• Molecules and Cells
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• 제43권1호
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• pp.58-65
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• 2020

Fat mass and obesity-associated (FTO) gene helps to regulate energy homeostasis in mammals by controlling energy expenditure. In addition, FTO functions in the regulation of obesity and adipogenic differentiation; however, a role in osteogenic differentiation is unknown. This study investigated the effects of FTO on osteogenic differentiation of C3H10T1/2 cells and the underlying mechanism. Expression of osteogenic and endoplasmic reticulum (ER) stress markers were characterized by reverse-transcriptase polymerase chain reaction and western blotting. Alkaline phosphatase (ALP) staining was performed to assess ALP activity. BMP2 treatment increased mRNA expression of osteogenic genes and FTO. Overexpression of FTO increased expression of the osteogenic genes distal-less homeobox5 (Dlx5) and runt-related transcription factor 2 (Runx2). Activation of adenosine monophosphate-activated protein kinase (AMPK) increased FTO expression, and there was a positive feedback loop between FTO and p-AMPK. p-AMPK and FTO induced mild ER stress; however, tunicamycin-induced severe ER stress suppressed FTO expression and AMPK activation. In summary, FTO induces osteogenic differentiation of C3H10T1/2 cells upon BMP2 treatment by inducing mild ER stress via a positive feedback loop with p-AMPK. FTO expression and AMPK activation induce mild ER stress. By contrast, severe ER stress inhibits osteogenic differentiation by suppressing FTO expression and AMPK activation.

• 한방비만학회지
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• 제20권2호
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• pp.109-121
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• 2020

Objectives: Tanshinone I is a bioactive constituent in Salvia miltiorrhiza. At present, the anti-obesity effect and mechanism of tanshinone I are not fully understood. Here we investigated the effect of tanshinone I on lipid accumulation in 3T3-L1 preadipocytes and zebrafish. Methods: Lipid accumulation and triglyceride (TG) content in 3T3-L1 cells were determined by Oil Red O staining and AdipoRed assay, respectively. The expression and phosphorylation levels of adipogenic/lipogenic proteins in 3T3-L1 cells were evaluated by Western blotting. The messenger RNA (mRNA) expression levels of adipogenic/lipogenic markers and leptin in 3T3-L1 cells were measured by reverse transcription polymerase chain reaction (RT-PCR). Lipid accumulation in zebrafish was assessed by LipidGreen2 staining. Results: Tanshinone I at 5 μM largely blocked lipid accumulation and reduced TG content in differentiating 3T3-L1 cells. Furthermore, tanshinone I decreased the expression of CCAAT/enhancer-binding protein-α (C/EBP-α), peroxisome proliferator-activated receptor-γ (PPAR-γ), fatty acid synthase (FAS), acetyl CoA carboxylase (ACC), and perilipin A but also the phosphorylation of signal transducer and activator of transcription-3 (STAT-3) in differentiating 3T3-L1 cells. In addition, tanshinone I increased the phosphorylation of adenosine 3',5'-cyclic monophosphate (cAMP)-activated protein kinase (AMPK) while decreased the intracellular adenosine triphosphate (ATP) content with no change in the phosphorylation and expression of liver kinase-B1 in differentiating 3T3-L1 cells. Importantly, tanshinone I also reduced the extent of lipid deposit formation in developing zebrafish. Conclusions: These findings demonstrate that tanshinone I has strong anti-adipogenic effects on 3T3-L1 cells and reduces adiposity in zebrafish, and these anti-adipogenic effect in 3T3-L1 cells are mediated through control of C/EBP-α, PPAR-γ, STAT-3, FAS, ACC, perilipin A, and AMPK.

• Journal of Nutrition and Health
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• 제56권6호
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• pp.641-654
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• 2023

Purpose: Sour cherry (Prunus cerasus L.) contains abounding phytochemicals, such as polyphenols and anthocyanins, and has antioxidative effects. Adenosine monophosphate-activated protein kinase (AMPK) is a crucial regulator in enhancing the lipid metabolism. This study hypothesized that the intake of sour cherry affects AMPK signaling. Therefore, this study examined whether sour cherry regulates AMPK to balance the hepatic lipid metabolism and exert ameliorating effects. Methods: Male C57BL/6J mice had obesity induced with a 45% fat diet. The mice were divided into four groups: control (CON), high-fat diet (HFD), low percentage sour cherry powder (LSC), and high percentage sour cherry powder (HSC). The mice in the sour cherry groups were fed 1% sour cherry or 5% sour cherry in their respective diets for 12 weeks. Results: The body weight, visceral fat weight, and lipid droplet size significantly decreased in the treatment groups. The serum and hepatic triglyceride and total cholesterol levels improved significantly in the HSC group. The low-density lipoprotein cholesterol levels were also reduced significantly, whereas the high-density lipoprotein cholesterol levels were increased significantly in both treatment groups. The sterol regulator binding protein-1c and fatty acid synthase expression levels as fatty acid synthesis-related enzymes were significantly lower in the treatment groups than in the high-fat diet group. Furthermore, the adipose triglyceride lipase and hormone-sensitive lipase expression levels as lipolytic enzyme activity and AMPK/acetyl-CoA carboxylase/carnitine palmitoyltransferase-1 as fatty acid β-oxidation-related pathway were upregulated significantly in both sour cherry groups. Conclusions: These results show that sour cherry intake improves hepatic lipid synthesis and chronic diseases by activating AMPK signaling. Therefore, this study suggests that phytochemical-rich sour cherry can be developed as a healthy functional food.

• Nutrition Research and Practice
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• 제17권6호
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• pp.1043-1055
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• 2023

BACKGROUND/OBJECTIVES: The fruit of Cydonia oblonga Miller (COM) is used traditionally in Mediterranean region medicine to prevent or treat obesity, but its mechanism of action is still unclear. Beyond a demonstrated anti-obesity effect, the fruit was tested for the mechanism of adipogenesis in 3T3-L1 preadipocytes. MATERIALS/METHODS: 3T3-L1 preadipocytes were cultured for 8 days with COM fruit extract (COME) at different concentrations (0-600 ㎍/mL) with adipocyte differentiation medium. The cell viability was measured using an MTT assay; triglyceride (TG) was stained with Oil Red O. The expression levels of the adipogenesis-related genes and protein expression were analyzed by reverse transcription polymerase chain reaction and Western blotting, respectively. RESULTS: COME inhibited intracellular TG accumulation during adipogenesis. A COME treatment in 3T3-L1 cells induced upregulation of the adenosine monophosphate-activated protein kinase (AMPK)α phosphorylation and downregulation of the adipogenic transcription factors, such as sterol regulatory element-binding protein 1c, peroxisome proliferator-activated receptor γ, and CCAAT/enhancer binding protein α. The COME treatment reduced the mRNA expression of fatty acyl synthetase, adenosine triphosphate-citrate lyase, adipocyte protein 2, and lipoprotein lipase. It increased the mRNA expression of hormone-sensitive lipase and carnitine palmitoyltransferase I in 3T3-L1 cells. CONCLUSIONS: COME inhibits adipogenesis via the AMPK signaling pathways. COME may be used to prevent and treat obesity.

• The Korean Journal of Physiology and Pharmacology
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• 제20권1호
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• pp.9-14
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• 2016

Adenosine 3',5'-cyclic monophosphate (cAMP) participates in the regulation of numerous cellular functions, including the $Na^+-K^+$-ATPase (sodium pump). Ouabain, used in the treatment of several heart diseases, is known to increase cAMP levels but its effects on the atrium are not understood. The aim of the present study was to examine the effect of ouabain on the regulation of atrial cAMP production and its roles in atrial endothelin-1 (ET-1) secretion in isolated perfused beating rabbit atria. Our results showed that ouabain ($3.0{\mu}mol/L$) significantly increased atrial dynamics and cAMP levels during recovery period. The ouabain-increased atrial dynamics was blocked by KB-R7943 ($3.0{\mu}mol/L$), an inhibitor for reverse mode of $Na^+-Ca^{2+}$ exchangers (NCX), but did not by L-type $Ca^{2+}$ channel blocker nifedipine ($1.0{\mu}mol/L$) or protein kinase A (PKA) selective inhibitor H-89 ($3.0{\mu}mol/L$). Ouabain also enhanced atrial intracellular cAMP production in response to forskolin and theophyline ($100.0{\mu}mol/L$), an inhibitor of phosphodiesterase, potentiated the ouabain-induced increase in cAMP. Ouabain and 8-Bromo-cAMP ($0.5{\mu}mol/L$) markedly increased atrial ET-1 secretion, which was blocked by H-89 and by PD98059 ($30{\mu}mol/L$), an inhibitor of extracellular-signal-regulated kinase (ERK) without changing ouabain-induced atrial dynamics. Our results demonstrated that ouabain increases atrial cAMP levels and promotes atrial ET-1 secretion via the mitogen-activated protein kinase (MAPK)/ERK signaling pathway. These findings may explain the development of cardiac hypertrophy in response to digitalis-like compounds.

• Journal of Ginseng Research
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• 제48권4호
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• pp.395-404
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• 2024

Background: Ginsenoside Rg₁ (Rg₁) is one of the main active components in Chinese medicines, Panax ginseng and Panax notoginseng. Research has shown that Rg₁ has a protective effect on the cardiovascular system, including anti-myocardial ischemia-reperfusion injury, anti-apoptosis, and promotion of myocardial angiogenesis, suggesting it a potential cardiovascular agent. However, the protective mechanism involved is still not fully understood. Methods: Based on network pharmacology, ligand-based protein docking, proteomics, Western blot, protein recombination and spectroscopic analysis (UV-Vis and fluorescence spectra) techniques, potential targets and pathways for Rg₁ against myocardial ischemia (MI) were screened and explored. Results: An important target set containing 19 proteins was constructed. Two target proteins with more favorable binding activity for Rg₁ against MI were further identified by molecular docking, including mitogen-activated protein kinase 1 (MAPK1) and adenosine kinase (ADK). Meanwhile, Rg₁ intervention on H9c2 cells injured by H₂O₂ showed an inhibitory oxidative phosphorylation (OXPHOS) pathway. The inhibition of Rg₁ on MAPK1 and OXPHOS pathway was confirmed by Western blot assay. By protein recombination and spectroscopic analysis, the binding reaction between ADK and Rg₁ was also evaluated. Conclusion: Rg₁ can effectively alleviate cardiomyocytes oxidative stress injury via targeting MAPK1 and ADK, and inhibiting oxidative phosphorylation (OXPHOS) pathway. The present study provides scientific basis for the clinical application of the natural active ingredient, Rg₁, and also gives rise to a methodological reference to the searching of action targets and pathways of other natural active ingredients.

• 대한임상검사과학회지
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• 제56권1호
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• pp.73-84
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• 2024

펄스 전자기장(pulsed electromagnetic field, PEMF)은 여러 항암제의 항암 효과를 향상시키는 것으로 알려져 있고 독소루비신(doxorubicin, DOX)은 유방암을 포함한 다양한 종류의 악성 종양을 치료하는 데 사용되는 항암제이다. 본 연구는 PEMF가 MCF-7 유방암 세포에 대한 DOX의 항암 효과 증진 여부를 조사하고 관련기전을 규명하기 위해 진행되었다. 본 연구팀은 DOX와 PEMF를 동시에 처리하면 DOX 단독 처리에 비해 MCF-7 유방암 세포의 생존율 감소가 더 커지는 것을 확인하였다. PEMF는 cyclin-dependent kinase 2의 인산화와 p53, p21, 사이클린 E2 및 polo like kinase 1의 단백질 발현에 영향을 주어 DOX 처리에 의한 G1 세포주기 정지를 더욱 증가시켰다. 또한, PEMF는 DOX 처리에 의한 Fas와 Bcl-2-associated X의 증가, myeloid leukemia 1과 survivin의 감소, 카스파제(caspase)-8/9/7의 활성 및 poly (adenosine diphosphate-ribose) polymerase 절단을 더욱 증가시켰다. 이러한 연구결과를 바탕으로, 본 연구팀은 PEMF는 DOX 처리에 의한 G1 세포주기 정지와 카스파제 의존적 세포자멸사를 더욱 증가시켜 DOX 처리에 의한 MCF-7 세포의 생존율 감소를 더욱 증진시킴을 확인할 수 있었다.

• 생명과학회지
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• 제28권2호
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• pp.162-169
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• 2018

세포기질에 존재하는 많은 종류의 단백질들은 N-말단에 존재하는 짧은 펩타이드들에 의해서 trans-golgi network(TGN)의 세포질쪽 막에 타기팅될때 중요한 역할을 수행한다고 보고되고 있다. 본 연구실에서도 이전에 바다달팽이인 군소에서 클로닝된 phosphodiesterase 4의 long-form의 경우 N-말단에 존재하는 20개의 아미노산 서열만으로도 충분히 HEK293T세포의 TGN의 세포질막에 타기팅 되게 하며, 이 펩타이드가 sulfatide와 PI4P에 결합성이 있다는 사실을 in vitro에서 확인하였다. 그래서, 본 연구에서는 sulfatide결합성과 TGN막 타기팅과의 연관성을 연구하고자 하였다. 이를 위해 우선 이전 문헌을 통해 sulfatide결합 펩타이드를 찾았고, 이를 GFP단백질과 융합하여 재조합 단백질(mHSBP-EGFP)을 만들어 세포내 타기팅을 실험해 보았다. 이러한 연구를 수행한 결과, mHSBP-EGFP가 HEK293T세포에서 TGN에 타기팅 되고, sulfatide결합이 망가진 돌연변이는 타기팅이 사라짐을 확인하였다. 또한, mHSBP-EGFP가 TGN에 타기팅 되는 것은 억제제인 antimycin A와 PAO와 adenosine에 의해 억제됨을 확인할 수 있었다. 이러한 사실을 통해, PAO와 adenosine에 민감한 인산화효소들, 그중에 PI4KII의 활성이 mHSBP-EGFP를 TGN으로 위치하게 하는데 중요한 역할을 수행한다고 추론할 수 있다.

• 한방비만학회지
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• 제15권2호
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• pp.131-136
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• 2015

Objectives: The prevalence of obesity and metabolic syndrome is increasing worldwide. Regulation of cellular energy metabolis has the potential to be manipulated therapeutically to serve as a target for obesity and insulin resistance. Skeletal muscle is regarded as a target for regulation of energy metabolism and insulin resistance. In this study, the authors investigated the regulatory effect of (Cinnamomum cassia Blume, CCB), Aconitum carmichaeli Debx (ACD), and Benth (Pueraria lobata Benth, PLB) on energy and glucose metabolism in C2C12 myotubes. Methods: The water extracts of CCB, ACD, and PLB (0.5 mg/ml) were treated in differentiated C2C12 myotubes. The expressions of adenosine monophosphate-activated protein kinase (AMPK) and phosphorylation AMPK were detected with western blotting. Glucose metabolism was investigated with glucose uptake assay and glucose consumption assay, total adenosine triphosphate (ATP) content was also analyzed. Results: CCB, ACD, and PLB activated the phophorylation of AMPK, they also increased the glucose metabolism and total ATP contents in C2C12 myotubes. Conclusions: This study suggests that CCB, ACD, and PLB have the potential to increase energy and glucose metabolism in skeletal muscle.

• 한국식품영양과학회지
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• 제9권1호
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• pp.59-73
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• 1980

A detailed procedure was described for the isolation of cratine kinase (ATP-Creatine phosphotransferase, E. C. 2. 7. 3. 2.) from the muscle of the snake Bungarus fasciatus. The original isolation procedure of Kuby et al. for the rabbit muscle enzyme has been modified and extended to include a chromatographic step. The properties of the enzyme have been investigated and kinetic constants for the reverse reactions determined as the followings: 1) A molecular weight of the enzyme was determined by gel filteration on Sephadex G-100 and by electrophoresis on SDS-polyacrylamide was 86,000. 2) Two reactive sulphydryl groups were detected with dithiobis nitrobenzoic acid (DTNB). 3) The nucleotide substrate specificity in the reverse reaction was determined as ADP*2'-dADP＞GDP＞XDP＞UDP with magnesium as the activating metal ion. 4) The order of the metal specificity in the reverse reaction Mg>Mn>$Ca{\sim}Co$ was determined with ADP as substrate. 5) A detailed kinetic analysis was carried out in the reverse direction with $MaADP^-$ as the nucleotide substrate. Initial velocity and product inhibition studies($MaADP^{2-}$ competitive with respect to MgADP- and noncompetitive with respect to $N-phosphorycreatine^{2-}$ ; Creatine competitive with respect to $N-phosphorycreatine^{2-}$ and noncompetitive with respect to Ma $ADP^-)$ indicated that the reaction obeyed a sequential mechanism of the rapid equilibrium random type.