• 제목/요약/키워드: $A_1-adenosine$ Receptor

검색결과 163건 처리시간 0.032초

Molecular signaling of ginsenosides Rb1, Rg1, and Rg3 and their mode of actions

  • Mohanan, Padmanaban;Subramaniyam, Sathiyamoorthy;Mathiyalagan, Ramya;Yang, Deok-Chun
    • Journal of Ginseng Research
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    • 제42권2호
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    • pp.123-132
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    • 2018
  • Ginseng has gained its popularity as an adaptogen since ancient days because of its triterpenoid saponins, known as ginsenosides. These triterpenoid saponins are unique and classified as protopanaxatriol and protopanaxadiol saponins based on their glycosylation patterns. They play many protective roles in humans and are under intense research as various groups continue to study their efficacy at the molecular level in various disorders. Ginsenosides Rb1 and Rg1 are the most abundant ginsenosides present in ginseng roots, and they confer the pharmacological properties of the plant, whereas ginsenoside Rg3 is abundantly present in Korean Red Ginseng preparation, which is highly known for its anticancer effects. These ginsenosides have a unique mode of action in modulating various signaling cascades and networks in different tissues. Their effect depends on the bioavailability and the physiological status of the cell. Mostly they amplify the response by stimulating phosphotidylinositol-4,5-bisphosphate 3-kinase/protein kinase B pathway, caspase-3/caspase-9-mediated apoptotic pathway, adenosine monophosphate-activated protein kinase, and nuclear factor kappa-light-chain-enhancer of activated B cells signaling. Furthermore, they trigger receptors such as estrogen receptor, glucocorticoid receptor, and N-methyl-$\text\tiny{D}$-aspartate receptor. This review critically evaluates the signaling pathways attenuated by ginsenosides Rb1, Rg1, and Rg3 in various tissues with emphasis on cancer, diabetes, cardiovascular diseases, and neurodegenerative disorders.

산두근 추출물의 세포주기 정지를 통한 3T3-L1 지방전구세포의 분화 억제 (Inhibition of Adipocyte Differentiation through G1 Arrest by Extract of Sophora tonkinensis Gapnep in 3T3-L1 Preadipocytes)

  • 정현영;현숙경;최영현;김병우;권현주
    • 생명과학회지
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    • 제21권9호
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    • pp.1346-1353
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    • 2011
  • 산두근(Sophora tonkinensis Gapnep)은 예로부터 동양지역에서 전통적인 약용식물로 사용되어 왔다. 본 연구에서는 3T3-L1 지방전구세포의 성숙지방세포로의 분화와 세포 내 지방생성에 대한 산두근 메탄올 추출물(STME)의 효과와 메커니즘에 대해 조사하였다. STME를 0-200 ${\mu}g$/ml의 농도로 처리한 다음, Oil Red O 염색으로 세포 내축적되는 지방구와 지질의 양을 측정한 결과 농도의존적으로 크게 감소됨을 확인하였으며 3T3-L1 지방전구세포의 분화와 관련된 단백질의 발현의 변화를 조사하였다. 지방세포의 특이적 marker인 peroxisome proliferator-activated receptor ${\gamma}$ (PPAR${\gamma}$), cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$, ${\beta}$ (C/EBP${\alpha}$, C/EBP${\beta}$) 그리고 sterol regulatory element binding protein (SREBP)의 발현이 STME를 처리하였을 때 현저하게 저해됨을 확인하였다. 세포주기의 변화를 분석한 결과 STME는 지방세포 분화초기 단계인 mitotic clonal expansion 단계에서 G1기로 세포주기를 정지시켰다. 더불어 G1 arrest와 관련된 단백질의 변화를 조사 한 결과, 3T3-L1 세포에 STME를 처리하였을 때 p21의 발현량이 확연하게 증가하였으며, Cdk2, E2F-1 그리고 phosphor-Rb의 발현량은 농도의존적으로 감소하였다. 이러한 결과들에 의하여 STME은 메탄올 추출물임에도 불구하고 3T3-L1 지방전구세포가 성숙지방세포로 분화할 때 G1 arrest를 통하여 지방세포 분화를 억제하며 관련 유전자의 발현 억제도 확연하게 확인할 수 있었으며, 이러한 결과는 항 비만 천연물 소재 탐구의 기초자료로 유용하게 쓰일 것으로 사료된다.

Pseudohypoparathyroidism: Clinical Review of Diagnosis and Genetic Etiology

  • Kyung Mi Jang
    • Journal of Interdisciplinary Genomics
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    • 제5권2호
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    • pp.29-31
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    • 2023
  • Pseudohypoparathyroidism (PHP) is very rare and shows heterogeneity with impaired genetic components. PHP is characterized by parathyroid hormone resistance to target organ, related with a GNAS (guanine nucleotide-binding protein α-subunit) mutation and epimutation. PHP receptor is coupled with the stimulatory G protein which activates cyclic adenosine monophosphate formation. PHP type 1A is caused by inactivating mutations on the maternal allele of the GNAS whereas paternal allele mutations cause pseudopseudohypoparathyroidism. PHP type 1B is caused by abnormal patterns of methylation in differentially methylated region which can be divided into partial or complete. This disease has some difficulties to diagnose according to these different molecular alterations caused by complex genetic and epigenetic defects. According to this different molecular alterations, genetic confirmation must be done to discriminate their etiology.

Cydonia oblonga Miller fruit extract exerts an anti-obesity effect in 3T3-L1 adipocytes by activating the AMPK signaling pathway

  • Hyun Sook Lee;Jae In Jung;Jung Soon Hwang;Myeong Oh Hwang;Eun Ji Kim
    • 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.

Extracellular ATP Induces Apoptotic Signaling in Human Monocyte Leukemic Cells, HL-60 and F-36P

  • Yoon, Mi-Jung;Lee, Hae-Jin;Kim, Jae-Hwan;Kim, Dong-Ku
    • Archives of Pharmacal Research
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    • 제29권11호
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    • pp.1032-1041
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    • 2006
  • Extracellular adenosine 5'-triphosphate (ATP) affects the function of many tissues and cells. To confirm the biological activity of ATP on human myeloid leukemic cells, F-36P and HL-60, cells were treated with a variety of concentrations of ATP. The stimulation with extracellular ATP induced the arrest of cell proliferation and cell death. from the analysis of Annexin-V staining and caspase activity by flow cytometry. The Annexin-V positive cells in both cell lines were dramatically increased following ATP stimulation. The expression of P2 purinergic receptor genes was confirmed, such as P2X1, P2X4, P2X5, P2X7 and P2Y1, P2Y2, P2Y4, P2Y5, P2Y6, P2Y11 in both leukemic cell lines. Interestingly, ATP induced intracellular calcium flux in HL-60 cells but not in F-36P cells, as determined by Fluo-3 AM staining. Cell cycle analysis revealed that ATP treatment arrested both F-36P and HL-60 cells at G1/G0. Taken together, these data showed that extracellular ATP via P2 receptor genes was involved in the cell proliferation and survival in human myeloid leukemic cells, HL-60 and F-36P cells by the induction of apoptosis and control of cell cycle. Our data suggest that treatment with extracellular nucleotides may be a novel and powerful therapeutic avenue for myeloid leukemic disease.

상엽(桑葉) 함유 한약복합제 추출물의 항비만(抗肥滿)효과 연구 (The Study on Anti-obesity Effects of Mulberry Leaves Contained Herbal Mixture)

  • 박종익;강경하;박은정
    • 대한한방소아과학회지
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    • 제27권4호
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    • pp.17-30
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    • 2013
  • Objectives This experimental study was designed to investigate the effects of Mulberry leaves contained herbal mixture (MLHM) on body weight, serum lipid level and adipocyte differentiation in high fat diet-fed obese mice. Methods Four-week old mice (wild-type C57/BL6) were used for all experiments. Cells were incubated with MLHM at the indicated concentration (0.04-4mg/ml) for 24h, and growth rate was assessed by MTT ((3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. 3T3-L1 preadipocytes were incubated in DMEM for 2 days with the indicated concentrations of MLHM, and on Day 6, the cells were fixed and the cellular lipid contents were assessed by Oil-Red-O staining. The expression of peroxisome proliferator-activated receptor ${\gamma}$ (PPAR ${\gamma}$) and cytidine-cytidine-adenosine-adenosine-thymine (CCAAT)/enhancer-binding proteins ${\alpha}$ (C/EBP ${\alpha}$) as adipocyte-specific proteins were determined by real time RT-PCR and western blotting. In addition, body weight gain and serum lipid levels were measured in the mice with obesity induced by the high fat-diet for four weeks. Results Though MLHM did not show toxicity even at the concentration of 4mg/ml, MLHM significantly inhibited the differentiation of 3T3-L1 preadipocites in a dose-dependent manner. Also, MLHM significantly reduced the expressions of PPAR ${\gamma}$ and C/EBP ${\alpha}$ in a dose-dependent manner. Furthermore, MLHM significantly reduced body weight gain and LDL-cholesterol contents in high fat diet-fed obese mice. Conclusions These results demonstrate that MLHM exerts anti-obesity effect in 3T3-L1 cells and mice with obesity by high-fat diet.

Constitutive Activating Eel Luteinizing Hormone Receptors Induce Constitutively Signal Transduction and Inactivating Mutants Impair Biological Activity

  • Byambaragchaa, Munkhzaya;Choi, Seung-Hee;Kim, Dong-Wan;Min, Kwan-Sik
    • 한국발생생물학회지:발생과생식
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    • 제25권3호
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    • pp.133-143
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    • 2021
  • In contrast to the human lutropin receptor (hLHR) and rat LHR (rLHR), very few naturally occurring mutants in other mammalian species have been identified. The present study aimed to delineate the mechanism of signal transduction by three constitutively activating mutants (designated M410T, L469R, and D590Y) and two inactivating mutants (D383N and Y546F) of the eel LHR, known to be naturally occurring in human LHR transmembrane domains. The mutants were constructed and measured cyclic adenosine monophosphate (cAMP) accumulation via homogeneous time-resolved fluorescence assays in Chinese hamster ovary (CHO)-K1 cells. The activating mutant cells expressing eel LHR-M410T, L469R, and D590Y exhibited a 4.0-, 19.1-, and 7.8-fold increase in basal cAMP response without agonist treatment, respectively. However, inactivating mutant cells expressing D417N and Y558F did not completely impaired signal transduction. Specifically, signal transduction in the cells expressing activating mutant L469R was not occurred with a further ligand stimulation, showing that the maximal response exhibited approximately 53% of those of wild type receptor. Our results suggested that the constitutively activating mutants of the eel LHR consistently occurred without agonist treatment. These results provide important information of LHR function in fish and regulation with regard to mutations of highly conserved amino acids in glycoprotein hormone receptors.

Presynaptic Mechanism Underlying Regulation of Transmitter Release by G Protein Coupled Receptors

  • Takahashi, Tomoyuki;Kajikawa, Yoshinao;Kimura, Masahiro;Saitoh, Naoto;Tsujimoto, Tetsuhiro
    • The Korean Journal of Physiology and Pharmacology
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    • 제8권2호
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    • pp.69-76
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    • 2004
  • A variety of G protein coupled receptors (GPCRs) are expressed in the presynaptic terminals of central and peripheral synapses and play regulatory roles in transmitter release. The patch-clamp whole-cell recording technique, applied to the calyx of Held presynaptic terminal in brainstem slices of rodents, has made it possible to directly examine intracellular mechanisms underlying the GPCR-mediated presynaptic inhibition. At the calyx of Held, bath-application of agonists for GPCRs such as $GABA_B$ receptors, group III metabotropic glutamate receptors (mGluRs), adenosine $A_1$ receptors, or adrenaline ${\alpha}2$ receptors, attenuate evoked transmitter release via inhibiting voltage-activated $Ca^{2+}$ currents without affecting voltage-activated $K^+$ currents or inwardly rectifying $K^+$ currents. Furthermore, inhibition of voltage-activated $Ca^{2+}$ currents fully explains the magnitude of GPCR-mediated presynaptic inhibition, indicating no essential involvement of exocytotic mechanisms in the downstream of $Ca^{2+}$ influx. Direct loadings of G protein ${\beta}{\gamma}$ subunit $(G{\beta}{\gamma})$ into the calyceal terminal mimic and occlude the inhibitory effect of a GPCR agonist on presynaptic $Ca^{2+}$ currents $(Ip_{Ca})$, suggesting that $G{\beta}{\gamma}$ mediates presynaptic inhibition by GPCRs. Among presynaptic GPCRs glutamate and adenosine autoreceptors play regulatory roles in transmitter release during early postnatal period when the release probability (p) is high, but these functions are lost concomitantly with a decrease in p during postnatal development.

기니픽 심장에서 histamine H2-수용체 자극에 의한 Mg2+ 유리에 대한 phosphodiesterase 억제제의 효과 (Regulation of histamine H2-receptor mediated Mg2+ release by phosphodiesterase inhibitors in the guinea pig hearts)

  • 강형섭;김진상
    • 대한수의학회지
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    • 제40권3호
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    • pp.479-487
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    • 2000
  • Several recent studies demonstrate that receptor-mediated cAMP (adenosine 3',5'-monophosphate) production evokes marked change in magnesium ($Mg^{2+}$) homeostasis. The effects of dimaprit or/and phosphodiesterase (PDE) inhibitors on the $Mg^{2+}$ release from perfused guinea pig heart and collagenase-dispersed myocytes was studied to clarify an association of $H_2-histaminergic$ receptor-mediated $Mg^{2+}$ regulation with intracellular cAMP-degradation system. $Mg^{2+}$ efflux was stimulated in perfused hearts and myocytes by IBMX (3-isobutyl-1-methylxanthine), a calmodulin-sensitive PDE inhibitor, but not by RO 20-1724(4-(3-butoxy-4-methoxybenzyl)-2-imidazolidinone) or papaverine, cAMP-specific PDE inhibitors. $Mg^{2+}$ efflux was also be induced by dimaprit, a H-2-agonist. $Mg^{2+}$ effluxes induced by dimaprit were augmented by the presence of the PDE inhibitors. The augmentation of dimaprit-induced $Mg^{2+}$ effluxes by the PDE inhibitors were inhibited by ranitidine, a $H_2-antagonist$, and imipramine, a $Na^{+}-Mg^{2+}$ exchange inhibitor, in perfused hearts and myocytes and were also inhibited by amiloride in perfused hearts. These results suggest that the $H_2$-stimulated $Mg^{2+}$ effluxes from guinea pig heart can be regulated by the cytosolic nonspecific-dependent PDE systems and that it is induced by the $Na^{+}-Mg^{2+}$ exchanger stimulation.

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ATP가 마우스 담관세포의 세포크기 조절에 미치는 영향 (Effects of ATP on Regulatory Volume Decrease in Mouse Cholangiocytes)

  • 박재승
    • 대한임상검사과학회지
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    • 제48권2호
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    • pp.153-157
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    • 2016
  • ATP 분비 경로는 담관세포종 세포주를 포함한 일부 세포의 RVD 조절에 있어서 주요한 조절 역할을 수행할 것으로 생각되나, 정상 담관세포의 RVD에 있어서의 역할은 잘 알려져 있지 않다. 정상 담관세포의 RVD에 있어서 세포 외 ATP와 ATP 경로의 역할을 알아보기 위하여, 정상마우스에서 담관세포를 분리하여 연구에 이용하였다. BDCCs의 크기 변화는 정량측정 비디오현미경을 이용하여 횡단면을 간접 측정하였다. 정상마우스의 BDCCs의 횡단면은 저장액에서 노출한 후 10분에 $1.20{\pm}0.02$ (n=20)이었으나, 40분에는 $1.06{\pm}0.03$로 감소하였다. ATP와 ATP 가수분해 효소인 아피라아제 또는 P2 수용체 차단제인 슈라민 RVD 과정 중에 처리 하였으나 처리하지 않은 대조군과 중요한 차이를 보이지 않았다. 더 나아가, PKC 저해제인 비신돌아마이드 I 과 Ro 31-8220을 처리하여 RVD에 미치는 영향을 알아 보았으나 대조군과 중요한 차이를 보이지 않았다. 이러한 결과들에서 정상 마우스 담관세포는 담관세포종 세포주와 다른 결과를 보였으며, 정상 마우스의 RVD에 있어서 ATP는 중요한 역할을 하지 않음을 알 수 있었다.