• 제목/요약/키워드: Beta cell function

검색결과 344건 처리시간 0.031초

Decreased Expression of Phospholipase C-$\beta$2 in Human Platelets with Impaired Function

  • Lee, Sang-Bong;A. Koneti Rao;Lee, Kweon-Haeng;Xu Yang;Bae, Yun-Soo
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 1996년도 제4회 추계심포지움
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    • pp.75-84
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    • 1996
  • Platelets from a patient with a mild inherited bleeding disorder and abnormal platelet aggregation and secretion show reduced generation of inositol 1,4,5-trisphosphate (IP$_3$), mobilization of intracellular Ca$\^$2+/, and phosphorylation of pleckstrin in response to several G protein mediated agonists, suggesting a possible defect at the level of phospholipase C (PLC) activation. A procedure was developed that allows quantitation of platelet PLC isozymes. After fractionation of platelet extracts by high-performance liquid chromatography, seven, out often known PLC isoforms were detected by immunoblot analysis. The amount of these isoforms in normal platelets decreased in the order PLC-${\gamma}$2 > PLC-${\beta}$2 > PLC-${\beta}$3 > PLC-${\beta}$l > PLC-${\gamma}$ > PLC-$\delta$1 > PLC-${\beta}$4. Compared with normal platelets, platelets from the patient contained approximately one-third the amount of PLC-${\beta}$2, whereas PLC-${\beta}$4 was increased threefold. These results suggest that the impaired platelet function in the patient in response to multiple G protein mediated agonists is attributable to a deficiency of PLC-${\beta}$2. They document for the first time a specific PLC isozyme deficiency in human platelets and provide an unique opportunity to understand the role of different PLC isozymes in normal platelet function.

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Dexamethasone Inhibits the Formation of Multinucleated Osteoclasts via Down-regulation of ${\beta}_3$ Integrin Expression

  • Kim, Yong-Hee;Jun, Ji-Hae;Woo, Kyung-Mi;Ryoo, Hyun-Mo;Kim, Gwan-Shik;Baek, Jeong-Hwa
    • Archives of Pharmacal Research
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    • 제29권8호
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    • pp.691-698
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    • 2006
  • Although glucocorticoids are known to affect osteoclast differentiation and function, there have been conflicting reports about the effect of glucocorticoids on osteoclast formation, leading to the assumption that microenvironment and cell type influence their action. We explored the effect of the synthetic glucocorticoid analog dexamethasone on the formation of osteoclasts. Dexamethasone inhibited the formation of tartrate-resistant acid phosphatase (TRAP)-positive multinucleated osteoclasts without affecting the formation of TRAP-positive mononuclear cells in a coculture of mouse osteoblasts and bone marrow cells. Dexamethasone did not inhibit mRNA expression levels of the receptor activator of nuclear factor-kB ligand and osteoprotegerin, the essential regulators of osteoclastogenesis. Dexamethasone down-regulated the expression of ${\beta}_3$ integrin mRNA and protein but did not alter expression of other osteoclast differentiation marker genes. Both dexamethasone and echistatin, a ${\beta}_3$ integrin function blocker, inhibited TRAP-positive multinucleated osteoclast formation but not TRAP-positive mononuclear cell formation. These results suggest that dexamethasone inhibits the formation of multinucleated osteoclasts, at least in part, through the down-regulation of ${\beta}_3$ integrin, which plays an important role in the formation of multinucleated osteoclasts.

Antioxidant effect of myricetin with other antioxidants, taurine and $\beta$-carotene on mouse melanoma cell

  • Yu, Ji-Sun;Kim, An-Keun
    • 한국응용약물학회:학술대회논문집
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    • 한국응용약물학회 2003년도 Annual Meeting of KSAP : International Symposium on Pharmaceutical and Biomedical Sciences on Obesity
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    • pp.69-69
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    • 2003
  • There are now increasing evidences that free radicals and reactive oxygen species are involved in a variety of pathological events. Reactive Oxygen Species (ROS) are produced during normal cellular function. ROS lead to lipid peroxidation, massive protein oxdiation and degradation. Under normal conditions, antioxidant are substnaces that either directly or indirectly protect cell against adverse effect of ROS. several biologically important compound include ${\beta}$-carotene, taruine and flavonoids reported have antioxidant function. The various antioxidant either scavange superoxide and free radicals or stimulate the detoxification mechanisms within cells resulting in increased detoxification of free radicals formation and thus in prevention of many pathophysiologic processes. This study carried out to investigate the antioxidant activity of flavonoids, myricetin with other antioxidants, ${\beta}$-carotene and taurine on B16Fl0. In order to investigate the efficacy of antioxidant activity, we measured cell viability, antioxidant enzyme activity (SOD, GPX, CAT) and intracellular reactive oxygen intermediate (ROI). In this results, we show that these flavonoids with other antioxidant substrates are increased antioxidant activity level.

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들깨 메탄올 추출물의 acetylcholinesterase 억제활성 및 세포독성 보호효과 (Acetylcholinesterase Inhibitory Activity and Protective Effect against Cytotoxicity of Perilla Seed Methanol Extract)

  • 최원희;엄민영;안지윤;김성란;강명화;하태열
    • 한국식품과학회지
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    • 제36권6호
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    • pp.1026-1031
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    • 2004
  • 들깨 메탄올 추출물이 acetylcholinesterase(AChE)의 활성 및 PC 12 cell 세포사멸에 미치는 영향을 검토하였다. AChE에 대한 억제환성은 들깨 메탄을 추출물의 농도가 높을수록 유의적으로 높았으며 추출물의 분획물 중에서는 n-butanol층이 가장 높은 억제율을 나타내었다. L-glutamate 또는 ${\beta}-amyloid$ protein $(A{\beta})$으로 유도된 PC 12 cell에 대한 세포사멸 억제효과도 추출물의 농도가 높을수록 유의적으로 증가하였다. 또한 rat brain에 $FeSO_{4^-}H_2O_2$로 산화적 스트레스를 유발시켜 추출물의 TBARS 생성 억제활성을 조사한 결과 들깨 메탄을 추출물은 농도가 높아질수록 산화적 스트레스에 대한 억제활성이 증가하였으며 분획물 중에서는 n-butanol층에서 가장 높은 억제활성을 나타내었다. 이상의 결과들로 미루어 볼 때 들깨 메탄을 추출물은 AChE 활성을 억제하고 glutamate 또는 $A{\beta}$에 의하여 유도된 PC12 cell의 세포사멸을 억제하며 이러한 효과는 들깨 메탄을 추출물의 항산화력에 기인할 수도 있을 것으로 사료되었다.

한국 비만성인의 대사증후군 유병에 따른 내장지방지수와 인슐린저항성, 췌장 베타세포기능과의 관련성 (Relationship between Visceral Adiposity Index, Insulin Resistance and Pancreatic Beta Cell Function According to the Prevalence of Metabolic Syndrome in Korean Obese Adults)

  • 신경아
    • 한국융합학회논문지
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    • 제11권9호
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    • pp.267-276
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    • 2020
  • 본 연구는 비만성인을 대상으로 대사증후군 유병에 따라 VAI와 인슐린저항성, 췌장 베타세포기능과의 관련성을 알아보고자 하였다. 2017년 1월부터 2019년 12월까지 분당지역 일개 종합병원에서 건강검진을 받은 만 19세 이상 비만성인 1,797명을 대상으로 분석하였다. 대사증후군은 NCEP-ATP III의 기준에 근거하였다. 인슐린저항성 및 췌장 베타세포기능은 HOMA 지수를 이용하였다. 대조군보다 대사증후군 진단군에서 VAI가 높았으며, 대사증후군 위험요인 개수가 증가할수록 높은 VAI값을 보였다(각각 p<.001). 또한 VAI 사분위수가 증가함에 따라 대사증후군 유병률이 증가하였다(p<.001). VAI는 대조군에서 HOMA-IR 및 HOMA-β와 관련이 있는 것으로 나타났으나, 대사증후군 진단군에서는 HOMA-IR 및 HOMA-β간에 관련이 없었다.

Moderate diet-induced weight loss is associated with improved insulin sensitivity in middle-aged healthy obese Korean women

  • Lee, Hye-Ok;Yim, Jung-Eun;Kim, Young-Seol;Choue, Ryowon
    • Nutrition Research and Practice
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    • 제8권4호
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    • pp.469-475
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    • 2014
  • BACKGROUND/OBJECTIVE: The goal of the present study was to investigate the effects of moderate caloric restriction on ${\beta}$-cell function and insulin sensitivity in middle-aged obese Korean women. SUBJECTS/METHODS: Fifty-seven obese pre-menopausal Korean women participated in a 12-week calorie restriction program. Data on total cholesterol (TC), high density lipoprotein cholesterol (HDL-C), low density lipoprotein cholesterol (LDL-C), triglycerides (TG), and fasting serum levels of glucose, insulin, C-peptide, blood pressure, leptin and anthropometrics were collected. A dietary intake assessment was based on three days of food recording. Additionally, ${\beta}$-cell function [homeostasis model assessment of ${\beta}$-cell (HOMA-${\beta}$), insulinogenic index (ISI), C-peptide:glucose ratio, and area under curve insulin/glucose ($AUC_{ins/glu}$)] and insulin sensitivity [homeostasis model assessment for insulin resistance (HOMA-IR), Quantitative insulin-sensitivity check index (QUICKI) and Matsuda index (MI)] were recorded. RESULTS: When calories were reduced by an average of 422 kcal/day for 12 weeks, BMI (-2.7%), body fat mass (-10.2%), and waist circumference (-5%) all decreased significantly (P < 0.05). After calorie restriction, weight, body fat percentage, hip circumference, BP, TC, HDL-C, LDL-C, plasma glucose at fasting, insulin at fasting and 120 min, $AUC_{glu}$ and the insulin area under the curve all decreased significantly (all P < 0.05), while insulin sensitivity (HOMA-IR, QUICKI and Matsuda index) measured by OGTT improved significantly (P < 0.01). CONCLUSIONS: Moderate weight loss due to caloric restriction with reduction in insulin resistance improves glucose tolerance and insulin sensitivity in middle-aged obese women and thereby may help prevent the development of type 2 diabetes mellitus.

HL-60 세포의 유전자 발현 및 topoisomerase의 기능 활성에 미치는 억제제의 영향 (Effects of Inhibitors on the Function and Activity of Topoisomerase, and Gene Expression in HL-60 Human Leukemia Cells)

  • 정인철;조무연;박장수
    • 생명과학회지
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    • 제18권1호
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    • pp.75-83
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    • 2008
  • 인체 DNA topoisomerase는 DNA를 단일 또는 두 가닥을 일시적인 절단을 촉매하여 DNA의 topological 문제를 조절함으로써, DNA 복제, 전사, 재조합과 유사분열 과정 등에 관여한다. 이 효소는 많은 항생, 항암제의 표적효소로서 널리 알려져 있으며, 이들 유도체를 이용한 다양한 억제제의 개발과 임상적 응용에 관한 연구가 활발하게 진행되고 있다. 본 실험에서는 인체 백혈병 HL-60 세포에서 topoisomerase 억제제가 topoisomerase 기능 활성과 유전자 발현을 조절하는지를 규명하기 위하여 본 연구를 수행하였다. 연구 방법은 HL-60세포에 topoisomerase type I과 type II의 대표적 억제제인 10-hydroxycamptothecin (10-CPT)과 doxorubicin을 투여한 후 total RNA를 분리하였고, 10K-oligo-nucleotide microarray 방법으로 분석하여 유전자의 발현 양상을 조사하였다. 연구 결과에 의하면 10-CPT 또는 doxorubicin을 투여한 HL-60세포에서의 유전자 발현 양상은 주로 signal transduction, cell adhesion, cell cycle, cell growth, cell proliferation, cell differentiation, transcription 및 immune response 등과 관련이 있었다. Topoisomerase type I의 억제제인 10-CPT를 HL-60 세포주에 투여 하였을 때 type I으로 분류되는 topoisomerase III${\alpha}$, III${\beta}$ 및 I의 발현은 증가하였으나 type II인 topoisomerase II${\alpha}$와 II${\beta}$의 유전자의 발현은 감소되었다. 반대로 type II의 억제제인 doxorubicin을 투여하였을 때는 앞의 결과와 상반된 topoisomerase II${\alpha}$와 II${\beta}$의 유전자의 발현이 현저히 증가되었으며, topoisomerase III${\alpha}$와 III${\beta}$의 mRNA의 발현은 약간 감소하는 양상을 보였으나 의미 있는 차이는 없었다. 이 연구 결과는 앞으로 항암제의 기전을 밝히고 약물에 대한 치료 반응을 예측하고 새로운 약제 개발에 기초자료가 될 것으로 여겨진다.

식이 지방이 췌장 90%를 제거한 당뇨 흰쥐의 인슐린 분비능과 췌장 베타세포의 양에 미치는 영향 (The Effect of Dietary Fat on Insulin Secretion and Pancreatic β-Cell Mass in 90% Pancreatectomized Diabetic Rats)

  • 박선민;박춘희;홍상미
    • 한국식품영양과학회지
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    • 제36권2호
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    • pp.186-193
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    • 2007
  • The prevalence of diabetes has increased to 8% of population. Unlike type 2 diabetes in the western countries, Korean diabetic patients are nonobese and have low serum insulin levels. As the increased prevalence of diabetes and the peculiar characteristics may be related to dietary fat contents, we determined their effects on insulin resistance, insulin secretion and pancreatic $\beta-cell$ mass in 90% pancreatectomized (Px) diabetic rats in the present study. The rats were provided with low fat diet (LF, 10 energy% fat), moderate fat diet (MF, 25 energy% fat) and high fat diet (HF, 40 energy% fat) for 6 months. HF increased body weight and epidydimal fat pads parallel with increased food intake compared to LF and MF. Fasting serum glucose and insulin levels and homeostasis model assessment of insulin resistance were higher in HF, compared to LF and MF, indicating that HF increased insulin resistance. Rats fed LF and MF diets reduced insulin resistance, but only rats fed MF improved pancreatic $\beta-cell$ mass and insulin secretion capacity, measured by hyperglycemic clamp and in situ pancreatic perfusion. LF had low insulin secretion capacity and pancreatic $\beta-cell$ mass, indicating the increased possibility of diabetic prevalence and progression. MF increased $\beta-cell$ mass by stimulating $\beta-cell$ proliferation and neogenesis and reducing $\beta-cell$ apoptosis. In conclusion, MF is effective for the prevention of prevalence and progression of diabetes.

The protective effect of Halal food extract in pancreatic beta cell lines.

  • Kim, Seong-sun;Jin, Yu-Mi;Song, Young-Jae;AYE, AYE;Soh, Ju-Ryoun;Jeon, Yong-Deok;Jin, Jong-Sik
    • 한국자원식물학회:학술대회논문집
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    • 한국자원식물학회 2019년도 춘계학술대회
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    • pp.121-121
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    • 2019
  • In Islamic dietary guidelines, Halal foods are allowed as edible blessed food. Most foods were categorized within halal for Muslims. The main point of Halal food is that foods are clean in every process and based on Halal standard which might be different in each country. Most pancreatic ${\beta}$ cells synthetize, store, and release insulin. Specific molecular, functional as well as ultrastructural traits of pancreatic ${\beta}$ cells could control their insulin secretion properties and survival phentoype. Insulin-secreting pancreatic ${\beta}$-cells are essential regulators of mammalian metabolism. In addition, the pancreatic ${\beta}$ cell plays an important role in the pathogenesis of type 1 and type 2 diabetes as improving glucose homeostasis by preserving, expanding and improving the function of this key cell type. However, the pharmacological effect of halal food has not been unclear yet, especially food habit-dependent diabetes. The aim of the this study was to determine the preventive effect of Iran plants extract (Almond, Garlic, Cumin, Ginkgo biloba, Holy basil, Psyllium, Satureja khuzistanica, Fenugreek, Green tea, Ipomoea betatas, Blueberry) on RINm5F cells and MIN6 cells as pancreatic ${\beta}$ cell line. The cytotoxicity of the extracts of Iran plants on RINm5F cells and MIN6 cells were measured by using MTT assays. The preventive effects of Iran plant extracts were measured by WST-8 cell proliferation assay on streptozotocin (STZ)-induced cell death in MIN6 cells. In presented result showed that all extract of Iran plants (0.01-10mg/ml) did not show cytotoxicity in RINm5F cells and MIN6 cells. Among non-cytotoxic extract, the protective effects could be detect in high dose concentration. These results suggest that the extract of Iran plants may serve as a potential therapy for diabetes.

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에스트로겐 수용체 및 Luciferase 리포터 유전자 도입 사람 간 종양세포(HepG2 Cell)에서 Toxaphene과 Chlordane의 내분비 독성 (Endocrinic Effects of Toxaphene and Chlordane in Human Hepatoma Cell (HepG2 Cell) Transfected with Estrogen Receptor and Luciferase Reporter Gene)

  • 김경배;정지원;양세란;강경선;이영순
    • Toxicological Research
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    • 제20권3호
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    • pp.205-211
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    • 2004
  • Concern that some chemicals in our environment may affect human health by disrupt-ing normal endocrine function has prompted a research on interactions of environmental contaminants with steroid hormone receptor. Toxaphene and chlordane are among the 12 persistent organic pollutants identified by the United Nations Environment Programme as requiring urgent attention. We compared the estrogenic activity of two organochlorine pesticides, toxaphene and chlordane, at estrogen receptor a (ER$\alpha$) and estrogen receptor $\beta$ (ER$\beta$). Human hepatoma cells (HepG2) were transiently transfected with rat ER$\alpha$ or ER$\beta$ plus an estrogen-responsive complement C3-luciferase (C3-Luc) reporter gene. After transfection, cells were treated with various concentrations of toxaphene and chlordane to investigate agonism or antagonism of these chemicals. Both toxaphene and chlordane were potent agonists in HepG2 cells for ER$\alpha$. In contrast, these chemicals had a minimal agonist activity with ER$\beta$ and almost abolished 17$\beta$-estradiol-induced ER$\beta$-mediated activity. Therefore, toxaphene and chlordane behaved as an ER$\alpha$ agonist and an ER$\beta$ antagonist with estrogen-responsive reporter plasmid C3-Luc, and exposure to these organochlorine pesticides could have a crictical effect on normal endocrine function.