• BMB Reports
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• v.52 no.6
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• pp.391-396
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• 2019

Receptor activator of nuclear factor kappa B ligand (RANKL) expression in osteoblasts is regulated by 1,25-dihydroxyvitamin D3 (1,25D3). CCAAT/enhancer-binding protein beta ($C/EBP{\beta}$) has been proposed to function as a transcription factor and upregulate RANKL expression, but it is still uncertain how $C/EBP{\beta}$ is involved in 1,25D3-induced RANKL expression of osteoblasts. 1,25D3 stimulation increased the expression of RANKL and $C/EBP{\beta}$ genes in osteoblasts and enhanced phosphorylation and stability of these proteins. Moreover, induction of RANKL expression by 1,25D3 in osteoblasts was downregulated upon knockdown of $C/EBP{\beta}$. In contrast, $C/EBP{\beta}$ overexpression directly upregulated RANKL promoter activity and exhibited a synergistic effect on 1,25D3-induced RANKL expression. In particular, 1,25D3 treatment of osteoblasts increased $C/EBP{\beta}$ protein binding to the RANKL promoter. In conclusion, $C/EBP{\beta}$ is required for induction of RANKL by 1,25D3.

• Biomedical Science Letters
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• v.14 no.3
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• pp.131-137
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• 2008

Adipogenesis is a complex sequence of events that culminates in the differentiation of fibroblast-like preadipocytes into specialized lipid-filled adipocytes and also involves a cascade of expression of many transcription factors such as peroxisome proliferator-activated receptor ${\gamma}(PPAR{\gamma})$ and CCAAT/enhancer-binding proteins (C/EBPs). $PPAR{\gamma}$ and C/EBPs transcriptionally transactivate adipocyte specific genes, including fatty acid transport protein (FAT/CD36) and leptin. To determine whether $17{\beta}$-estradiol modulates $C/EBP{\alpha}$ actions on adipogenesis in high fat diet-fed female ovariectomized (OVX) C57BL/6 mice, mice were treated with $17{\beta}$-estradiol for 7 days and the effects of $17{\beta}$-estradiol on adipose tissue mass and expression of adipocyte specific gene as well as $C/EBP{\alpha}$ were measured. Compared to vehicle-treated OVX control mice, OVX mice treated with $17{\beta}$-estradiol for 7 days had lower adipose tissue weights that were similar to weights in high fat diet-fed sham-operated (Sham) mice. OVX mice showed the increased expression of $C/EBP{\alpha}$ mRNA compared with Sham mice. However, $17{\beta}$-estradiol treatment in OVX mice inhibited OVX induced-$C/EBP{\alpha}$ activation, indicating that $17{\beta}$-estradiol may act as an inhibitor of $C/EBP{\alpha}$ action. Moreover, $17{\beta}$-estradiol decreased mRNA levels of adipocyte marker genes, such as lipoprotein lipase, FAT/CD36 and leptin, to levels in Sham mice. These results suggest that down-regulation of adipogenesis by $17{\beta}$-estradiol may be due to reduced adipose $C/EBP{\alpha}$ activities in female OVX C57BL/6 mice.

• Journal of Life Science
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• v.22 no.10
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• pp.1399-1406
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• 2012

The present study was conducted to evaluate the effects of various extracts of Hizikia fusiforme on the anti-obesity effects in 3T3-L1 preadipocytes. We used H. fusiforme extracts from ethanol (EEHF), dichloromethane (CFHF), ethyl acetate (EAFHF), butanol (BFHF), and water (WFHF). Treatment with these extracts significantly suppressed terminal differentiation of 3T3-L1 preadipocytes in a dose-dependent manner as confirmed by a decrease in lipid droplet content through Oil Red O staining; this effect was higher in WFHF than in other extracts. The concentrations of cellular triglyceride were also reduced in 3T3-L1 cells by exposure with these extracts, especially when compared with the controls. Treatment with 200 ${\mu}g/ml$ of WFHF and CFHF caused approximately 42.6% and 23.7% reduction, respectively. In addition, the extracts of H. fusiforme significantly reduced the expression levels of key pro-adipogenic transcription factors, including peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) and CCAAT/enhancer binding proteins ${\alpha}$ (C/$EBP{\alpha}$) and C/$EBP{\beta}$ as compared with controls. Accordingly, our data indicated that WFHF has a preeminent effect on inhibition of adipocyte differentiation among various extracts, and H. fusiforme extracts may be an ideal candidate for obesity relief.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.3
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• pp.288-295
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• 2014

Bojungchiseub-tang (BJCST) has been used in symptoms and signs of edema, dampness-phlegm, kidney failure, and so on. BJCST is also expected to have strong anti-obesity activities. However, little is known about the mechanisms of its inhibitory effects on adipocyte differentiation and adipogenesis. In the present study, we examined the effects and mechanism of BJCST on transcription factors and adipogenic genes of 3T3-L1 preadipocytes to understand its inhibitory effects on adipocyte differentiation and adipogenesis. Our results showed that BJCST significantly inhibited differentiation and adipogenesis of 3T3-L1 preadipocytes in a dose-dependent manner. To elucidate the mechanism of the effects of BJCST on lowering lipid content in 3T3-L1 adipocytes, we examined whether BJCST modulate the expressions of transcription factors to induce adipogenesis and adipogenic genes related to regulate accumulation of lipids. As a result, the expression of steroid regulatory element-binding protein (SREBP)1, cytidine-cytidine-adenosine-adenosine-thymidine (CCAAT)/enhancer binding proteins ${\alpha}$ ($C/EBP{\alpha}$), $C/EBP{\beta}$, $C/EBP{\delta}$, and peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$) genes, which induce the adipose differentiation, liver X receptor $(LXR){\alpha}$ and fatty acid synthase (FAS) genes, which induce lipogenesis and adipose-specific aP2, Adipsin, lipoprotein lipase (LPL), CD36, TGF-${\beta}$, leptin and adiponectin genes, which compose fat formation were decreased. BJCST also reduced the expression of acyl CoA oxidase (ACO) and uncoupling protein (UCP) genes related to lipid oxidation. In conclusion, BJCST could regulate transcript factor related to induction of adipose differentiation and inhibited the accumulation of lipids and expression of adipogenic genes.

• Journal of Life Science
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• v.22 no.12
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• pp.1688-1696
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• 2012

Oenanthe javanica has been used as a food source and also in traditional folk medicine for its detoxifying properties and anti-microbial effects since ancient times. In this study, we evaluated the effect and mechanism of O. javanica seed methanol extract (OJSE) on adipocyte differentiation by 3T3-L1 preadipocytes. Under non-toxic conditions, OJSE treatment resulted in a dose-dependent inhibition of lipid droplet generation and triglyceride accumulation by suppressing adipocyte differentiation, which are associated with the decreased expression of key proadipogenic transcription factors including CCAAR/enhancer binding protein ${\alpha}$, ${\beta}$ ($C/EBP{\alpha}$, $C/EBP{\beta}$) and peroxisome proliferator-activated receptor ${\gamma}$ ($PPAR{\gamma}$). OJSE also significantly inhibited proliferation and differentiation of 3T3-L1 preadipocytes through G1-phase arrest, indicating that OJSE blocked mitotic clonal expansion during adipocyte differentiation. Investigation of the alteration of G1 phase arrest-related proteins indicated a dose-dependent increase in the expression of p21 and reduction in expression of cyclin E, Cdk2, E2F-1 and phospho-Rb by OSJE. Taken together, these results suggest that OJSE inhibits adipocyte differentiation by blocking the mitotic clonal expansion, which is accompanied by preadipocyte cell cycle arrest.

• Journal of Life Science
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• v.21 no.9
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• pp.1346-1353
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• 2011

Sophora tonkinensis Gapnep has been used as a traditional herbal medicine in oriental regions since ancient times. In this study, the effect and mechanism of the MeOH extract of Sophora tonkinensis Gapnep (STME) on adipocite differentiation and adipogenesis in 3T3-L1 preadipocites were investigated. Treatment with STME in the concentration range of 0-200 ${\mu}g$/ml significantly inhibited the differentiation of 3T3-L1 preadipocites in a dose-dependent manner, as determined by a decrease in intracellular lipid droplets and lipid contents measured by Oil Red O staining. In association with the inhibitory effect of lipid accumulation, the expressions of the proteins concerned with adipogenesis in 3T3-L1 preadipocites were also investigated. Treatment with STME reduced the expressions of peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$ and ${\beta}$ (C/EBP${\alpha}$ and C/EBP${\beta}$) and sterol regulatory element binding protein (SREBP), which are adipocyte specific markers. In flow cytometry analysis, the inhibitory effect of differentiation was caused by G1 arrest and following mitotic clonal expansion cease. Therefore, we also investigated the alteration of G1 phase arrest-related proteins. As a result, the expression of p21 protein was significantly increased, while the expressions of Cdk2, E2F-1 and phospho-Rb were reduced in a dose-dependent manner in STME treated 3T3-L1 cells. According to these results, STME might inhibit differentiation through G1 arrest in 3T3-L1 preadipocytes adipogenesis, and further studies, which are in progress, have to be completed to identify the active compounds.

• Korean Journal of Acupuncture
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• v.31 no.4
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• pp.168-178
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• 2014

Objectives : Mahuang-Chuanwu(Mahwang-Cheonoh) Pharmacopuncture(MCP) has been used to treat obesity in Clinical Korean Medicine. MCP solution(MCPS) is also expected to have strong anti-obesity activities. However, little is known about the mechanisms of its inhibitory effects on adipocyte differentiation and lipogenesis. Methods : In the present study, we examined the effects of MCPS on differentiation and lipogenesis of 3T3-L1 adipocytes. To elucidate the mechanism of the effects of MCPS on lowering lipid content in 3T3-L1 adipocytes, we examined whether MCPS modulates the expressions of transcription factors to induce lipogenesis and adipogenic genes related to regulate the accumulation of lipids. Results : Our results showed that MCPS significantly inhibited differentiation and lipogenesis of 3T3-L1 adipocytes in a dose-dependent manner. MCPS suppressed the mRNA expressions of cytidine-cytidine-adenosine-adenosine-thymidine(CCAAT)/enhancer binding proteins ${\alpha}$($C/EBP{\alpha}$), C/EBP ${\beta}$, $C/EBP{\delta}$, and peroxisome proliferator-activated receptor ${\gamma}$($PPAR{\gamma}$) genes related to the induction of adipose differentiation. MCPS inhibited the mRNA expressions of adipose-specific aP2, adipsin, lipoprotein lipase(LPL), CD36, TGF-${\beta}$, and leptin genes related to the fat formation. MCPS downregulated the mRNA expressions of liver X receptor(LXR) ${\alpha}$ and fatty acid synthase(FAS) genes related to the induction of lipogenesis. In addition, MCPS reduced the production of adipocyte-induced pro-inflammatory cytokines. Conclusions : MCPS could regulate the accumulation of lipids and expression of adipogenic genes via inhibition of transcript factors related to induction of adipose differentiation.

• Journal of Nutrition and Health
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• v.48 no.1
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• pp.9-18
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• 2015

Purpose: Poncirus trifoliata has been reported to have anti-inflammatory, antioxidant, and immune activities. However, its anti-obesity activity and the mechanism by which the water extract of dried, immature fruit of Poncirus trifoliata (PF-W) acts are not clear. This study suggests a potential mechanism associated with the anti-obesity activity of PF-W. Methods: We measured the effect of PF-W on lipoprotein lipase (LPL) regulation using enzyme-linked immunosorbent assay (ELISA) and an activity assay. The LPL regulation mechanism was examined by reverse transcription polymerase chain reaction (RT-PCR) to measure the mRNA expression of biomarkers related to protein transport and by western blot for analysis of the protein expression of the transcription factor CCAAT-enhancer-binding protein ($C/EBP{\beta}$). Results: The total polyphenol and flavonoid content of PF-W was $52.15{\pm}4.02$ and $6.56{\pm}0.47mg/g$, respectively. PF-W treatment decreased LPL content in media to $58{\pm}5%$ of that in control adipocyte media, and increased LPL content to $117{\pm}3.5%$ of that in control adipocytes, but did not affect the mRNA expression of LPL. PF-W also increased the mRNA expression of sortilin-related receptor (SorLA), a receptor that induces endocytosis and intracellular trafficking of LPL, in a concentration- and time-dependent manner. Finally, cell fractionation revealed that PF-W treatment induced the expression of $C/EBP{\beta}$, a SorLA transcription factor, in the nuclei of 3T3-L1 adipocytes. Conclusion: The LPL secretion and activity assay showed PF-W to be an LPL secretion inhibitor, and these results suggest the potential mechanism of PF-W involving inhibition of LPL secretion through $C/EBP{\beta}$-mediated induction of SorLA expression.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.6
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• pp.927-931
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• 2010

The objective of this study was to evaluate the effect of defatted grape seed extract (DGSE) on adipocyte differentiation in 3T3-L1 preadipocytes. DGSE at 100 ${\mu}g$/mL significantly suppressed lipid accumulation and glycerol-3-phosphate dehydrogenase activity in hormonally stimulated adipocytes, an indicator of adipocyte differentiation. In order to understand the anti-adipogenic effects of DGSE, the changes in the expression of several adipogenic transcription factors including peroxisome proliferator-activated receptor (PPAR) $\gamma$, CCAAT/enhancer-binding protein (C/EBP) $\alpha$ and $\beta$ were investigated using immunoblotting. DGSE suppressed the expression of PPAR$\gamma$, C/EBP$\alpha$, and C/EBP$\beta$ proteins compared with control adipocytes in a dose-dependent manner. This results indicated that DGSE may alter fat mass by directly affecting adipogensis in maturing preadipocytes and thus may have applications for the treatment of obesity.

• Korean Journal of Food Science and Technology
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• v.50 no.6
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• pp.688-696
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• 2018

This study aimed to investigate the effects of red ginseng-derived saponin fraction (SF) on lipid accumulation, reactive oxygen species (ROS) production, and nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/Kelch-like ECH-associated protein 1 (Keap1) signaling during adipocyte differentiation. SF effectively inhibited lipid accumulation, with the downregulation of adipogenic factors such as peroxisome proliferator-activated receptor gamma ($PPAR{\gamma}$) and CCAAT/enhancer-binding protein alpha ($C/EBP{\alpha}$). A high dose of SF decreased the protein levels of $PPAR{\gamma}$ and $C/EBP{\alpha}$ by over 90% compared to the control. SF-mediated downregulation of adipogenic factors was due to the regulation of early adipogenic factors including $C/EBP{\beta}$ and $Kr{\ddot{u}}ppel$-like Factor 2 (KLF2). In addition, SF ($200{\mu}g/mg$) decreased intracellular ROS generation by 40% during adipocyte differentiation. However, the SF significantly upregulated Nrf2 and its target proteins, hemoxygenase-1 (HO-1) and NADPH dehydrogenase quinone 1 (NQO1). Furthermore, SF ($200{\mu}g/mg$) promoted the nuclear translocation of Nrf2. The SF-mediated reduction of lipid accumulation was associated with the regulation of the Nrf2/Keap1 pathway.