the phWRAP53-siRNA group, much lower than in the control group ($D_0$ and $SF_2$ of 3.213 and 0.592) (P<0.01). The relative telomere length in the phWRAP53-siRNA group was $0.185{\pm}0.01$, much lower than in the untreated group ($0.523{\pm}0.06$) and the control group ($0.435{\pm}0.01$). Conclusions: Decreasing the expression of WRAP53 using RNA interference technique can enhance the radiosensitivity of Hep-2 cell lines by influencing the telomere length. WRAP53 is expected to be a new target to regulate the radiosensitization of tumor cells.

The Effects of Armeniacae Arnarum Semen and Platycodi Radix on IL-4, IL-5, IL-6 in Asthma Model (행인(杏仁)과 길경(桔梗)이 Asthma model 내(內)의 Cytokine IL-4, IL-5, IL-6에 미치는 영향(影響))

  • Jung, Hee-Jae;Jung, Sung-Ki;Rhee, Hyung-Koo;Chung, Wook
    • The Journal of Internal Korean Medicine
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    • v.21 no.1
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    • pp.31-38
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    • 2000
  • Background : Nowadays asthma is considered to be the inflammatory disease characterized by airway hyperresponsiveness and pulmonary eosinophilia, and mediated by Th lymphocytes expressing the Th2 cytokine pattern. In many recent studies, molecular biological methods have been used to investigate the role of cytokines in pathogenesis and new therapeutic targets of asthma. Objective : We aimed to identify the effect of Armeniacae Arnarum Semen and Platycodi Radix on the transcriptional activities of cytokine IL-4, IL-5 and IL-6 involved in asthma model. Materials and Methods : RBL-2H3 cell lines were used. Cells were stimulated with calcium inophore for maximal gene expression. After 24 hours of Armeniacae Arnarum Semen and Platycodi Radix-treatment, total cellular RNAs were collected using Trizol solution method. Then transcriptional activities of IL-4, IL-S and IL-6 were measured by RT-PCR with electrophoresis. Results : In IL-4 study, Armeniacae Arnarum Semen treated group showed 48.4% of transcriptional activities compared to the control group and Platycodi Radix treated group showed 45.4% of transcriptional activities compared to the control group. In IL-5 study, Armeniacae Arnarum Semen treated group showed 52.7%of transcriptional activities compared to the control group and Platycodi Radix treated group showed 60.2% of transcriptional activities compared to the control group. In IL-6 study, Armeniacae Amarum Semen treated group showed 42.3% of transcriptional activities compared to the control group and Platycodi Radix treated group showed 69.1% of transcriptional activities compared to the control group. Conclusion : This study shows that Armeniacae Arnarum Semen and Platycodi Radix have the inhibitory effect on the transcription of IL-4, IL-5 and IL-6 gene expression in RBL-2H3 cell lines. Advanced studies are required to investigate the mechanisms of inhibition by herbal medicine in asthma model.

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Alaria esculenta Extract Protects against Oxidative Damage by Inducing Heme Oxygenase-1 Expression via Akt and Nrf2

  • Choi, Chun-Yeon;Jo, Guk-Heui;Lee, Jung-Im;Seo, Young-Wan;Han, Tae-Jun;Choi, Il-Whan;Liu, Kwang-Hyeon;Oh, Sang-Taek;Kim, Dong-Eun;Jang, Won-Hee;Seog, Dae-Hyun;Park, Yeong-Hong;Yea, Sung-Su
    • Molecular & Cellular Toxicology
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    • v.5 no.2
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    • pp.120-125
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    • 2009
  • Alaria esculenta is a brown seaweed found in the Arctic. This study investigated the protective effect of A. esculenta extract (AEE) against oxidant-mediated injury and its mode of action in RAW264.7 macrophages. The methyl thiazolyl tetrazolium (MTT) assay showed that $H_2O_2$ treatment reduced cell viability, whereas AEE protected cells from $H_2O_2$-mediated cytotoxicity in a dose-dependent manner. Because heme oxygenase-1 (HO-1) is known to protect cells against oxidative damage, we investigated the effect of AEE on HO-1 gene expression and HO enzyme activity. The protective effect of AEE against $H_2O_2$-induced injury was correlated with increased HO enzyme activity. AEE also induced HO-1 mRNA and protein expression, as determined RT-PCR and Western blotting, respectively. To characterize the mechanisms by which AEE induces HO-1 gene expression, we examined the effect of AEE on the nuclear translocation of NF-E2-related factor-2 (Nrf2) and Akt phosphorylation. AEE treatment activated upstream signaling for HO-1 gene expression, including the nuclear translocation of Nrf2 and Akt phosphorylation. Collectively, these results suggest that AEE has anti-oxidant activity that is mediated, at least in part, via the activation of Nrf2 and Akt and the subsequent induction of HO-1 gene expression.

Expression of the Floral Repressor miRNA156 is Positively Regulated by the AGAMOUS-like Proteins AGL15 and AGL18

  • Serivichyaswat, Phanu;Ryu, Hak-Seung;Kim, Wanhui;Kim, Soonkap;Chung, Kyung Sook;Kim, Jae Joon;Ahn, Ji Hoon
    • Molecules and Cells
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    • v.38 no.3
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    • pp.259-266
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    • 2015
  • The regulation of flowering time has crucial implications for plant fitness. MicroRNA156 (miR156) represses the floral transition in Arabidopsis thaliana, but the mechanisms regulating its transcription remain unclear. Here, we show that two AGAMOUS-like proteins, AGL15 and AGL18, act as positive regulators of the expression of MIR156. Small RNA northern blot analysis revealed a significant decrease in the levels of mature miR156 in agl15 agl18 double mutants, but not in the single mutants, suggesting that AGL15 and AGL18 co-regulate miR156 expression. Histochemical analysis further indicated that the double mutants showed a reduction in MIR156 promoter strength. The double mutants also showed reduced abundance of pri-miR156a and pri-miR156c, two of the primary transcripts from MIR156 genes. Electrophoretic mobility shift assays demonstrated that AGL15 directly associated with the CArG motifs in the MIR156a/c promoters. AGL18 did not show binding affinity to the CArG motifs, but pull-down and yeast two-hybrid assays showed that AGL18 forms a heterodimer with AGL15. GFP reporter assays and bimolecular fluorescence complementation (BiFC) showed that AGL15 and AGL18 co-localize in the nucleus and confirmed their in vivo interaction. Overexpression of miR156 did not affect the levels of AGL15 and AGL18 transcripts. Taking these data together, we present a model for the transcriptional regulation of MIR156. In this model, AGL15 and AGL18 may form a complex along with other proteins, and bind to the CArG motifs of the promoters of MIR156 to activate the MIR156 expression.

MiR-204 acts as a potential therapeutic target in acute myeloid leukemia by increasing BIRC6-mediated apoptosis

  • Wang, Zhiguo;Luo, Hong;Fang, Zehui;Fan, Yanling;Liu, Xiaojuan;Zhang, Yujing;Rui, Shuping;Chen, Yafeng;Hong, Luojia;Gao, Jincheng;Zhang, Mei
    • BMB Reports
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    • v.51 no.9
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    • pp.444-449
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    • 2018
  • Acute myeloid leukemia (AML) is one of the most common hematological malignancies all around the world. MicroRNAs have been determined to contribute various cancers initiation and progression, including AML. Although microRNA-204 (miR-204) exerts anti-tumor effects in several kinds of cancers, its function in AML remains unknown. In the present study, we assessed miR-204 expression in AML blood samples and cell lines. We also investigated the effects of miR-204 on cellular function of AML cells and the underlying mechanisms of the action of miR-204. Our results showed that miR-204 expression was significantly downregulated in AML tissues and cell lines. In addition, overexpression of miR-204 induced growth inhibition and apoptosis in AML cells, including AML5, HL-60, Kasumi-1 and U937 cells. Cell cycle analysis further confirmed an augmentation in theapoptotic subG1 population by miR-204 overexpression. Mechanistically, baculoviral inhibition of apoptosis protein repeat containing 6 (BIRC6) was identified as a direct target of miR-204. Enforcing miR-204 expression increased the luciferase activity and expression of BIRC6, as well as p53 and Bax expression. Moreover, restoration of BIRC6 reversed the pro-apoptotic effects of miR-204 overexpression in AML cells. Taken together, this study demonstrates that miR-204 causes AML cell apoptosis by targeting BIRC6, suggesting miR-204 may play an anti-carcinogenic role in AML and function as a novel biomarker and therapeutic target for the treatment of this disease.

Anti-oxidative Activity of Lycopene Via the Induction of HO-1 Expression by MAPK/Nrf2 Signaling Pathway in RAW 264.7 Cells (RAW 264.7 세포에서 Lycopene의 MAPK/Nrf2/HO-1 신호 전달 체계를 통한 항산화 효과)

  • Chung-Mu Park;Hyun An;Hyun-Seo Yoon
    • Journal of The Korean Society of Integrative Medicine
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    • v.12 no.1
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    • pp.1-10
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    • 2024
  • Purpose: Lycopene is abundantly contained in Tomatoes and is known for diverse biological activities such as antioxidant, anti-inflammatory, and anticancer effects. In this study, the antioxidative potential of lycopene was investigated through the induction of hemeoxygenase (HO)-1 by nuclear factor-erythroid 2 p45-related factor2 (Nrf2) and upstream signaling molecules, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K)/Aktin RAW 264.7 cells. Methods: The antioxidative potential of lycopene against oxidative stress and its molecular mechanisms were determined by the cell viability assay, intracellular reactive oxygen species (ROS) formation assay, and Western blot analysis in RAW 264.7 cells. Results: Lycopene treatment significantly attenuated tert-butyl hydroperoxide (t-BHP) induced intracellular ROS formation in a dose-dependent manner without any cytotoxicity. In addition, 50 µM of lycopene for 6 h treatment induced potent HO-1 expression and its transcription factor, Nrf2. MAPK and PI3K/Aktwere also analyzed due to their critical roles in the regulation of cellular redox homeostasis against oxidative damage. As a result, phosphorylation of extracellular regulated kinase (ERK) was significantly induced by lycopene treatment while the activated status of c-Jun NH2-terminal kinase (JNK), p38, and Akt, were not given any effect. To confirm the antioxidative mechanism of HO-1 mediated by ERK activation, each selective inhibitor was employed in a protection assay, in which oxidative damage occurred by t-BHP. Lycopene, SnPP, and CoPP treatments reflected accelerated HO-1 expression could be a protective role against oxidative damage-initiated cell death. A selective inhibitor for ERK significantly inhibited the lycopene-induced cytoprotective effect but selective inhibitors for other signaling molecules did not attenuate the rate of t-BHP-induced cell death. Conclusion: In conclusion, lycopene potently scavenged intracellular ROS formation and enhanced the HO-1 mediated antioxidative potential through the modulation of Nrf2, MAPK signaling pathway in RAW 264.7 cells.

Effects of Sodium Butyrate, a Histone Deacetylase Inhibitor, on TRAIL-mediated Apoptosis in Human Bladder Cancer Cells (인체 방광암세포에서 histone deacetylase 억제제인 sodium butyrate이 TRAIL에 의한 apoptosis 유도에 미치는 영향)

  • Han, Min-Ho;Choi, Yung Hyun
    • Journal of Life Science
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    • v.26 no.4
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    • pp.431-438
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    • 2016
  • The tumour necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is considered a promising anticancer agent due to its unique ability to induce cancer cell death having only negligible effects on normal cells. However, many cancer cells tend to be resistant to TRAIL. In this study, we investigated the effects and molecular mechanisms of sodium butyrate (SB), a histone deacetylase inhibitor, in sensitizing TRAIL-induced apoptosis in 5637 human bladder cancer cells. Our results indicated that co-treatment with SB and TRAIL significantly increased the apoptosis induction, compared with treatment with either agent alone. Co-treatment with SB and TRAIL effectively increased the cell-surface expression of death receptor (DR) 5, but not DR4, which was associated with the inhibition of cellular Fas-associated death domain (FADD)-like interleukin-1β-converting enzyme (FLICE) inhibitory protein (c-FLIP). Furthermore, the activation of caspases (caspase-3, -8 and -9) and degradation of poly(ADP-ribose) were markedly increased in 5637 cells co-treated with SB and TRAIL; however, the synergistic effect was perfectly attenuated by caspase inhibitors. We also found that combined treatment with SB and TRAIL effectively induced the expression of pro-apoptotic Bax, cytosolic cytochrome c and cleave Bid to truncated Bid (tBid), along with down-regulation of anti-apoptotic Bcl-xL expression. These results collectively suggest that a combined regimen of SB plus TRAIL may offer an effective therapeutic strategy for safely and selectively treating TRAIL-resistant bladder cancer cells.

Expression of mRNAs characteristic of cartilage and bone in the developing mandibular condyle of mice (발육중인 생쥐 하악 과두에서 연골 및 골의 특이 유전자 발현)

  • Ji, Kuk-Soep;Yoon, Young-Jooh;Park, Joo-Cheol;Kim, Kwang-Won
    • The korean journal of orthodontics
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    • v.34 no.2 s.103
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    • pp.143-152
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    • 2004
  • It has not been elucidated whether the initiation of condylar development of the mandible is related with the periosteum of the mandible, or if it derives from a separate programmed blastema not related with the mandible. Also, although the mandibular condylar cartilage is known to promote growth, few studies have dealt with molecular-biologic mechanisms such as the expression of specific genes according to the differentiation of the mandibular condyle. To elucidate the unique cellular characteristics, development, and differentiation process of the mandibular condyle, an examination of expressions of genes characteristic of cartilage and bone were carried out using RT-PCR and mRNA in situ hybridization. 1. Type? collagen mRNA was detected with type II collagen mRNA in the differentiation and growth process of the cartilage of the mandibular condyle. TypeII collagen mRNA was demonstrated in the whole resting md upper part of the poliferative zone, whereas type II collagen mRNA was observed in the resting, proliferative and upper hypertrophic cartilage zone of the mandibular condyle. 2. The condylar cartilage rapidly increased in size due to the accumulation of hypertrophic chondrocytes as characterized by the expression of type II collagen mRNA during postnatal development. 3. BMP-4 mRNA was present in the anlage of the future condylar process and also in the ossifying mandibular body. 4. IHH mRNA was limited exclusively to the lower part of the proliferative zone and the upper part of the hypertrophic cartilage zone during condylar development. These findings were different from those in the growth-plate cartilage of the long bone, indicating a characteristic feature of the differentiation of the chondrocytes in the condylar cartilage present in prenatal and postnatal development. Furthermore, it was also suggested that chondroblasts of condylar cartilage rapidly differentiate into hypertrophic chondrocytes with increased functional Load force such as muscle activity and mastication.

A novel method for high-frequency genome editing in rice, using the CRISPR/Cas9 system (벼에서 CRISPR/Cas9 활용 고빈도 유전자 편집 방법)

  • Jung, Yu Jin;Bae, Sangsu;Lee, Geung-Joo;Seo, Pil Joon;Cho, Yong-Gu;Kang, Kwon Kyoo
    • Journal of Plant Biotechnology
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    • v.44 no.1
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    • pp.89-96
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    • 2017
  • The CRISPR/Cas9 is a core technology that can result in a paradigm for breeding new varieties. This study describes in detail the sgRNA design, vector construction, and the development of a transgenic plant and its molecular analysis, and demonstrates how gene editing technology through the CRISPR/Cas9 system can be applied easily and accurately. CRISPR/Cas9 facilitates targeted gene editing through RNA-guided DNA cleavage, followed by cellular DNA repair mechanisms that introduce sequence changes at the site of cleavage. It also allows the generation of heritable-targeted gene mutations and corrections. Here, we present detailed procedures involved in the CRISPR/Cas9 system to acquire faster, easier and more cost-efficient gene edited transgenic rice. The protocol described here establishes the strategies and steps for the selection of targets, design of sgRNA, vector construction, and analysis of the transgenic lines. The same principles can be used to customize the versatile CRISPR/Cas9 system, for application to other plant species.

Fortified Antioxidative Potential by Chrysoeriol through the Regulation of the Nrf2/MAPK-mediated HO-1 Signaling Pathway in RAW 264.7 Cells (생쥐 대식세포에서 HO-1 발현 유도를 통한 chrysoeriol의 항산화 효과)

  • Park, Chung Mu
    • Journal of Life Science
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    • v.28 no.1
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    • pp.43-49
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    • 2018
  • Chrysoeriol is a widespread flavone, and it is usually found in alfalfa, which has been used as a traditional medicine to treat dyspepsia, asthma, and urinary system disorders. Recently, analysis has been conducted on the anti-inflammatory activity of chrysoeriol, but information on its antioxidative capacity is limited. In this study, the antioxidative potential of chrysoeriol against oxidative damage and its molecular mechanisms were evaluated by analysis of the cell viability, reactive oxygen species (ROS) formation, and Western blots in the RAW 264.7 cell line. Chrysoeriol significantly scavenged lipopolysaccharide (LPS)-induced intracellular ROS formation in a dose-dependent manner, without any cytotoxicity. Heme oxygenase-1 (HO-1), a phase II enzyme that exerts antioxidative activity, was also potently induced by chrysoeriol treatment, which corresponded to the translocation of nuclear factor-erythroid 2 p45-related factor 2 (Nrf2) into the nucleus. Moreover, mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) were analyzed due to their important role in maintaining cellular redox homeostasis against oxidative stress. As a result, chrysoeriol-induced HO-1 upregulation was mediated by extracellular signal - regulated kinase (ERK), c-Jun $NH_2$-terminal kinase (JNK), and p38 phosphorylation. To identify the antioxidative potential exerted by HO-1, tert-butyl hydroperoxide (t-BHP)-induced oxidative damage was applied and mitigated by chrysoeriol treatment, which was confirmed by the HO-1 selective inhibitor and inducer, respectively. Consequently, chrysoeriol strongly strengthened the HO-1-mediated antioxidative potential through the regulation of the Nrf2/MAPK signaling pathways.