• Bulletin of the Korean Chemical Society
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• 제31권9호
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• pp.2627-2632
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• 2010

Hormone sensitive lipase (HSL) plays a major role in energy homeostasis and lipid metabolism. Several crystal structures of HSL-homolog proteins have been identified, which has led to a better understanding of its molecular function. HSL-homolog proteins exit as both monomer and dimer, but the biochemical and structural basis for such oligomeric states has not been successfully elucidated. Therefore, we determined the crystal structure of HSL-homolog protein EstE7 from a metagenome library at $2.2\;{\AA}$ resolution and characterized the oligomeric states of EstE7 both structurally and biochemically. EstE7 protein prefers the dimeric state in solution, which is supported by its higher enzymatic activity in the dimeric state. In the crystal form, EstE7 protein shows two-types of dimeric interface. Specifically, dimerization via the external ${beta}8$-strand occurred through tight association between two pseudosymmetric folds via salt bridges, hydrogen bonds and van der Waals interactions. This dimer formation was similar to that of other HSL-homolog protein structures such as AFEST, BEFA, and EstE1. We anticipate that our results will provide insight into the oligomeric state of HSL-homolog proteins.

• 한국식품과학회지
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• 제52권3호
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• pp.255-262
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• 2020

Obesity is a critical health issue in Korea, where half of all adults are overweight and a third obese. Aronia melanocarpa -rich in flavonoids and phenolics- with antioxidant and anti-inflammatory activities, could have anti-obesity activity and reduce body fat mass by upregulating lipolysis and β-oxidation in obese mice. Male C57BL/6J mice (n=12) were assigned into four groups: normal chow (18% kcal from fat); high-fat diet control (HFD, 45% kcal from fat); HFD+A. melanocarpa (200 mg/kg diet); HFD+Xenical (500 mg/kg diet, positive control). Antioxidant capacity of A. melanocarpa was established in vitro and in vivo. Weight loss was induced as decreased adiposity and lowered respiratory quotient at rest suggested oxidation of stored fat. Adiposity reduction, accompanied with elevated fat utilization, was owing to enhanced activity of hormone-sensitive lipase. Thus, A. melanocarpa lowered adiposity by enhancing lipolysis and utilization of fatty acids in visceral fat.

• 대한약리학회지
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• 제10권1호
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• pp.41-45
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• 1974

Krebs-Ringer bicarbonate 완충용액(pH 7.4, 4%(w/v) bovine serum albumin 함유)에 백서부고환지방조직을 incubation 하면서 FFA 유리에 대한 인삼 saponin의 작용을 관찰한 saponin 농도 1mg/ml에서 FFA의 유리가 현저히 증가되었으며 0.01mg/ml에서는 오히려 감소하였다. Epinephrine으로 전처치하여 hormone-sensitive lipase system을 활성화시킨 백서부고환지방조직 homogenate에서는 $0.1{\sim}1mg/ml$의 인삼 saponin에 의하여 FFA 동원이 현저히 증가하였으며 0.01mg/ml에서는 역시 감소하였다. 유효농도에서의 인삼 saponin은 epinephrine에 의한 지방조직으로 부터의 FFA 동원에 아마도 협동적으로 작용할 것으로 사료된다.

• Journal of Microbiology and Biotechnology
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• 제19권9호
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• pp.888-897
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• 2009

Lipase diversity in glacier soil was assessed by culture-independent metagenomic DNA fragment screening and confirmed by cell culture experiments. A set of degenerate PCR primers specific for lipases of the hormone-sensitive lipase family was designed based on conserved motifs and used to directly PCR amplify metagenomic DNA from glacier soil. These products were used to construct a lipase fragment clone library. Among the 300 clones sequenced for the analysis, 201 clones encoding partiallipases shared 51-82% identity to known lipases in GenBank. Based on a phylogenetic analysis, five divergent clusters were established, one of which may represent a previously unidentified lipase subfamily. In the culture study, 11 lipase-producing bacteria were selectively isolated and characterized by 16S rDNA sequences. Using the above-mentioned degenerate primers, seven lipase gene fragments were cloned, but not all of them could be accounted for by the clones in the library. Two full-length lipase genes obtained by TAIL-PCR were expressed in Pichia pastoris and characterized. Both were authentic lipases with optimum temperatures of ${\le}40^{\circ}C$. Our study indicates the abundant lipase diversity in glacier soil as well as the feasibility of sequence-based screening in discovering new lipase genes from complex environmental samples.

• 생명과학회지
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• 제22권8호
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• pp.1052-1056
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• 2012

미역(Undaria pinnatifada)은 낮은 칼로리 및 요오드의 원료로써 천연체중조절식품으로 알려져 있다. 미역이 체중조절식품으로 알려져 있음에도 불구하고, 지방세포 분화 및 지방축적에 관한 저해 기작은 연구가 미비하다. 본 연구에서는 3T3-L1에서 지방세포로 분화가 일어나는 단계에서 미역에탄올추출물의 효과 및 기작을 확인하였다. 미역에탄올추출물의 독성과 지방축적저해효과는 MTT assay, Oil red O staining, RT-PCR과 western blot으로 분석하였다. 미역에탄올추출물은 50 ${\mu}g/ml$의 농도에서 독성을 띄지 않았다. 3T3-L1의 분화 및 지방세포에서 triglyceride축적과정동안 50 ${\mu}g/ml$의 미역에탄올추출물을 처리하였으며, 미역에탄올추출물은 지방세포에서 triglyceride의 축적을 40% 감소시켰다. 지방세포 특이적 단백질인 Peroxisome proliferator activated receptor ${\gamma}$ ($PPAR{\gamma}$), leptin과 Hormone sensitive lipase (HSL)의 발현은 RT-PCR과 western blot으로 확인하였다. $PPAR{\gamma}$의 과발현은 지방세포의 분화를 촉진시킨다. 또한 지방세포 크기의 증가와 세포 내 triglyceride의 함량에 따라 leptin은 세포 외로 분비된다. 그러므로 $PPAR{\gamma}$와 leptin은 비만의 지표로 사용된다. 첨가한 미역에탄올추출물의 농도가 높아질수록 $PPAR{\gamma}$와 leptin의 발현이 억제되었다. 이상의 결과를 통하여, 미역의 에탄올 추출물은 지방전구세포의 분화를 억제시키며, 지방세포 내 triglyceride의 축적을 저해하는 것으로 판단된다.

• 동의생리병리학회지
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• 제26권4호
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• pp.455-461
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• 2012

Obesity is associated with numerous diseases such as type 2 diabetes, hypertension and cancer. Inhibition of adipogenesis is a effectite strategy to anti-obesity. In this study, Galla Chinenisis extract (GCE) inhibited adipocyte differentiation in OP9 cells. There was no cytotoxicity when cells were treated with GCE in designated time intervals, unaffected by concentration. In this cell model, increases in fat storage were inhibited by 2 days treatment with various concentration of GCE, visualized by Oil red-O, BODIPY and DAPI staining. To understand the underlying mechanism at the molecular level, the effects of GCE were examined on the expression of the genes involved in adipogenesis by real-time PCR. In the progress of adipocyte differentiation with GCE-treated, the mRNA level of adipogenic genes such as peroxisome-proliferator-activated receptors gamma ($PPAR{\gamma}$), computer-assisted axial tomography/enhancer binding protein-alpha ($C/EBP{\alpha}$) were decreased. Also, GCE treatment inhibited increase of mRNA expression, which is adipogenic factor such as fatty acid synthase (FAS), hormone-sensitve lipase (HSL), lipoprotein lipase (LPL), and adipocyte-specific lipid binding protein (aP2). Therefore, the result of this study suggest that Galla Chinenisis extract can prevent adipocyte differentiation and GCE may have a great potential as a novel anti-adipogenic agent.

• Food Science and Biotechnology
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• 제18권6호
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• pp.1500-1504
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• 2009

Effects of methanol extract from turmeric (Curcuma longa L.) (CME) on underlying mechanisms of lipolysis were investigated in 3T3-L1 adipocytes. Compared to the control, lipid accumulation with 72 hr treatment of CME at the concentration $20\;{\mu}g/mL$ was significantly decreased by 19.9% as quantified by Oil red O dye. Intracellular triglyceride (TG) content was also lowered by 19.3%. To determine the mechanism for TG content reduction, glycerol release level was measured. Incubation of 3T3-L1 adipocytes with 15 and $20\;{\mu}g/mL$ of CME significantly elevated the level of free glycerol released into the cultured medium by 20.4 and 28.6%, respectively. In subsequent measurements using quantitative real-time polymerase chain reaction (PCR), mRNA levels of hormone-sensitive lipase (HSL) and adipose triglyceride lipase (ATGL) were significantly increased by 21.2 and 24.9%, respectively, at the concentration $20\;{\mu}g/mL$. Results indicated that CME stimulated lipolysis through induction of HSL and ATGL mRNA expressions, resulting in increased glycerol release.

• Nutrition Research and Practice
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• 제9권6호
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• pp.606-612
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• 2015

BACKGROUND/OBJECTIVES: Several medicinal properties of Smilax china L. have been studied including antioxidant, anti-inflammatory, and anti-cancer effects. However, the antiobesity activity and mechanism by which the water-soluble fraction of this plant mediates its effects are not clear. In the present study, we investigated the lipolytic actions of the water-soluble fraction of Smilax china L. leaf ethanol extract (wsSCLE) in 3T3-L1 adipocytes. MATERIALS/METHODS: The wsSCLE was identified by measuring the total polyphenol and flavonoid content. The wsSCLE was evaluated for its effects on cell viability, lipid accumulation, glycerol, and cyclic adenosine monophosphate (cAMP) contents. In addition, western blot analysis was used to evaluate the effects on protein kinase A (PKA), PKA substrates (PKAs), and hormone-sensitive lipase (HSL). For the lipid accumulation assay, 3T3-L1 adipocytes were treated with different doses of wsSCLE for 9 days starting 2 days post-confluence. In other cell experiments, mature 3T3-L1 adipocytes were treated for 24 h with wsSCLE. RESULTS: Results showed that treatment with wsSCLE at 0.05, 0.1, and 0.25 mg/mL had no effect on cell morphology and viability. Without evidence of toxicity, wsSCLE treatment decreased lipid accumulation compared with the untreated adipocyte controls as shown by the lower absorbance of Oil Red O stain. The wsSCLE significantly induced glycerol release and cAMP production in mature 3T3-L1 cells. Furthermore, protein levels of phosphorylated PKA, PKAs, and HSL significantly increased following wsSCLE treatment. CONCLUSION: These results demonstrate that the potential antiobesity activity of wsSCLE is at least in part due to the stimulation of cAMP-PKA-HSL signaling. In addition, the wsSCLE-stimulated lipolysis induced by the signaling is mediated via activation of the ${\beta}$-adrenergic receptor.

• 대한화장품학회지
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• 제38권2호
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• pp.189-195
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• 2012

Slim813은 2-사이클로펜텐-1-온 옥심 유도체로서 다양한 염증성 자극원에 대한 TNF 생성을 억제하는 항 자극 및 UV에 의한 MMP1 억제를 통한 항 노화 효능을 갖는 물질이다. 본 연구를 통하여 이와 같은 효능 외에도 완전히 분화된 지방 세포에서 cAMP (cyclic adenosine monophosphate) 생성 촉진을 통한 HSL (hormone sensitive lipase) 활성을 증대시킴으로써 지방분해를 증가시킴을 확인하였다. 또한 Slim813을 사람의 팔과 허벅지 부위에 2주간 도포하였을 때 지방의 두께 감소를 유발하는 것으로 나타나 체내 피하 지방을 분해하는 효능을 갖는 것으로 사료된다.

• Animal Bioscience
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• 제35권9호
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• pp.1444-1453
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• 2022

Objective: Acetate plays an important role in host lipid metabolism. However, the network of acetate-regulated lipid metabolism remains unclear. Previous studies show that mitogen-activated protein kinases (MAPKs) and mechanistic target of rapamycin (mTOR) play a crucial role in lipid metabolism. We hypothesize that acetate could affect MAPKs and/or mTOR signaling and then regulate lipid metabolism. The present study investigated whether any cross talk occurs among MAPKs, mTOR and acetate in regulating lipid metabolism. Methods: The ceramide C6 (an extracellular signaling-regulated kinases 1 and 2 [ERK1/2] activator) and MHY1485 (a mTOR activator) were used to treat rabbit adipose-derived stem cells (ADSCs) with or without acetate, respectively. Results: It indicated that acetate (9 mM) treatment for 48 h decreased the lipid deposition in rabbit ADSCs. Acetate treatment decreased significantly phosphorylated protein levels of ERK1/2 and mTOR but significantly increased mRNA level of hormone-sensitive lipase (HSL). Acetate treatment did not significantly alter the phosphorylated protein level of p38 MAPK and c-Jun aminoterminal kinase (JNK). Activation of ERK1/2 and mTOR by respective addition in media with ceramide C6 and MHY1485 significantly attenuated decreased lipid deposition and increased HSL expression caused by acetate. Conclusion: Our results suggest that ERK1/2 and mTOR signaling pathways are associated with acetate regulated HSL gene expression and lipid deposition.