• Asian-Australasian Journal of Animal Sciences
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• 제25권9호
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• pp.1300-1308
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• 2012

The 5'-adenosine monophosphate-activated protein kinase (AMPK) is a key part of a kinase-signaling cascade that acts to maintain energy homeostasis. The objective of this experiment was to investigate the possible effects of fasting and refeeding on the gene expression of hypothalamic AMPK, some appetitive regulating peptides and lipid metabolism related enzymes. Seven-day-old male broiler (Arbor Acres) chicks were allocated into three equal treatments: fed ad libitum (control); fasted for 24 h; fasted for 24 h and then refed for 24 h. Compared with the control, the hypothalamic gene expression of $AMPK{\alpha}2$, $AMPK{\beta}1$, $AMPK{\beta}2$, $AMPK{\gamma}1$, Ste20-related adaptor protein ${\beta}$ ($STRAD{\beta}$), mouse protein $25{\alpha}$ ($MO25{\alpha}$) and agouti-related peptide (AgRP) were increased after fasting for 24 h. No significant difference among treatments was observed in mRNA levels of $AMPK{\alpha}1$, $AMPK{\gamma}2$, LKB1 and neuropeptide Y (NPY). However, the expression of $MO25{\beta}$, pro-opiomelanocortin (POMC), corticotropin-releasing hormone (CRH), ghrelin, fatty acid synthase (FAS), acetyl-CoA carboxylase ${\alpha}$ ($ACC{\alpha}$), carnitine palmitoyltransferase 1 (CPT-1) and sterol regulatory element binding protein-1 (SREBP-1) were significantly decreased. The present results indicated that 24 h fasting altered gene expression of AMPK subunits, appetite regulation peptides and lipometabolism related factors in chick's hypothalamus; the hypothalamic FAS signaling pathway might be involved in the AMPK regulated energy homeostasis and/or appetite regulation in poultry.

• 생명과학회지
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• 제21권2호
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• pp.202-210
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• 2011

지방세포 분화 과정 중에 key regulator로서 기능을 하는 여러 전사조절인자(PPAR$\gamma$, C/EBP$\alpha$, SREBP, LXR)가 동정되었고, 주로 DNA 복제나 DNA 수선 단계에서 중요한 역할을 한다고 밝혀진 복제 조절인자인 RFC140이 지방세포 분화에도 중요한 인자임이 밝혀졌다. 이 연구에서 우리는 RFC140과 RFC38에 대한 발현조절을 확인하였으며, RFC140이 PPAR$\gamma$와의 단백질-단백질 결합을 통하여 PPAR$\gamma$에 의해 조절되는 유전자의 발현을 증가시킴을 확인하였다. 이러한 결과들은 특이적인 지방세포 전사인자에 의해 발현이 조절되는 RFC140과 RFC38이 지방세포의 분화과정에 필수적임을 제시한다.

• 동의생리병리학회지
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• 제36권5호
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• pp.181-186
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• 2022

Atractylodes macrocephala (AM) and Amomum villosum (AV) are the most common herbs in Korean Medicine to treat digestive diseases. In this study, we investigated the cholesterol lowering effects of mixtures of AM and AV extracts on high cholesterol diet (HCD) induced dyslipidemia mouse model. We classified animals into six different groups; Group 1: Normal diet, Group 2: HCD, Group 3: AV extracts : AM extracts (1:1) (200 mg/kg) + HCD, Group 4: AV extracts : AM extracts (1:2) (200 mg/kg) + HCD, Group 5: AV extracts : AM extracts (1:3) (200 mg/kg) + HCD, Group 6: Simvastatin 40 mg/kg + HCD. After 4 weeks of oral administration of respective drugs, we checked body, liver and epididymal fatweights along with liver and serum triacylglyceride (TG) concentration, total and low density lipoprotein (LDL) cholesterol in serum. Moreover, 3-hydroxy-3-methylglutaryl-CoA (HMG-CoA) reductase (HMGCR), LDL receptor (LDLR), and sterol regulatory element-binding protein 2 (SREBP2) were detected by RT PCR or western blot analysis. The overall results showed that mixtures of AM and AV extracts inhibited HCD-induced increases of total cholesterol and LDL cholesterol in serum. Those effects seem to be caused by AM and AV extracts through inhibition of HMGCR expression. And thus blood cholesterol is induced into the liver by increasing LDLR expression, which is regulated by SREBP2 transcrption factor. The cholesterol lowering effects and mechanism of mixtures of AM and AV extracts was similar to the statin. We have identified the potential mixtures of AM and AV extracts as a new treatment for dyslipidemia.

• 대한의생명과학회지
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• 제18권3호
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• pp.227-236
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• 2012

Previous study showed that swimming improved obesity but was not through $PPAR{\alpha}$ activation in liver and skeletal muscle in high fat diet-fed female mice with functioning ovaries as an animal model of obese premenopausal women. Thus, this study was aimed at investigation of the effects of swimming on the promotion of health and its molecular mechanism in adipose tissue of high fat diet-fed female mice. Eight-week-old female C57BL/6J mice were randomly divided into two groups (a non-swim control group and a swim group, n=8/group). Mice in the swim group swam for 2 h daily for 6 weeks in water bath with temperature of $35{\pm}1^{\circ}C$. All the animals received high fat diet (45% kcal fat) for 6 weeks. Reverse transcription-polymerase chain reaction was used to elucidate the molecular mechanism. Female mice subjected to swimming had significantly decreased body weight gain and white adipose tissue mass compared with the female control mice. Histological studies illustrated that swimming decreases the hepatic lipid accumulation. As expected, swimming did not affect the expression of mRNA levels of peroxisome proliferator-activated receptor (PPAR) ${\alpha}$ and $PPAR{\alpha}$ target genes responsible for mitochondrial fatty acid ${\beta}$-oxidation, such as carnitine palmitoyltransgerase-1 and medium chain acyl-CoA dehydrogenase in the white adipose tissue. However, mice that underwent 6-weeks of swimming exercise had decreased the mRNA expression of lipogenic genes, such as sterol regulatory element-binding proteins-1C and fatty acid synthase in comparison to sedentary control mice, with decreased $PPAR{\gamma}$ target genes involved in adipocyte-specific marker genes, such as adipocyte fatty acid binding protein and leptin in the white adipose tissue. These results suggest that swimming can effectively prevent obesity induced by high fat diet-fed, in part through down-regulation of adipogenesis and lipogenesis in white adipose tissue of female obese mice. Moreover, these results suggest that swimming maybe contributing the promotion of health through regulation of adipogenesis and lipogenesis in overweight premenopausal women.

• BMB Reports
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• 제57권2호
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• pp.92-97
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• 2024

Elevated blood glucose is associated with an increased risk of atherosclerosis. Data from the current study showed that glucosamine (GlcN), a normal glucose metabolite of the hexosamine biosynthetic pathway (HBP), promoted lipid accumulation in RAW264.7 macrophage cells. Oleic acid- and lipopolysaccharide (LPS)-induced lipid accumulation was further enhanced by GlcN in RAW264.7 cells, although there was no a significant change in the rate of fatty acid uptake. GlcN increased acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), scavenger receptor class A, liver X receptor, and sterol regulatory element-binding protein-1c (SREBP-1c) mRNA expression, and; conversely, suppressed ATP-binding cassette transporter A1 (ABCA-1) and ABCG-1 expression. Additionally, GlcN promoted O-GlcNAcylation of nuclear SREBP-1 but did not affect its DNA binding activity. GlcN stimulated phosphorylation of mammalian target of rapamycin (mTOR) and S6 kinase. Rapamycin, a mTOR-specific inhibitor, suppressed GlcN-induced lipid accumulation in RAW264.7 cells. The GlcN-mediated increase in ACC and FAS mRNA was suppressed, while the decrease in ABCA-1 and ABCG-1 by GlcN was not significantly altered by rapamycin. Together, our results highlight the importance of the mTOR signaling pathway in GlcN-induced macrophage lipid accumulation and further support a potential link between mTOR and HBP signaling in lipogenesis.

• 대한의생명과학회지
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• 제18권3호
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• pp.291-298
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• 2012

The antiobesity effect of the mixture of black garlic and Garsinia cambogia extracts (BGG) was investigated by measuring the Oil red O staining and the expressions of adipogenic genes during preadipocyte differentiation by real-time PCR in the 3T3-L1 adipocytes. BGG reduced contents of Oil red O dye in the 3T3-L1 adipocytes. mRNA expression levels of SREBP1c, C/EBPa, aP2/FABP4, and $PPAR{\gamma}$ which are adipogenic transcription factor, in cells treated with BGG were also significantly down regulated. Also, the phosphorylation of AMP-activated protein kinase (AMPK) in L6 cells was more increased by BGG. These results indicate that BGG seems to be more attractive compound for application of industry than individual extracts such as black garlic and Garsinia cambogia, considering it has two effects not only inhibit the preadipocyte differentiation but also activate the phosphorylation of AMPK unlike other two compound.

• Molecules and Cells
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• 제44권2호
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• pp.116-125
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• 2021

Cardiovascular diseases (CVDs) are the most common cause of death in patients with nonalcoholic fatty liver disease (NAFLD) and dyslipidemia is considered at least partially responsible for the increased CVD risk in NAFLD patients. The aim of the present study is to understand how hepatic de novo lipogenesis influences hepatic cholesterol content as well as its effects on the plasma lipid levels. Hepatic lipogenesis was induced in mice by feeding a fat-free/high-sucrose (FF/HS) diet and the metabolic pathways associated with cholesterol were then analyzed. Both liver triglyceride and cholesterol contents were significantly increased in mice fed an FF/HS diet. Activation of fatty acid synthesis driven by the activation of sterol regulatory element binding protein (SREBP)-1c resulted in the increased liver triglycerides. The augmented cholesterol content in the liver could not be explained by an increased cholesterol synthesis, which was decreased by the FF/HS diet. HMG-CoA reductase protein level was decreased in mice fed an FF/HS diet. We found that the liver retained more cholesterol through a reduced excretion of bile acids, a reduced fecal cholesterol excretion, and an increased cholesterol uptake from plasma lipoproteins. Very low-density lipoproteintriglyceride and -cholesterol secretion were increased in mice fed an FF/HS diet, which led to hypertriglyceridemia and hypercholesterolemia in Ldlr-/- mice, a model that exhibits a more human like lipoprotein profile. These findings suggest that dietary cholesterol intake and cholesterol synthesis rates cannot only explain the hypercholesterolemia associated with NAFLD, and that the control of fatty acid synthesis should be considered for the management of dyslipidemia.

• 한국식품과학회지
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• 제53권2호
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• pp.149-153
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• 2021

본 연구는 감귤 가공공정 중에 발생하는 가공부산물인 감귤피의 산업적 이용성 및 유용성을 증대시키고자 효소적 추출법을 적용하여 추출물을 제조하고 항비만 활성을 측정하였다. 감귤피 효소적 추출물(MPCE)의 폴리페놀 함량은 이전의 연구에서 보고한 유기용매 추출물보다 높은 함량을 나타내었다. MPCE의 항비만 활성을 알아보기 위해 지방세포 분화억제에 미치는 영향을 확인한 결과 MPCE는 농도 의존적으로 지방세포의 분화 및 지방축적을 감소시켰으며 이는 세포독성에 의한 것이 아님을 세포생존율 측정을 통해 확인하였다. 또한 MPCE는 adipogenesis 관련 전사인자인 C/EBPα, SREBP-1, PPARγ, FABP4의 단백질 발현을 감소시켰다. 이러한 결과들을 통해 MPCE는 adipogenesis 관련 전사인자의 단백질 발현 억제하여 지방세포의 분화 및 지방축적을 억제하였으며, 이를 통해 항비만 효과를 나타낸다는 것을 확인하였다. 따라서 MPCE는 비만 예방 효능을 가진 기능성 식품 소재로서의 활용 가치가 있는 것으로 판단되며, 보다 명확한 항비만 효능을 확인하기 위해 추후 동물 실험 등에 대한 연구가 필요할 것으로 생각된다.

• 한국식품과학회지
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• 제47권1호
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• pp.111-118
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• 2015

본 연구는 항비만 소재로 연구된 도라지와 울금 소재를 대상으로 발효 전과 후 3T3-L1 지방세포의 분화 억제효능을 확인하고자 하였다. 그 결과 발효 전 도라지와 울금은 3T3-L1 세포의 분화에 영향을 미치지 못하는 것을 확인할 수 있었다. Apsergillus oryzae 발효를 통해 만들어진 소재들은 도라지 발효물의 플라보노이드 증가를 제외하면 모든 소재에서 폴리페놀과 플라보노이드의 함량 및 항산화 활성이 감소하는 것을 확인할 수 있었다. 그러나 발효 전과 다르게 발효 후 도라지, 울금 및 도라지와 울금 혼합물의 발효물에서 3T3-L1 세포의 분화억제능이 oil red O 염색법을 통해 관찰되었으며, mRNA 발현 확인을 통해 SREBP-1c와 $PPAR{\gamma}$의 발현을 억제하여 분화를 억제할 수 있음을 확인하였다. 이는 Apsergillus oryzae 발효과정이 도라지와 울금의 항비만효과를 개선할 수 있으며, 발효과정을 통해 새로운 항비만 유효성분이 생성되었음을 예측할 수 있었다. 본 연구결과를 통해 Apsergillus oryzae 발효공정이 도라지와 울금의 기능을 향상시켜 우수한 기능성 제품의 개발에 유용하게 활용될 수 있음을 확인할 수 있었으며, 개발공정의 기초자료를 제공할 것으로 사료된다.

• 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.