• 제목/요약/키워드: AMP-activated protein kinase

검색결과 273건 처리시간 0.026초

Adenine attenuates lipopolysaccharide-induced inflammatory reactions

  • Silwal, Prashanta;Lim, Kyu;Heo, Jun-Young;Park, Jong IL;Namgung, Uk;Park, Seung-Kiel
    • The Korean Journal of Physiology and Pharmacology
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    • 제22권4호
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    • pp.379-389
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    • 2018
  • A nucleobase adenine is a fundamental component of nucleic acids and adenine nucleotides. Various biological roles of adenine have been discovered. It is not produced from degradation of adenine nucleotides in mammals but produced mainly during polyamine synthesis by dividing cells. Anti-inflammatory roles of adenine have been supported in IgE-mediated allergic reactions, immunological functions of lymphocytes and dextran sodium sulfate-induced colitis. However adenine effects on Toll-like receptor 4 (TLR4)-mediated inflammation by lipopolysaccharide (LPS), a cell wall component of Gram negative bacteria, is not examined. Here we investigated anti-inflammatory roles of adenine in LPS-stimulated immune cells, including a macrophage cell line RAW264.7 and bone marrow derived mast cells (BMMCs) and peritoneal cells in mice. In RAW264.7 cells stimulated with LPS, adenine inhibited production of pro-inflammatory cytokines $TNF-{\alpha}$ and IL-6 and inflammatory lipid mediators, prostaglandin $E_2$ and leukotriene $B_4$. Adenine impeded signaling pathways eliciting production of these inflammatory mediators. It suppressed $I{\kappa}B$ phosphorylation, nuclear translocation of nuclear factor ${\kappa}B$ ($NF-{\kappa}B$), phosphorylation of Akt and mitogen activated protein kinases (MAPKs) JNK and ERK. Although adenine raised cellular AMP which could activate AMP-dependent protein kinase (AMPK), the enzyme activity was not enhanced. In BMMCs, adenine inhibited the LPS-induced production of $TNF-{\alpha}$, IL-6 and IL-13 and also hindered phosphorylation of $NF-{\kappa}B$ and Akt. In peritoneal cavity, adenine suppressed the LPS-induced production of $TNF-{\alpha}$ and IL-6 by peritoneal cells in mice. These results show that adenine attenuates the LPS-induced inflammatory reactions.

생 마늘과 절인 마늘의 In Vitro 항비만 효과 (In Vitro Anti-Obesity Effects of Raw Garlic and Pickled Garlic)

  • 이다빈;표영희
    • 한방비만학회지
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    • 제21권2호
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    • pp.69-79
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    • 2021
  • Objectives: This study aimed to compare the anti-obesity effects of raw and pickled garlic in vitro in 3T3-L1 preadipocytes. Methods: The pickled garlic samples comprised the following: garlic aged in vinegar (VG), garlic aged in soy sauce, and vinegar (1:1, v/v) (PG) and raw garlic (RG) as control. Hexane, butanol, and distilled water were used to prepare the fractions. The pancreatic lipase inhibitory activity was used as a measure of anti-obesity effects of the extracts. The lipid droplet accumulation and triglyceride content in the 3T3-L1 cells were measured using Oil red O staining and triglyceride assay kits, respectively. The adipogenesis related protein expression levels were analyzed using the kits and the western blot method. Results: The pancreatic lipase inhibitory activity of the garlic extracts (VG, PG, RG) was the highest in the butanol fraction, and the inhibitory effect was the highest in RG, followed by PG and VG. All garlic butanol extracts suppressed triglyceride accumulation in differentiated adipocytes (P<0.05) through the activation of cyclic adenosine monophosphate (AMP), AMP-activated protein kinase, carnitine palmitoyl transferase-1, and the inhibition of fatty acid synthase. Raw garlic extracts significantly inhibited the expression of proteins involved in adipogenesis as compared to pickled garlic. Conclusions: Raw garlic has the potential to be an effective natural material for reducing obesity compared to pickled garlic with vinegar or soy sauce.

고지방식이 유도 비만쥐에서 이묘산의 항비만 효과 (Anti-Obesity Effects of Imyo-san on High Fat Diet Induced Obese Mice)

  • 강석범;손우석;김영준;우창훈
    • 한방재활의학과학회지
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    • 제32권2호
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    • pp.19-36
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    • 2022
  • Objectives This study is to investigate the effects and mechanisms of Imyo-san (IMS) on the obese mice model induced by high-fat diet. Methods Antioxidative capacity was measured by in vitro method. C57BL/6 mice were randomly assigned into 5 groups (n=7). Normal group was fed general diet (Normal). The other 4 groups were fed high fat diet (HFD) with water (Control), with Garcinia gummi-gutta (GG, Garcinia gummi-gutta 200 mg/kg), with low-dose IMS (IMSL, Imyo-san 0.54 g/kg) and with high-dose IMS (IMSH, Imyo-san 1.08 g/kg). Results IMS showed high radical scavenging activity. After 6 week experiment, body weight, food intake, food efficiency ratio (FER), epididymal fat and liver weight, triglyceride (TG), total cholesterol (TC), high density lipoprotein (HDL) cholesterol, low density lipoprotein (LDL) cholesterol, very low density lipoprotein (VLDL) cholesterol, sterol regulatory element-binding protein-1 (SREBP-1), phospho-acetyl-CoA carboxylase (p-ACC), fatty acid synthase (FAS), stearoyl-CoA desaturase-1 (SCD-1), SREBP-2, 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), phospho-liver kinase B1 (p-LKB1), phospho-AMP-activated protein kinase (p-AMPK), peroxisome proliferator-activated receptor 𝛼 (PPAR𝛼), peroxisome proliferator-activated receptor 𝛾 coactivator-1𝛼 (PGC-1𝛼), uncoupling protein-2 (UCP-2), carnitine palmitoyltransferase 1A (CPT-1A), and histology of liver and epididymal fat were measured and analysed. Body weight gain, FER, liver and epididymal fat weight of IMS groups were significantly decreased. There were significant improvements in blood lipids with less TG, TC, LDL-cholesterol, VLDL-cholesterol and more HDL-cholesterol. Proteins associated with lipid synthesis (SREBP-1, p-ACC, FAS, SCD-1) and cholesterol (SREBP-2, HMGCR) was improved. Factors regulating lipid synthesis and lipid catabolism (p-LKBI, p-AMPK, PPARα, PGC-1α, UCP-2, CPT-1A) were increased. In histological examinations, IMS group had smaller fat droplets than control group. All results increased depending on concentration. Conclusions It can be suggested that IMS has anti-obesity effects with improving lipid metabolism.

Neuroprotective effects of hesperetin on H2O2-induced damage in neuroblastoma SH-SY5Y cells

  • Ha-Rin Moon;Jung-Mi Yun
    • Nutrition Research and Practice
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    • 제17권5호
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    • pp.899-916
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    • 2023
  • BACKGROUND/OBJECTIVES: Oxidative stress is a fundamental neurodegenerative disease trigger that damages and decimates nerve cells. Neurodegenerative diseases are chronic central nervous system disorders that progress and result from neuronal degradation and loss. Recent studies have extensively focused on neurodegenerative disease treatment and prevention using dietary compounds. Heseperetin is an aglycone hesperidin form with various physiological activities, such as anti-inflammation, antioxidant, and antitumor. However, few studies have considered hesperetin's neuroprotective effects and mechanisms; thus, our study investigated this in hydrogen peroxide (H2O2)-treated SH-SY5Y cells. MATERIALS/METHODS: SH-SY5Y cells were treated with H2O2 (400 µM) in hesperetin absence or presence (10-40 µM) for 24 h. Three-(4,5-Dimethyl-2-thiazolyl)-2,5-diphenyl-2H-tetrazolium bromide assays detected cell viability, and 4',6-diamidino-2-phenylindole staining allowed us to observe nuclear morphology changes such as chromatin condensation and apoptotic nuclei. Reactive oxygen species (ROS) detection assays measured intracellular ROS production; Griess reaction assays assessed nitric oxide (NO) production. Western blotting and quantitative polymerase chain reactions quantified corresponding mRNA and proteins. RESULTS: Subsequent experiments utilized various non-toxic hesperetin concentrations, establishing that hesperetin notably decreased intracellular ROS and NO production in H2O2-treated SH-SY5Y cells (P < 0.05). Furthermore, hesperetin inhibited H2O2-induced inflammation-related gene expression, including interluekin-6, tumor necrosis factor-α, and nuclear factor kappa B (NF-κB) p65 activation. In addition, hesperetin inhibited NF-κB translocation into H2O2-treated SH-SY5Y cell nuclei and suppressed mitogen-activated protein kinase protein expression, an essential apoptotic cell death regulator. Various apoptosis hallmarks, including shrinkage and nuclear condensation in H2O2-treated cells, were suppressed dose-dependently. Additionally, hesperetin treatment down-regulated Bax/Bcl-2 expression ratios and activated AMP-activated protein kinase-mammalian target of rapamycin autophagy pathways. CONCLUSION: These results substantiate that hesperetin activates autophagy and inhibits apoptosis and inflammation. Hesperetin is a potentially potent dietary agent that reduces neurodegenerative disease onset, progression, and prevention.

Identification of Novel Target Proteins of Cyclic GMP Signaling Pathways Using Chemical Proteomics

  • Kim, Eui-Kyung;Park, Ji-Man
    • BMB Reports
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    • 제36권3호
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    • pp.299-304
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    • 2003
  • For deciphering the cyclic guanosine monophosphate (cGMP) signaling pathway, we employed chemical proteomics to identify the novel target molecules of cGMP. We used cGMP that was immobilized onto agarose beads with linkers directed at three different positions of cGMP. We performed a pull-down assay using the beads as baits on tissue lysates and identified 9 proteins by MALDI-TOF (Matrix-Assisted Laser Desorption/Ionization Time-of-Flight) mass spectrometry. Some of the identified proteins were previously known cGMP targets, including cGMP-dependent protein kinase and cGMP-stimulated phosphodiesterase. Surprisingly, some of the co-precipitated proteins were never formerly reported to associate with the cGMP signaling pathway. The competition binding assays showed that the interactions are not by nonspecific binding to either the linker or bead itself, but by specific binding to cGMP. Furthermore, we observed that the interactions are highly specific to cGMP against other nucleotides, such as cyclic adenosine monophosphate (cAMP) and 5'-GMP, which are structurally similar to cGMP. As one of the identified targets, MAPK1 was confirmed by immunoblotting with an anti-MAPK1 antibody. For further proof, we observed that the membrane-permeable cGMP (8-bromo cyclic GMP) stimulated mitogen-activated protein kinase 1 signaling in the treated cells. Our present study suggests that chemical proteomics can be a very useful and powerful technique for identifying the target proteins of small bioactive molecules.

ICP5249 Promotes Hair Growth by Activating the AMPK-Autophagy Signaling Pathway

  • Jung Ok Lee;Yu-jin Kim;You Na Jang;Jung min Lee;Kayoung Shin;Sekyoo Jeong;Hwa-Jee Chung;Beom Joon Kim
    • Journal of Microbiology and Biotechnology
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    • 제34권9호
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    • pp.1810-1818
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    • 2024
  • Autophagy is essential for regulating hair growth. Accordingly, we developed autophagy activator ICP5249 (pentasodium tetracarboxymethyl palmitoyl dipeptide) and investigated its potential role in hair growth. We evaluated its effect on hair growth using in vitro human dermal papilla cells (hDPCs) culture model, human hair follicles (hHFs) organ culture model, and telogenic mouse model. ICP5249 increased hDPCs proliferation and alkaline phosphatase (ALP) expression. It also increased microtubule-associated protein (MAP) light chain 3-II (LC3-II) expression and AMP-activated protein kinase α (AMPKα) and unc-51-like kinase 1 (ULK1) phosphorylation in hDPCs. ICP5249 extended the length of hHFs and increased LC3-II please revised from LC3 II to LC3-II in all manuscript expression. Consistently, ICP5249 also significantly increased hair growth area, dermis thickness, and anagen and telogen ratio in telogenic mice. Furthermore, it upregulated Ki-67 and LC3-II expression and AMPKα phosphorylation on the mice's dorsal skin. To investigate whether AMPK regulates ICP5249-induced hair growth, following treatment with the compound C, AMPK inhibitor, the activity of ICP5249 was evaluated. The effects of ICP5249 on hair growth were assessed following pretreatment with the AMPK inhibitor compound C. The results showed that compound C suppressed ICP5249-mediated proliferation and hair inductivity in hDPCs. Additionally, compound C inhibited ICP5249-mediated hair growth area, dermis thickness, anagen and telogen ration, and LC3-II expression in mice, suggesting that ICP5249 promotes hair growth by modulating autophagy, with AMPKα playing a regulatory role in this process. Taken together, we demonstrate that ICP5249 has the potential as an ingredient for improving hair growth.

Arctiin inhibits adipogenesis in 3T3-L1 cells and decreases adiposity and body weight in mice fed a high-fat diet

  • Min, Byulchorong;Lee, Heejin;Song, Ji Hye;Han, Myung Joo;Chung, Jayong
    • Nutrition Research and Practice
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    • 제8권6호
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    • pp.655-661
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    • 2014
  • BACKGROUND/OBJECTIVES: The purpose of this study was to examine the effects and associated mechanisms of arctiin, a lignan compound found in burdock, on adipogenesis in 3T3-L1 cells. Also, the effects of arctiin supplementation in obese mice fed a high-fat diet on adiposity were examined. MATERIALS/METHODS: 3T3-L1 cells were treated with arctiin (12.5 to $100{\mu}M$) during differentiation for 8 days. The accumulation of lipid droplets was determined by Oil Red O staining and intracellular triglyceride contents. The expressions of genes related to adipogenesis were measured by real-time RT-PCR and Western blot analyses. For in vivo study, C57BL/6J mice were first fed either a control diet (CON) or high-fat diet (HF) to induce obesity, and then fed CON, HF, or HF with 500 mg/kg BW arctiin (HF + AC) for four weeks. RESULTS: Arctiin treatment to 3T3-L1 pre-adipocytes markedly decreased adipogenesis in a dose-dependent manner. The arctiin treatment significantly decreased the protein levels of the key adipogenic regulators $PPAR{\gamma}$ and $C/EBP{\alpha}$, and also significantly inhibited the expression of SREBP-1c, fatty acid synthase, fatty acid-binding protein and lipoprotein lipase. Also, arctiin greatly increased the phosphorylation of AMP-activated protein kinase (AMPK) and its downstream target phosphorylated-acetyl CoA carboxylase. Furthermore, administration of arctiin significantly decreased the body weight in obese mice fed with the high-fat diet. The epididymal, perirenal or total visceral adipose tissue weights of mice were all significantly lower in the HF + AC than in the HF. Arctiin administration also decreased the sizes of lipid droplets in the epididymal adipose tissue. CONCLUSIONS: Arctiin inhibited adipogenesis in 3T3-L1 adipocytes through the inhibition of $PPAR{\gamma}$ and $C/EBP{\alpha}$ and the activation of AMPK signaling pathways. These findings suggest that arctiin has a potential benefit in preventing obesity.

Opening of ATP-sensitive $K^+$ Channel by Pinacidil Requires Serine/Threonine Phosphorylation in Rat Ventricular Myocytes

  • Kwak, Yong-Geun;Chae, Soo-Wan
    • The Korean Journal of Physiology and Pharmacology
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    • 제3권3호
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    • pp.293-303
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    • 1999
  • The influences of specific protein phosphatase and protein kinase inhibitors on the ATP-sensitive $K^+\;(K_{ATP})$ channel-opening effect of pinacidil were investigated in single rat ventricular myocytes using patch clamp technique. In cell-attached patches, pinacidil $(100\;{\mu}M)$ induced the opening of the $K_{ATP}$ channel, which was blocked by the pretreatment with H-7 $(100\;{\mu}M)$ whereas enhanced by the pretreatment with genistein $(30\;{\mu}M)$ or tyrphostin A23 $(10\;{\mu}M)$. In inside-out patches, pinacidil $(10\;{\mu}M)$ activated the $K_{ATP}$ channels in the presence of ATP (0.3 mM) or AMP-PNP (0.3 mM) and in a partial rundown state. The effect of pinacidil $(10\;{\mu}M)$ was not affected by the pretreatment with protein tyrosine phosphatase 1B $(PTP1B,\;10\;{\mu}g\;ml^{-1}),$ but blocked by the pretreatment of protein phosphatase 2A $(PP2A,\;1\;U\;ml^{-1})$. In addition, pinacidil $(10\;{\mu}M)$ could not induce the opening of the reactivated $K_{ATP}$ channels in the presence of H-7 $(100\;{\mu}M)$ but enhanced it in the presence of ATP (1 mM) and genistein $(30\;{\mu}M).$ These results indicate that the $K_{ATP}$ channel-opening effect of pinacidil is not mediated via phosphorylation of $K_{ATP}$ channel protein or associated protein, although it still requires the phosphorylation of serine/threonine residues as a prerequisite condition.

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Quercetin induces cell death in cervical cancer by reducing O-GlcNAcylation of adenosine monophosphate-activated protein kinase

  • Ali, Akhtar;Kim, Min Jun;Kim, Min Young;Lee, Han Ju;Roh, Gu Seob;Kim, Hyun Joon;Cho, Gyeong Jae;Choi, Wan Sung
    • Anatomy and Cell Biology
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    • 제51권4호
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    • pp.274-283
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    • 2018
  • Hyper-O-GlcNAcylation is a general feature of cancer which contributes to various cancer phenotypes, including cell proliferation and cell growth. Quercetin, a naturally occurring dietary flavonoid, has been reported to reduce the proliferation and growth of cancer. Several reports of the anticancer effect of quercetin have been published, but there is no study regarding its effect on O-GlcNAcylation. The aim of this study was to investigate the anticancer effect of quercetin on HeLa cells and compare this with its effect on HaCaT cells. Cell viability and cell death were determined by MTT and terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labelling assays. O-GlcNAcylation of AMP-activated protein kinase (AMPK) was examined by succinylated wheat germ agglutinin pulldown and immunoprecipitation. Immunofluorescence staining was used to detect the immunoreactivitiy of O-linked N-acetylglucosamine transferase (OGT) and sterol regulatory element binding protein 1 (SREBP-1). Quercetin decreased cell proliferation and induced cell death, but its effect on HaCaT cells was lower than that on HeLa cells. O-GlcNAcylation level was higher in HeLa cells than in HaCaT cells. Quercetin decreased the expression of global O-GlcNAcylation and increased AMPK activation by reducing the O-GlcNAcylation of AMPK. AMPK activation due to reduced O-GlcNAcylation of AMPK was confirmed by treatment with 6-diazo-5-oxo-L-norleucine. Our results also demonstrated that quercetin regulated SREBP-1 and its transcriptional targets. Furthermore, immunofluorescence staining showed that quercetin treatment decreased the immunoreactivities of OGT and SREBP-1 in HeLa cells. Our findings demonstrate that quercetin exhibited its anticancer effect by decreasing the O-GlcNAcylation of AMPK. Further studies are needed to explore how quercetin regulates O-GlcNAcylation in cancer.

3T3-L1 전구지방세포에서 개구리자리(Ranunculus sceleratus) 추출물의 AMPK 신호전달을 통한 지방생성 억제 효과 (Extract of Ranunculus sceleratus Reduced Adipogenesis by Inhibiting AMPK Pathway in 3T3-L1 Preadipocytes)

  • 김예지;조성필;이희주;홍금란;김경현;류시윤;정주영
    • 한방비만학회지
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    • 제22권1호
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    • pp.30-37
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    • 2022
  • Objectives: Adipogenesis is the process by which pre-adipocytes are differentiated into adipocytes. It also plays an important role in adipocyte formation and lipid accumulation. Ranunculus sceleratus (R. sceleratus) extracts are used for the treatment of various diseases such as hepatitis, jaundice, and tuberous lymphadenitis in oriental medicine. However, its effect on adipogenesis has not yet been studied. In this study, we investigated the effects of R. sceleratus on adipogenesis in 3T3-L1 cells. Methods: Cells were treated with 50, 100, and 200 ㎍/ml of R. sceleratus and cell viability was evaluated. To differentiate the 3T3-L1 preadipocytes, a 3-isobutyl-1-methylxanthine, dexamethasone, and insulin (MDI) solution were used. The accumulation of lipid droplets was determined by Oil Red O staining. The expression levels of adipogenesis-related proteins were also determined. Results: MDI solution differentiated the preadipocytes into adipocytes and accumulation of lipids was observed in the differentiated 3T3-L1 cells. Interestingly, the amount of lipid droplets was reduced after R. sceleratus treatment. In addition, the expression levels of key adipogenic transcription factors, such as CCAAT/enhancer-binding proteins-𝛼 (C/EBP-𝛼) and peroxisome proliferator-activated receptors-𝛾 (PPAR-𝛾) were also reduced after R. sceleratus treatment. Furthermore, R. sceleratus increased AMP-activated kinase (AMPK) phosphorylation and decreased sterol regulatory element-binding protein-1 expression. Conclusions: Our results showed that R. sceleratus reduced preadipocyte differentiation by inhibiting C/EBP-𝛼 and PPAR-𝛾 levels via the AMPK pathway. Therefore, we suggest that R. sceleratus may be potentially used as an anti-adipogenic agent.