• Title/Summary/Keyword: Beta cell function

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Protective effect of lycopene against cytokine-induced β-cell apoptosis in INS-1 cells (라이코펜이 사이토카인에 의해 유도된 베타세포 사멸에 미치는 효과 및 기전 연구)

  • Kim, Kyong;Jang, Se-Eun;Bae, Gong Deuk;Jun, Hee-Sook;Oh, Yoon Sin
    • Journal of Nutrition and Health
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    • v.51 no.6
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    • pp.498-506
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    • 2018
  • Purpose: Lycopene, a carotenoid with anti-oxidant properties, occurs naturally in tomatoes and pink grapefruit. Although the beneficial effects of lycopene on various disorders have been established, little attention has been paid to the possible anti-diabetic effects of lycopene focusing on ${\beta}$-cells. Therefore, this study investigated the potential of lycopene to protect ${\beta}$-cells against apoptosis induced by a cytokine mixture. Methods: For toxicity experiments, the cells were treated with 0.1 ~ 10 nM of lycopene, and the cell viability in INS-1 cells (a rat ${\beta}$-cell line) was measured using a MTT assay. To induce cytokine toxicity, the cells were treated with a cytokine mixture (20 ng/mL of $TNF{\alpha}$ + 20 ng/mL of IL-$1{\beta}$) for 24 h, and the effects of lycopene (0.1 nM) on the cytokine toxicity were measured using the MTT assay. The expression levels of the apoptotic proteins were analyzed by Western blotting, and the level of intracellular reactive oxidative stress (ROS) was monitored using a DCFDA fluorescent probe. The intracellular ATP levels were determined using a luminescence kit, and mRNA expression of the genes coding for anti-oxidative stress response and mitochondrial function were analyzed by quantitative reverse-transcriptase PCR. Results: Exposure of INS-1 cells to 0.1 nM of lycopene increased the cell viability significantly, and protected the cells from cytokine-induced death. Lycopene upregulated the mRNA and protein expression of B-cell lymphoma-2 (Bcl-2) and reduced the expression of the Bcl-2 associated X (Bax) protein. Lycopene inhibited apoptotic signaling via a reduction of the ROS, and this effect correlated with the upregulation of anti-oxidative stress response genes, such as GCLC, NQO1, and HO-1. Lycopene increased the mRNA expression of mitochondrial function-related genes and increased the cellular ATP level. Conclusion: These results suggest that lycopene reduces the level of oxidative stress and improves the mitochondrial function, contributing to the prevention of cytokine-induced ${\beta}$-cell apoptosis. Therefore, lycopene could potentially serve as a preventive and therapeutic agent for the treatment of type 2 diabetes.

Adzuki bean (Vigna angularis) extract reduces amyloid-β aggregation and delays cognitive impairment in Drosophila models of Alzheimer's disease

  • Miyazaki, Honami;Okamoto, Yoko;Motoi, Aya;Watanabe, Takafumi;Katayama, Shigeru;Kawahara, Sei-ichi;Makabe, Hidefumi;Fujii, Hiroshi;Yonekura, Shinichi
    • Nutrition Research and Practice
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    • v.13 no.1
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    • pp.64-69
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    • 2019
  • BACKGROUND/OBJECTIVES: Alzheimer's disease is a neurodegenerative disease that induces symptoms such as a decrease in motor function and cognitive impairment. Increases in the aggregation and deposition of amyloid beta protein ($A{\beta}$) in the brain may be closely correlated with the development of Alzheimer's disease. In this study, the effects of an adzuki bean extract on the aggregation of $A{\beta}$ were examined; moreover, the anti-Alzheimer's activity of the adzuki extract was examined. MATERIALS/METHODS: First, we undertook thioflavin T (ThT) fluorescence analysis and transmission electron microscopy (TEM) to evaluate the effect of an adzuki bean extract on $A{\beta}_{42}$ aggregation. To evaluate the effects of the adzuki extract on the symptoms of Alzheimer's disease in vivo, $A{\beta}_{42}$-overexpressing Drosophila were used. In these flies, overexpression of $A{\beta}_{42}$ induced the formation of $A{\beta}_{42}$ aggregates in the brain, decreased motor function, and resulted in cognitive impairment. RESULTS: Based on the results obtained by ThT fluorescence assays and TEM, the adzuki bean extract inhibited the formation of $A{\beta}_{42}$ aggregates in a concentration-dependent manner. When $A{\beta}_{42}$-overexpressing flies were fed regular medium containing adzuki extract, the $A{\beta}_{42}$ level in the brain was significantly lower than that in the group fed regular medium only. Furthermore, suppression of the decrease in motor function, suppression of cognitive impairment, and improvement in lifespan were observed in $A{\beta}_{42}$-overexpressing flies fed regular medium with adzuki extract. CONCLUSIONS: The results reveal the delaying effects of an adzuki bean extract on the progression of Alzheimer's disease and provide useful information for identifying novel prevention treatments for Alzheimer's disease.

Chemical Constituents from Acer mandshuricum and Their Effects on the Function of Osteoblastic MC3T3-E1 Cells

  • Ding, Yan;Liang, Chun;Nguyen, Huu Tung;Choi, Eun-Mi;Kim, Jeong-Ah;Kim, Young-Ho
    • Bulletin of the Korean Chemical Society
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    • v.31 no.4
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    • pp.929-933
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    • 2010
  • A new compound, 4-methoxyl 5-hydroxymethyl benzoic 3-O-$\beta$-D-glucopyranoside (1), has been isolated from the leaves and stems of Acer mandshuricum, along with nine known compounds (2-10). Their structures were determined by a variety of spectroscopic analyses. The effect of compounds 1-10 on the function of osteoblastic MC3T3-E1 cells was examined by determining alkaline phosphatase (ALP) activity, collagen synthesis, and mineralization. Compound 1 significantly increased the function of osteoblastic MC3T3-E1 cells; $5.0\;{\mu}M$ of 1 increased ALP activity, collagen synthesis, and mineralization of MC3T3-E1 cells to 114.7, 119.5, and 108.2% (P < 0.05) of the basal value, respectively. In addition, compounds 2-10 also potently increased the function of osteoblastic MC3T3-E1 cells.

EFFECT OF OXYGEN TENSION ON THE ACTIVITY AND FUNCTION OF THE CELLS DERIVED FROM HUMAN PERIODONTAL LIGAMENT (산소 장력이 치주인대에서 유래한 세포의 활성과 기능에 미치는 영향)

  • Sa, Muyng-Hee;Yang, Won-Sik
    • The korean journal of orthodontics
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    • v.27 no.3 s.62
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    • pp.503-513
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    • 1997
  • This study was undertaken to investigate the effect of oxygen tension on the activity and function of the cells derived from human periodontal ligament by measuring cell activity, total protein synthesis, collagen synthesis, $IL-1{\beta},\;IL-6,\;TNF-{\alpha}$ Human periodontal ligament fibroblasts were collected from premolars extracted for orthodontic treatment and incubated in the environment of $37^{\circ}C,\;5\%\;CO_2,\100\%$ humidity. After the fifth to sixth passage they were used for the experiment. Gaspack system to which $0.2{\mu}m$ Millipore filter was attached was connected to mixed-gas tanks. The mixed gases were composed of $10\%\;O_2,\;5\%\;CO_2,\;85\%\;N_2$ in hyoxic group or $90\%\;O_2,\;5\%\;CO_2,\;5\%\;N_2$ in hyperoxic group and $5\%\;CO_2,\;95\%$ air for control. After incubation in $37^{\circ}C$ for 2, 4, 6 days, cell activity was determined by tetrazolium(MTT) assay and total protein synthesis was assayed using sulforhodamine B(SRB). And measurement of 4-hydroxyproline was performed to assess collagen synthesis md $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ were measured by enzymeimmunoassay. The results were as follows. 1. The cell activity and total protein synthesis in hypoxic group were a little higher than or almost the same with those in control group. 2. In hyperoxic group, the cell activity was lower than that in control group and total protein synthesis was decreased. 3. Collagen synthesis was significantly decreased initially in both hypoxic and hyperoxic group and increased nearly to the level of control group as the duration of cell incubation was longer 4. As a result of enzymeimmunoassay, the amount of cytokines was $IL-6,\;TNF-{\alpha}\;and\;IL-1{\beta}$ in order. 5. $IL-6,\;TNF-{\alpha}\;and\;IL-1{\beta}$ were increased more rapidly in both hypoxic and hyperoxic group than in control group as the duration of cell incubation was longer. 6. There were more $IL-6\;and\;TNF-{\alpha}$ in hyperoxic group than in control group after 6 days, and there were more $IL-6\;and\;TNF-{\alpha}$ after 6 days than after 2 or 4 days in hyperoxic group. These results suggested that oxygen tension might modulate the production of extracellular matrix and cytokines in the cells derived from human periodontal ligament.

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The Relationship between the Progression of Chronic Kidney Disease and Beta Cell Function in Non-Diabetic Korean Adults (대한민국 비당뇨 성인에서 만성신장질환과 인슐린저항성 및 베타세포기능의 관련성)

  • Kim, Hyung Rag
    • Korean Journal of Clinical Laboratory Science
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    • v.52 no.3
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    • pp.165-171
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    • 2020
  • This study examined the relationship between chronic kidney disease (CKD) and the homeostasis model assessment of insulin resistance (HOMA-IR) and beta-cell function (HOMA-B) in non-diabetic Korean adults. This study included 4,380 adults aged 20 or older (50.32±16.14) using the 2015 Korea National Health and Nutrition Examination Survey (KNHANES) data, which represents the national data in Korea. The present study had several key findings. First, in terms of HOMA-IR, after adjusting for the related variables (Model 4), the HOMA-IR (M±SE, 95% confidence interval [CI]) in group 1 (G1; estimated glomerular filtration rate [eGFR], ≥90 mL/min/1.73 ㎡), group 2 (G2; eGFR, 60~89 mL/min/1.73 ㎡), group 3a (G3a; eGFR, 30~59 mL/min/1.73 ㎡), and ≥group 3b (≥G3b; eGFR, <30 mL/min/1.73 ㎡) were 1.78±0.03 (1.73~1.83), 1.87±0.03 (1.81~1.93), 2.16±0.13 (1.91~2.42), and 2.59±0.24 (2.12~3.06), respectively. The HOMA-IR was positively associated with the progression of CKD (P<0.001). Second, in terms of the HOMA-B, after adjusting for the related variables (Model 4), the HOMA-B (M±SE, 95% CI) in G1, G2, G3a, and ≥G3b were 87.46±1.21 (85.08~89.84), 89.11±1.38 (86.40~91.81), 104.82±5.91 (93.23~116.42), and 123.97±10.87 (102.66~145.29), respectively. HOMA-B was positively associated with the progression of CKD (P<0.001). Both insulin resistance and the beta-cell function were positively associated with CKD in non-diabetic Korean adults.

Continuos-Flow culture of Hepatocytes in Sugar-derivatized poly (lactide-co-glycolide) Scaffolds Prepared by Gas-foaming/salt-leaching Method

  • Yun, Jun-Jin;Park, Tae-Gwan
    • 한국생물공학회:학술대회논문집
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    • 2000.04a
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    • pp.141-144
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    • 2000
  • Highly open porous polymer matrices are required for high density cell seeding, efficient nutrient, and oxygen supply to the cells cultured in the three dimensional matrices. However, there are severe problems of mass transfer limitations within the cell/scaffolds culture system. Thus we hypothesize that continuos-flow culture conditioning of cells with the scaffolds may improve the cell viability and the differentiated function. In this study, we fabricated porous PLGA scaffolds by using gas-foaming/salt-leaching method as previous described. Viscous PLGA gel paste contains ammonium bicarbonate particulates, acting as a gas-foaming agent as well as a salt-leaching porogen, were cast into Teflon mold and dried. Ammonium bicarbonate salt upon contact to an acidic aqueous solution evloves gaseous ammonia and carbon dioxide by itself. And we conjugated galactose moiety [AGA; $N-(aminobuty1)-O-{\beta}-D-galactopyranosyl-(1{\rightarrow}4)-D-glucoamide]$ to the terminal end group of a PLGA to increase the cell adhesion and matain the differentiated function of hepatocytes. Cell-seeded scaffolds were secured in a flow bioreactor chamber and exposed to continuous flow at 5 ml/min. As a result of our study, the high yield of hepatocytes attachment was accomplished by increasing the concentration of PLGA-AGA conjugate in polymer scaffolds and cells in the scaffolds under continuos flow condition maintained a high level of viability and albumin secretion rate of cultured hepatocytes showed a higher level that of control groups.

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Kinetics and Biological Function of Transforming Growth Factor-$\beta$ Isoforms in Bovine and Human Colostrum

  • CHUN, SUNG-KI;NAM, MYOUNG-SOO;GOH, JUHN-SU;KIM, WAN-SUP;HAN, YOUNG-HWAN;KIM, PYEUNG-HYEUN
    • Journal of Microbiology and Biotechnology
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    • v.14 no.6
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    • pp.1267-1274
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    • 2004
  • Colostrum contains various kinds of cytokines including TGF-$\beta$ that has potent regulatory effects on cells of the immune system. We compared the levels of TGF-$\beta$1 and TGF-$\beta$2 in bovine and human colostrum. Based on the isoform-specific ELISA, bovine colostrum collected on day 1 post-delivery retained $53.71{\pm}29.55\;ng/ml$ of TGF-$\beta$1 and $40.41{\pm}21.78\;{\mu}g/ml$ of TGF-$\beta$2 (n=4), while in human, $381.45{\pm}158.24\;ng/ml$ of TGF-$\beta$1 and $41.47{\pm}9.63\;ng/ml$ of TGF-$\beta$2 (n=5). Thus, dominant TGF-$\beta$ isoforms were completely opposite between human and bovine colostrum samples. The concentrations of both isoforms declined as lactation proceeded. Biological activities of the colostrum samples were determined using an MV1LU cell line. Consistent with the result from the immunoassay, TGF-$\beta$1 in human and TGF-$\beta$2 in bovine colostrum were responsible for the anti proliferative activity against MV1LU cells. Furthermore, bovine colostrum increased IgA secretion by LPS-stimulated mesenteric lymph node (MLN) cells, and this effect was abrogated by either anti­TGF-$\beta$2 antibody or combined anti-TGF-$\beta$1/$\beta$2 antibody, but not by anti- TGF-$\beta$1 antibody alone. Similarly, TGF-$\beta$2 in bovine colostrum enhanced the Ig germ line (GL) promoter activity, which is the earliest event toward IgA isotype switching. Taken together, these results suggest that TGF-$\beta$ isoforms, differentially expressed in human and bovine colostrum, may promote IgA isotype production in the neonatal intestine.

Protective Effect of Sesaminol Glucosides on Memory Impairment and ${\beta}$, ${\gamma}$-Secretase Activity In Vivo (Sesaminol Glucosides의 기억력 회복능 및 ${\beta}$, ${\gamma}$-Secretase)

  • Lee, Sun-Young;Son, Dong-Ju;Ha, Tae-Youl;Hong, Jin-Tae
    • YAKHAK HOEJI
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    • v.49 no.2
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    • pp.168-173
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    • 2005
  • Alzheimers disease (AD) is the most prevalent form of neurodegenerations associated with aging in the human population. This disease is characterized by the extracellular deposition of beta-amyloid (A ${\beta}$) peptide in cerebral plaques. The A ${\beta}$ peptide is derived from the ${\beta}$-amyloid precursor protein ( ${\beta}$APP). Photolytic processing of ${\beta}$APP by ${\beta}$-secretase(beta-site APP-cleaving enzyme, BASE) and ${\gamma}$-secretase generates the A ${\beta}$ peptide. Several lines of evidence support that A ${\beta}$-induced neuronal cell death is major mechanisms of development of AD. Accordingly, the ${\beta}$-and ${\gamma}$-secretase have been implicated to be excellent targets for the treatment of AD. We previously found that sesaminol glucosides have improving effect on memory functions through anti-oxidative mechanism. In this study, to elucidate possible other mechanism (inhibition of ${\beta}$-and ${\gamma}$-secretase) of sesaminol glucosides, we examined the improving effect of sesaminol glucosides in the scopolamine (1 mg/kg/mouse)-induced memory dysfunction using water maze test in the mice. Sesaminol glucosides (3.75, 7.5 mg/kg/6ml/day p.o., for 3 weeks) reversed the latency time, distance and velocity by scopolamine in dose dependent manner. Next, ${\beta}$-and ${\gamma}$-secretase activities were determined in different regions of brain. Sesaminol glucosides dose-dependently attenuated scopolamine-induced ${\beta}$-secretase activities in cortex and hippocampous and ${\gamma}$-secretase in cortex. This study therefore suggests that sesaminol glucosides may be a useful agent for prevention of the development or progression of AD, and its inhibitory effect on secretase may play a role in the improving action of sesaminol glucosides on memory function.

Fibronectin-Dependent Cell Adhesion is Required for Shear-Dependent ERK Activation

  • Park, Heonyong;Shin, Jaeyoung;Lee, Jung Weon;Jo, Hanjoong
    • Animal cells and systems
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    • v.8 no.1
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    • pp.27-32
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    • 2004
  • Endothellial cells are subjected to hemodynamic shear stress, the dragging force generated by blood flow. Shear stress regulates endothelial cell shape, structure, and function, including gene expression. Since endothelial cells must be anchored to their extracellular matrices(ECM) for their survival and growth, we hypothesized that ECMs are crucial for shear-dependent activation of extracellular signalactivated regulated kinase(ERK) that is important for cell proliferation. Shear stress-dependent activation of ERK was observed in cells plated on two different matrices, fibronectin and vitronectin(the two most physiologically relevant ECM in endothelial cells). We then treated bovine aortic endothelial cells(BAECs) with Arg-Gly-Asp(RGD) peptides that block the functional activation of integrin binding to fibronectin and vitronectin, and a nonfunctional peptide as a control. Treatment of cells with the RGD peptides, but not the control peptide, significantly inhibited ERK activity in a concentration-dependent manner. This supports the idea that integrin adhesion to the ligands, fibronectin and vitronectin, mediates shear stress-dependent activation of ERK. Subsequently, whereas antagonists of vitronectin(LM 609, an antibody for integrin ${\alpha}_{\gamma}$/${\beta}_3$ and XT 199, an antagonist specific for integrin ${\alpha}_{\gamma}$/${\beta}_3$) did not have any effect on shear-dependent activation of ERK, antagonists of fibronectin(a neutralizing antibody for integrin ${\alpha}_5$/${\beta}_1$or ${\alpha}_4$${\beta}_1$ and SM256) had an inhibitory effect. These results clearly demonstrate that mechanoactivation of ERK requires anchoring of endothelial cells to fibronectin through integrins.

Enhancing Effect of Sorghum bicolor L. Moench (Sorghum, su-su) Extracts on Mouse Spleen and Macrophage Cell Activation (수수 추출물에 의한 마우스 비장세포 및 대식세포 활성의 항진 효과)

  • Ryu Hye-Sook;Kim Jin;Kim Hyun-Sook
    • The Korean Journal of Food And Nutrition
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    • v.19 no.2
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    • pp.176-182
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    • 2006
  • Sorghum bicolor L. Moench(Sorghum, Su-Su) is a major cereal food crop used in many parts of the world. It is used as a human food resource and folk medicines in Asia and Africa. The stem of sorghum has been used as a digestive aid and an anti-diarrheal agent. Sorghum hybrids contain high levels of diverse phenolic compounds that may provide health benefits. High levels of polyflavanols, anthocyanins, phenolic acids, and other antioxidant compounds have been reported in sorghums, which have also been shown to possess various biological activities such as anti-mutagenic, anti-carcinogenic, and HMG-CoA reductase inhibitory activities. In an in vitro experiment, we examined mice splenocyte proliferation and production of three types of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by peritoneal macrophages cultured with ethanol and water extracts of Sorghum bicolor L. Moench. A single cell suspension of splenocytes was prepared and the cell proliferation of the splenocytes was examined by MTT assay. The splenocyte proliferation was increased when water extracts of Sorghum bicolor L. Moench were used as supplements in all concentrations investigated. The production of cytokine($IL-1{\beta},\;IL-6,\;TNF-{\alpha}$) by activated peritoneal macrophage was detected by ELISA using the cytokine kit. $IL-1{\beta},\;IL-6,\;and\;TNF-{\alpha}$ production by activated macrophages were increased by supplementation with Sorghum bicolor L. Moench water extracts. This study suggests that supplementation of with Sorghum bicolor L. Moench water extracts may enhance immune function by regulating the splenocyte proliferation and enhancing the cytokine production by activated macrophages in vitro.