• 제목/요약/키워드: Beta cell

검색결과 3,972건 처리시간 0.031초

Cell Cycle Regulation and Induction of Apoptosis by β-carotene in U937 and HL-60 Leukemia Cells

  • Upadhyaya, K.R.;Radha, K.S.;Madhyastha, H.K.
    • BMB Reports
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    • 제40권6호
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    • pp.1009-1015
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    • 2007
  • In this communication, we report the efficacy of $\beta$-carotene towards differentiation and apoptosis of leukemia cells. Dose ($20{\mu}M$) and time dependence (12 h) tests of $\beta$-carotene showed a higher magnitude of decrease (significance p < 0.05) in cell numbers and cell viability in HL-60 cells than U937 cells but not normal cell like Peripheral blood mononuclear cell (PBMC). Microscopical observation of $\beta$-carotene treated cells showed a distinct pattern of morphological abnormalities with inclusion of apoptotic bodies in both leukemia cell lines. When cells were treated with $20{\mu}M$ of $\beta$-carotene, total genomic DNA showed a fragmentation pattern and this pattern was clear in HL-60 than U937 cells. Both the cell lines, on treatment with $\beta$-carotene, showed a clear shift in $G_1$ phase of the cell cycle. In addition the study also revealed anti-oxidant properties of $\beta$-carotene since there was reduction in relative fluorescent when treated than the control at lower concentration. Collectively this study shows the dual phenomenon of apoptosis and differentiation of leukemia cells on treatment with $\beta$-carotene.

Loss of βPix Causes Defects in Early Embryonic Development, and Cell Spreading and Platelet-Derived Growth Factor-Induced Chemotaxis in Mouse Embryonic Fibroblasts

  • Kang, TaeIn;Lee, Seung Joon;Kwon, Younghee;Park, Dongeun
    • Molecules and Cells
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    • 제42권8호
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    • pp.589-596
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    • 2019
  • ${\beta}Pix$ is a guanine nucleotide exchange factor for the Rho family small GTPases, Rac1 and Cdc42. It is known to regulate focal adhesion dynamics and cell migration. However, the in vivo role of ${\beta}Pix$ is currently not well understood. Here, we report the production and characterization of ${\beta}Pix$-KO mice. Loss of ${\beta}Pix$ results in embryonic lethality accompanied by abnormal developmental features, such as incomplete neural tube closure, impaired axial rotation, and failure of allantois-chorion fusion. We also generated ${\beta}Pix$-KO mouse embryonic fibroblasts (MEFs) to examine ${\beta}Pix$ function in mouse fibroblasts. ${\beta}Pix$-KO MEFs exhibit decreased Rac1 activity, and defects in cell spreading and platelet-derived growth factor (PDGF)-induced ruffle formation and chemotaxis. The average size of focal adhesions is increased in ${\beta}Pix$-KO MEFs. Interestingly, ${\beta}Pix$-KO MEFs showed increased motility in random migration and rapid wound healing with elevated levels of MLC2 phosphorylation. Taken together, our data demonstrate that ${\beta}Pix$ plays essential roles in early embryonic development, cell spreading, and cell migration in fibroblasts.

A Correlative Study on Amyloid β-Induced Cell Death Independent of Caspase Activation

  • Tuyet, Pham Thi Dieu
    • 통합자연과학논문집
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    • 제7권2호
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    • pp.87-91
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    • 2014
  • Amyloid beta ($A{\beta}$) peptide has been implicated in the pathogenesis of Alzheimer's disease and has been reported to induce apoptotic death in cell culture. Cysteine Proteases, a family of enzymes known as caspases, mediate cell death in many models of apoptosis. In the present study, we examined the caspase activity and cell death in $A{\beta}$-treated SHSY5Y cells, as an attempt to elucidate the relationship between the type of caspase and $A{\beta}$-induced cell death. $A{\beta}$ at 20 ${\mu}M$ induce activation of caspase-3, 8 and 9 activity, but not the caspase-1. Caspase-3, 8 and 9 were processed by Ab treatment, consistent with the activity assay. Inhibition of the caspase activities by the selective inhibitors, however, marginally affected the cell death induced by $A{\beta}$. Taken together, the results indicate that $A{\beta}$-induced cell death may be independent of caspase activity and rather, the enzymes might be activated as a result of the cell death.

Overexpression of Protein Kinase $C{\beta}_1$ Restores Mitogenic Responses of Enterocytic Differentiated Colon Carcinoma Cells to Diacylglycerol and Basic FGF

  • Lee, Han-Soo
    • BMB Reports
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    • 제30권3호
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    • pp.194-199
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    • 1997
  • Previous studies have shown that the HD3 human enterocytic differentiated colon carcinoma cell lines having low $PKC{\beta}$ activity did not respond to diacylglycerol and basic FGF by growth and by activation of pp57 MAP kinase, but undifferentiated cell lines exhibiting high $PKC{\beta}$ activity did. To confirm a role of $PKC{\beta}$ in colonocyte mitogenesis, derivatives of HD3 cell line that stably overexpress a full-length of cDNA encoding the ${\beta}_1$ isoform of human PKC were generated. The abundance and activity of $PKC{\beta}$ in two of the these cell lines, PKC3 and PKC8 were much higher than those in the C1 control cell line that carries the vector lacking the $PKC{\beta}_1\;cDNA$ insert. Following exposure to diacylglycerol or basic FGF, proliferation of PKC3 and PKC8 cells increased about 50%; but this effect was not seen with the control C1 cells. Also, in contrast to the control cells, the $PKC{\beta}_1-overproducing$ cells displayed activation of pp57 MAP kinase when treated with diacylglycerol and basic FGF as undifferentiated cell lines did. These results provide direct evidence that $PKC{\beta}_1$ which plays a key role in mitogenic responses of colon carcinoma cells to diacylglycerol and basic FGF is down-regulated in enterocytic differentiation of colon cells.

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Cellular and Molecular Roles of $\beta$ Cell Autoantigens, Macrophages and T Cells in the Pathogenesis of Automimmune Diabetes

  • Yoon, Ji-Won;Jun, Hee-Sook
    • Archives of Pharmacal Research
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    • 제22권5호
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    • pp.437-447
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    • 1999
  • Type I diabetes, also known as insulin-dependent diabetes mellitus (IDDM) results from the destruction of insulin-producing pancreatic $\beta$ cells by a progressive $\beta$ cell-specific autoimmune process. The pathogenesis of autoimmune IDDM has been extensively studied for the past two decades using animal models such as the non-obese diabetic (NOD) mouse and the Bio-Breeding (BB) rat. However, the initial events that trigger the immune responses leading to the selective destruction of the $\beta$ cells are poorly understood. It is thought that $\beta$ cell auto-antigens are involved in the triggering of $\beta$ cell-specific autoimmunity. Among a dozen putative $\beta$ cell autoantigens, glutamic acid decarboxylase (GAD) has bee proposed as perhaps the strongest candidate in both humans and the NOD mouse. In the NOD mouse, GAD, as compared with other $\beta$ cell autoantigens, provokes the earliest T cell proliferative response. The suppression of GAD expression in the $\beta$ cells results in the prevention of autoimmune diabetes in NOD mice. In addition, the major populations of cells infiltrating the iselts during the early stage of insulitis in BB rats and NOD mice are macrophages and dendritic cells. The inactivation of macrophages in NOD mice results in the prevention of T cell mediated autoimmune diabetes. Macrophages are primary contributors to the creation of the immune environment conducive to the development and activation of $\beta$cell-specific Th1-type CD4+ T cells and CD8+ cytotoxic T cells that cause autoimmune diabetes in NOD mice. CD4+ and CD8+ T cells are both believed to be important for the destruction of $\beta$ cells. These cells, as final effectors, can kill the insulin-producing $\beta$ cells by the induction of apoptosis. In addition, CD8+ cytotoxic T cells release granzyme and cytolysin (perforin), which are also toxic to $\beta$ cells. In this way, macrophages, CD4+ T cells and CD8+ T cells act synergistically to kill the $\beta$ cells in conjunction with $\beta$ cell autoantigens and MHC class I and II antigens, resulting in the onset of autoimmune type I diabetes.

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TGF-$\beta$3는 마우스 IgA, IgG2b 항체의 선택적 유도작용 (TGF-$\beta$3 Selectively Induces Mouse IgA and IgG2b isotype)

  • 이은경;박석래;전계택;김평현;이세원;최의열
    • 미생물학회지
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    • 제35권2호
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    • pp.164-168
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    • 1999
  • TGF-$\beta$1은 LPS 로 자극시킨 마우스의 spleen B cell 의 IgA와 IgG2b의 항체 합성을 선택적으로 증가시킨다고 알려져있다. 본 연구에서는 TGF-$\beta$1과 80%의 아미노산을 공유하는 TGF-$\beta$3가 마우스 spleen B cell 과 mesenteric lymph node B cell의 항체 합성에 미치는 영향을 IL-5와 함께 조사하였다. LPS로 활성화된 spleen B cell 에 TGF-$\beta$3만을 처리한 조건에서 IgA 항체합성이 약간 증가하였고, IL-5와 함께 넣어 준 배양조건에서는 IgA 항체가 현격히 증가하였다 IgG2b 합성의 증가는 TGF-$\beta$3 자극만으로도 가능하였고 IgA 와는 달리 IL-5 의 첨가 효과는 관찰되지 않았다. 한편, TGF-$\beta$3는 IgM 과 IgG1 항체 합성을 감소시켰고, IL-5와 함께 존재한 경우에도 의미있는 합성 증가는 볼 수 없었다. ELISPOT assay로 IgA 합성 세포수의 변화를 조사해본 결과, TGF-$\beta$3 단독으로도 IgA 합성세포수를 증가시켰으며, 이때 IL-5가 존재하였을 때 세포수가 조금 더 증가하였다. 이상의 결과는 TGF-$\beta$3가 약간의 차이는 있지만 TGF-$\beta$1과 유사하게 항체합성 패턴에 영향을 미침을 보여준다. 마지막으로, TGF-$\beta$3과 IL-5에 대한 MLN B cell 의 IgA와 IgG2b 항체합성 패턴은 spleen B cell 과 비슷하였다. 그러나 MLN B cell 의 IgG1 항체 합성은 spleen B cell과는 달리 TGF-$\beta$3에 의해 증가하였다. 본 실험의 결과는 전반적으로 TGF-$\beta$3가 TGF-$\beta$1과 비슷한 정도로 마우스 B cell의 항체합성에 영향을 미침을 보여준다. 그렇지만, 생체 내에서TGF-$\beta$3의 발현조절이 TGF-$\beta$1과 다를 것으로 예상됨으로 과연 TGF-$\beta$3가 B cell 분화에서 중요한 조절인자로 작용할지는 좀 더 연구되어야 할 것이다.

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Increase in Insulin Secretion Induced by Panax ginseng Berry Extracts Contributes to the Amelioration of Hyperglycemia in Streptozotocin-induced Diabetic Mice

  • Park, Eun-Young;Kim, Ha-Jung;Kim, Yong-Kyoung;Park, Sang-Un;Choi, Jae-Eul;Cha, Ji-Young;Jun, Hee-Sook
    • Journal of Ginseng Research
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    • 제36권2호
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    • pp.153-160
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    • 2012
  • Panax ginseng has long been used as a traditional herbal medicine. More recently, it has received attention for its anti-diabetic and anti-obesity effects in humans and in animal models of type 2 diabetes. In the present study, we tested the hypoglycemic effects of ginseng berry extract in beta-cell-deficient mice and investigated the mechanisms involved. Red (ripe) and green (unripe) berry extracts were prepared and administered orally (100 or 200 mg/kg body weight) to streptozotocin-induced diabetic mice daily for 10 wk. The body weight was measured daily, and the nonfasting blood glucose levels were measured after 5 and 10 wk after administration. Glucose tolerance tests were performed, and the serum insulin levels were measured. The proliferation of beta-cells was measured in vitro. The administration of red or green ginseng berry extract significantly reduced the blood glucose levels and improved the glucose tolerance in beta-cell deficient mice, with the higher doses resulting in better effects. Glucose-stimulated insulin secretion was significantly increased in berry extract-treated mice compared with streptozotocin-induced diabetic control mice. Treatment with ginseng berry extract increased beta-cell proliferation in vitro. Both red berry and green berry extracts improved glycemic control in streptozotocin-induced diabetic mice and increased insulin secretion, possibly due to increased beta-cell proliferation. These results suggest that ginseng berry extracts might have beneficial effects on beta-cell regeneration.

Cyanidin-3-glucoside inhibits amyloid β25-35-induced neuronal cell death in cultured rat hippocampal neurons

  • Yang, Ji Seon;Jeon, Sujeong;Yoon, Kee Dong;Yoon, Shin Hee
    • The Korean Journal of Physiology and Pharmacology
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    • 제22권6호
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    • pp.689-696
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    • 2018
  • Increasing evidence implicates changes in $[Ca^{2+}]_i$ and oxidative stress as causative factors in amyloid beta ($A{\beta}$)-induced neuronal cell death. Cyanidin-3-glucoside (C3G), a component of anthocyanin, has been reported to protect against glutamate-induced neuronal cell death by inhibiting $Ca^{2+}$ and $Zn^{2+}$ signaling. The present study aimed to determine whether C3G exerts a protective effect against $A{\beta}_{25-35}$-induced neuronal cell death in cultured rat hippocampal neurons from embryonic day 17 fetal Sprague-Dawley rats using MTT assay for cell survival, and caspase-3 assay and digital imaging methods for $Ca^{2+}$, $Zn^{2+}$, MMP and ROS. Treatment with $A{\beta}_{25-35}$ ($20{\mu}M$) for 48 h induced neuronal cell death in cultured rat pure hippocampal neurons. Treatment with C3G for 48 h significantly increased cell survival. Pretreatment with C3G for 30 min significantly inhibited $A{\beta}_{25-35}$-induced $[Zn^{2+}]_i$ increases as well as $[Ca^{2+}]_i$ increases in the cultured rat hippocampal neurons. C3G also significantly inhibited $A{\beta}_{25-35}$-induced mitochondrial depolarization. C3G also blocked the $A{\beta}_{25-35}$-induced formation of ROS. In addition, C3G significantly inhibited the $A{\beta}_{25-35}$-induced activation of caspase-3. These results suggest that cyanidin-3-glucoside protects against amyloid ${\beta}$-induced neuronal cell death by reducing multiple apoptotic signals.

당귀작약산, 월비가출탕이 Mesangial Cell 증식과 ICAM-l 및 ${\beta}1-integrin$ 발현에 미치는 영향 (The Effects of Dangguijakyak-san and Wuelbigachul-tang on Mesangial Cell Proliferation and on ICAM-1 and ${\beta}1-integrin$ Expression)

  • 장원만;안세영;두호경
    • 대한한의학회지
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    • 제21권3호
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    • pp.140-148
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    • 2000
  • Objectives : This experiment was conducted to investigate the suppressive effects of Dangguijakyak-san and Wuelbigachul-tang on the expression of ICAM-l and ${\beta}1-integrin$, which mediate cell-cell or cell-matrix interaction, and on the proliferation of mesangial cells. Methods : After in vitro culturing of human mesangial cells with the supernatant which was obtained from the monocytes separated from human blood with Con-A, hydrocortisone, Dangguijakyak-san and Wuelbigachul-tang respectively, we evaluated suppressive effects by measuring the mesangial cell surface enzyme immunoassay or flow cytometry. Results : The results are summarized as follows: 1. Dangguijakyak-san and Wuelbigachul-tang induced marked suppressive effects on the mesangial cell proliferation in the 50% and 25% supernatant concentration stimulating experiments, but hydrocortisone had little effect in these experiments. 2. Dangguijakyak-san and Wuelbigachul-tang induced marked suppressive effects on ICAM-l and ${\beta}1-integrin$ expression, but were less effective than hydrocortisone was. Conclusions : Based on these results, Dangguijakyak-san and Wuelbigachul-tang were found to be effective in the suppression of mesangial cell proliferation and in ICAM-1 and ${\beta}1-integrin$ expression. Further in vitro investigations as conducted above, with the in vivo experiments reflected, may prove that Dangguijakyak-san and Wuelbigachul-tang contribute to the prevention of the glomerular disease.

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취장소도세포와 면역세포에 미치는 팔미원의 영향 (Effects of PALMIWON on Cell Viability of Immune Cell and ${\beta}-cell$)

  • 이인순;이인자
    • 약학회지
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    • 제39권5호
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    • pp.541-547
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    • 1995
  • In order to investigate the usability of PALMIWON as antidiabetic immuno-modulating prescription for Insulin-dependent diabetes, we studies the effects of PALMIWON on immune cell and ${\beta}-cell$. U937 was used as the model of immune cell and RINm5F as the model of ${\beta}-cell$. The effects of PALMIWON was measured by cell viability in terms of MIT assay. As a result, PALMIWON and the compositional drugs showed the different effects m immune cell and ${\beta}-cell$. Cell viability of U937 was significantly decreased wheras that of RINm5F was no significantly difference between drug treated group and control, or significantly less reduction compared with U937. It implies that PALMIWON is useful as immunotherapeutic agents in the prevention and therapy of type 1 diabetes.

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