• Journal of Nutrition and Health
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• 제24권3호
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• pp.179-188
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• 1991

Twenty college women were led experimental diet which composed ot basal diet plus different kinds of dietary rats at 27% Cal. Equal amount of 13.5g of corn oil, perilla oil or fish oil was supplied for 2 weeks as a source of n6 linoleic acid(LA). n3 $\alpha$-linolenic acid (LL). or n3 EPA + DHA. respectively. Plasma total Chol level was reduced by perilla and fish oils, significantly only by fish oil. Plasma Chol level was rather increased by corn oil(P<0.05), but was decreased by double amount of corn oil supplement. Therefore, hypocholesterolemic effect of fatty acids was in the order of n3 EPA+DHA>n3 LL>n6 LA and influenced by the degree of fat unsaturation. Plasma TG level was also significantly decreased by n3 EPA+ DHA and increased by n6 LA. Hypotriglyceridemic effect of fatty acids was also in the order of n3 EPA + DHA> n3 LL>n6 LA and influenced by the unsaturation. However, the reduction of plasma TG was more influenced by the fatty acid structure rather than the fat unsaturation. There were no significant effects on lipoprotein pattern 3nd chemical compositions of lipoprotein by different dietary PUFAs. but fish oil diet significantly increased the relative proportion of HDL-Chol. In conclusion. cholesterol- lowering effect of dietary PUFAS seemed to be a function of total fat unsaturation but hypotriglyceridemic effect seemed to be more linked to the ratty acid structure rather than the degree of unsaturation. The hypolipidemic effect of n3 PUFAs was significant so that fish oil or perilla oil may have important nutritional applications in the prevention and treatment of atherosclerotic disease.

• Asian Pacific Journal of Cancer Prevention
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• 제15권9호
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• pp.4101-4107
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• 2014

Protein phosphatase 1 (PP1) is a major serine/threonine phosphatase that controls gene expression and cell cycle progression. The active mutant IPP5 ($8-60hIPP5^m$), the latest member of the inhibitory molecules for PP1, has been shown to inhibit the growth of human cervix carcinoma cells (HeLa). In order to elucidate the underlying mechanisms, the present study assessed overexpression of $8-60hIPP5^m$ in HeLa cells. Flow cytometric and biochemical analyses showed that overexpression of $8-60hIPP5^m$ induced G2/M-phase arrest, which was accompanied by the upregulation of cyclin B1 and phosphorylation of G2/M-phase proteins ATM, p53, $p21^{cip1/waf1}$ and Cdc2, suggesting that $8-60hIPP5^m$ induces G2/M arrest through activation of the ATM/p53/$p21^{cip1/waf1}$/Cdc2/cyclin B1 pathways. We further showed that overexpression of $8-60hIPP5^m$ led to delayed nuclear translocation of cyclin B1. $8-60hIPP5^m$ also could translocate to the nucleus in G2/M phase and interact with $pp1{\alpha}$ and Cdc2 as demonstrated by co-precipitation assay. Taken together, our data demonstrate a novel role for $8-60hIPP5^m$ in regulation of cell cycle in HeLa cells, possibly contributing to the development of new therapeutic strategies for cervix carcinoma.

• Toxicological Research
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• 제33권3호
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• pp.211-218
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• 2017

Cytochrome P450 1B1 (CYP1B1) acts as a hydroxylase for estrogen and activates potential carcinogens. Moreover, its expression in tumor tissues is much higher than that in normal tissues. Despite this association between CYP1B1 and cancer, the detailed molecular mechanism of CYP1B1 on cancer progression in HeLa cells remains unknown. Previous reports indicated that the mRNA expression level of Herc5, an E3 ligase for ISGylation, is promoted by CYP1B1 suppression using specific small interfering RNA, and that ISGylation may be involved in ubiquitination related to ${\beta}-catenin$ degradation. With this background, we investigated the relationships among CYP1B1, Herc5, and ${\beta}-catenin$. RT-PCR and western blot analyses showed that CYP1B1 overexpression induced and CYP1B1 inhibition reduced, respectively, the expression of $Wnt/{\beta}-catenin$ signaling target genes including ${\beta}-catenin$ and cyclin D1. Moreover, HeLa cells were treated with the CYP1B1 inducer $7,12-dimethylbenz[{\alpha}]anthracene$ (DMBA) or the CYP1B1 specific inhibitor, tetramethoxystilbene (TMS) and consequently DMBA increased and TMS decreased ${\beta}-catenin$ and cyclin D1 expression, respectively. To determine the correlation between CYP1B1 expression and ISGylation, the expression of ISG15, a ubiquitin-like protein, was detected following CYP1B1 regulation, which revealed that CYP1B1 may inhibit ISGylation through suppression of ISG15 expression. In addition, the mRNA and protein expression levels of Herc5 were strongly suppressed by CYP1B1. Finally, an immunoprecipitation assay revealed a direct physical interaction between Herc5 and ${\beta}-catenin$ in HeLa cells. In conclusion, these data suggest that CYP1B1 may activate $Wnt/{\beta}-catenin$ signaling through stabilization of ${\beta}-catenin$ protein from Herc5-mediated ISGylation for proteosomal degradation.

• Molecules and Cells
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• 제42권11호
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• pp.783-793
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• 2019

When endoplasmic reticulum (ER) functions are perturbed, the ER induces several signaling pathways called unfolded protein response to reestablish ER homeostasis through three ER transmembrane proteins: inositol-requiring enzyme 1 (IRE1), PKR-like ER kinase (PERK), and activating transcription factor 6 (ATF6). Although it is important to measure the activity of ATF6 that can indicate the status of the ER, no specific cell-based reporter assay is currently available. Here, we report a new cell-based method for monitoring ER stress based on the cleavage of $ATF6{\alpha}$ by sequential actions of proteases at the Golgi apparatus during ER stress. A new expressing vector was constructed by using fusion gene of GAL4 DNA binding domain (GAL4DBD) and activation domain derived from herpes simplex virus VP16 protein (VP16AD) followed by a human $ATF6{\alpha}$ N-terminal deletion variant. During ER stress, the GAL4DBD-VP16AD(GV)-$hATF6{\alpha}$ deletion variant was cleaved to liberate active transcription activator encompassing GV-$hATF6{\alpha}$ fragment which could translocate into the nucleus. The translocated GV-$hATF6{\alpha}$ fragment strongly induced the expression of firefly luciferase in HeLa Luciferase Reporter cell line containing a stably integrated 5X GAL4 site-luciferase gene. The established double stable reporter cell line HLR-GV-$hATF6{\alpha}$(333) represents an innovative tool to investigate regulated intramembrane proteolysis of $ATF6{\alpha}$. It can substitute active pATF6(N) binding motif-based reporter cell lines.

• Bulletin of the Korean Chemical Society
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• 제31권12호
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• pp.3803-3805
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• 2010

• Biomolecules & Therapeutics
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• 제27권3호
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• pp.276-282
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• 2019

${\beta}$-amyloid precursor protein (APP) can be cleaved by ${\alpha}$-, and ${\gamma}$-secretase at plasma membrane producing soluble ectodomain fragment ($sAPP{\alpha}$). Alternatively, following endocytosis, APP is cleaved by ${\beta}$-, and ${\gamma}$-secretase at early endosomes generating ${\beta}$-amyloid ($A{\beta}$), the main culprit in Alzheimer's disease (AD). Thus, APP endocytosis is critical for $A{\beta}$ production. Recently, we reported that Monsonia angustifolia, the indigenous vegetables consumed in Tanzania, improved cognitive function and decreased $A{\beta}$ production. In this study, we examined the underlying mechanism of justicidin A, the active compound of M. angustifolia, on $A{\beta}$ production. We found that justicidin A reduced endocytosis of APP, increasing $sAPP{\alpha}$ level, while decreasing $A{\beta}$ level in HeLa cells overexpressing human APP with the Swedish mutation. The effect of justicidin A on $A{\beta}$ production was blocked by endocytosis inhibitors, indicating that the decreased APP endocytosis by justicidin A is the underlying mechanism. Thus, justicidin A, the active compound of M. angustifolia, may be a novel agent for AD treatment.

• Asian-Australasian Journal of Animal Sciences
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• 제17권5호
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• pp.712-718
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• 2004

This study was carried out to separate the calcium-binding protein derived from enzymatic hydrolysates of cheese whey protein. CWPs (cheese whey protein) heated for 10 min at $100^{\circ}C$ were hydrolyzed by trypsin, papain W-40, protease S, neutrase 1.5 and pepsin, and then properties of hydrolysates, separation of calcium-binding protein and analysis of calcium-binding ability were investigated. The DH (degree of hydrolysis) and NPN (non protein nitrogen) of heated-CWP hydrolysates by commercial enzymes were higher in trypsin than those of other commercial enzymes. In the result of SDS-PAGE (sodium dodecyl sulphate polyacrylamide gel electrophoresis), $\beta$-LG and $\alpha$-LA in trypsin hydrolysates were almost eliminated and the molecular weight of peptides derived from trypsin hydrolysates were smaller than 7 kDa. In the RP-HPLC (reverse phase HPLC) analysis, $\alpha$-LA was mostly eliminated, but $\beta$-LG was not affected by heat treatment and the RP-HPLC patterns of trypsin hydrolysates were similar to those of SDS-PAGE. In ion exchange chromatography, trypsin hydrolysates were shown to peak from 0.25 M NaCl and 0.5 M NaCl, and calcium-binding ability is associated with the large peak, which was eluted at a 0.25 M NaCl gradient concentration. Based on the results of this experiment, heated-CWP hydrolysates by trypsin were shown to have calcium-binding ability.

• 한국미생물·생명공학회지
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• 제33권3호
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• pp.184-188
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• 2005

HRF는 Na,K-ATPase의 ${\alpha}$ subunit에 결합하여 이의 활성을 저해하는 것으로 알려져 있으며, PKC에 의해 Ser98 잔기가 인산화 될 수 있다는 것을 anti-HRFpS98 항체와 HRF S98A mutant를 이용한 실험으로 확인할 수 있었다. 또한 $^{86}Rb^{+}-uptake$ assay 실험에서 HRF의 serine 98 잔기의 탈인산화는 Na,K-ATPase의 활성에 약간의 영향을 미치는 것으로 미루어 PKC에 의해 인산화되는 98 serine 잔기가 Na,K-ATPase 활성 저해에 큰 영향을 미치지 않는 것으로 보인다.

• 폴리머
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• 제36권4호
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• pp.455-460
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• 2012

Poly(N-isopropylacrylamide)(PNIPAM)는 체온과 비슷한 온도에서 부피상 변화 혹은 온도 감응성 팽윤 거동의 특성을 보여 약물전달시스템에서 중요하게 연구되고 있다. 그러나 PNIPAM의 친수성 특징 때문에 소수성 약물을 그 네트워크 안에 고르게 넣기는 쉽지 않다. 항산화제인 알파 리포익산은 개환중합으로 고분자화(polylipoic acid, PLA) 될 수는 있으나, 분자량이 낮고 분해되기 쉬워 고분자 재료로 사용되기에는 어려움이 많다. 이러한 결점들을 극복하기 위해 소수성 활성성분인 알파 리포익산을 NIPAM과 반응시켜 안정적인 하이드로젤을 만들었다. 단순한 혼합과 가열에 의한 라디칼 반응으로 하이드로젤(PNIPAM/PLA)이 성공적으로 만들어졌고, 이를 DSC, FTIR, Raman spectroscopy를 통해서 확인하였다. PNIPAM/PLA는 온도 감응성 특성을 보여주며, 리포익산의 함량이 증가할수록 부피팽창 정도는 감소하였다. 이러한 하이드로젤을 사용하여 PNIPAM에 소수성 약물을 쉽게 담지할 수 있고 리포익산은 항산화제로 효과가 있어, 본 하이드로젤은 최종 약물전달체로서도 유용하다.

• Preventive Nutrition and Food Science
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• 제8권3호
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• pp.253-259
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• 2003

Conjugated linoleic acid (CLA) is a class of positional, geometric conjugated dienoic isomers of linoleic acid (LA). CLA activates the immune system, protects against tumorigenesis, and reduces the incidence of atherosclerosis. Trans-10, cis-12 CLA has specific effects on lipid metabolism, it has been shown to reduce body fat gain and regulates some adipocyte secreted proteins in vivo and in vitro. Here we report that a CLA mixture affects cytokine secretion from rat primary adipocytes. Rat primary adipocytes were treated with 1 mM, 100 $\mu$M, 1 $\mu$M or 100 nM CLA mixture doses; and leptin, tumor necrosis factor alpha (TNF a ), interleukin-6 (IL-6) and glycerol levels in the medium were measured. Leptin secretion was lower, TNF $\alpha$ secretion higher and IL-6 secretion did not change in response to the CLA mixture. Leptin and TNF $\alpha$ secretions did not change with CLA mixture treatment in a dose-dependent manner. In addition, the CLA mixture did not appear to enhance lipolysis in rat primary adipocytes. In conclusion, our study demonstrates that the decrease in leptin and increase in TNF $\alpha$ secretion in adipocytes treated with CLA mixture may be due to the apoptotic effect and to a reduction in peroxisome proliferator-activated receptor gamma (PPAR ${\gamma}$ ) ligands.