• Molecules and Cells
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• 제41권8호
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• pp.705-716
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• 2018

The endoplasmic reticulum (ER) is a critical organelle for protein synthesis, folding and modification, and lipid synthesis and calcium storage. Dysregulation of ER functions leads to the accumulation of misfolded- or unfolded-protein in the ER lumen, and this triggers the unfolded protein response (UPR), which restores ER homeostasis. The UPR is characterized by three distinct downstream signaling pathways that promote cell survival or apoptosis depending on the stressor, the intensity and duration of ER stress, and the cell type. Mammalian cells express the UPR transducers IRE1, PERK, and ATF6, which control transcriptional and translational responses to ER stress. Direct links between ER stress and immune responses are also evident, but the mechanisms by which UPR signaling cascades are coordinated with immunity remain unclear. This review discusses recent investigations of the roles of ER stress in immune responses that lead to differentiation, maturation, and cytokine expression in immune cells. Further understanding of how ER stress contributes to the pathogenesis of immune disorders will facilitate the development of novel therapies that target UPR pathways.

• Archives of Pharmacal Research
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• 제27권11호
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• pp.1099-1105
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• 2004

The peroxisome proliferator-activated receptors (PPARs) are a primary regulator of lipid metabolism. Potency for activation of PPAR$\gamma$, one of a subfamily of PPARs, particularly mirrors glucose lowering activity. We prepared thiazolidinediones featuring benzoxazole moiety for subtype selective PPAR$\gamma$ activators. 5-[4-[2-(Benzoxazol-2-yl-alkylamino)ethoxy]benzyl]thiazolidine-2,4-diones have been prepared by Mitsunobu reaction of benzoxazolylalkylaminoethanol 8 and hydroxybenzylthiazolidinedione 6 and their activities were evaluated. Most compounds tested were identified as potent PPAR$\gamma$ agonists.

• Journal of Plant Biology
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• 제36권3호
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• pp.293-296
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• 1993

Effects of dark treatment and N1-dichlorophenyl-N3-dimethylurea (DCMU) on the desaturation of galactolipids of Dunaliella salina were investigated to see whether light-driven photosynthetic electron transport is involved in in vivo desaturation of galactolipids. The incorporation of radioactive fatty acid precursors ([14C]lauric acid) into galactolipids, mainly composed of prokaryotic molecular species, was most affected among different polar lipid classes by both treatments. The analysis of specific radioactivities of individual galactolipid molecular species revealed that their synthesis was greatly inhibited by the treatments except for eukaryotic molecular species, 18 : 3/ 18 : 3 digalactosyldiacylglycerol, whose desaturation occurs in endoplasmic reticulum.

• Journal of Plant Biology
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• 제33권1호
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• pp.49-54
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• 1990

Chlorella cells were cultured with M4N media treated with glucose (5 mM) sucrose (10 mM) and raffinose (30 mM). Phospholipids and their fatty acid compositions were analyzed in the chloroplast isolated from cultured Chlorella cells. Growth rate was prominently raised in the treatment with raffinose. Glucose was the most excellent carbon source in the biosynthesis of total lipid, phosphatidylcholine(PC), phosphatidylethanolamine(PE), phosphatidylinositol(PI) of the chloroplast. Also, the major fatty acids were palmitic, linoleic and linolenic acid during the biosynthesis of phospholipid in the control and in the treatment with carbon sources.

• 한방비만학회지
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• 제24권1호
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• pp.1-12
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• 2024

Objectives: Ephedrae herba (EH) and Coicis semen (CS) has been frequently prescribed for the treatment of obesity. However, effects of combinational extracts of these two herbs on non-alcoholic fatty liver disease are unknown. The aim of the present study was to investigate the effects of EH and CS on lipid accumulation and glucose absorption in free fatty acids (FFAs) or palmitic acid (PA)-treated HepG2 cells. Methods: Five samples of EH and CS were extracted by combination ratios (S1=0:100, S2=25:75, S3=50:50, S4=75:25, S5=100:0). Oil Red O staining was used to measure lipid accumulation in FFAs-induced steatosis cells. Intracellular triglycerides and total cholesterol levels were measured in FFAs-induced steatotic HepG2 cells. In PA-treated cells, intracellular 2-NBDG was detected using a fluorescence microplate reader and flow cytometry. Phosphorylation of key metabolism-related factors of AMP-activated protein kinase and acetyl-CoA carboxylase, expression of key lipid synthesis-related factors carnitine palmitoyltransferase 1 alpha (CPT1α), sterol regulatory element-binding protein 1 (SREBP1), peroxisome proliferator-activated receptor gamma (PPARγ) and CCAAT enhancer binding protein alpha (C/EBPα) were confirmed by western blot. Results: Treatment of EH-CS combination in the FFAs-induced steatotic HepG2 cells significantly reduced lipid accumulation. As the relative ratio of Ephedrae herba increased, the lipid-lowering effects of the combination were increased. However, S1 and S5 of Ephedrae herba and Coicis semen did not significantly reduce triglycerides and total cholesterol induced by FFAs. However, the combination of Ephedrae herba and Coicis semen restored glucose absorption in PA-induced HepG2 cells. Major makers of SREBP1, PPARγ, C/EBPα, and CPT1α expression tended to decrease with EH ratio. Conclusions: The EH-CS combination has advantages over sole EH and CS extracts in improving lipid and glucose metabolism in liver steatosis models.

• 한국식품영양과학회지
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• 제46권8호
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• pp.910-918
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• 2017

당 및 지질 대사 조절의 이상으로 인한 대사성 질환 중의 하나인 고지혈증은 현대사회에서 급격하게 증가하고 있다. 이러한 문제를 해결하기 위하여 부작용이 적은 천연물을 사용하는 사례들이 급증하고 있는데, 특히 이 연구에서는 초미세 분말을 첨가한 홍삼을 이용하여 지방세포 및 쥐 혈액, 간, 그리고 지방조직에서 지질, 콜레스테롤, 당, 과산화 수치를 확인함으로써 홍삼의 효능을 관찰하였다. 세포 실험 결과, 특정한 홍삼 농도($50{\mu}g/mL$)에서 지질 형성을 미세하게 억제하고 있음을 알 수 있으며, 동물 실험에서도 마찬가지로 저농도의 홍삼을 처리하였을 때 혈중 총 콜레스테롤 수치가 가장 감소하였고 HDL-콜레스테롤 수치 또한 증가하는 것으로 밝혀졌으며, 이는 심혈관위험지수 및 동맥경화지수를 낮춰준다. 그뿐만 아니라 저농도 홍삼 식이법 시행군에서 지질대사 관련 단백질인 AMPK의 발현량이 증가하였는데, 이는 특정 농도의 홍삼이 AMPK 활성화를 높임으로써 지방 및 콜레스테롤 합성 억제를 돕는 것으로 판단된다. 따라서 본 연구는 홍삼이 대사성 질환인 고지혈증 치료 및 예방에 도움을 주는 천연물 후보임을 시사하는 바이다.

• Asian-Australasian Journal of Animal Sciences
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• 제29권11호
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• pp.1646-1652
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• 2016

Mammalian target of rapamycin complex 1 (mTORC1) is a central regulator of cell growth and metabolism and is sufficient to induce specific metabolic processes, including de novo lipid biosynthesis. Elongation of very-long-chain fatty acids 1 (ELOVL1) is a ubiquitously expressed gene and the product of which was thought to be associated with elongation of carbon (C) chain in fatty acids. In the present study, we examined the effects of rapamycin, a specific inhibitor of mTORC1, on ELOVL1 expression and docosahexaenoic acid (DHA, C22:6 n-3) synthesis in bovine mammary epithelial cells (BMECs). We found that rapamycin decreased the relative abundance of ELOVL1 mRNA, ELOVL1 expression and the level of DHA in a time-dependent manner. These data indicate that ELOVL1 expression and DHA synthesis are regulated by mTORC1 in BMECs.

• 동의생리병리학회지
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• 제17권4호
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• pp.996-1001
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• 2003

It is well known that oxidative stress of reactive oxygen species(ROS) may be a causative factor in the pathogenesis of bone disorder. The purpose of this study was to evaluate the cytotoxicity of oxidative stress. Cell viability by MTS assay or INT assay, activity of glutathione peroxidase(GPx), lipid peroxidation(LPO) activity and cell viablity. And also protctive effect of glutamate receptors against ROS-induced osteotoxicity was examined by protein synthesis, alkaline phosphatase (ALP) activity and lactate dehydrogenase (LDH) activity in cultured rat osteoblasts and osteoclasts. XO/HX decreased cell viability and GPx activity, protein synthesis and ALP activity, but increased LPO activity and LDH activity. In the protective effect, N-methyl-D-aspartate (NMDA) receptor antagonists or AMPA/kainate receptor antagonists such as D-2-amino-5-phosphonovaleric acid (APV), 7-chlorokynurenic acid (CKA), 6-cyano-7-nitroquinoxaline-2,3-dione (CNQX) and 6,7-dinitroquinoxaline-2,3-dione (DNQX), NMDA receptor antagonists but AMPA/kainate receptor antagonists showed protective effect on xanthine oxidase (XO) and hypoxanthine (HX) in these cultures by the increse of protein synthesis, ALP activity.

• 대한한방내과학회지
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• 제33권4호
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• pp.438-447
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• 2012

Objectives : In this study, we investigated the effect and the underlying mechanism of ethanol extract of Benincasa seeds on a cellular model of non-alcoholic fatty liver disease (NAFLD) established by treating HepG2 cells with palmitate. Methods : We evaluated ethanol extract of Benincasa seeds (EEBS) for its hepatic lipid-lowering potential in fatty acid overloaded HepG2 cells. After incubation in palmitate containing media with or without EEBS, intracellular neutral lipid accumulations were quantified by Nile red staining. We also investigated the effect of EEBS on lipogenesis and ${\beta}$-oxidation. $LXR{\alpha}$-dependent SREBP-1c activation, expression of lipogenic genes, and expression of ${\beta}$-oxidation related genes were determined with or without pretreatment of EEBS. Results : EEBS significantly attenuated palmitate-induced intracellular neutral lipid accumulation in HepG2 cells. EEBS suppressed fatty acid synthesis by inhibiting $LXR{\alpha}$-dependent SREBP-1c activation. EEBS also repressed SREBP-1c mediated induction of lipogenic genes, including ACC, FAS, and SCD-1. However, EEBS had no effect on ${\beta}$-oxidation related CPT-1 and $PPAR{\alpha}$ gene expression. Conclusions : Our results suggest that EEBS has an efficacy to decrease hepatic lipid accumulation, and this effect was mediated by inhibiting the $LXR{\alpha}$-SREBP-1c pathway that leads to expression of lipogenic genes and hepatic steatosis. Therefore, the Benincasa seeds may have a potential clinical application for treatment of this chronic liver disease.

• Korean Chemical Engineering Research
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• 제51권1호
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• pp.87-92
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• 2013

미세조류는 바이오연료를 생산하기 위해 필요한 성분인 지방질의 생산성이 우수하기 때문에 바이오연료의 유망한 원료로서 최근 많은 주목을 받고 있다. 본 연구에서는, 이러한 미세조류의 성장 속도와 미세조류 내부의 지방의 함량이 최대가 되도록 하기 위한 목적으로, 미세조류의 성장과 지방의 생성을 설명하는 제일원리(first principle)에 근거한 상미분방정식(ODE) 모델에 대하여 조사하였다. 모델은 6개의 상태변수와 12개의 파라미터로 이루어져 있으며, 미세조류의 성장을 영양분의 흡수와 흡수된 영양분에 의한 성장으로 두 단계로 나누어 설명한 Droop 모델의 가정을 따른다. 본 연구에서는 민감도 분석(Sensitivity analysis)을 위한 최대의 정보를 줄 수 있는 입력 신호를 결정하기 위해 D-optimality criterion을 이용한 최적 입력 설계(Optimal input design)를 수행하였으며, 구하여진 입력 신호를 적용하여 민감도 분석을 수행하여 모델에 좀 더 중요한 파라미터를 결정하였다. 또한 미세조류의 성장속도와 지방의 함량이 최대가 되도록 하기 위하여 모델 예측 제어(MPC)를 수행하였다.