• Journal of Microbiology and Biotechnology
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• v.30 no.2
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• pp.306-312
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• 2020

Despite the importance of brown adipocytes as a therapeutic target for the prevention and treatment of obesity, the molecular mechanism underlying brown adipocyte differentiation is not fully understood. In particular, the role of post-translational modifications in brown adipocyte differentiation has not been extensively studied. Histidine phosphorylation is increasingly recognized an important process for protein post-translational modifications. In this study, we show that histidine phosphorylation patterns change during brown adipocyte differentiation. In addition, the expression level of protein histidine phosphatase 1 (PHPT1), a major mammalian phosphohistidine phosphatase, is reduced rapidly at the early phase of differentiation and recovers at the later phase. During white adipocyte differentiation of 3T3-L1 preadipocytes, however, the expression level of PHPT1 do not significantly change. Knockdown of PHPT1 promotes brown adipocyte differentiation, whereas ectopic expression of PHPT1 suppresses brown adipocyte differentiation. These results collectively suggest that histidine phosphorylation is closely linked to brown adipocyte differentiation and could be a therapeutic target for obesity and related metabolic diseases.

• Food Science of Animal Resources
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• v.35 no.2
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• pp.171-178
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• 2015

This study aimed to investigate the effects of Lactobacillus plantarum FH185 on the reduction of adipocyte size and gut microbial changes in mice with diet-induced obesity. The strain was found to have a lipase inhibitory activity of 70.09±2.04% and inhibited adipocyte differentiation of 3T3-L1 cells (18.63±0.98%) at a concentration of 100 µg/mL. To examine the effect of the strain supplementation on gut microbial changes in mice with diet-induced obesity, male C57BL/6J mice were fed on four different diets (i.e., A, normal diet (ND); B, high-fat diet (HFD); C, HFD with ABT-3 (10⁹ CFU/day); and D, HFD with L. plantarum FH185 (10⁹ CFU/day)) for 6 wk. According to the results of fecal pyrosequencing, the ratio of Firmicutes to Bacteroidetes in groups C and D was lower than in the control groups at the phylum level. At the family level, Lactobacillaceae in groups C and D was observed to dominate, while Lachnospiraceae in groups A and B was observed to dominate. At the genus level, Lactobacillus in groups C and D was comparatively higher than in groups A and B. To examine the effects of strain supplementation on the reduction of adipocyte size, the left and right epididymal fat pads were quickly isolated after the animals were sacrificed, and the adipocyte sizes were measured. In groups A, C and D, the percentage of 2,000 m² of adipocyte was higher than in the other size of adipocyte, while the percentage of over 5,000 m² of adipocyte was highest in group B. The mean adipocyte size of group D was significantly larger than that of group A, but smaller than that of group B.

• Journal of Life Science
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• v.19 no.4
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• pp.423-428
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• 2009

Selenium was investigated using human origin preadipocytes to see whether it possesses preventive or therapeutic effects for obesity. Unveiling the potential of selenium in the reduction of adipogenesis can help predict the therapeutic capabilities of selenium in obesity. In the present study, the molecular mechanism of the inhibition of adipogenesis by selenium was explored to unravel the involvement of the AMP-activated protein kinase. There is emerging evidence that AMPK, a sensor of cellular energy status, is a possible molecular target of controlling adipocyte differentiation on the basis of discovery that AMPK is responsible for the major metabolic responses to exercise, and integration of nutritional and hormonal signals to modulate feeding behavior or energy expenditure in the hypothalamus. Treatment of selenium resulted in inhibition of the adipocyte differentiation process and induction of mature apoptosis in 3T3-L1 adipocytes. We hypothesized that selenium may exert anti-adipogenic potential though modulating AMPK. We have found that selenium significantly activated AMPK and phosphorylated its substrate acetyl-CoA carboxylase ($ACC-serine^{79}$) during the inhibitory process of adipocytes. Also, the inhibition process of adipocyte differentiation by selenium was comparable to either reveratrol or a synthetic AMPK activator, AICAR (5-aminoimidazole-4-carboxamide-1-${\beta}$-D-ribofuranoside). To evaluate the involvement of AMPK in anti-lipogensis, we applied AICAR and Compound C, an AMPK inhibitor, to 3T3-L1-adipocytes and found that AMPK is required for the adipocyte differentiation blocking process. These results suggest that selenium has a potential to control adipogenesis and that this effect is mediated by AMPK, an essential kinase for both inhibition of adipocyte differentiation and apoptosis of mature adipocytes.

• Journal of Life Science
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• v.32 no.7
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• pp.542-549
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• 2022

Polymethoxyflavones (PMFs) are flavonoids mainly found in citrus fruits and have been reported to exhibit a wide range of bioactivities, including anti-obesity, anti-cancer, and anti-inflammatory actions. To utilize PMFs as functional materials, it is necessary to develop a simple method of obtaining PMFs from citrus tissues containing a large amount of PMFs. It has been reported that Jinkyool (C. sunki Hort ex. Tanaka) peel contained a large amount of PMFs, but there are no studies on PMFs isolated from its leaves. In this study, we established a simple procedure for obtaining the PMF-rich fraction (PRF) from the leaves of Jinkyool and investigated the effects of PRF on lipid metabolism in 3T3-L1 cells. PRF inhibited lipogenesis during the differentiation of 3T3-L1 preadipocytes. It decreased the expression of peroxisome proliferator-activated receptor gamma (PPAR𝛾) and CCAAT/enhancer binding protein alpha (CEBP𝛼), FAS, and adipocyte fatty-acid-binding protein 2 (aP2). In mature 3T3-L1 adipocytes, PRF increases the phosphorylation of protein kinase A (PKA)/hormone-sensitive lipase (HSL), which are key factors involved in lipolysis. Moreover, it increases the phosphorylation of the AMP-activated protein kinase (AMPK)/acetyl-CoA carboxylase (ACC) involved in fatty acid oxidation. These results suggest that PRF from Jinkyool leaves can be used as an anti-obesity agent with the action of inhibiting lipogenesis and promoting lipolysis and fatty acid oxidation in 3T3-L1 adipocytes.

• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.5
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• pp.486-493
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• 2014

Adipocytes are endocrine cells that release bioactive mediators called adipokines. In condition of obesity characterized by low-grade chronic inflammation, adipocytes release inflammatory adipokines, which is related to insulin resistance. Bojungchiseub-tang (BJCST) has been used in symptoms and signs of edema, dampness-phlegm, kidney failure, and so on in Korean medicine. BJCST is also expected to have anti-obesity activities. In the present study, we examined whether BJCST modulate the production of inflammatory adipokines and the activations of the mitogen-activated protein kinases (MAPK) signaling pathway related to induce adipocyte inflammation to elucidate the effects and its mechanism of BJCST on lowering the content of inflammatory adipokines in 3T3-L1 adipocytes. As a result, BJCST suppressed the production of proinflammatory cytokines, tumor necrosis factor (TNF) $-{\alpha}$, interleukin (IL) $-1{\beta}$, IL-6, interferon (IFN) -${\gamma}$, granulocyte-macrophage colony-stimulating factor (GM-CSF), monocyte chemoattractant protein-1 (MCP-1), and the production of other inflammatory mediators, prostaglandin $E_2(PGE_2)$ and nitric oxide(NO)viadownregulationofcyclooxygenase-2(COX-2)andinducible NO synthase (iNOS) gene expressions. In addition, BJCST decreased the phosphorylation of MAPK that promotes the production of inflammatory adipokines in 3T3-L1 mature adipocytes. In conclusion, BJCST could regulate the production of inflammatory adipokines and MAPK signaling pathway related to induction of adipose inflammation.

• Journal of Life Science
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• v.30 no.10
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• pp.835-843
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• 2020

Obesity, the world's leading metabolic disease, is a serious health problem in both industrialized and developing countries. Natural substances are of great interest in preventative medicine, especially in the field of metabolic syndromes-from insulin resistance to obesity and diabetes. In the present study, we investigated the effect of A. pullulans SM-2001 Extract (Polycan^®) on the adipocyte differentiation of 3T3-L1 preadipocytes and the anti-obesity effect of 3T3-L1 adipocytes. Although β-glucan has been found to have health benefits in the regulation of the immune system and blood cholesterol levels, its role in obesity has not been fully investigated. Polycan^® suppressed lipid accumulation and glycerol-3-phosphate dehydrogenase (GPDH) activity without affecting cell viability in 3T3-L1 preadipocytes and adipocytes. Polycan^® also inhibited cellular lipid accumulation through down-regulation of transcription factors, such as PPARγ and C/EBPα, and induced dose-dependent phosphorylation of AMP-activated protein kinase (AMPK)-a cellular energy sensor-while the total AMPK protein content remained unchanged. Taken together, this shows that the activation of AMPK by Polycan^® in adipocytes plays a critical role in Polycan^®-induced inhibition of adipocyte differentiation. Our results show that Polycan^® has an anti-obesity action in vitro, suggesting a potential novel preventative agent for obesity and other metabolic diseases.

• Biomedical Science Letters
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• v.15 no.3
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• pp.179-185
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• 2009

In our previous report, we showed that $PPAR{\gamma}$ does not influence adipogenesis in females with functioning ovaries, indicating that $PPAR{\gamma}$ activity on adipogenesis is associated with sex-related factors. Among the sex-related factors, estrogen has been recognized as a major factor in inhibiting adiposgenesis in females. Thus, we hypothensized that $17{\beta}$-estradiol (E) inhibits 3T3-L1 cell adipogenesis by preventing $PPAR{\gamma}$ activity. E decreased triglyceirde accumulation in differentiated 3T3-L1 cells compared with control group. E also decreased the expression of $PPAR{\gamma}$ mRNA as well as $PPAR{\gamma}$ dependent adipocyte-specific genes, such as adipocyte fatty acid binding protein and tumor necrosis factor $\alpha$. In addition, E not only decreased luciferase reporter activity by $PPAR{\gamma}$, but also transfection of estrogen receptor $\alpha$ ($ER{\alpha}$) or $ER{\beta}$ led to decreases in $PPAR{\gamma}$ reporter gene activation. Moreover, E-activated ERs significantly decreased the luciferase reporter gene activation induced by $PPAR{\gamma}$ transfection, suggesting that estrogen-activated ERs inhibit $PPAR{\gamma}$-dependent transactivation. Accordingly, our results demonstrate that E inhibits the action of $PPAR{\gamma}$ on adipogenesis through E activated ER, providing evidence that lack of estrogen may potentiate $PPAR{\gamma}$ action on adipogenesis.

• Journal of Marine Bioscience and Biotechnology
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• v.15 no.2
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• pp.59-66
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• 2023

Dictyopteris divaricata, a type of marine brown algae, has been studied for its various biological properties, including anti-inflammatory, antidiabetic, and whitening effects. However, its potential antiobesity effects have not been extensively explored. This study aimed to examine the impact of D. divaricata ethanol extract (DDE) on adipocyte differentiation and adipogenesis using 3T3-L1 preadipocytes. Our results showed that when 3T3-L1 preadipocytes were treated with noncytotoxic concentrations of DDE there was a concentration-dependent decrease in fat accumulation rate and triglycerid production compared with the control. Furthermore, DDE significantly reduced the expression of transcription factors (PPARγ, C/EBPα, and SREBP-1) and fatty acid transport protein (FABP4), which are crucial for 3T3-L1 preadipocyte differentiation. These findings suggest that DDE may exhibit antiobesity effects by suppressing the expression of lipogenic transcription factors and fatty acid transport proteins. Therefore, DDE holds potential as a therapeutic agent for obesity.

• Korean Journal of Oriental Medicine
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• v.9 no.2
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• pp.45-54
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• 2003

Obesity is caused by unbalance of energy intake and expenditure, which results in extra accumulation of adipose tissue. Obesity is directly related to metabolic diseases such as diabetes, hyperlipidemia, fatty liver and so on. To investigate the anti-obesity effects of Scutellariae Radix, 70% EtOH extract and water extract of it were tested by in vitro and in vivo studies of fat accumulation. 3T3-L1 preadipocyte cell line was used in a in vitro study of fat accumulation. After 3T3-L1 cells were induced to differentiate into adipocytes, S. radix extract were added and fat accumulation was measured by oil red O staining. In vivo study showed that weight and epididymal/ retro-peritoneal adipose tissues were significantly reduced in mice fed Scutellariae Radix extract compared with control group. Especially, mice fed Scutellariae Radix extract showed reduced serum triglyceride and glucose levels. When adipose tissues were analyzed by microscope, mean adipocyte size was significantly reduced in Scutellariae Radix extract-fed mice. Therefore, this study showed inhibitory effects of Scutellariae Radix on in vitro and in vivo fat accumulation.

• Korean Journal of Acupuncture
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• v.32 no.3
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• pp.116-123
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• 2015

Objectives : The present study was designed to investigate effects and molecular mechanisms of Atractylodes macrocephala Koidzumi extracts(AMK) on the improvement of adipocyte dysfunction induced by TNF-${\alpha}$ in 3T3-L1 adipocytes. We examined whether AMK could directly influence the inflammation and insulin resistance in 3T3-L1 adipocytes. Methods : Potential roles of AMK in the lipolysis, production of inflammatory adipokines and ROS, expression and phosphorylation of ERK, JNK, and $I{\kappa}B{\alpha}$ protein, and expression of $PPAR{\gamma}$ and C/EBP${\alpha}$ were investigated in this study. Results : Our data demonstrated that TNF-${\alpha}$ significantly increased lipolysis, levels of MCP-1, IL-6, and ROS and phosphorylation of ERK, JNK, and $I{\kappa}B{\alpha}$ protein, while TNF-${\alpha}$ reduced the expression of $PPAR{\gamma}$ and C/EBP${\alpha}$ in adipocytes, suggesting that TNF-${\alpha}$ induced a condition with the occurrence of inflammation and insulin resistance. Those alterations induced by TNF-${\alpha}$ were prevented by the treatment of AMK. AMK down-regulated the phosphorylation of ERK, JNK, and $I{\kappa}B{\alpha}$ protein and up-regulated the expression of $PPAR{\gamma}$ and C/EBP${\alpha}$ on TNF-${\alpha}$-induced inflammation and insulin resistance. Conclusions : Thus, our results indicate that AMK can be used to prevent from the TNF-${\alpha}$-induced adipocyte dysfunction through MAPK, $NF{\kappa}B$ and $PPAR{\gamma}$ pathways.