• Title/Summary/Keyword: Beta cell

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The Mechanism of Lotus Root Extract (LRE) as Neuro-Protective Effect in Alzheimer Disease (AD) (연근(蓮根)의 신경 보호 효과 및 기전연구)

  • Hong, Seung-Chul;Lee, Chia-Hung;Kim, Sang-Heon;Lee, Jin-Hee;Koo, Byung-Soo
    • Journal of Oriental Neuropsychiatry
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    • v.24 no.3
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    • pp.309-320
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    • 2013
  • Objectives : There is a possibility LRE as remedy in Alzheimer disease (AD), but it's nerve protection effect and mechanism have to be elucidate. In this research, we applied LRE on $A{\beta}_{25-35}$ pre-treated SH-SY5Y cells, to find out the nerve protection effect and mechanism in AD cell model. Methods : We tried to confirm that effect by experimenting with 20, 50, and $100{\mu}g/ml$ concentration of LRE as a medicine. Next experiment, we assessed damage effect which induced $A{\beta}_{25-35}$, known to cause AD, on SH-SY5Y cell. In addition, cellular viability test is executed under $H_2O_2$ treatment condition in a SH-SY5Y cell. Results : 1. In $A{\beta}_{25-35}$ treated SH-SY5Y cell, LRE exhibited an anti-phosphorylation effect about tau protein, JNK, and IKB. 2. LRE prevent nerve cell apoptosis, which indued $A{\beta}_{25-35}$ and oxidative stress, modify JNK engaged synaptic structure and $NF{\kappa}B$ induced p75-neurotrophin receptor polymorphism. Conclusions : We found that LRE prevented oxidative stress-induced cellular destruction, for example, increased SOD activity of $A{\beta}_{25-35}$ treated SH-SY5Y cell and reduced toxicity of oxygen free radical. Consequently, the ingredients of LRE have a role as a catalyzer for $A{\beta}_{25-35}$ clearance and as scavenger for active oxygen free radical.

The Anti-Proliferation Effects and Its Mechanism of Bupleurum falcatum on Human Mesangial Cell (시호의 사구체 메산지움 세포 증식억제 효능 및 작용기전 연구)

  • Lee, Byung-Cheol;Ahn, Young-Min;Doo, Ho-Kyung;Ahn, Se-Young
    • The Journal of Internal Korean Medicine
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    • v.25 no.4
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    • pp.9-17
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    • 2004
  • Objective : Mesangial cell proliferation and excessive accumulation of extracellular matrix (ECM) proteins is the common pathologic feature of glomerulosclerosis, and platelet-derived growth factor (PDGF) BB-chain, transforming growth factor betal $(TGF-{\beta}1)$, cyclin dependent kinases (CDK) and CDK inhibitors mediated in these pathophysiological processes. Bupleurum falcatum which is one of the most widely used components in traditional oriental medicines, has multiple pharmacological effects, such as antipyretic, analgesic, immune modulating, anti-inflammatory, anti-allergic, anti-thrombotic, anti-atherosclerotic, and antitussive effects. Methods : In this study, we evaluated the influence of Bupleurum falcatum on mesangial cell proliferation, DNA synthesis and expression of PDGF-BB chain, $TGF-{\beta}1$, CDKI, CDK2, CDK4, p21 and p27 in fetal bovine serum (FBS)-activated human mesangial cell. Results : Bupleurum falcatum reduced the mesangial cell proliferation and DNA synthesis more than control and captopril. And in the ELISA analysis of $TGF-{\beta}1$, and RT-PCR of PDGF-BB chain, CDK1, CDK2, CDK4, p21, and p27, Bupleurum falcatum inhibited the expression of $TGF-{\beta}1$ protein and PDGF-BB, CDK1, CDK2 gene and promoted that of p21 gene in a dose-dependent manner in comparing with control and captopril. Conclusions: These results suggest that Bupleurum falcatum may inhibit the mesangial cell proliferation and DNA synthesis by regulation of PDGF-BB and $TGF-{\beta}1$ expressions, and by modulation of CDK1, CDK2 and p21 expression.

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CHOP Deficiency Ameliorates ERK5 Inhibition-Mediated Exacerbation of Streptozotocin-Induced Hyperglycemia and Pancreatic β-Cell Apoptosis

  • Nam, Dae-Hwan;Han, Jung-Hwa;Lim, Jae Hyang;Park, Kwon Moo;Woo, Chang-Hoon
    • Molecules and Cells
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    • v.40 no.7
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    • pp.457-465
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    • 2017
  • Streptozotocin (STZ)-induced murine models of type 1 diabetes have been used to examine ER stress during pancreatic ${\beta}$-cell apoptosis, as this ER stress plays important roles in the pathogenesis and development of the disease. However, the mechanisms linking type 1 diabetes to the ER stress-modulating anti-diabetic signaling pathway remain to be addressed, though it was recently established that ERK5 (Extracellular-signal-regulated kinase 5) contributes to the pathogeneses of diabetic complications. This study was undertaken to explore the mechanism whereby ERK5 inhibition instigates pancreatic ${\beta}$-cell apoptosis via an ER stress-dependent signaling pathway. STZ-induced diabetic WT and CHOP deficient mice were i.p. injected every 2 days for 6 days under BIX02189 (a specific ERK5 inhibitor) treatment in order to evaluate the role of ERK5. Hyperglycemia was exacerbated by co-treating C57BL/6J mice with STZ and BIX02189 as compared with mice administered with STZ alone. In addition, immunoblotting data revealed that ERK5 inhibition activated the unfolded protein response pathway accompanying apoptotic events, such as, PARP-1 and caspase-3 cleavage. Interestingly, ERK5 inhibition-induced exacerbation of pancreatic ${\beta}$-cell apoptosis was inhibited in CHOP deficient mice. Moreover, transduction of adenovirus encoding an active mutant form of $MEK5{\alpha}$, an upstream kinase of ERK5, inhibited STZ-induced unfolded protein responses and ${\beta}$-cell apoptosis. These results suggest that ERK5 protects against STZ-induced pancreatic ${\beta}$-cell apoptosis and hyperglycemia by interrupting the ER stress-mediated apoptotic pathway.

The Effects of Rheum palmatum(RHP) Extract on the the Alzheimer's Disease Model (대황(大黃)이 Alzheimer's Disease 병태(病態) 모델에 미치는 영향(影響))

  • Park, Chul-Hwan;Jung, In-Chul;Lee, Sang-Ryong
    • Journal of Oriental Neuropsychiatry
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    • v.16 no.1
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    • pp.67-80
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    • 2005
  • This experiment was designed to investigate the effect of Rheum palmatum(RHP) on the Alzheimer's disease. The effects of RHP extract on amyloid precursor proteins(APP), acetylcholinesterase(AChE), glial fibrillary acidic protein(GFAP) mRNA of PC-12 cell treated by $A{\beta}\;and\;IL-1{\beta},\;IL-6,\;TNF-{\alpha}$ mRNA of THP-1 cell treated by LPS and AChE activity of PC-12 cell lysate treated by $A {\beta}$and behavior of memory deficit rats induced by scopolamine and mice glucose, uric acid, AChE activity of memory deficit rats induced by scopolamine were investigated, respectively. The results were summarized as follows ; 1. RHP extract suppressed APP, AChE, GFAP mRNA in PC-12 cell treated by $A{\beta} $. 2. RHP extract suppressed $IL-1{\beta} $, IL-6 $TNF-{\alpha}$ mRNA in THP-1 cell treated by LPS. 3. RHP extract suppressed AChE activity in cell lysate of PC-12 cell treated by $A{\beta}$. 4. HP extract increased glucose, decreased uric acid and AChE significantly in the serum of the memory deficit rats induced by scopolamine. 5. RHP extract group showed significantly inhibitory effect on the memory deficit of mice induced by scopolamine in the experiment of Morris water maze. According to the above results, it is suggested that RHP extract might be usefully applied for prevention and treatment of Alzheimer’s disease and memory deficit symptom.

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The Effects of 2,3,7,8-Tetrachlorodibenzo-p-Dioxin (TCDD) on Proliferation of MCF-7 and Hec-1B Cell Lines

  • Ryu, Y.H.;Seo, D.S.;Ko, Y.
    • Proceedings of the KSAR Conference
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    • 2003.06a
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    • pp.94-94
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    • 2003
  • Endocrine disrupters (EDs) are exogenous chemicals that interfere with the production, releasing, metabolism, excretion, binding of natural hormones, and whole endocrine systems. EDs are very dangerous since they are extremely stable, not easily degraded, and accumulated in fat and tissue. 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD) is known as the most toxic EDs. Therefore, this study was conducted to investigate the effects of TCDD on proliferation of human breast cancer (MCF-7) and endometrial adenocarcinoma (Hec-1B) cells. 10, 100, and 1000 nM of TCDD were treated with steroid free condition. Viable cell counting, MTT, and BrdU assay was performed to investigate cell proliferation. Apoptosis was investigated using DNA laddering. Although, DNA fragmentation as the evidence of apoptosis was not detected, all of these cell lines showed restricted proliferation at 48 hrs after 100 and 1000 nM TCDD treatments. Recently, it has been reported that the expression of transforming growth factor $\beta$s (TGF-$\beta$s) are increased in TCDD treatment and also involved in regulation of cell cycle. Therefore, these results were considered that the decreased cell prolifcration by TCDD is related to the expression of TGF-$\beta$s.

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Proteolysis of $\beta$-Catenin in Apoptotic Jurkat Cells

  • Hwang, Sang-Gu;Park, Jeong-Uck;Lee, Hyung-Chul;Joo, Woo-Hong;Cho, Yong-Kweon;Moon, Ja-Young
    • Journal of Life Science
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    • v.10 no.1
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    • pp.57-63
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    • 2000
  • ${\beta}$-catenin, which plays a critical role in both the cytoskeleton and in transcriptional regulation in variousadherent cell types, undergoes degradation during adherent cell apoptosis. Although ${\beta}$-catenin has been reported to be present in Jurkat T-acute lymphoblastic leukemia cells, the regulation of ${\beta}$-catenin in hematologic malignancies have not been examined. The data presented here demonstrate that treatment of the T cell leukemia Jurkat iwht the apoptosis inducer anti-Fas induced proteolytic cleavage of ${\beta}$-catenin. ${\beta}$-catenin was cleaved at both the N- and C-terminus after anti-Fas treatment. Cleavage of intact ${\beta}$-catenin was completely inhibited by caspase selective protease inhibitors. These data demonstrate that ${\beta}$ -catenin proteolysis is triggered by the cross-linking of the Fas receptor on Jurkat cells and subsequent activation of caspase protease. There was a clear accumulatio of the large proteolytic fragment in Jurkat cells treated with lactacystin of ALLM. These are potent inhibitors of proteasome and calpain. these results suggest that both the proteasome and clapain may recognize the large ${\beta}$-catenin fragment as a substrate fot further degradation and that these pathewasy may act downstream of scapase in response to Fas receptor activation. Therefore, we suggest that ${\beta}$-catenin may play a role in promoting Jurkat survival.

Involvement of TGF-β1 Signaling in Cardiomyocyte Differentiation from P19CL6 Cells

  • Lim, Joong-Yeon;Kim, Won Ho;Kim, Joon;Park, Sang Ick
    • Molecules and Cells
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    • v.24 no.3
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    • pp.431-436
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    • 2007
  • Stem cell-based therapy is being considered as an alternative treatment for cardiomyopathy. Hence understanding the basic molecular mechanisms of cardiomyocyte differentiation is important. Besides BMP or Wnt family proteins, $TGF-{\beta}$ family members are thought to play a role in cardiac development and differentiation. Although $TGF-{\beta}$ has been reported to induce cardiac differentiation in embryonic stem cells, the differential role of $TGF-{\beta}$ isoforms has not been elucidated. In this study, employing the DMSO-induced cardiomyocyte differentiation system using P19CL6 mouse embryonic teratocarcinoma stem cells, we investigated the $TGF-{\beta}$-induced signaling pathway in cardiomyocyte differentiation. $TGF-{\beta}1$, but not the other two isoforms of $TGF-{\beta}$, was induced at the mRNA and protein level at an early stage of differentiation, and Smad2 phosphorylation increased in parallel with $TGF-{\beta}1$ induction. Inhibition of $TGF-{\beta}1$ activity with $TGF-{\beta}1$-specific neutralizing antibody reduced cell cycle arrest as well as expression of the CDK inhibitor $p21^{WAF1}$. The antibody also inhibited induction of the cardiac transcription factor Nkx2.5. Taken together, these results suggest that $TGF-{\beta}1$ is involved in cardiomyocyte differentiation by regulating cell cycle progression and cardiac gene expression in an autocrine or paracrine manner.

Effects of TGF ${\beta}_1$ on the Growth and Biochemical Changes in Cultured Rat Glial Cells (Transforming growth factor ${\beta}_1$이 배양랫트 신경교세포의 성장 및 생화학적 변화에 미치는 영향)

  • Kim, Yong-Sik;Youn, Yong-Ha;Park, Nan-Hyang;Park, Chan-Woong
    • The Korean Journal of Pharmacology
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    • v.30 no.2
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    • pp.167-179
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    • 1994
  • Recent evidence indicates that glial cells have a wide range of funtions which are critical for maintaining a balanced homeostatic environment in the central nervous system(CNS) peripheral nervous system(PNS). Morever, astrocytes are known to participate in the tissue repair and neuroimmunologic events within the CNS through many kinds of growth factors and cytokines. We investigated the effect of $TGF\;{\beta}_1$, on the growth and biochemical changes of rat glial cells in culture. The proliferative effect was determined by $^3H-thymidine$ uptake and the double immunostain with anti-cell-specific marker and anti-Bromodeoxyuridine(BrdU) antibody. To check the effect of biochemical changes we compared the amounts of glial fibrillar acidic protein(GFAP) and the activity of glutamine synthetase(GS) in astrocyte. And the amounts of myelin basic protein and the activity of 2',3'-cyclic nucleotide phosphohydrolase(CNPase) were measured in oligodendrocyte and the amounts of peripheral myelin in Schwann cell. When $TGF\;{\beta}_1$, was treated for 2 days with cultured glial cell, $TGF\;{\beta}_1$, decreased the $^3H-thymidine$ uptake and proliferation index of double immunostain of astrocytes, which indicates the inhibition of astroglial DNA synthesis, but stimulated the growth of Schwann cell. Also, $TGF\;{\beta}_1$, decrease the GS activity and increased the amounts of GFAP in astrocyte. In the case of Schwann cells the amounts of peripheral myelin was increased when treated with $TGF\;{\beta}_1$. However, $TGF\;{\beta}_1$, didn't show any effect on the proliferation and biochemical changes in oligodendrocyte. These results suggest that $TGF\;{\beta}_1$, might have a critical action in the regulation of proliferation and biochemical changes in glial cells, especially astrocyte.

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Repeated-Batch Operation of Immobilized ${\beta}$-Galactosidase Inclusion Bodies-Containing Escherichia coli Cell Reactor for Lactose Hydrolysis

  • Yeon, Ji-Hyeon;Jung, Kyung-Hwan
    • Journal of Microbiology and Biotechnology
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    • v.21 no.9
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    • pp.972-978
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    • 2011
  • In this study, we investigated the performance of an immobilized ${\beta}$-galactosidase inclusion bodies-containing Escherichia coli cell reactor, where the cells were immobilized in alginate beads, which were then used in repeated-batch operations for the hydrolysis of o-nitrophenyl-${\beta}$-D-galactoside or lactose over the long-term. In particular, in the Tris buffer system, disintegration of the alginate beads was not observed during the operation, which was observed for the phosphate buffer system. The o-nitrophenyl-${\beta}$-D-galactoside hydrolysis was operated successfully up to about 80 h, and the runs were successfully repeated at least eight times. In addition, hydrolysis of lactose was successfully carried out up to 240 h. Using Western blotting analyses, it was verified that the ${\beta}$-galactosidase inclusion bodies were sustained in the alginate beads during the repeated-batch operations. Consequently, we experimentally verified that ${\beta}$-galactosidase inclusion bodies-containing Escherichia coli cells could be used in a repeated-batch reactor as a biocatalyst for the hydrolysis of o-nitrophenyl-${\beta}$-D-galactoside or lactose. It is probable that this approach can be applied to enzymatic synthesis reactions for other biotechnology applications, particularly reactions that require long-term and stable operation.

Characterizations of DNA-polymerases Induced by SV40 Virus Infection of African Green Monkey Kidney Cells (AGMK) (SV 40 바이러스가 유도한 DNA 합성효소의 특성에 대한 연구)

  • 강현삼
    • Korean Journal of Microbiology
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    • v.14 no.3
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    • pp.135-145
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    • 1976
  • Confluent AGMK cells were infected by large plaque SV40 virus. Levels of DNA polymeras $({\alpha}\;and\;{\beta})$ were measured in the cytoplasm and the cell nucleus. The activities of DNA $polymerase-{\alpha}$ which found in both the cell nucleus and the cytoplasm were increased approximately eight folds at 48 hours after infection of SV40 virus. Only insignificant but constant amounts of DNA $polymerase-{\beta}$ were found either in the nucleus of the SV40 infected cell or of the uninfected cell. The characteristics of the SV40 virus induced DNA polymerases were compared with that of the uninfected cellular DNA polymerase in regard of the effects of pH, salt concentration, NEM concentration and temperature on those enzyme activities. No differential effect was found between both enzymes. Endouclease activities wre examined in the purified DNA $polymerase-{\alpha}\;and\;{\beta}$. The low level of endonuclease activity which might cut SV40 DNA 1 at one site was observed in the DNA $polymerase-{\alpha}$ whereas high but nonspecific endonuclease activities were found in the DNA $polymerase-{\beta}$.

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