• 대한본초학회지
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• 제31권1호
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• pp.1-5
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• 2016

Objectives : The purpose of this study was to investigate inhibitory effects of steamed Polygonatum odoratum extract (POE) on insulin resistance in rat skeletal muscle cells, L6 cells.Methods : Polygonatum odoratum (P. odoratum) extract was extracted with ethyl acetate. Activity of α-glucosidase in POE was measured for blood glucose regulation. MTT assay was examined for cell toxicity. Western blot analysis for measurement of adiponectine, peroxisome proliferator-activated receptorγ (PPARγ), insulin receptor substrate (IRS), glucose transporter 4 (Glut-4) and phosphorylation of serine/threonine-specific protein kinase (Akt) expressions were performed. Akt signaling pathway were analyzed with LY294002, which is a specific PI3K/Akt inhibitor.Results : The results revealed that POE inhibited α-glucosidase activity. Treatment of POE in L6 cells inhibited the differentiation of L6 cells compared to those of vehicl control. Additionally, protein expressions of adiponectine, PPARγ, IRS and Glut-4 were significantly regulated compared to those of vehicle control (p < 0.05), respectively. Futhermore, phosphorylation of Akt was increased in L6 cells treated with POE compared to that of vehicle control (p < 0.05). pAkt expression was significantly accentuated with Akt inhibitor (LY294002).Conclusions : These results suggest that POE may have potential as a natural agent for prevention/improvement of diabetes, especially, regulation of blood glucose. Therefore, further additional study should be conducted to elucidate in depth the pharmaceutical efficacy of these.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.186-196
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• 2023

Dyglomera^® is an aqueous ethanol extract derived from the fruit and pods of Dichrostachys glomerata. A previous study has revealed that Dyglomera regulates adipogenesis and lipolysis by modulating AMP-activated protein kinase (AMPK) phosphorylation and increased expression levels of lipolysis-related proteins in white adipose tissue of high fat diet-induced mice and 3T3-L1 adipocyte cells. To further investigate mechanisms of Dyglomera, additional studies were performed using 3T3-L1 cells. Results revealed that Dyglomera downregulated adipogenesis by inhibiting the protein kinase B/mammalian target of rapamycin signaling pathway and reconfirmed that it downregulated gene expression levels of proliferator-activated receptor (PPAR)-γ, CCAAT enhancer binding protein α, sterol-regulation element-binding protein-1c. Dyglomera also reduced adipokines such as tumor necrosis factor alpha, interleukin-1β, and interleukin 6 by regulating leptin expression. Moreover, Dyglomera promoted beige-and-brown adipocyte-related phenotypes and regulated metabolism by increasing mitochondrial number and expression levels of genes such as T-box protein 1, transmembrane protein 26, PR domain 16, and cluster of differentiation 40 as well as thermogenic factors such as uncoupling protein 1, proliferator-activated receptor-gamma co-activator-1α, Sirtuin 1, and PPARα through AMPK activation. Thus, Dyglomera not only can inhibit adipogenesis, but also can promote lipolysis and thermogenesis and regulate metabolism by affecting adipokine secretion from 3T3-L1 adipocytes.

• Journal of Microbiology and Biotechnology
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• 제34권2호
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• pp.240-248
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• 2024

In cancer treatment, multi-target approach has paid attention to a reasonable strategy for the potential agents. We investigated whether (E)-2-methoxy-4-(3-(4-methoxyphenyl) prop-1-en-1-yl) phenol (MMPP) could exert an anticancer effect by dual-regulating VEGFR2 and PPARγ. MMPP showed modulating effects in TNBC type (MDA-MB-231 and MDA-MB-468) and luminal A type (MCF7) breast cancer cell lines. MMPP enhanced PPARγ transcriptional activity and inhibited VEGFR2 phosphorylation. MMPP-induced signaling by VEGFR2 and PPARγ ultimately triggered the downregulation of AKT activity. MMPP exhibited anticancer effects, as evidenced by growth inhibition, inducement of apoptosis, and suppression of migration and invasion. At the molecular level, MMPP activated pro-apoptotic proteins (caspase3, caspase8, caspase9, and bax), while inhibiting the anti-apoptotic proteins (bcl2). Additionally, MMPP inhibited the mRNA expressions of EMT-promoting transcription factors. Therefore, our findings showed molecular mechanisms of MMPP by regulating VEGFR2 and PPARγ, and suggested that MMPP has potential to treat breast cancer.

• The Korean Journal of Physiology and Pharmacology
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• 제20권6호
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• pp.649-655
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• 2016

TonEBP belongs to the Rel family of transcription factors and plays important roles in inflammation as well as kidney homeostasis. Recent studies suggest that TonEBP expression is also involved in differentiation of several cell types such as myocytes, chondrocytes, and osteocytes. In this study, we investigated the roles of TonEBP during adipocyte differentiation in 3T3-L1 cells. TonEBP mRNA and protein expression was dramatically reduced during adipocyte differentiation. Sustained expression of TonEBP using an adenovirus suppressed the formation of lipid droplets as well as the expression of FABP4, a marker of differentiated adipocytes. TonEBP also inhibited the expression of $PPAR{\gamma}$, a known master regulator of adipocytes. RNAi-mediated knock down of TonEBP promoted adipocyte differentiation. However, overexpression of TonEBP did not affect adipogenesis after the initiation of differentiation. Furthermore, TonEBP expression suppressed mitotic clonal expansion and insulin signaling, which are required early for adipocyte differentiation of 3T3-L1 cells. These results suggest that TonEBP may be an important regulatory factor in the early phase of adipocyte differentiation.

• 동의생리병리학회지
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• 제34권1호
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• pp.24-29
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• 2020

In this study, we investigated the inhibition effects of mixtures of Atractylodes macrocephala (AM) and Amomum villosum (AV) water extracts on adipocyte differentiation. Treatment with mixtures of AM and AV extracts in a ratio of 3:1 for 24 and 48 hours did not show any cytotoxicity in OP9 cells. Mixtures of AM(3) and AV(1) extracts inhibited adipocyte differentiation, expression of peroxisome proliferator-activated receptor gamma (PPARγ) and CCAT/enhancer-binding protein alpha (C/EBPα), the major transcription factors of differentiation. It also inhibited the expression of lipoprotein lipase (LPL), adipocyte protein 2 (aP2), which are PPARγ-target genes in adipocyte. We also checked the inhibition effects on cell proliferation during the early stage of differentiation by treatment with mixtures of AM(3) and AV(1) extracts. It markedly inhibited adipocyte proliferation after 48 hours, and also the phosphorylation of ERK1/2 and Akt after 10 min or 3 hour. These results identify a possible mechanism of action of mixtures of AM(3) and AV(1) extracts, suggesting that the mixtures of AM(3) and AV(1) extracts-induced inhibition of ERK and Akt phosphorylation suppresses adipogenesis by inhibiting other signaling cascades that include PPARγ and C/EBPα during the process of OP9 adipocyte differentiation.

• Nutrition Research and Practice
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• 제8권6호
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• pp.655-661
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• 2014

BACKGROUND/OBJECTIVES: The purpose of this study was to examine the effects and associated mechanisms of arctiin, a lignan compound found in burdock, on adipogenesis in 3T3-L1 cells. Also, the effects of arctiin supplementation in obese mice fed a high-fat diet on adiposity were examined. MATERIALS/METHODS: 3T3-L1 cells were treated with arctiin (12.5 to $100{\mu}M$) during differentiation for 8 days. The accumulation of lipid droplets was determined by Oil Red O staining and intracellular triglyceride contents. The expressions of genes related to adipogenesis were measured by real-time RT-PCR and Western blot analyses. For in vivo study, C57BL/6J mice were first fed either a control diet (CON) or high-fat diet (HF) to induce obesity, and then fed CON, HF, or HF with 500 mg/kg BW arctiin (HF + AC) for four weeks. RESULTS: Arctiin treatment to 3T3-L1 pre-adipocytes markedly decreased adipogenesis in a dose-dependent manner. The arctiin treatment significantly decreased the protein levels of the key adipogenic regulators $PPAR{\gamma}$ and $C/EBP{\alpha}$, and also significantly inhibited the expression of SREBP-1c, fatty acid synthase, fatty acid-binding protein and lipoprotein lipase. Also, arctiin greatly increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target phosphorylated-acetyl CoA carboxylase. Furthermore, administration of arctiin significantly decreased the body weight in obese mice fed with the high-fat diet. The epididymal, perirenal or total visceral adipose tissue weights of mice were all significantly lower in the HF + AC than in the HF. Arctiin administration also decreased the sizes of lipid droplets in the epididymal adipose tissue. CONCLUSIONS: Arctiin inhibited adipogenesis in 3T3-L1 adipocytes through the inhibition of $PPAR{\gamma}$ and $C/EBP{\alpha}$ and the activation of AMPK signaling pathways. These findings suggest that arctiin has a potential benefit in preventing obesity.

• IMMUNE NETWORK
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• 제9권2호
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• pp.64-73
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• 2009

Background: 15d-$PGJ_2$ has been known to act as an anti-inflammatory agent and has anti-hypertensive effects. As a result of these properties, we examined the effect of 15d-$PGJ_2$ on the LPS-induced IL-8/CXCL8 mRNA expression in VSMCs from SHR. Methods: Effect and action mechanism of 15d-$PGJ_2$ on the expression of LPS-induced IL-8/CXCL8 mRNA in VSMCs from SHR and WKY were examined by using real-time polymerase chain reaction, electrophoretic mobility shift assay for NF-${\kappa}B$ avtivity, Western blotting analysis for ERK and p38 phosphorylation and flow cytometry for NAD(P)H oxidase activity. Results: 15d-$PGJ_2$ decreased the expression of LPS-induced IL-8/CXCL8 mRNA in WKY VSMCs, but increased the expression of LPS-induced IL-8/CXCL8 mRNA in SHR VSMCs. The upregulatory effect of 15d-$PGJ_2$ in SHR VSMCs was mediated through PPAR${\gamma}$, and dependent on NF-${\kappa}B$ activation and ERK phosphorylation. However, inhibition of the p38 signaling pathway augmented the upregulatory effect of 15d-$PGJ_2$ on LPS-induced IL-8/CXCL8 mRNA. A NAD(P)H oxidase inhibitor inhibited the upregulatory effect of 15d-$PGJ_2$ on LPS-induced IL-8/CXCL8 mRNA expression in SHR VSMCs, and an increase in NAD(P)H oxidase activity was detected in SHR VSMCs treated with 15d-$PGJ_2$/LPS. Conclusion: Our results indicate that the upregulatory effect of 15d-$PGJ_2$ on LPS-induced IL-8/CXCL8 expression in SHR VSMCs is mediated through the PPAR${\gamma}$ and ERK pathway, and may be related to NAD(P)H oxidase activity. However, p38 inactivation may also play an important role in 15d-$PGJ_2$/LPS-induced IL-8/CXCL8 expression in SHR VSMCs.

• Asian-Australasian Journal of Animal Sciences
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• 제28권8호
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• pp.1075-1083
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• 2015

Adipose tissue deposited within muscle fibers, known as intramuscular fat (IMF or marbling), is a major determinant of meat quality and thereby affects its economic value. The biological mechanisms that determine IMF content are therefore of interest. In this study, 48 genes involved in the bovine peroxisome proliferator-activated receptor signaling pathway, which is involved in lipid metabolism, were investigated to identify candidate genes associated with IMF in the longissimus dorsi of Hanwoo (Korean cattle). Ten genes, retinoid X receptor alpha, peroxisome proliferator-activated receptor gamma (PPARG), phospholipid transfer protein, stearoyl-CoA desaturase, nuclear receptor subfamily 1 group H member 3, fatty acid binding protein 3 (FABP3), carnitine palmitoyltransferase II, acyl-Coenzyme A dehydrogenase long chain (ACADL), acyl-Coenzyme A oxidase 2 branched chain, and fatty acid binding protein 4, showed significant effects with regard to IMF and were differentially expressed between the low- and high-marbled groups (p<0.05). Analysis of the gene co-expression network based on Pearson's correlation coefficients identified 10 up-regulated genes in the high-marbled group that formed a major cluster. Among these genes, the PPARG-FABP4 gene pair exhibited the strongest correlation in the network. Glycerol kinase was found to play a role in mediating activation of the differentially expressed genes. We categorized the 10 significantly differentially expressed genes into the corresponding downstream pathways and investigated the direct interactive relationships among these genes. We suggest that fatty acid oxidation is the major downstream pathway affecting IMF content. The PPARG/RXRA complex triggers activation of target genes involved in fatty acid oxidation resulting in increased triglyceride formation by ATP production. Our findings highlight candidate genes associated with the IMF content of the loin muscle of Korean cattle and provide insight into the biological mechanisms that determine adipose deposition within muscle.

• BMB Reports
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• 제53권4호
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• pp.212-217
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• 2020

Activation of peroxisome proliferator-activated receptor γ (PPARγ) serves as a key factor in the proliferation and invasion of breast cancer cells and is a potential therapeutic target for breast cancer. However, the mechanisms underlying this effect remain largely unknown. Heme oxygenase-1 (HO-1) is induced and over-expressed in various cancers and is associated with features of tumor aggressiveness. Recent studies have shown that HO-1 is a major downstream target of PPARγ. In this study, we investigated the effects of induction of HO-1 by PPARγ on TPA-induced MMP-9 expression and cell invasion using MCF-7 breast cancer cells. TPA treatment increased NF-κB /AP-1 DNA binding as well as MMP-9 expression. These effects were significantly blocked by 15d-PGJ₂, a natural PPARγ ligand. 15d-PGJ₂ induced HO-1 expression in a dose-dependent manner. Interestingly, HO-1 siRNA significantly attenuated the inhibition of TPA-induced MMP-9 protein expression and cell invasion by 15d-PGJ₂. These results suggest that 15d-PGJ₂ inhibits TPA-induced MMP-9 expression and invasion of MCF-7 cells by means of a heme oxygenase-1-dependent mechanism. Therefore, PPARγ/HO-1 signaling-pathway inhibition may be beneficial for prevention and treatment of breast cancer.

• Journal of Microbiology and Biotechnology
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• 제26권11호
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• pp.1836-1844
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• 2016

Adipogenesis is one of the cellular processes and a highly controlled program. Nowadays, inhibition of adipogenesis has received attention as an effective way to regulate obesity. In the current study, we investigated the inhibition effect of a chloroform extract of Pleurotus eryngii var. ferulae 'Beesan No. 2' (CEBT) on adipogenesis in 3T3-L1 murine preadipocytes. Pleurotus eryngii var. ferulae is one of many varieties of King oyster mushroom and has been reported to have various biological activities, including antitumor and anti-inflammation effects. Biological activities of 'Beesan No. 2', a new cultivar of Pleurotus eryngii var. ferulae, have not yet been reported. In this study, we found that CEBT suppressed adipogenesis in 3T3-L1 cells through inhibition of key adipogenic transcription factors, such as peroxisome proliferatoractivated receptor ${\gamma}$ and CCAAT/enhancer binding protein ${\alpha}$. Additionally, CEBT reduced the expression of the IRS/PI3K/Akt signaling pathway and its downstream factors, including mammalian target of rapamycin and p70S6 kinase, which stimulate adipogenesis. Furthermore, ${\beta}-catenin$, a suppressor of adipogenesis, was increased in CEBT-treated cells. These results indicate that Pleurotus eryngii var. ferulae 'Beesan No. 2' effectively inhibited adipogenesis, so this mushroom has potential as an anti-obesity food and drug.