• Title/Summary/Keyword: $\beta-cell$ function

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An inhibitory role of NEK6 in TGFβ/Smad signaling pathway

  • Zuo, Jie;Ma, Haijie;Cai, Hao;Wu, Yanhua;Jiang, Wei;Yu, Long
    • BMB Reports
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    • v.48 no.8
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    • pp.473-478
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    • 2015
  • The NEK6 (NIMA-related kinases 6) is reported to play po-tential roles in tumorigenesis. Although it is suggested to function in several cellular pathways, the underlying mechanism in tumorigenesis is still largely unknown. In the present study, we discovered interaction of NEK6 with Smad4, a key member of transforming growth factor beta (TGFβ) pathway. Over-expression of NEK6 in hepatocellular carcinoma (HCC) cell lines suppresses TGFβ-mediated transcription activity in a kinase activity-dependent manner. In addition, NEK6 suppresses the cell growth arrest induced by TGFβ. Mechanically, NEK6 blocks nuclear translocation of Smad4, which is essential for TGFβ function. Moreover, we identified that NEK6 could be regulated by TGFβ and hypoxia. Our study sheds new light on the roles of NEK6 in canonical TGFβ/Smad pathway and tum-origenesis. [BMB Reports 2015; 48(8): 473-478]

Inhibition of ClC-5 suppresses proliferation and induces apoptosis in cholangiocarcinoma cells through the Wnt/β-catenin signaling pathway

  • Shi, Zhe;Zhou, Liyuan;Zhou, Yan;Jia, Xiaoyan;Yu, Xiangjun;An, Xiaohong;Han, Yanzhen
    • BMB Reports
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    • v.55 no.6
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    • pp.299-304
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    • 2022
  • Chloride channel-5 (ClC-5), an important branch of the ClC family, is involved in the regulation of the proliferation and cell-fate of a variety of cells, including tumor cells. However, its function in cholangiocarcinoma (CCA) cells remains enigmatic. Here, we discovered that ClC-5 was up-regulated in CCA tissues and CCA cell lines, while ClC-5 silencing inhibited CCA cell proliferation and induced apoptosis. Further mechanism studies revealed that ClC-5 inhibition could inhibit Wnt/β-catenin signaling activity and further activate the mitochondria apoptotic pathway in CCA cells. Furthermore, rescuing Wnt/β-catenin signaling activation eliminated the anti-tumor function of ClC-5 knockdown. Together, our research findings illustrated that ClC-5 inhibition plays an anti-tumor role in CCA cells via inhibiting the activity of the Wnt/β-catenin pathway, which in turn activates the mitochondrial apoptotic pathway.

The Effects of Several Herbal Medicine Concentrated Solution on the Hyperglycemic Mice Induced with Streptozotocin (수종의 한약재가 Streptozotocin으로 유발된 고혈당 생쥐에 미치는 영향)

  • Chae, Jung-Won;Ju, Suk-Hyun
    • The Journal of Pediatrics of Korean Medicine
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    • v.20 no.1
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    • pp.165-180
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    • 2006
  • Objective : This study has been carried out to understand the effect of several herbal medicine concentrated solution on the hyperglycemic mice Induced with streptozotocin(STZ). Methods : The 60 mg/kg of STZ injection into mice twice by 24 h interval and then 120 mg/kg of STZ injection again 3 days after the earlier injection. Control group was subjected to natural recovery, however, treated groups were fed 0.2 ml of several herbal medicine-concentrated solution (PA (x2, several herbal medicine-concentrated solution 1 group); PB (x4 several herbal medicine-concentrated solution 2 group) daily for 6 weeks. Result : The weight of PA was higher than that of control, but weight of PB was lower than control. The blood level of control increased continuously, reaching to 350mg/dL after 6 weeks, however, PA and PB showed a fast reduction of blood glucose. In blood glucose tolerance test, PA and PB showed better resistance than control. The GOT level in significantly(p<0.05) decreased in PA and PB compared with control group. The BUN and creatinine levels are significantly(p<0.01) decreased in PA compared with control group. Feeding of several herbal medicine-concentrated solution in a concentration of PA had an efficient effect on regeneration or recovery of Langerhans islet and ${\beta}-cell$ damaged by STZ. More Langerhans islet and high insulin-immunohistochemical resistance were observed in PA compared with control, but they were higher in PB than in PA. The number of Langerhans islet ${\beta}-cell$ and Langerhans islet. Conclusions : The result from the six weeks of observation demonstrates that the several herbal medicine concentrated solution have a positive effect of lowering the level of blood sugar and they increased insulin concentration. They have an effect for recovery of pancreas tissue and recovery of kidney, liver function from a diabetes mellitus.

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The Effects of Lycium Chinense Milie on the $H_{2}O_{2}$-treated $LLC-PK_1$ Cell's Redox Status and $NF-{\kappa}B$Signaling (지골피(地骨皮)가 $H_{2}O_{2}$에 의한 $LLC-PK_1$ 세포의 Redox Status 및 $NF-{\kappa}B$ Signaling에 미치는 영향)

  • Choi, Gyu-Ho;Shin, Hyeon-Cheol
    • The Journal of Internal Korean Medicine
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    • v.30 no.1
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    • pp.36-50
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    • 2009
  • Objectives : This study was aimed to verify the cytoprotective function, antioxidative effect and inflammation genes inhibitory effects of Lycium chinense Milie. Therefore the generation of superoxide anion radical ( $O_2\;^-$), peroxynitrite ($ONOO^-$), nitric oxide (NO) and prostaglandin $E_2$ $(PGE_2)$ was investigated in the renal epithelial cells of mouse. Effects of Lycium chinense Milie on the expression of inflammation-related proteins, $IKK-{\alpha}$. $p-IKK-\alpha\beta$, $p-I{\kappa}B-\alpha$, $NF-{\kappa}B$ (p50, p65), COX-2 and iNOS, were examined by western blotting. Methods : For this study, the fluorescent probes were used, namely dihydrorhodamine 123 (DHR 123), 4.5-diaminofluorescein (DAF-2) and 2',7'-dichlorodihydrofluorescein diacetate (DCFDA). Western blotting was performed using anti-$IKK-\alpha$, anti-phospho $IKK-\alpha\beta$, anti-phospho $I{\kappa}B-\alpha$, anti-$NF-{\kappa}B$ (p50, p65), anti-COX-2 and anti-iNOS, respectively. Results : Lyciutn chinense Milie reduced $H_{2}O_{2}$-induced cell death dose-dependently. It inhibited the generation of $O_2\;^-$, $ONOO^-$, NO and $PGE_2$ in the $H_{2}O_{2}$-treated renal epithelial cells of mouse in vitro. Lycium chinense Milie inhibited the expression of $IKK-\alpha$, $p-IKK-\alpha\beta,\;p-I{\kappa}B-\alpha$, COX-2 and iNOS genes by means of decreasing activation of $NF-{\kappa}B$. Conclusions : According to above results. Lycium chinense Milie recommended to be applied in treatment for the inflammatory process and inflammation-related diseases.

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Insulin Receptor Substrate Proteins and Diabetes

  • Lee Yong Hee;White Morris F.
    • Archives of Pharmacal Research
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    • v.27 no.4
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    • pp.361-370
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    • 2004
  • The discovery of insulin receptor substrate (IRS) proteins and their role to link cell surface receptors to the intracellular signaling cascades is a key step to understanding insulin and insulin-like growth factor (IGF) action. Moreover, IRS-proteins coordinate signals from the insulin and IGF receptor tyrosine kinases with those generated by proinflammatory cytokines and nutrients. The IRS2-branch of the insulin/IGF signaling cascade has an important role in both peripheral insulin response and pancreatic $\beta$-cell growth and function. Dysregulation of IRS2 signaling in mice causes the failure of compensatory hyperinsulinemia during peripheral insulin resistance. IRS protein signaling is down regulated by serine phosphorylation or protea-some-mediated degradation, which might be an important mechanism of insulin resistance during acute injury and infection, or chronic stress associated with aging or obesity. Under-standing the regulation and signaling by IRS1 and IRS2 in cell growth, metabolism and survival will reveal new strategies to prevent or cure diabetes and other metabolic diseases.

Effects of Sagunjatang-Gami on Uterine and Ovarian Function in the Ovariectomized Rat Postmenopause Model (사군자탕가미방(四君子湯加味方)이 난소적출 폐경 병태 모델의 자궁 및 난소 기능에 미치는 영향)

  • Maeng, Yu-Sook;Choi, Min-Sun;Ahn, In-Suk;Kim, Dong-Il
    • The Journal of Korean Obstetrics and Gynecology
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    • v.25 no.4
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    • pp.12-26
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    • 2012
  • Objectives: The purpose of this study is to examine the effects of Sagunjatang-Gami(SGJT) on uterine and ovarian function in the ovariectomized rat postmenopause model. Methods: SGJT was administered in ovariectomized Wister albino female rats for three month. After that, uterine weight, uterine index, serum estradiol-$17{\beta}$ levels and phosphorylation of ERK or AKT, and histological analysis of uterus were measured to assess the impact on uterine and ovarian function in ovariectomized rats. In addition, phosphorylation of $ER{\alpha}$, ERK, AKT by SGJT in MDA-MB-231 cells were measured. To identify safety of SGJT, the cell cytoxicity in MDA-MB-231 cells and serum GOT, GPT levels were measured in ovariectomized rats. Results: The results were as follows. 1. SGJT decreased the viability of MDA-MB-231 cells in a dose-dependent manner. 2. The level of serum GOT, GPT in SGJT-treated group showed significant decrease in comparison with control group. 3. Phosphorylation of $ER{\alpha}$, ERK, AKT by SGJT in MDA-MB-231 cells were increased. 4. Uterus index in SGJT-treated group showed significant increase in comparison with control group. The level of serum estradiol-$17{\beta}$ in SGJT-treated group showed significant increase in comparison with control group. Phosphorylation of ERK or AKT by SGJT in the uterus of ovariectomized rats was increased significantly. 5. Uterus index and the level of serum estradiol-$17{\beta}$ in SGJT-treated group increased at higher rates in comparison with estrogen-treated group. Conclusions: Taken together, we suggest that SGJT has been shown to be effective in preventing postmenopausal uterine and ovarian degeneration and curing postmenopausal low estrogen related symptoms.

Ginsenoside (20S)Rg3 Ameliorates Synaptic and Memory Deficits in an Animal Model of Alzheimer's Disease

  • Kim, Tae-Wan
    • 한국약용작물학회:학술대회논문집
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    • 2011.09a
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    • pp.31-45
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    • 2011
  • The amyloid ${\beta}$-peptide ($A{\beta}$), which originates from the proteolytic cleavage of amyloid precursor protein (APP), plays a central role in the pathogenesis of Alzheimer's disease (AD). Mounting evidence indicates that different species of $A{\beta}$, such as $A{\beta}$ oligomers and fibrils, may contribute to AD pathogenesis via distinct mechanisms at different stages of the disease. Importantly, elevation and accumulation of soluble $A{\beta}$ oligomers closely correlate with cognitive decline and/or disease progression in animal models of AD. In agreement with these studies, oligomers of $A{\beta}$ have been shown to directly affect synaptic plasticity, a neuronal process that is known to be essential for memory formation. Our previous studies showed that $A{\beta}$ induces the breakdown of phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2), a phospholipid that regulates key aspects of neuronal function. PI(4,5)P2 breakdown was found to be a key step toward synaptic and memory dysfunction in a mouse model of AD. To this end, we seek to identify small molecules that could elevate the levels of PI(4,5)P2 and subsequently block $A{\beta}$ oligomer-induced breakdown of PI(4,5)P2 and synaptic dysfunction.. We found that (20S)Rg3, an active triterpene glycoside from heat-processed ginseng, serves as an agonist for phosphatidylinositol 4-kinase IIalpha (PI4KIIalpha), which is a lipid kinase that mediates a rate-limiting step in PI(4,5)P2 synthesis. Consequently, (20S)Rg3 stimulates PI(4,5)P2 synthesis by directly stimulating the activity of PI4KIIalpha. Interestingly, treatment of a mouse model of AD with (20S)Rg3 leads to reversal of memory deficits. Our data suggest that the PI(4,5)P2-promoting effects of (20S)Rg3 may help mitigate the cognitive symptoms associated with AD.

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Identification of Critical Residues for Plasminogen Binding by the αX I-domain of the β2 integrin, αXβ2

  • Gang, Jongyun;Choi, Jeongsuk;Lee, Joo Hee;Nham, Sang-Uk
    • Molecules and Cells
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    • v.24 no.2
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    • pp.240-246
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    • 2007
  • The ${\beta}2$ integrins on leukocytes play important roles in cell adhesion, migration and phagocytosis. One of the ${\beta}2$ integrins, ${\alpha}X{\beta}2$ (CD11c/CD18), is known to bind ligands such as fibrinogen, Thy-1 and iC3b, but its function is not well characterized. To understand its biological roles, we attempted to identify novel ligands. The functional moiety of ${\alpha}X{\beta}2$, the ${\alpha}X$ I-domain, was found to bind plasminogen, the zymogen of plasmin, with moderate affinity ($1.92{\times}10^{-6}M$) in the presence of $Mg^{2+}$ or $Mn^{2+}$. The ${\beta}D-{\alpha}5$ loop of the ${\alpha}X$ I-domain proved to be responsible for binding, and lysine residues ($Lys^{242}$, $Lys^{243}$) in the loop were the most important for recognizing plasminogen. An excess amount of the lysine analog, 6-aminohexanoic acid, inhibited ${\alpha}X$ I-domain binding to plasminogen, indicating that binding is lysine-dependent. The results of this study indicate that leukocytes regulate plasminogen activation, and consequently plasmin activities, through an interaction with ${\alpha}X{\beta}2$ integrin.

Dectin-1 Stimulation Selectively Reinforces LPS-driven IgG1 Production by Mouse B Cells

  • Seo, Beom-Seok;Lee, Sang-Hoon;Lee, Ju-Eon;Yoo, Yung-Choon;Lee, Junglim;Park, Seok-Rae
    • IMMUNE NETWORK
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    • v.13 no.5
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    • pp.205-212
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    • 2013
  • Dectin-1, which specifically recognizes ${\beta}$-glucan of fungal cell walls, is a non-Toll-like receptor (TLR) pattern recognition receptor and a representative of C-type lectin receptors (CLRs). The importance of Dectin-1 in innate immune cells, such as dendritic cells and macrophages, has previously been well studied. However, the function of Dectin-1 in B cells is very poorly understood. To determine the role of Dectin-1 in B cell activation, we first investigated whether mouse B cells express Dectin-1 and then assessed the effect of Dectin-1 stimulation on B cell proliferation and antibody production. Mouse B cells express mRNAs encoding CLRs, including Dectin-1, and surface Dectin-1 was expressed in B cells of C57BL/6 rather than BALB/c strain. Dectin-1 agonists, heat-killed Candida albicans (HKCA) and heat-killed Saccharomyces cerevisiae (HKSC), alone induced B cell proliferation but not antibody production. Interestingly, HKSC, HKCA, and depleted zymosan (a selective Dectin-1 agonist) selectively enhanced LPS-driven IgG1 production. Taken together, these results suggest that, during fungal infection, ${\beta}$-glucan-stimulated Dectin-1 may cooperate with TLR4 to specifically enhance IgG1 production by mouse B cells.

Effects of Liriope muscari Water Extracts on the Cell Death and Inflammatory Cytokine Expression of Poly I:C-treated Lung Carcinoma Cells (맥문동 열수 추출물이 Poly I:C를 처리한 폐암세포주의 사멸 및 염증성 사이토카인 발현에 미치는 영향)

  • Kang, Dayeon;Cho, Namjoon;Renchinkhand, Gereltuya;Lee, Bo-Hee;Kim, Eun-Mi;Nam, Myoung Soo;Kim, Keekwang
    • The Korea Journal of Herbology
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    • v.36 no.1
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    • pp.97-102
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    • 2021
  • Objectives : Virus infection through the respiratory tract causes various inflammatory diseases such as pneumonia, cystic fibrosis, and obstructive pulmonary disease, causing enormous social damage. Therefore, it is very important to develop a treatment and prevention of infectious diseases. In this study, we investigated the effect of water extracts of Liriope muscari (WELM), known to improve lung function, on the inflammatory response of lung carcinoma cell line A549 cells induced by the viral double stranded RNA mimetic Polyinosinic:polycytidylic acid (Poly I:C). Methods : The cell viability by WELM treatment was analyzed using MTS assay in A549 cells. After inducing an inflammatory response to WELM-treated A549 cells with Poly I:C, the degree of apoptosis was confirmed through bright field microscopy. Interferon beta (IFN-β) mRNA expression level in A549 cells was analyzed by quantitative reverse transcription PCR (qRT-PCR). Results : WELM treatment has no significant effect on cell viability of A549 cells. We confirmed that pre-treatment of WELM effectively reduces the Poly I:C-induced apoptotic cell death in A549 cells. In addition, it was confirmed that the mRNA expression level of IFN-β, a pro-inflammatory cytokine increased by Poly I:C treatment, was significantly suppressed by WELM treatment in A549 cells. Conclusions : These results provide the evidence that WELM is effective at inhibiting inflammation on respiratory viral infections and suggest that Liriope muscari might be a valuable natural substance in the prevention and treatment of infectious diseases.