• Title/Summary/Keyword: fluorescence microscopy.

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Effects of miR-152 on Cell Growth Inhibition, Motility Suppression and Apoptosis Induction in Hepatocellular Carcinoma Cells

  • Dang, Yi-Wu;Zeng, Jing;He, Rong-Quan;Rong, Min-Hua;Luo, Dian-Zhong;Chen, Gang
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.12
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    • pp.4969-4976
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    • 2014
  • Background: miR-152 is involved in the genesis and development of several malignancies. However, its role in HCC has not been fully clarified. The aim of this study was to investigate the clinicopathological significance of miR-152 and its effect on the malignant phenotype of HCC cells. Methods: miR-152 expression was detected using real-time quantitative RT-PCR in 89 pairs of HCC formalin-fixed paraffin-embedded and their adjacent tissues. Functionally, in vitro effects and mechanisms of action of miR-152 on proliferation, viability, caspase activity, apoptosis and motility were explored in HepG2, HepB3 and SNU449 cells, as assessed by spectrophotometry, fluorimetry, fluorescence microscopy, wound-healing and Western blotting, respectively. Results: miR-152 expression in HCC was downregulated remarkably compared to that in adjacent hepatic tissues. miR-152 levels in groups of advanced clinical stage, larger tumor size and positive HBV infection, were significantly lower than in other groups. A miR-152 mimic could suppress cell growth, inhibit cell motility and increase caspase activity and apoptosis in HCC cell lines. Furthermore, Western blotting showed that the miR-152 mimic downregulated Wnt-1, DNMT1, ERK1/2, AKT and TNFRS6B signaling. Intriguingly, inverse correlation of TNFRF6B and miR-152 expression was found in HCC and bioinformatics confirmed that TNFRF6B might be a target of miR-152. Conclusions: Underexpression of miR-152 plays a vital role in hepatocarcinogenesis and lack of miR-152 is related to the progression of HCC through deregulation of cell proliferation, motility and apoptosis. miR-152 may act as a tumor suppressor miRNA by also targeting TNFRSF6B and is therefore a potential candidate biomarker for HCC diagnosis, prognosis and molecular therapy.

Roles of p53 and Caspases in Induction of Apoptosis in MCF-7 Breast Cancer Cells Treated with a Methanolic Extract of Nigella Sativa Seeds

  • Alhazmi, Mohammed I.;Hasan, Tarique N.;Shafi, Gowhar;Al-Assaf, Abdullah H.;Alfawaz, Mohammed A.;Alshatwi, Ali A.
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.22
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    • pp.9655-9660
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    • 2014
  • Background: Nigella Sativa (NS) is an herb from the Ranunculaceae family that exhibits numerous medicinal properties and has been used as important constituent of many complementary and alternative medicines (CAMs). The ability of NS to kill cancer cells such as PC3, HeLa and hepatoma cells is well established. However, our understanding of the mode of death caused by NS remains nebulous. The objective of this study was to gain further insight into the mode and mechanism of death caused by NS in breast cancer MCF-7 cells. Materials and Methods: Human breast cancer cells (MCF-7) were treated with a methanolic extract of NS, and a dose- and time-dependent study was performed. The $IC_{50}$ was calculated using a Cell Titer $Blue^{(R)}$ viability assay assay, and evidence for DNA fragmentation was obtained by fluorescence microscopy TUNEL assay. Gene expression was also profiled for a number of apoptosis-related genes (Caspase-3, -8, -9 and p53 genes) through qPCR. Results: The $IC_{50}$ of MCF-7 cells was $62.8{\mu}L/mL$. When MCF-7 cells were exposed to $50{\mu}L/mL$ and $100{\mu}L/mL$ NS for 24h, 48h and 72h, microscopic examination (TUNEL assay) revealed a dose- and time-dependent increase in apoptosis. Similarly, the expression of the Caspase-3, -8, -9 and p53 genes increased significantly according to the dose and time. Conclusions: NS induced apoptosis in MCF-7 cells through both the p53 and caspase pathways. NS could potentially represent an alternative source of medicine for breast cancer therapy.

Desalinated underground seawater of Jeju Island (Korea) improves lipid metabolism in mice fed diets containing high fat and increases antioxidant potential in t-BHP treated HepG2 cells

  • Noh, Jung-Ran;Gang, Gil-Tae;Kim, Yong-Hoon;Yang, Keum-Jin;Lee, Chul-Ho;Na, O-Su;Kim, Gi-Ju;Oh, Won-Keun;Lee, Young-Don
    • Nutrition Research and Practice
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    • v.4 no.1
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    • pp.3-10
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    • 2010
  • This study was performed to investigate the effect of desalinated underground seawater (named as 'magma seawater', MSW) of Jeju Island in Korea on lipid metabolism and antioxidant activity. MSW was collected from underground of Han-Dong in Jeju Island, and freely given to high fat diet (HFD)-fed C57BL/6 mice for 10 weeks. Although there were no significant differences in the body weight changes and plasma lipid levels, hepatic triglyceride levels were significantly lower in the MSW group than in the normal tap water (TW)-drunken control group. Furthermore, the activity of fatty acid synthase (FAS) was significantly decreased and carnitine palmitoyltransferase (CPT) activity was increased in MSW group compared to TW group. Similarly, real-time PCR analysis revealed that mRNA expressions of lipogenic genes were lowered in MSW groups compared to the control group. In a morphometric observation on the liver tissue, accumulation of fats was remarkably reduced in MSW group. Meanwhile, in vitro assay, tree radical scavenging activity measured by using diphenylpicrylhydrazyl (DPPH) was increased in MSW group. The 2'-7'-dichlorofluorescein diacetate (DCF-DA) staining followed with fluorescent microscopy showed a low intensity of fluorescence in MSW-treated HepG2 cells, compared to TW-treated HepG2 cells, which indicated that the production of reactive oxygen species by tert-butyl hydroperoxide (t-BHP) in HepG2 cells was decreased by MSW treatment. The antioxidant effect of MSW on t-BHP-induced oxidative stress in HepG2 cells was supported by the increased activities of intracellular antioxidant enzymes such as catalase and glutathione reductase. From these results, we speculate that MSW has an inhibitory effect on lipogenesis in liver and might play a protective role against cell damage by t-BHP-induced oxidative stress.

Dexamethasone Interferes with Autophagy and Affects Cell Survival in Irradiated Malignant Glioma Cells

  • Komakech, Alfred;Im, Ji-Hye;Gwak, Ho-Shin;Lee, Kyue-Yim;Kim, Jong Heon;Yoo, Byong Chul;Cheong, Heesun;Park, Jong Bae;Kwon, Ji Woong;Shin, Sang Hoon;Yoo, Heon
    • Journal of Korean Neurosurgical Society
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    • v.63 no.5
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    • pp.566-578
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    • 2020
  • Objective : Radiation is known to induce autophagy in malignant glioma cells whether it is cytocidal or cytoprotective. Dexamethasone is frequently used to reduce tumor-associated brain edema, especially during radiation therapy. The purpose of the study was to determine whether and how dexamethasone affects autophagy in irradiated malignant glioma cells and to identify possible intervening molecular pathways. Methods : We prepared p53 mutant U373 and LN229 glioma cell lines, which varied by phosphatase and tensin homolog (PTEN) mutational status and were used to make U373 stable transfected cells expressing GFP-LC3 protein. After performing cell survival assay after irradiation, the IC50 radiation dose was determined. Dexamethasone dose (10 μM) was determined from the literature and added to the glioma cells 24 hours before the irradiation. The effect of adding dexamethasone was evaluated by cell survival assay or clonogenic assay and cell cycle analysis. Measurement of autophagy was visualized by western blot of LC3-I/LC3-II and quantified by the GFP-LC3 punctuated pattern under fluorescence microscopy and acridine orange staining for acidic vesicle organelles by flow cytometry. Results : Dexamethasone increased cell survival in both U373 and LN229 cells after irradiation. It interfered with autophagy after irradiation differently depending on the PTEN mutational status : the autophagy decreased in U373 (PTEN-mutated) cells but increased in LN229 (PTEN wild-type) cells. Inhibition of protein kinase B (AKT) phosphorylation after irradiation by LY294002 reversed the dexamethasone-induced decrease of autophagy and cell death in U373 cells but provoked no effect on both autophagy and cell survival in LN229 cells. After ATG5 knockdown, radiation-induced autophagy decreased and the effect of dexamethasone also diminished in both cell lines. The diminished autophagy resulted in a partial reversal of dexamethasone protection from cell death after irradiation in U373 cells; however, no significant change was observed in surviving fraction LN229 cells. Conclusion : Dexamethasone increased cell survival in p53 mutated malignant glioma cells and increased autophagy in PTEN-mutant malignant glioma cell but not in PTEN-wildtype cell. The difference of autophagy response could be mediated though the phosphatidylinositol 3-kinase/AKT/mammalian target of rapamycin signaling pathway.

Gemological Comparison between Gwangdong Tektite and Baikdusan Obsidian (텍타이트와 흑요석의 보석학적 특징비교 - 중국 광동 텍타이트와 백두산 흑요석을 중심으로 -)

  • Kim, Won-Sa
    • Journal of the Mineralogical Society of Korea
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    • v.20 no.3
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    • pp.181-191
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    • 2007
  • The gemological charateristics of Gwangdong tektites and Baikdusan obsidians were investigated, using microscopy, density and refractive index measurements, X-ray fluorescence spectrometry, Inductively Coupled Plasma Mass spectrometry, X-ray powder diffraction, and electron microprobe analysis. The Gwangdong tektites and Baikdusan obsidians are both black in colour and slightly trans-lucent with various shades of brown when cut into a few mm thick. Both the materials yield conchoidal fracture on broken surface. The tektites occur as tear-drop shapes, ranging from 4 to 10 cm long, and in spheres, from 3 to 5 cm in diameter. On the surface numerous shallow pits up to 3 mm in diameter are present. Mohs' hardness and specific gravity are 5 to 5.5 and 2.66, respectively. The tektites are singly refractive, with an refractive index of 1.51. Numerous spherical air bubbles are randomly scattered throughout the tektites, and silica-rich glass inclusions are occasionally seen. X-ray powder diffraction analysis verifies that they are non-crystalline. The Baikdusan obsidians show very similar properties to those of the Gwangdong tektites, especially in hardness, amorphous nature and fracture. Nevertheless, the Baikdusan obsidian can readily be distinguished from the Gwangdong tektites by refractive index ($1.49{\sim}1.50$), specific gravity (2.67 to 2.68), and inclusions (absence of bubbles and presence of sanidine and magnetite crystals).

Effects of TGF-$\beta$3 on Epithelial-mesenchymal transformation and Epidermal growth factor receptor expression in palatogenesis of chicken embryo (계태아 발생시 TGF-$\beta$3가 구개판 내측돌기상피의 상피간엽변환 및 상피성장인자수용체 발현에 미치는 영향)

  • Yang Byoung-Eun;Lee Jong-Ho
    • Korean Journal of Cleft Lip And Palate
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    • v.4 no.1
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    • pp.13-26
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    • 2001
  • Cleft lip and/or palate is the congenital orofacial malformation most commonly occurred in humans, The disease is multifactorial and is probably caused by genetic and/or environmental factors, So, there are many problems in research concerning etiology and in treatment of the disease, Even the most practiced and sophisticated methods of surgical repair are necessarily followed by scar contraction and fibrosis, which result in skeletal defects, dental abnormalities, cosmetic disfigurement, and speech impairment, As a result, Fetal surgery can be considered but practiced rarely when the deformity is not fatal to life, And treatment of cleft palate is performed in the form of medicine projection into uterus in animal experiments, Many studies show that growth factor and its receptor emerge from the developing palate; and the epidermal growth factor receptors have a important role in craniofacial development and in palatal fusion, The palatal morphogenesis of the avine is different from the mammal's; it takes the form of physiologic cleft palate, Recently, cleft palate fusion experiment was performed when the avine were in the period of palate formation through the exogenous TGF-β3 addition, and it showed that the exogenous TGF-β3 makes fusion of divided palate through certain process when cleft palate is occurred in palatal formation, In this study, I had the conformation of the fusion of cleft palate through the addition of TGF-β in case of chicken embryo, and observed the effect of TGF-β in EGF receptor distribution, And the following is the results of this study, 1. In case of the TGF-βl and β3 addition group, there was the decrease of EGFR(Epidermal Growth Factor Receptor) immunoreactivity in mesenchymal cells beneath the medial edge epithelium and also in epithelial mesenchymal interface which is between medial edge epithelium and nasal septum in 72 hours, 2, The immunoreactivity of the control group resembles that of normal chicken embryo palate in development, 3. In the view through fluorescence confocal microscopy, there was confluence in TGF-β3 addition group, This shows that the confluence induced by exogenous TGF-β3 is related to EGFR expression in palate of chicken embryo, which is a physiologic cleft palate model.

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The Effect of Remifentanil Preconditioning on Injured Keratinocyte

  • Hong, Hun Pyo;Kim, Cheul Hong;Yoon, Ji Young;Kim, Yong Deok;Park, Bong Soo;Kim, Yong Ho;Yoo, Ji Uk
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.14 no.3
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    • pp.157-165
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    • 2014
  • Background: Incisional site of surgical operation become transient ischemic state and then occur reoxygenation due to vasodilatation by inflammatory reaction, the productive reactive oxygen species (ROS) give rise to many physiologic results. Apoptosis have major role on elimination of inflammatory cell and formation of granulation tissue in normal wound healing process. Remifentanil can prevent the inflammatory response and can suppress inducible nitric oxide synthase expression in a septic mouse model. After cardiopulmonary bypass for coronary artery surgery, remifentanil can also inhibit the release of biomarkers of myocardial damage. Here we investigated whether remifentanil pretreatment has cellular protective effect against hypoxia-reoxygenation in HaCaT human keratinocytes, if so, the role of apoptosis and autophagy on this phenomenon. Methods: The HaCaT human keratinocytes were exposed to various concentrations of remifentanil (0.01, 0.05, 0.1, 0.5 and 1 ng/ml) for 2 h before hypoxia (RPC/HR group). These cells were cultured under 1% oxygen tension for 24h at $37^{\circ}C$. After hypoxia, to simulate reoxygenation and recovery, the cells were reoxygenated for 12 h at $37^{\circ}C$. 3-MA/RPC/HR group was treated 3-methyladenine (3-MA), autophagy inhibitor for 1h before remifentanil treatment. Cell viability was measured using a quantitative colorimetric assay with thiazolyl blue tetrazoliumbromide (MTT, amresco), showing the mitochondrial activity of living cells. To investigate whether the occurrence of autophagy and apoptosis, we used fluorescence microscopy and Western blot analysis. Results: The viability against hypoxia-reoxygenation injury in remifentanil preconditioning keratinocytes were increased, and these cells were showed stimulated expression of autophagy 3-MA suppressed the induction of autophagy effectively and the protective effects on apoptosis. Atg5, Beclin-1, LC3-II and p62 were elevated in RPC/HR group. But they were decreased when autophagy was suppressed by 3-MA. Conclusions: Remifentanil preconditioning showed the protective effect in human keratinocytes, and we concluded that autophagy may take the major role in the recovery of wound from hypoxia-reoxygenation injury. We suggest that further research is needed about the cell protective effects of autophagy.

Propofol protects against oxidative-stress-induced COS-7 cell apoptosis by inducing autophagy

  • Yoon, Ji-Young;Baek, Chul-Woo;Kim, Eun-Jung;Park, Bong-Soo;Yu, Su-Bin;Yoon, Ji-Uk;Kim, Eok-Nyun
    • Journal of Dental Anesthesia and Pain Medicine
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    • v.17 no.1
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    • pp.37-46
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    • 2017
  • Background: In oxidative stress, reactive oxygen species (ROS) production contributes to cellular dysfunction and initiates the apoptotic cascade. Autophagy is considered the mechanism that decreases ROS concentration and oxidative damage. Propofol shows antioxidant properties, but the mechanisms underlying the effect of propofol preconditioning (PPC) on oxidative injury remain unclear. Therefore, we investigated whether PPC protects against cell damage from hydrogen peroxide ($H_2O_2$)-induced oxidative stress and influences cellular autophagy. Method: COS-7 cells were randomly divided into the following groups: control, cells were incubated in normoxia (5% $CO_2$, 21% $O_2$, and 74% $N_2$) for 24 h without propofol; $H_2O_2$, cells were exposed to $H_2O_2$ ($400{\mu}M$) for 2 h; $PPC+H_2O_2$, cells pretreated with propofol were exposed to $H_2O_2$; and 3-methyladenine $(3-MA)+PPC+H_2O_2$, cells pretreated with 3-MA (1 mM) for 1 h and propofol were exposed to $H_2O_2$. Cell viability was determined using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide thiazolyl blue (MTT) reduction. Apoptosis was determined using Hoechst 33342 staining and fluorescence microscopy. The relationship between PPC and autophagy was detected using western blot analysis. Results: Cell viability decreased more significantly in the $H_2O_2$ group than in the control group, but it was improved by PPC ($100{\mu}M$). Pretreatment with propofol effectively decreased $H_2O_2$-induced COS-7 cell apoptosis. However, pretreatment with 3-MA inhibited the protective effect of propofol during apoptosis. Western blot analysis showed that the level of autophagy-related proteins was higher in the $PPC+H_2O_2$ group than that in the $H_2O_2$ group. Conclusion: PPC has a protective effect on $H_2O_2$-induced COS-7 cell apoptosis, which is mediated by autophagy activation.

PEP-1-HO-1 prevents MPTP-induced degeneration of dopaminergic neurons in a Parkinson's disease mouse model

  • Youn, Jong Kyu;Kim, Dae Won;Kim, Seung Tae;Park, Sung Yeon;Yeo, Eun Ji;Choi, Yeon Joo;Lee, Hae-Ran;Kim, Duk-Soo;Cho, Sung-Woo;Han, Kyu Hyung;Park, Jinseu;Eum, Won Sik;Hwang, Hyun Sook;Choi, Soo Young
    • BMB Reports
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    • v.47 no.10
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    • pp.569-574
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    • 2014
  • Heme oxygenase-1 (HO-1) degrades heme to carbon dioxide, biliverdin, and $Fe^{2+}$, which play important roles in various biochemical processes. In this study, we examined the protective function of HO-1 against oxidative stress in SH-SY5Y cells and in a Parkinson's disease mouse model. Western blot and fluorescence microscopy analysis demonstrated that PEP-1-HO-1, fused with a PEP-1 peptide can cross the cellular membranes of human neuroblastoma SH-SY5Y cells. In addition, the transduced PEP-1-HO-1 inhibited generation of reactive oxygen species (ROS) and cell death caused by 1-methyl-4-phenylpyridinium ion ($MPP^+$). In contrast, HO-1, which has no ability to transduce into SH-SY5Y cells, failed to reduce $MPP^+$-induced cellular toxicity and ROS production. Furthermore, intraperitoneal injected PEP-1-HO-1 crossed the blood-brain barrier in mouse brains. In a PD mouse model, PEP-1-HO-1 significantly protected against 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced toxicity and dopaminergic neuronal death. Therefore, PEP-1-HO-1 could be a useful agent in treating oxidative stress induced ailments including PD.

Expression of Human Cytochrome b5 in Zebrafish (Zebrafish에서 human cytochrome b5의 발현)

  • Han, Se Mi;Yoo, Min
    • Journal of Life Science
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    • v.27 no.6
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    • pp.617-622
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    • 2017
  • In this study, we sought to develop an effective cloning system by which human cytochrome $b_5$ (cyt $b_5$) is introduced and expressed in zebrafish. First, the 414 bp human cyt $b_5$ gene was amplified from RNA extracts of HeLa cells using RT-PCR, and the amplicon was subsequently sequenced to confirm that it was intact. Next, cyt $b_5$ was cloned into the pEGFP-N3 vector, which also encodes a fluorescent gene. One-cell stage zebrafish embryos were microinjected with the recombinant vector containing the cyt $b_5$ gene. Fluorescence microscopy confirmed high expression of the fluorescent gene in the injected fry compared to the non-fluorescent control fry. Finally, we extracted RNA from the injected fry and performed RT-PCR to determine whether the human cyt $b_5$ gene is expressed in the transgenic zebrafish. Sequencing analysis further confirmed that the cloned human cyt $b_5$ gene was intact. The transgenic zebrafish model produced in this study will be a useful tool to study therapeutic approaches to cure various diseases related to the deficiency of functional human cyt $b_5$ as well as tools for cloning useful genes in fish.