• Title/Summary/Keyword: Mechanism reduction

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Upregulation of adiponectin by Ginsenoside Rb1 contributes to amelioration of hepatic steatosis induced by high fat diet

  • Li, Yaru;Zhang, Shuchen;Zhu, Ziwei;Zhou, Ruonan;Xu, Pingyuan;Zhou, Lingyan;Kan, Yue;Li, Jiao;Zhao, Juan;Fang, Penghua;Yu, Xizhong;Shang, Wenbin
    • Journal of Ginseng Research
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    • v.46 no.4
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    • pp.561-571
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    • 2022
  • Background: Ginsenoside Rb1 (GRb1) is capable of regulating lipid and glucose metabolism through its action on adipocytes. However, the beneficial role of GRb1-induced up-regulation of adiponectin in liver steatosis remains unelucidated. Thus, we tested whether GRb1 ameliorates liver steatosis and insulin resistance by promoting the expression of adiponectin. Methods: 3T3-L1 adipocytes and hepatocytes were used to investigate GRb1's action on adiponectin expression and triglyceride (TG) accumulation. Wild type (WT) mice and adiponectin knockout (KO) mice fed high fat diet were treated with GRb1 for 2 weeks. Hepatic fat accumulation and function as well as insulin sensitivity was measured. The activation of AMPK was also detected in the liver and hepatocytes. Results: GRb1 reversed the reduction of adiponectin secretion in adipocytes. The conditioned medium (CM) from adipocytes treated with GRb1 reduced TG accumulation in hepatocytes, which was partly attenuated by the adiponectin antibody. In the KO mice, the GRb1-induced significant decrease of TG content, ALT and AST was blocked by the deletion of adiponectin. The elevations of GRb1-induced insulin sensitivity indicated by OGTT, ITT and HOMA-IR were also weakened in the KO mice. The CM treatment significantly enhanced the phosphorylation of AMPK in hepatocytes, but not GRb1 treatment. Likewise, the phosphorylation of AMPK in liver of the WT mice was increased by GRb1, but not in the KO mice. Conclusions: The up-regulation of adiponectin by GRb1 contributes to the amelioration of liver steatosis and insulin resistance, which further elucidates a new mechanism underlying the beneficial effects of GRb1 on obesity.

The Interactive Effect of Translational Drift and Torsional Deformation on Shear Force and Torsional Moment (전단력 및 비틀림 모멘트에 의한 병진 변형 및 비틀림 변형의 상호 작용 효과)

  • Kim, In-Ho;Abegaz, Ruth A.
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.35 no.5
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    • pp.277-286
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    • 2022
  • The elastic and inelastic responses obtained from the experimental and analytical results of two RC building structures under the service level earthquake (SLE) and maximum considered earthquake (MCE) in Korea were used to weinvestigate the characteristics of the mechanisms resisting shear and torsional behavior in torsionally unbalanced structures. Equations representing the interactive effect of translational drift and torsional deformation on the shear force and torsional moment were proposed. Because there is no correlation in the behavior between elastic and inelastic forces and strains, the incremental shear forces and incremental torsional moments were analyzed in terms of their corresponding incremental drifts and incremental torsional deformations with respect to the yield, unloading, and reloading phases around the maximum edge-frame drift. In the elastic combination of the two dominant modes, the translational drift mainly contributes to the shear force, whereas the torsional deformation contributes significantly to the overall torsional moment. However, this phenomenon is mostly altered in the inelastic response such that the incremental translational drift contributes to both the incremental shear forces and incremental torsional moments. In addition, the given equation is used to account for all phenomena, such as the reduction in torsional eccentricity, degradation of torsional stiffness, and apparent energy generation in an inelastic response.

Translocalization of enhanced PKM2 protein into the nucleus induced by cancer upregulated gene 2 confers cancer stem cell-like phenotypes

  • Yawut, Natpaphan;Kaowinn, Sirichat;Cho, Il-Rae;Budluang, Phatcharaporn;Kim, Seonghye;Kim, Suhkmann;Youn, So Eun;Koh, Sang Seok;Chung, Young-Hwa
    • BMB Reports
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    • v.55 no.2
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    • pp.98-103
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    • 2022
  • Increased mRNA levels of cancer upregulated gene (CUG)2 have been detected in many different tumor tissues using Affymetrix microarray. Oncogenic capability of the CUG2 gene has been further reported. However, the mechanism by which CUG2 overexpression promotes cancer stem cell (CSC)-like phenotypes remains unknown. With recent studies showing that pyruvate kinase muscle 2 (PKM2) is overexpressed in clinical tissues from gastric, lung, and cervical cancer patients, we hypothesized that PKM2 might play an important role in CSC-like phenotypes caused by CUG2 overexpression. The present study revealed that PKM2 protein levels and translocation of PKM2 into the nucleus were enhanced in CUG2-overexpressing lung carcinoma A549 and immortalized bronchial BEAS-2B cells than in control cells. Expression levels of c-Myc, CyclinD1, and PKM2 were increased in CUG2-overexpressing cells than in control cells. Furthermore, EGFR and ERK inhibitors as well as suppression of Yap1 and NEK2 expression reduced PKM2 protein levels. Interestingly, knockdown of β-catenin expression failed to reduce PKM2 protein levels. Furthermore, reduction of PKM2 expression with its siRNA hindered CSC-like phenotypes such as faster wound healing, aggressive transwell migration, and increased size/number of sphere formation. The introduction of mutant S37A PKM2-green fluorescence protein (GFP) into cells without ability to move to the nucleus did not confer CSC-like phenotypes, whereas forced expression of wild-type PKM2 promoted such phenotypes. Overall, CUG2-induced increase in the expression of nuclear PKM2 contributes to CSC-like phenotypes by upregulating c-Myc and CyclinD1 as a co-activator.

Induction of apoptotic cell death in human bladder cancer cells by ethanol extract of Zanthoxylum schinifolium leaf, through ROS-dependent inactivation of the PI3K/Akt signaling pathway

  • Park, Cheol;Choi, Eun Ok;Hwangbo, Hyun;Lee, Hyesook;Jeong, Jin-Woo;Han, Min Ho;Moon, Sung-Kwon;Yun, Seok Joong;Kim, Wun-Jae;Kim, Gi-Young;Hwang, Hye-Jin;Choi, Yung Hyun
    • Nutrition Research and Practice
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    • v.16 no.3
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    • pp.330-343
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    • 2022
  • BACKGROUND/OBJECTIVES: Zanthoxylum schinifolium is traditionally used as a spice for cooking in East Asian countries. This study was undertaken to evaluate the anti-proliferative potential of ethanol extracts of Z. schinifolium leaves (EEZS) against human bladder cancer T24 cells. MATERIALS/METHODS: Subsequent to measuring the cytotoxicity of EEZS, the anti-cancer activity was measured by assessing apoptosis induction, reactive oxygen species (ROS) generation, and mitochondrial membrane potential (MMP). In addition, we determined the underlying mechanism of EEZS-induced apoptosis through various assays, including Western blot analysis. RESULTS: EEZS treatment concentration-dependently inhibited T24 cell survival, which is associated with apoptosis induction. Exposure to EEZS induced the expression of Fas and Fas-ligand, activated caspases, and subsequently resulted to cleavage of poly (ADP-ribose) polymerase. EEZS also enhanced the expression of cytochrome c in the cytoplasm by suppressing MMP, following increase in the ratio of Bax:Bcl-2 expression and truncation of Bid. However, EEZS-mediated growth inhibition and apoptosis were significantly diminished by a pan-caspase inhibitor. Moreover, EEZS inhibited activation of the phosphoinositide 3-kinase (PI3K)/Akt pathway, and the apoptosis-inducing potential of EEZS was promoted in the presence of PI3K/Akt inhibitor. In addition, EEZS enhanced the production of ROS, whereas N-acetyl cysteine (NAC), a ROS scavenger, markedly suppressed growth inhibition and inactivation of the PI3K/Akt signaling pathway induced by EEZS. Furthermore, NAC significantly attenuated the EEZS-induced apoptosis and reduction of cell viability. CONCLUSIONS: Taken together, our results indicate that exposure to EEZS exhibits anti-cancer activity in T24 bladder cancer cells through ROS-dependent induction of apoptosis and inactivation of the PI3K/Akt signaling pathway.

Diverse Mechanisms of Relaxin's Action in the Regulation of Smooth Muscles and Extracellular Matrix of Vasculature and Fibrosis (혈관과 섬유증의 평활근 및 세포외기질 조절에 대한 릴랙신의 다양한 작용기전)

  • Min, Gyesik
    • Journal of Life Science
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    • v.32 no.2
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    • pp.175-188
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    • 2022
  • Relaxin has been demonstrated to have regulatory functions on both the smooth muscle and extracellular matrix (ECM) of blood vessels and fibrotic organs. The diverse mechanisms by which relaxin acts on small resistance arteries and fibrotic organs, including the bladder, are reviewed here. Relaxin induces vasodilation by inhibiting the contractility of vascular smooth muscles and by increasing the passive compliance of vessel walls through the reduction of ECM components, such as collagen. The primary cellular mechanism whereby relaxin induces arterial vasodilation is mediated by the endothelium-dependent production of nitric oxide (NO) through the activation of RXFP1/PI3K, Akt phosphorylation, and eNOS. In addition, relaxin triggers different alternative pathways to enhance the vasodilation of renal and mesenteric arteries. In small renal arteries, relaxin stimulates the activation of the endothelial MMPs and EtB receptors and the production of VEGF and PlGF to inhibit myogenic contractility and collagen deposition, thereby bringing about vasodilation. Conversely, in small mesenteric arteries, relaxin augments bradykinin (BK)-evoked relaxation in a time-dependent manner. Whereas the rapid enhancement of the BK-mediated relaxation is dependent on IKCa channels and subsequent EDH induction, the sustained relaxation due to BK depends on COX activation and PGI2. The anti-fibrotic effects of relaxin are mediated by inhibiting the invasion of inflammatory immune cells, the endothelial-to-mesenchymal transition (EndMT), and the differentiation and activation of myofibroblasts. Relaxin also activates the NOS/NO/cGMP/PKG-1 pathways in myofibroblasts to suppress the TGF-β1-induced activation of ERK1/2 and Smad2/3 signaling and deposition of ECM collagen.

Uplift Capacity for Bond Type Anchored Foundations in Rock Masses (부착형 암반앵커기초의 인발지지력 평가)

  • Kim, Dae-Hong;Lee, Yong-Hee
    • Journal of the Korean Geotechnical Society
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    • v.24 no.10
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    • pp.147-160
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    • 2008
  • This paper presents the results of full-scale loading tests performed on 54 passive anchors and 4 group anchored footings grouted to various lengths at several sites in Korea. The test results, the failure mechanisms as well as uplift capacities of rock anchors depend mostly on rock type and quality, embedded fixed length, properties of the discontinuities, and the strength of rebar. Anchors in poor quality rocks generally fail along the grout/rock interfaces when their depths are very shallow (a fixed length of less than 1 m). However, even in such poor rocks, we can induce a more favorable mode of rock pull-up failure by increasing the fixed length of the anchors. On the other hand, anchors in good quality rocks show rock pull-up failures with high uplift resistance even when they are embedded at a shallow depth. Laboratory test results revealed that a form of progressive failure usually occurs starting near the upper surface of the grout, and then progresses downward. The ultimate tendon-grout bond strength was measured from $18{\sim}25%$ of unconfined compressive strength of grout. One of the important findings from these tests is that the measured strains along the corrosion protection sheath were so small that practically the reduction of bond strength by the presence of sheath would be negligible. Based on test results, the main parameters governing the uplift capacity of the rock anchor system were determined. By evaluation of the ultimate uplift capacity of anchor foundations in a wide range of in situ rock masses, rock classification suitable for a transmission tower foundation was developed. Finally, a very simple and economical design procedure is proposed for rock anchor foundations subjected to uplift tensile loads.

Recent Studies of Breast Cancer in Traditional Chinese Medicine Journals (중의학 논문에 나타난 유방암의 연구 동향에 대한 고찰 - 중의학 논문을 중심으로 -)

  • Jerng, Ui-Min;Jeong, Jong-Soo;Park, Jae-Woo;Jung, Hyun-Sik;Yoon, Seong-Woo
    • The Journal of Korean Obstetrics and Gynecology
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    • v.22 no.1
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    • pp.263-278
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    • 2009
  • Purpose: The purpose of this study is to research trends in the study of breast cancer in Traditional Chinese Medicine (TCM) and to establish the further direction for its study. Methods: We reviewed TCM papers published in the last 29 years (1979-2008). Results: 1. We researched 49 papers and the patterns of study were as follows: in vitro studies were 27 papers (55.1%), in vivo studies were 9 papers (18.4%) and clinical studies were 19 papers (38.8%). 2. In vitro studies on breast cancer research in TCM were focused on cytotoxicity (17 papers) and apoptosis (8 papers). Most of in vivo studies (6 papers) were done for the purpose of inducing growth suppression of tumor cell after administration of the test drug. Each drug acted on this effect through various types of mechanism. 3. Unlike in vitro and in vivo studies, clinical studies on growth suppression of tumor cell were rare (4 papers). Most of the studies were focused on reduction of side effect of chemotherapy or synergistic effect with chemotherapy (7 papers), immune regulation (7 papers), and improvement of quality of life (6 papers). 4. Among the treatment method we reviewed, 'Runing Ⅱ(Ⅱ號方)' was the only medication that further studied as clinical trial after experimental study. 5. Since almost all studies have defects like poorly designed model or insufficient data description, it was difficult to make any definite conclusion about these studies. Conclusion: More subsequent clinical studies based on experimental study will be needed afterwards. Strict and high-level study design with detailed description will be needed in further study.

Experimental Assessment of Reduction in the Negative Skin Friction Using a Pile with a Member Responding to Ground Deformation (지반 변형 대응 부재를 적용한 말뚝의 부마찰력 저감 성능의 실험적 검증)

  • Shin, Sehee;Lee, Haklin;Woo, Sang Inn
    • Journal of the Korean Geotechnical Society
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    • v.38 no.3
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    • pp.5-16
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    • 2022
  • Ground in extremely cold and hot regions can sink by various environmental factors. Ground settlement can generate the negative skin friction to pile shaft, increase the base load of pile, and cut the stability of the pile. This study proposed a member responding ground deformation which can be inserted inside the pile. The member slightly compresses according to the ground settlement to reduce the negative skin friction. As the member materials, this study considered spring and spring-dashpot. To assess the ability of the member, the present research performed model tests for piles with or without the member within settled ground. In the model tests, the base load, total shaft resistance, and horizontal earth pressure were monitored and analyzed. Experimental results show that the pile with spring member can reduce the negative skin friction under small settlement conditions whereas it acts similar to the pile without the member under large settlement conditions as the spring was no longer compressed. However, the pile with the spring-dashpot member can reduce the negative skin friction continuously upon the ground settlement as the dashpot delays the load transfer to the spring and locates friction force on the unloading path.

A Study on Effects of the Fall Prevention in the Rehabilitation Pilates Exercise (노인의 재활 필라테스 운동이 낙상 예방 효과에 대한 고찰)

  • Ji-Sun Kim
    • Journal of the Korean Applied Science and Technology
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    • v.40 no.2
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    • pp.290-300
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    • 2023
  • This study was understood the risk mechanism of falls in the elderly and reviewed previous research data to see if the principle of Pilates rehabilitation exercise could have a positive effect on balance ability and postural stabilization in the elderly, and the purpose of this study is to present literature-based data on the fall prevention effect of rehabilitation Pilates exercise. First, the rehabilitation Pilates exercise makes it available for strengthening the center of the body to stabilize the spine and pelvis and stimulates the nerve root, thereby having an effect on the balance and the joint stabilization. Second, a proprioceptive sensory impairment and a musculoskeletal degenerative disease due to aging increase the loss of balance ability and the instability in posture maintenance, thereby coming to raise the risk of a fall damage caused by the difficulty in performing motor functions and by the gait disturbance. Third, the rehabilitation Pilates exercise leads to improving the core muscle strength in older adults, resulting in being capable of expecting the betterment in the balance and the reaction time motor function. And there is a positive impact on the improvement in body imbalance and on the stability in movement involved in the fall prevention, resulting in being able to suggest the possibility of likely contributing to a reduction in a fall risk rate. In conclusion, the rehabilitation Pilates as the elderly exercise program showed effects on the improvement in the body's muscular strength, on the upgrade in a sense of balance, and on the stabilization of core. Thus, it was considered to diminish the risk factors for a fall damage caused by musculoskeletal degeneration and to be capable of preventing a serious disorder of activity due to a chronic senile disease.

Alleviation Technology of Cold Stress of Maize(Zea mays L.) by Low Temperatures Damage

  • Youngchul Yoo;Mi-jin Chae;Jeong Ju Kim;Seuk Ki Lee;AReum Han;Won Tae Jeon;Dae-Woo Lee;Beom-Young Son
    • Proceedings of the Korean Society of Crop Science Conference
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    • 2022.10a
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    • pp.95-95
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    • 2022
  • Maize is one of the world's three largest crops and has a long cultivation history, and is an important crop used for various purposes such as food, feed, and industrial raw materials. Recently, the agricultural environment is changing, in which the limit of cultivation of crops is shifted to the north due to the rise in temperature due to climate change. This study was conducted in experimental field of Suwon in 2022 by setting a seeding period earlier than the sowing time to establish the North Korean agricultural climatic zone and meteorological conditions. The test cultivars were silage cultivars, Kwangpyeongok and Dacheongok. As a priming test method, it was used to directly plant seeds in the field through immersion using 4mM zinc (Zn) and 2.5mM manganese (Mn), which are trace elements for seeds. The planting season was early on March 15th, April 1st, and April 15th. The number of days from sowing to silk stage of the two cultivars sown on March 15, April 1, and April 15 was 107, 93, and 85 days for Kwangpyeongok and 109, 95, and 87 days for Dacheongok, respectively. The seed priming test did not show any difference from the control group in the growth survey up to the middle stage of growth. In another test, low-temperature recovery was confirmed through nitrogen (2-5%) foliar fertilization after 3 days, 5 days, and 7 days in refrigeration (0 degrees), a selective low temperature treatment for com in the third leaf stage. As a result of this study, it was confirmed that the low-temperature damaged com treated at 0℃ showed the same growth as that of the untreated com through nitrogen foliar fertilization. These results suggest that urea foliar fertilization for low-temperature damage reduction of corn for silage in high-latitude climates will be helpful. In addition, through the results of the study, additional studies are needed on the recovery mechanism and field application through urea foliar fertilization.

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