• Nutrition Research and Practice
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• 제15권5호
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• pp.568-578
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• 2021

BACKGROUND/OBJECTIVES: Psidium guajava L. (guava) leaves have been shown to exhibit hypoglycemic and antidiabetic effects in rodents. This study investigated the effects of guava leaf extract on adipogenesis, glucose uptake, and lipolysis of adipocytes to examine whether the antidiabetic properties are mediated through direct effects on adipocytes. MATERIALS/METHODS: 3T3-L1 cells were treated with 25, 50, 100 ㎍/mL of methanol extract from guava leaf extract (GLE) or 0.1% dimethyl sulfoxide as a control. Lipid accumulation was evaluated with Oil Red O Staining and AdipoRed assay. Immunoblotting was performed to measure the expression of adipogenic transcription factors, fatty acid synthase (FAS), and AMP-activated protein kinase (AMPK). Glucose uptake under basal or insulin-stimulated condition was measured using a glucose analog 2-[N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl) amino]-2-deoxy-D-glucose. Lipolysis from fully differentiated adipocytes was measured by free fatty acids release into the culture medium in the presence or absence of epinephrine. RESULTS: Oil Red O staining and AdipoRed assay have shown that GLE treatment reduced lipid accumulation during adipocyte differentiation. Mitotic clonal expansion, an early essential event for adipocyte differentiation, was inhibited by GLE treatment. GLE inhibited the expression of transcription factors involved in adipocyte differentiation, such as peroxisome proliferator-activated receptor 𝛄 (PPAR𝛄), CCAAT/enhancer-binding protein α (C/EBPα), and sterol regulatory element-binding protein-1c (SREBP-1c). FAS expression was also decreased while the phosphorylation of AMPK was increased by GLE treatment. In addition, GLE increased insulin-induced glucose uptake into adipocytes. In lipid-filled mature adipocytes, GLE enhanced epinephrine-induced lipolysis but reduced basal lipolysis dose-dependently. CONCLUSIONS: The results show that GLE inhibits adipogenesis and improves adipocyte function by reducing basal lipolysis and increasing insulin-stimulated glucose uptake in adipocytes, which can be partly associated with antidiabetic effects of guava leaves.

• Journal of Animal Science and Technology
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• 제62권6호
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• pp.854-863
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• 2020

This study was aimed to investigate the inhibitory effects of Porphyra dentata (P. dentata) extract on the adipogenesis of 3T3-L1 cells and evaluate its anti-obesity effect. The proliferation of 3T3-L1 cells and differentiation of adipocytes under treatment of P. dentata extract was examined by measuring the cell viability using alamarBlue assay and lipid droplets by Oil Red O staining. Results showed that P. dentata extract has no cytotoxicity effect and lipid droplets formation decreased in a concentration-dependent manner in 3T3-L1 cells. It has been confirmed that transcription factors affecting lipid accumulation and anti-adipogenic effects during cell differentiation are linked to P. dentata extract. We observed that P. dentata shows lowering the mRNA expression of peroxisome proliferator-activated receptor γ2 (PPARγ2), CCAAT/enhancer binding protein α (C/EBPα) that adipogenesis-associated key transcription factors and inhibiting adipogenesis in the early stages of differentiation. Treating the cells with P. dentata did not only suppressed PPARγ2 and C/EBPα but also significantly decreased the mRNA expression of adiponectin, Leptin, fatty acid synthase, adipocyte protein 2, and Acetyl-coA carboxylase 1. Overall, the P. dentata extract demonstrated inhibitory property in adipogenesis, which has a potential effect in anti-obesity in 3T3-L1 cells.

• Nutrition Research and Practice
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• 제9권6호
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• pp.592-598
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• 2015

BACKGROUND/OBJECTIVES: Increased mass of adipose tissue in obese persons is caused by excessive adipogenesis, which is elaborately controlled by an array of transcription factors. Inhibition of adipogenesis by diverse plant-derived substances has been explored. The aim of the current study was to examine the effects of the aqueous methanol extract of laver (Porphyra yezoensis) on adipogenesis and apoptosis in 3T3-L1 adipocytes and to investigate the mechanism underlying the effect of the laver extract. MATERIALS/METHODS: 3T3-L1 cells were treated with various concentrations of laver extract in differentiation medium. Lipid accumulation, expression of adipogenic proteins, including CCAAT enhancer-binding protein ${\alpha}$, peroxisome proliferator-activated receptor ${\gamma}$, fatty acid binding protein 4, and fatty acid synthase, cell viability, apoptosis, and the total content and the ratio of reduced to oxidized forms of glutathione (GSH/GSSG) were analyzed. RESULTS: Treatment with laver extract resulted in a significant decrease in lipid accumulation in 3T3-L1 adipocytes, which showed correlation with a reduction in expression of adipogenic proteins. Treatment with laver extract also resulted in a decrease in the viability of preadipocytes and an increase in the apoptosis of mature adipocytes. Treatment with laver extract led to exacerbated depletion of cellular glutathione and abolished the transient increase in GSH/GSSG ratio during adipogenesis in 3T3-L1 adipocytes. CONCLUSION: Results of our study demonstrated that treatment with the laver extract caused inhibition of adipogenesis, a decrease in proliferation of preadipocytes, and an increase in the apoptosis of mature adipocytes. It appears that these effects were caused by increasing oxidative stress, as demonstrated by the depletion and oxidation of the cellular glutathione pool in the extract-treated adipocytes. Our results suggest that a prooxidant role of laver extract is associated with its antiadipogenic and proapoptotic effects.

• Journal of Microbiology and Biotechnology
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• 제22권6호
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• pp.806-813
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• 2012

Adipocyte differentiation is strongly associated with obesity, which causes metabolic disorders. In this study, we investigated the inhibitory effects of widdrol on 3T3-L1 preadipocyte growth and differentiation. Widdrol decreased lipid droplet accumulation and down-regulated adipogenic transcription factors such as C/$EBP{\alpha}$, C/$EBP{\beta}$, and $PPAR{\gamma}$. Widdrol blocked preadipocyte proliferation and differentiation through the inhibition of mitotic clonal expansion, which was accompanied by the failure of degradation of p21, a cyclin-dependent kinase inhibitor. Cell-cycle analysis clearly indicated that widdrol actively induces cell-cycle arrest at the G1-S phage transition, causing cells to remain in the preadipocyte state. Moreover, widdrol increased p21 expression and inhibited Rb phosphorylation in preadipocyte incubated in a hormone medium. Therefore, these findings clearly suggest that widdrol blocks preadipocyte growth and differentiation through the inhibition of mitotic clonal expansion by p21-and Rb-dependent G1 arrest and can be developed as a potent anti-adipogenic agent for reducing obesity.

• Ocean and Polar Research
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• 제44권1호
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• pp.29-38
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• 2022

Halophytes are plants that live in harsh environments in coastal regions and are known for their diverse chemical compositions. Limonium tetragonum, a halophyte endemic to Korean shores, is known for its bioactive compounds and is utilized in folk medicine. In this study L. tetragonum extract (LHE) was used to determine and evaluate its anti-osteoporotic properties. Pre-adipocyte and pre-osteoblasts were induced to differentiate along with LHE treatment, and their differentiation was evaluated using differentiation markers. LHE treatment decreased lipid accumulation in 3T3-L1 preadipocytes during adipogenesis. Results indicated that the LHE treatment also decreased the levels of key adipogenic transcription factors: PPARγ, SREBP1c, and C/EBPα. Enhancing osteoblastogenesis by LHE treatment was confirmed in osteoblastogenesis-induced MC3T3-E1 pre-osteoblasts. Cells treated with LHE resulted in increased calcification and alkaline phosphatase (ALP) activity compared with osteoblasts without LHE treatment. Pro-osteogenic and anti-adipogenic effects were also confirmed in D1 murine mesenchymal stromal cells which are capable of differentiation into both adipocytes and osteoblasts. LHE hindered adipogenesis and enhanced osteoblastogenesis in D1 MSCs in a similar fashion. In conclusion, L. tetragonum is believed to possess the potential to be utilized as a nutraceutical ingredient against osteoporotic conditions.

• 생명과학회지
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• 제29권4호
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• pp.447-454
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• 2019

비만은 에너지의 불균형으로 인하여 체내 지방조직에 지방이 축적되는 대사성질환으로 심혈관계 질환, 고혈압, 2형 당뇨, 고지혈증 및 각종 암의 발생 빈도를 증가시키는 요인이다. 지방의 축적은 지방전구세포가 지방세포로 분화하는 과정을 의미하는 adipogenesis라는 과정을 거쳐서 일어난다. 지방세포로의 분화는 다양한 호르몬과 전사인자들의 상호작용에 의해서 일어난다. 본 연구에서는 팔각회향이 항비만 소재로 활용 가능한지 확인하기 위해, 팔각회향 물 추출물을 분획하여 지방축적 억제 활성이 좋은 dichloromethane층을 선정하였다. 3T3-L1 지방전구세포가 성숙한 지방세포로 분화할 때 팔각회향 dichloromethane 층이 어떠한 기전으로 분화를 조절하는지 확인한 결과, 지방세포 분화에서 중요한 전사인자인 C/EBP family, $PPAR{\gamma}$의 발현이 억제되었고, 지방세포 최종 분화 마커로 알려져 있는 FAS 및 LPL의 발현 또한 감소되었다. 또한 G1기에서의 세포주기 정지를 통해 지방세포 분화 단계에서 필수적인 mitotic clonal expansion 단계를 억제한다는 결과를 얻었다. 이러한 연구 결과는 팔각회향이 항비만 효과를 가지는 천연물 소재로의 활용가능성을 보여주는 기초 자료가 될 것으로 사료된다.

• BMB Reports
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• 제49권2호
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• pp.111-115
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• 2016

Caffeine has been proposed to have several beneficial effects on obesity and its related metabolic diseases; however, how caffeine affects adipocyte differentiation has not been elucidated. In this study, we demonstrated that caffeine suppressed 3T3-L1 adipocyte differentiation and inhibited the expression of CCAAT/enhancer binding protein (C/EBP)α and peroxisome proliferator-activated receptor (PPAR)γ, two main adipogenic transcription factors. Anti-adipogenic markers, such as preadipocyte secreted factor (Pref)-1 and Krüppel-like factor 2, remained to be expressed in the presence of caffeine. Furthermore, 3T3-L1 cells failed to undergo typical mitotic clonal expansion in the presence of caffeine. Investigation of hormonal signaling revealed that caffeine inhibited the activation of AKT and glycogen synthase kinase (GSK) 3 in a dose-dependent manner, but not extracellular signal-regulated kinase (ERK). Our data show that caffeine is an anti-adipogenic bioactive compound involved in the modulation of mitotic clonal expansion during adipocyte differentiation through the AKT/GSK3 pathway.

• 생명과학회지
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• 제30권8호
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• pp.713-721
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• 2020

Adipogenesis의 연구는 인간의 지방생물학의 기초적인 분자기전을 이해하고, 비만, 당뇨 및 대사성 증후군의 발병기전을 밝히는데 필요하다. Adipogenesis의 많은 연구가 adipocytes 특이적인 핵심 전사인자인 PPARγ와 C/EBPα를 중심으로 하는 유전자 발현조절 및 세포 내 신호전달에 초점이 맞추어 활발하게 연구가 진행되었다. 그러나, 에피지놈 변형효소나 히스톤 돌연변이에 의한 에피지놈 관점에서 adipogenesis 연구는 미흡한 실정이다. 포유동물에서 히스톤 methylation은 유전자 발현에 대한 주요 후성유전적(epigenome) 변형 중 하나이며, 특히 히스톤 H3 lysine methylation은 다양한 조직 및 기관 발생과정과 세포 분화에 매우 중요한 히스톤 변형이다. 세포 특이적 enhancer는 adipogenesis에서 active enhancer 표지자인 H3K27ac와 함께 H3K4me1로 변형된다. MLL4는 Pparg 및 Cebpa 유전자 ehancers에서 중요한 adipogenic H3K4 mono-methyltransferase이다. 따라서 MLL4는 adipogenesis에 중요한 에피지놈 변형효소라고 할 수 있다. 유전자 발현 억제를 유발하는 대표적인 히스톤 변형인 H3K27me3은 Polycomb repressive complex 2의 효소활성 subunit인 Ezh2에 의해 매개된다. Wnt 유전자에서 Ezh2에 의한 H3K27me3 히스톤 methylation 변형은 adipogenesis를 증가시키는데, 이는 WNT 신호 전달이 adipogenesis의 억제 조절자로 알려져 있기 때문이다. 본 논문은 유전자 발현을 근본적으로 조절하는 히스톤 H3 methylation에 의한 후성 유전학적인 조절이 어떻게 adipogenesis를 조절하는지에 대해 요약한다.

• 한국융합학회논문지
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• 제10권3호
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• pp.127-133
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• 2019

본 연구는 3T3-L1 세포로 하늘타리(Trichosanthes kirilowii Maxim) 뿌리 에탄올 추출물(TKM)의 항비만 활성을 조사하였다. TKM 처리 한 3T3-L1 지방세포의 분화억제를 통한 지방생성 억제에 초점을 두었다. 세포독성을 나타내지 않는 100ug/ml 농도에서 TG 함량을 현저히 억제하고, 세포 초기분화 전사인자 $PPAR{\gamma}$, $C/EBP{\alpha}$, SREBP-1c의 발현 억제, 세포내 에너지 향상성 조절인자 pAMPK, 중성지방산의 합성분해 조절인자 pACC, CPT-1, 지방산 합성 효소(FAS) 발현 억제, 호르몬자극지방분해 효소(HSL) 활성화 등 지방합성 관련인자들의 발현 조절 효능이 있는 것으로 확인되었다. 이상의 결과로 TKM은 지방세포 분화와 지방대사 관련 인자들의 발현을 조절함으로써 지방 생성과 축적 저해 효능을 보여 항비만 융합치료제로의 가능성을 제시하였다.

• Journal of Applied Biological Chemistry
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• 제66권
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• pp.369-378
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• 2023

본 연구는 청가시덩굴 에탄올 추출물을 이용하여 3T3-L1 지방전구세포에서 지방세포를 통해 항비만 활성을 확인하고자 하였다. 청가시덩굴 에탄올 추출물에 의한 지방세포 분화 억제 활성 및 지방형성에 미치는 영향을 확인하기 위해 3T3-L1 지방전구세포에 분화를 유도하여 추출물을 농도별로 처리하였다. 그 결과 청가시덩굴 에탄올 추출물 처리 시 지방세포 분화 및 세포 내 중성지방 축적 수준이 농도 의존적으로 감소하였다. 이러한 지방형성 억제 효과가 어떠한 작용기전에 의해 유도되는지 확인하기 위해 청가시덩굴 추출물과 그로부터 분리된 화합물인 acertannin을 이용하여 지방세포 분화 조절인자들의 유전자 및 단백질 발현을 확인하고자 하였다. 청가시덩굴 에탄올 추출물은 지방형성 및 지방산 합성 관련 인자인 PPARγ, C/EBPα, ADD1/SREBP1c, FAS, aP2의 유전자 및 단백질 발현을 유의적으로 억제하였다. 이러한 결과들로 볼 때 청가시덩굴 에탄올 추출물은 지방세포분화 및 지방축적 인자의 조절 효과를 나타냄으로써 산림자원의 항비만 및 고지혈증 개선 기능성 소재로의 활용 가능성을 확인하였다.