• Title/Summary/Keyword: IRS1

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Retinoid X Receptor α Overexpression Alleviates Mitochondrial Dysfunction-induced Insulin Resistance through Transcriptional Regulation of Insulin Receptor Substrate 1

  • Lee, Seung Eun;Koo, Young Do;Lee, Ji Seon;Kwak, Soo Heon;Jung, Hye Seung;Cho, Young Min;Park, Young Joo;Chung, Sung Soo;Park, Kyong Soo
    • Molecules and Cells
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    • v.38 no.4
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    • pp.356-361
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    • 2015
  • Mitochondrial dysfunction is associated with insulin resistance and diabetes. We previously showed that retinoid X receptor ${\alpha}$ ($RXR{\alpha}$) played an important role in transcriptional regulation of oxidative phosphorylation (OXPHOS) genes in cells with mitochondrial dysfunction caused by mitochondrial DNA mutation. In this study, we investigated whether mitochondrial dysfunction induced by incubation with OXPHOS inhibitors affects insulin receptor substrate 1 (IRS1) mRNA and protein levels and whether $RXR{\alpha}$ activation or overexpression can restore IRS1 expression. Both IRS1 and $RXR{\alpha}$ protein levels were significantly reduced when C2C12 myotubes were treated with the OXPHOS complex inhibitors, rotenone and antimycin A. The addition of $RXR{\alpha}$ agonists, 9-cis retinoic acid (9cRA) and LG1506, increased IRS1 transcription and protein levels and restored mitochondrial function, which ultimately improved insulin signaling. $RXR{\alpha}$ overexpression also increased IRS1 transcription and mitochondrial function. Because $RXR{\alpha}$ overexpression, knock-down, or activation by LG1506 regulated IRS1 transcription mostly independently of mitochondrial function, it is likely that $RXR{\alpha}$ directly regulates IRS1 transcription. Consistent with the hypothesis, we showed that $RXR{\alpha}$ bound to the IRS1 promoter as a heterodimer with peroxisome proliferator-activated receptor ${\delta}$ ($PPAR{\delta}$). These results suggest that $RXR{\alpha}$ overexpression or activation alleviates insulin resistance by increasing IRS1 expression.

A Pilot Project on Producing Topographic Map Using Medium Resolution Satellite Image (중해상도 위성영상을 이용한 지도제작 시험연구)

  • 박희주;한상득;안기원;박병욱
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.19 no.4
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    • pp.373-383
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    • 2001
  • This study conducted pilot mapping project to know the possibility of mapping with medium resolution satellite imageries. For this purpose, mapping experiments were conducted with each stereo model imageries of SPOT, KOMPSAT, and IRS- lC. And positional accuracy, analysis of detectable and describable features, and comparison with existing digital map were checked, possible mapping scale and cost analysis were conducted with these results. Regarding SPOT imagery, digital photogrammetric workstation was used for stereoplotting. Regarding KOMPSAT and IRS-lC imageries, because there were data format support problems. head-up digitizing was performed with ortho imageries rectified with DEMs generated by image matching. The results of experiments show that such features as wide road, river, coast line, etc are possible to detect and depict but many other features are not for SPOT, KOMPSAT, and IRS-lC imageries. On the aspect of mapping, therefore, SPOT is available for 1/50,000 topographic map revision, KOMPSAT and IRS-lC for 1/25.000 topographic map revision.

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Effect of amaranth seed extracts on glycemic control in HepG2 cells (HepG2 세포에서 아마란스 종자 에탄올 추출물이 포도당 흡수 조절에 미치는 효과)

  • Park, So Jin;Park, Jong Kun;Hwang, Eunhee
    • Journal of Nutrition and Health
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    • v.54 no.6
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    • pp.603-617
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    • 2021
  • Purpose: This study was carried out to investigate the effect of amaranth seed extracts on glycemic regulation in HepG2 cells. The 80% ethanol extracts of amaranth seeds were used to evaluate α-amylase and α-glucosidase activities, cell viability, glucose uptake and messenger RNA (mRNA) expression levels of acetyl-CoA carboxylase (ACC), glucose transporter (GLUT)-2, GLUT-4, insulin receptor substrate (IRS)-1 and IRS-2. Methods: The samples were prepared and divided into 4 groups, including germinated black amaranth (GBA), black amaranth (BA), germinated yellow amaranth (GYA) and yellow amaranth (YA). Glucose hydrolytic enzyme, α-amylase and α-glucosidase activities were examined using a proper protocol. In addition, cell viability was measured by MTT assay. Glucose uptake in cells was measured using an assay kit. The mRNA expression levels of ACC, GLUT-2, GLUT-4, IRS-1 and IRS-2 were measured by reverse transcription polymerase chain reaction. Results: The inhibitory activities of α-amylase and α-glucosidase were highly observed in GBA, followed by BA, GYA and YA. Similar results were observed for glucose. The GBA effect was similar compared to the positive control group. The mRNA expression levels of ACC, GLUT-2, GLUT-4, IRS-1, and IRS-2 were significantly increased. The potential hypoglycemic effects of amaranth seed extracts were observed due to the increase in glucose metabolic enzyme activity, and glucose uptake was mediated through the upregulation of ACC, GLUT-2, GLUT-4, IRS-1, and IRS-2 expression levels. Conclusion: Our findings suggest that the amaranth seed is a potential candidate to prevent a diabetes. The present study demonstrated the possibility of using amaranth seeds, especially GBA and BA for glycemic control.

"Dust, Ice, and Gas In Time" (DIGIT) Herschel observations of GSS30-IRS1

  • Je, Hyerin;Lee, Jeong-Eun
    • The Bulletin of The Korean Astronomical Society
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    • v.38 no.1
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    • pp.50.1-50.1
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    • 2013
  • As part of the DIGIT key program, we observed GSS30-IRS1, a Class I object located in Ophiuchus (d=125 pc), with Herschel-PACS. More than 70 lines were detected: CO lines of $J=14{\rightarrow}13$ to $41{\rightarrow}40$, several $H_2O$ lines of Eu=100 to 1500 K, 16 OH lines, and two atomic [OI] lines at 63 and 145 ${\mu}m$. All lines, except for [OI], were detected only at the central spaxel of $9.4^{\prime\prime}{\times}9.4^{\prime\prime}$ while the [OI] emission is extended along the NE-SW direction. One interesting feature in GSS30-IRS1 is that the continuum is extended beyond PSF, unlike the line emission. For detail analysis, we apply the non-LTE LVG model, RADEX as well as simple rotational diagrams to the detected line fluxes. We will discuss about the physical conditions around GSS30-IRS1, learned by the line flux analysis.

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Patterns of Insulin Resistance Syndrome in the Taegu Community for the Development of Nutritional Service Improvement Programs (영양서비스 개발을 위한 대구지역의 인슐린저항성증후군 패턴의 인구학적 특성 분석)

  • 이희자;윤진숙;신동훈
    • Korean Journal of Community Nutrition
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    • v.6 no.1
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    • pp.97-107
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    • 2001
  • The clustering of insulin resistance with hypertension, glucose intolerance, hyperinsulinemia, increased triglyceride and decreased HDL cholesterol levels, and central and overall obesity has been called syndrome X, or the insulin resistance syndrome(IRS). To develop a nutrition service for IRS, this study was performed to evaluate the prevalence of each component of the metabolic abnormalities of IRS and analyze the clustering pattern of IRS among subjects living in the Taegu community. Participants in this study were 9234(mean age ; M/F 48/40yrs);63.5% were men, 24.4% were obese, 13.3% had hypertension. 3.7% had hyperglycemia, and 32.4% had hyperlipidemia. The IRS was defined as the coexistence of two or more components among metabolic abnormalities; obesity, hypertension. hyperglucemia and hyperlipidemia. The prevalence of IRS in Taegu was 19.2%(M/F:20.8%/16.4%), the clustering of these fisk variables was higher in advanced age group. Among the subjects of IRS having two of more diseases, 75.6% were obese, the pattern were similar in men and women. The younger, the higher the prevalence of obesity associated clustering patterns. The prevalence of obesity associated patterns among the hyperglycemia associated clustering patterns was 44.5%. The samples of the representative clustering patterns were obesity and hyperlipidemia (8.0%), hypertension and hyperlipidemia(3.2%), hypertension, obesity and hyperlipiemia(3.1%), hypertension and obesity(2.3%), and hyperglycemia and hyperlipidemia(0.8%). The clustering of obesity and hyperlipidemia until 50 year old groups, and the clustering of hypertension and hyperlipidemia in the 60 and 70 age groups were the most prevalent. We concluded that insulin resistance syndrome was a relatively common disorder in the Taegu community, and prevalence and the characteristics of the intervention strategies for IRS are desired, an effective improvement will be achieved.

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Insulin induces nuclear translocation of insulin receptor and tyrosine phosphorylation of nuclear proteins in osteoblast (조골세포에서 인슐린 수용체의 세포핵으로의 이동과 타이로신 인산화)

  • Seol, Ki-Chun;Kim, Sung-Jin
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 2001.11a
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    • pp.101-101
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    • 2001
  • In the present study, we explored to determine if insulin has any effect on the nuclear translocation of insulin receptor and tyrosine phosphoryaltion of nuclear proteins in the UMR-106 cells. Significant amount of insulin receptors and IRS-1 proteins were detected in the nucleus. IRS-1 and PI$_3$-Kinase appeared to translocate to the nucleus in a time dependent manner. Tyrosine phosphorylation of a number of proteins including 180 KDa, 85 KDa protein in the nucleus was significantly stimulated by insulin, suggesting IRS-1 and PI$_3$-Klnase was activated in the nucleus by insulin treatment. In addition, p70 S6 Kinase, a downstream target of PI3-Kinase was transiently appeared in the nucleus by insulin and its activity was stimulated by insulin. These results suggest that the insulin signaling system containing insulin receptor, IRS-1, PI$_3$-Kinase and p70 S6 Kinase operates in the nucleus of osteoblast cells. The nuclear insulin-mediated tyrosine phosphorylation may play an essential role in the gene expression, differentiation and growth of osteoblast cells.

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SED MODELING FOR CLASS 0 PROTOSTAR L1527 IRS

  • Baek, Giseon;Lee, Jeong-Eun;Lee, Seokho
    • The Bulletin of The Korean Astronomical Society
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    • v.40 no.2
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    • pp.42.1-42.1
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    • 2015
  • We model the Spectral Energy Distribution (SED) of Class 0 protostar L1527 IRS using a radiative transfer code RADMC-3D. In addition to the photometry data from literatures, we include the Herschel/PACS data which well covers the far-infrared SED peak of L1527 IRS, providing precise constraints to the density structure and other physical properties of its circumstellar envelope. Previously, Tobin et al. (2013) presented a dust continuum modeling results using a rotating and infalling envelope (Terebey and Shu, & Cassen 1984 ; TSC envelope), which originally describes a power-law density profile (${\rho}{\propto}r-{\alpha}$) with the power-law index (${\alpha}$) of 1.5. However, we find that Herschel/PACS data are better fitted with a shallower power-law density profile. This smaller power-law might be attributed to a inner envelope. Thus, we fit the SED of L1527 IRS with a Bonnor-Ebert sphere, which is a combination of the inner flat-topped and the outer power-law (${\alpha}=2$) density profiles. This Bonnor-Ebert sphere is often used to explain the density profile of prestellar cores, which is considered the earliest stages of star formation. The well-fitted SED with a Bonnor-Ebert sphere suggests that L1527 IRS might have collapsed from a Bonnor-Ebert sphere rather than a singular isothermal sphere.

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Cytoprotective Effect of Lespedeza Cuneata Extract on Glucose Toxicity (야관문(夜關門)의 포도당 독성에 대한 세포 보호 효과)

  • Choi, Jeong-Sik;Cho, Chung-Sik;Kim, Cheol-Jung
    • The Journal of Korean Medicine
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    • v.31 no.4
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    • pp.79-100
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    • 2010
  • Objective: Production of ROS from glucose toxicity results in injury of pancreatic $\beta$-cells in diabetes models. This study was undertaken to examine the influence of Lespedeza Cuneata extract (LCE) on cytoprotective effects on glucose toxicity, insulin secretion and gene expression in RIN-m5F cells. Methods: First, we measured LCE's antioxidant activity by DPPH free radical-scavenging activity and SOD activity. After the various concentrations of LCE were added to the RIN-m5F cells, we measured cell viability with glucose stimulation by MTT assay and glucose-stimulated insulin secretion. We analyzed gene expression with Agilent whole mouse genome 44K oligo DNA microarray and searched for related pathways in KEGG (Kyoto Encyclopedia of Genes and Genomes). Lastly we measured INS-1, INS-2, INS-R, IRS-1, IRS-2, IRS-3, GLP-1R, and GLP-2R mRNA expression by real time RT-PCR. Results: Free radical-scavenging activity, SOD activity and insulin secretion increased dependent on LCE concentration, but LCE did not show considerable cytoprotective effect on RIN-m5F cells. More than twice expressed gene was 6362 in Oligo DNA chip. In KEGG, the most related pathway was the metabolic pathway. In the insulin signaling pathway, up expressed genes were Irs1, Mapk8, Akt1, and Lipe and down expressed genes were Rhoq, Fbp2, Prkar2b, Gck, and Prkag1. In real time RT-PCR, IRS-2, and IRS-3 expression increased significantly compared to the control group on LCE $12{\mu}g/m{\ell}$ concentration and GCK expression decreased significantly compared to the control group. Conclusions: These results show that LCE encourages insulin secretion and insulin metabolism by complicated gene mechanisms. Further mechanism study and clinical study seem to be necessary about Lespedeza Cuneata.

A Survey of Open Access Institutional Repositories in Nigerian University Libraries: The Current State

  • Victor Okeoghene Idiedo;Christopher Agbeniaru Omigie;Loveth Ebhomeye
    • International Journal of Knowledge Content Development & Technology
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    • v.14 no.1
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    • pp.53-73
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    • 2024
  • The purpose of the study is to investigate the development of institutional repositories in university libraries in Nigeria. The study adopted a survey research design. Online questionnaire, IRs investigation, and interview methods were used to collect data from the 21 university libraries that have developed IRs in Nigeria. The study revealed that only few universities have successfully developed open access IRs to preserve and manage their intellectual outputs emanating from their universities. Contents such as journal articles, theses/dissertations, and conference / workshop papers were found to be the most popular contents that are hosted in the IRs. The interview revealed that although few respondents mentioned having IR policy statements in areas such as access policy, submission policy, preservation policy, content policy and copyright policy, the majority mentioned not having any defined policy in their IR. Also in the interview, inadequate fund, challenge of collecting contents for the IR, shortage of skilled ICT personnel, and inadequate facilities were the most mentioned challenges encountered in the development of IRs in Nigeria. Findings from this study will inform University Librarians, university management and policy makers on the need to provide the necessary infrastructure and formulate policies for smooth development of institutional repositories to make research visible globally. The results will therefore provide important data and insight into the development of institutional repositories in university libraries in the context of developing countries.

MOLECULAR LINE STUDY OF L1014 WITH SRAO 6M TELESCOPE (L1014 분자운 핵에 대한 SRAO 6m 망원경을 이용한 분자선 관측연구)

  • Lee, Chang-Won
    • Publications of The Korean Astronomical Society
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    • v.20 no.1 s.24
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    • pp.1-5
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    • 2005
  • We report molecular line observations of CO(1-0), $^{13}CO(1-0)$, CS(2-1), and HCN(1-0) with SRAO 6m telescope toward L1014-IRS which is thought to be a very faint infrared source embedded in previously known 'starless' core L1014. The CO(1-0) observations find several components with different velocities along the line of sight of L1014, $4km\;s^{-1}$ and between $40{\sim}50km\;s^{-1}$. We find a parsec scale CO molecular outflow at the $4km\;s^{-1}$ component for the first time the direction of which is coincident with that of the small scale (${\sim}500pc$) outflow previously found. Although the observation is not covered for whole area of the outflow, the size of the molecular outflow seems not very inconsistent with the expected age of L1014-IRS. More accurate size and shape of the molecular outflow from L1014-IRS will be determined from the full coverage mapping in CO over the outflow region in very near future.