• Title/Summary/Keyword: and receptors

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

  • Kim, Yae-Ji;Cho, Sung-Pil;Lee, Hui-Ju;Hong, Geum-Lan;Kim, Kyung-Hyun;Ryu, Si-Yun;Jung, Ju-Young
    • Journal of Korean Medicine for Obesity Research
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    • v.22 no.1
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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.

Rhodopsin Chromophore Formation and Thermal Stabilities in the Opsin Mutant E134Q/M257Y (옵신 mutant E134Q/M257Y의 로돕신 형성과 열안정성 분석)

  • Kim, Jong-Myoung
    • Journal of Life Science
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    • v.22 no.7
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    • pp.863-870
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    • 2012
  • Rhodopsin, a dim light photoreceptor, has been regarded as one of the model systems for the structural and functional study of G protein-coupled receptors (GPCRs). Constitutively active mutant GPCRs leading to the activation of heterotrimeric GDP/GTP-binding protein signaling in the absence of ligand binding are of interest for the study of the activation mechanism in GPCRs. The present study focused on the opsin mutant E134Q/M257Y, which showed a moderate level of constitutive activity and the formation of two distinct rhodopsin chromophores with absorption maxima of 500 nm and 380 nm, depending on the presence of an inverse agonist, 11-cis-retinal, and an agonist, all-trans-retinal, respectively. Reconstitution of the mutant rhodopsin upon incubation with different ratios of 11-cis-retinal and the all-trans-retinal, as well as upon sequential binding of the two retinals, indicated its preferential binding to 11-cis-retinal. The thermal stability of the 11-cis-retinal-bound form of the E134Q/M257Y mutant was lower than that of the mutants containing a single replacement but higher than that of the all-trans-retinal-bound forms. The mutant also showed a lower stability in its opsin state as compared with that of the wild-type opsin but had little effects on the binding affinity to 11-cis-retinal. Information obtained in this study will be helpful for analyzing the structural changes associated with the activation of rhodopsin and GPCRs.

Studies on Adherance Inhibition and Detachment of Helicobacter pylori Using Egg Yolk IgY and Additives (난황항체 및 첨가제를 이용한 헬리코박터 파이로리의 부착 억제)

  • 구재경;최태부
    • KSBB Journal
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    • v.16 no.1
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    • pp.41-47
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    • 2001
  • H. pylori is known to be a key pathogen of chronic gastric and duodenal ulcers. Bacterial adhesion to hosts is an essential step for bacterial infection and the inhibition of this adhesion provides a possible method for the treatment of the infection. The inhibitory effect of antibody lgY, produced from immunized hens with H. pylori antigen, was studied in vitro. The inhibition of H. pylori adhesion to AGS was as high as 90% using 0.5mg/ml of lgY, and almost 80% of the detachmentwas also achieved. The inhibitory effect of adhesion-inhibition candidates was investigated. Additives in combination with lgY increased the adhesion-inhibiting effect by about 30-50%. However, the adhesion molecules of H. pylori were varied and complex, therefore the further studies are necessary to develop an adhesion inhibitor and effective enough to be employed for the treatment of H.pylori, in vivo.

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Effect of Sojukgunbihwan granule on Gastric Motility in Rats (소적건비환과립(消積健脾丸顆粒)이 흰쥐의 위운동성(胃運動性)에 미치는 영향)

  • Hong, Jong-Hee;Kim, Jin-Sung;Ryu, Bong-Ha;Yoon, Sang-Hyub
    • The Journal of Internal Korean Medicine
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    • v.27 no.1
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    • pp.276-287
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    • 2006
  • Background & Objective : The herbal medicine Sojukgunbihwan granule has been used for the treatment of functional dyspepsia, generally categorized as a gastric dysmotility disease. However, its mechanisms are not yet well known. Therefore, the effects of Sojukgunbihwan granules on gastric motility in rats was investigated. Methods : The myoelectrical activity of the gastric smooth muscle was recorded by a bipolar electrode placed at the gastric antrum of rats. The contractile waves were measured for 30 minutes before and after intragastric administration of each solution(normal saline, Pyungwisan 40mg/kg, Sojukgunbihwan granules 60mg/kg) and expressed as the motility index. Gastric emptying was measured by the number of glass beads expelled from the stomach(containing one hundred 1mm glass beads) within an hour after glass beads and test drugs(normal saline, Pyungwisan 40mg/kg, Pyungwisan 120mg/kg, Sojukgunbihwan granules 60mg/kg, Sojukgunbihwan granules 180mg/kg) were administered. In another series of experiments to evaluate the mechanisms of Sojukgunbihwan granules under delayed conditions, the rats were treated with atropine sulfate(1 mg/kg, s.c.), cisplatin(10mg/kg, i.p.), and NAME($N^G$-nitro-L-arginine methyl ester, 75mg/kg, s.c.) respectively. Results : Intragastric administration of Sojukgunbihwan granules increased the myoelectrical activity significantly, gastric motility index rose 25%, and gastric emptying of glass beads was significantly enhanced over a period of 60minutes. Under the delayed gastric emptying induced by atropine sulfate, cisplatin, and NAME, Sojukgunbihwan granules aggravated gastric emptying in the atropine sulfate($5.71{\pm}3.45\;vs\;3.71{\pm}4.42$) and cisplatin($13.86{\pm}3.53\;vs\;5.14{\pm}5.05$, p<0.01) treated groups, but enhanced gastric emptying in the NAME treated group($5.00{\pm}3.21\;vs\;11.71{\pm}5.65$, p<0.05). Conclusions : Results suggest that Sojukgunbihwan granules stimulate gastric motility through cholinergic and 5-hydroxytryptamine 3 receptors. Results are indicative of Sojukgunbihwan as an especially effective remedy in dysmotility-like functional dyspepsia with impaired reservoir functions such as gastric adaptive relaxation.

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A Study on the Restoration Priority Decision Model of Oil Contaminated Military Sites (유류로 오염된 군사기지의 복원 우선순위 결정 모델 연구)

  • Roh, Kyung-Hee;Yang, Im-Suk;Han, Uk
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2000.05a
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    • pp.59-63
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    • 2000
  • At military bases, environmental restoration activities resulting from oil contamination are growing concerns of preventing adverse effects on human health and environments. Its technologies are still under developing stage through some countries such as United States and Germany. This study is focused on developing model for a decision-maker to assist the restoration priority under the situation of limited resources such as budget and time. The Model, named the Base Restoration Priority Decision model(BRP model), is composed of the three factors : oil contaminants receptors, and the potential migration pathways. Each risk rating of factor is combined in the 27 matrix blocks and set immediate, moderate, and delayed action category designated restoration priority. This is categorized to group sites into three degree using the simplest of assessment system. As a result, the model will be able to apply to the effective allocation of resources for the restoration by any decision-maker because the model is easy to understand. Also, the continuous study will have established risk assessment system for the restoration of contaminated military with this study as the starting point.

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EFFECTS OF PROINFLAMMATORY CYTOKINE ON THE BIOLOGICAL ACTIVITIES OF PROMYELOCYTIC CELL LINE HL - 60 (Promyelocytic Cell Line HL - 60의 생물학적 활성에 대한 기염증성 Cytokines의 작용)

  • Lee, In-Kyu;Oh, Kwi-Ok;Kim, Hyung-Seop
    • Journal of Periodontal and Implant Science
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    • v.25 no.3
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    • pp.635-647
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    • 1995
  • Human polymorphonuclear leukocytes(PMN) constitute a first line of defense against all forms of injury and microbial challenge, which share a common cell lineage with macrophage. Microbial component LPS activates macrophages to produce IL-1, MIP-1${\alpha}$, -1${\beta}$, TNF-${\alpha}$ and IL-6, etc. Those cytokines have autocrine function to the macrophages, and paracrine function to other cell such as PMN and affect them to produce some biological functions. Having a responsive homogeneous cell line, HL-60, offers us the possibility of studying extensively on the function of PMN, which were not possible previously with peripheral PMN, due to the short-lived nature and difficulty of getting a purified PMN. In the present study, I performed MIP-1 receptor binding assay using HL-60 cell and human peripheral PMN. Also, in vitro antimicrobial assay was performed using differentiated or undifferentiated HL-60 cell. Differentiation was induced by treatment with 500 M of $N^6,O^2-dibutyryl$ adenosine 3'5' cyclic monophosphate(dbcAMP) (PMN-like cell), or 20ng/ml of 12-O-tetradecanoylphorbol-13-acetate(TPA) (macrophage/monocyte-like cell). Receptors for MIP-1${\alpha}$ were identified on dbcAMP-treated HL-60 as well as peripheral PMN. However, bound radioactive MIP-1${\alpha}$ on differentiated HL-60 was much higher than that of peripheral PMN, which suggest receptor number of differentiated HL-60 cell is higher than that of peripheral PMN. Although both of TPA and dbcAMP treatment significantly enhanced antimicrobial action of HL-60 cell, dbcAMP-treated cell(PMN-like HL-60) killed S.aureus more effectively in this experiment. TPA or dbcAMP treatment significantly enhanced antimicrobial action of undifferentiated HL-60 cell. MIP-1${\alpha}$ further increased enhancing effect of TPA or dbcAMP. IL-1${\alpha}$, however, increased only dbcAMP-induced enhancing effect of antimicrobial action of HL-60 cell. These results suggest that differentiated HL-60 cell could replace peripheral PMN in analysis of various biological functions of cytokines on PMN cell.

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The Effects of Anticholinesterase Drugs on Gastric Motility (항콜린에스테라제 약물의 소화관 운동성에 대한 영향)

  • Choi, Hyoung-Chul;Kim, Jong-Ho;Ha, Jeoung-Hee;Lee, Kwang-Yoon;Kim, Won-Joon;Kwak, Dong-Suk;Kim, Sung-Hee;Song, Phil-Hyun;Yeo, Ji-Hyun
    • Journal of Yeungnam Medical Science
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    • v.16 no.2
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    • pp.318-325
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    • 1999
  • Background: Anticholinesterase drug inhibits acetylcholinesterase(AChE), induce accumulation of acetylcholine(ACh) near cholinergic receptors and cholinergic stimulation. This experiment was performed to study the effects of anticholinesterase drugs on gastric motility and the effect of ethanol on anticholinesterase drug-induced motility change. Materials and Methods: After excision of stomach, $2{\times}10mm$ circular muscle strips were made, which were then fixed to the isolated muscle chamber. An isometric tension transducer was used to measure the contraction change of the gastric smooth muscle strips after drug addition. Results: Fenthion, an irreversible anticholinesterase drug, increased ACh induced contraction of gastric smooth muscle strips and PAM, a cholinesterase activator, antagonized this action. Physostigmine, a reversible anticholinesterase drug, also increased the ACh induced contraction. The gastric motility was decreased by PAM. Ethanol, which is known to induce smooth muscle relaxation, inhibited the increase of contraction by fenthion. Conclusion: These results indicate that irreversible and reversible anticholinesterase drugs increase gastric motility and antagonized by cholinesterase activating drugs. And when exposed to both ethanol and anticholinesterase drug, gastric motility was decreased by the smooth muscle relaxation effect by ethanol.

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Isomeric Folate-Conjugated Polymeric Micelles Bind to Folate Receptors and Display Anticancer Effects

  • Dong, Qing;Xie, Zuo-Xu;Xie, Cao;Lu, Wei-Yue;Zhang, Qian;Li, Xue;Liu, Min
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.17
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    • pp.7363-7369
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    • 2014
  • The present study aimed to prepare and evaluate polymeric micelles conjugated with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups for antitumor efficacy. The isomeric block copolymers, ${\alpha}$- and ${\gamma}$-folate-polyethyleneglycol-distearoyl phosphatidylethanolamine (${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE), were produced by solid phase peptide synthesis. Three types of doxorubicin (DOX)-loaded polymeric micelles (MPEG-DSPE-DOX and ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPEDOX micelles) were prepared via the film formation method. Compared with MPEG-DSPE-DOX micelles, the ${\alpha}$- / ${\gamma}$-Fol-PEG-DSPE-DOX micelles presented a higher cellular uptake behavior in the live cell study. Cell viability percentages were 81.8%, 57.3%, 56.6% at 2 hours for MPEG-DSPE-DOX, ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles, respectively (p<0.05). Using the KB xenograft tumor model, both ${\alpha}$- and ${\gamma}$-folate-conjugated micelles were found to have better antitumor effects with lower toxicity in comparison with MPEG-DSPE-DOX micelles. No difference in in vivo antitumor efficacy was found between ${\alpha}$- and ${\gamma}$-Fol-PEG-DSPE-DOX micelles. The folate-conjugated micelles might be a potentially useful strategy for tumor targeting of therapeutic agents, whether grafting with folic acid through ${\alpha}$- or ${\gamma}$-carboxyl groups.

Impact of RGD Peptide Tethering to IL24/mda-7 (Melanoma Differentiation Associated Gene-7) on Apoptosis Induction in Hepatocellular Carcinoma Cells

  • Bina, Samaneh;Shenavar, Fatemeh;Khodadad, Mahboobeh;Haghshenas, Mohammad Reza;Mortazavi, Mojtaba;Fattahi, Mohammad-Reza;Erfani, Nasrollah;Hosseini, Seyed Younes
    • Asian Pacific Journal of Cancer Prevention
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    • v.16 no.14
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    • pp.6073-6080
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    • 2015
  • Background: Melanoma differentiation-associated gene-7 (MDA-7)/interleukin-24 (IL-24), a unique tumor suppressor gene, has killing activity in a broad spectrum of cancer cells. Herein, plasmids producing mda-7 proteins fused to different RGD peptides (full RGD4C and shortened RGD, tRGD) were evaluated for apoptosis induction with a hepatocellular carcinoma cell line, Hep-G2. The study aim was to improve the apoptosis potency of mda-7 by tethering to RGD peptides. Materials and Methods: Three plasmids including mda-7, mda-7-RGD and mda-7-tRGD genes beside a control vector were transfected into Hep-G2 cells. After 72 hours incubation, cell viability was evaluated by MTT assay. In addition, the rate of apoptosis was analyzed by flow cytometry using PI/annexin staining. To detect early events in apoptosis, 18 hours after transfection, expression of the BAX gene was quantified by real time PCR. Modeling of proteins was also performed to extrapolate possible consequences of RGD modification on their structures and subsequent attachment to receptors. Results and Conclusions: In MTT assays, while all mda-7 forms showed measurable inhibition of proliferation, unmodified mda-7 protein exhibited most significant effect compared to control plasmid (P<0.001). Again, flow cytometry analysis showed a significant apoptosis induction by simple mda-7 gene but not for those RGD-fused mda-7 proteins. These findings were also supported by expression analysis of BAX gene (P<0.001). Protein modelling analysis revealed that tethering RGD at the end of IL-24/Mda7 disrupt attachment to cognate receptor, IL-20R1/IL-20R2. In conclusion, fusion of RGD4C and shortened RGD peptides to carboxyl terminal of mda7, not only reduce apoptosis property in vitro but also disrupt receptor attachment as demonstrated by protein modelling.

The Inhibitory Effects of 5-Hydroxytryptamine on the Intestine (5-Hydroxytryptamine의 장억제작용(腸抑制作用))

  • Chang, Il-Hwan
    • The Korean Journal of Pharmacology
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    • v.2 no.1 s.2
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    • pp.71-82
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    • 1966
  • The inhibitory effect of 5-hydroxytryptamine (5-HT) on the isolated intestinal strips of the tortoise (Amyda japonica), rat, rabbit and guinea pig was investigated. 1) The strips from the middle or lower part of the tortoise intestine responded with relaxation to 5-HT $(10^{-9}{\sim}10^{-5}g/ml)$, and the magnitude of the relaxation was proportional to the dose of 5-HT. The rectal part of the tortoise intestine, in contrast, showed contraction, the magnitude of which also was proportional to the dose of 5-HT. 2) Various blocking agents such as methysergide, morphine, tetracaine, nethalide, bretylium, hexamethonium, mecamylamine and chlorisondamine, showed no selective blocking activity on the relaxant effect of 5-HT on the tortoise intestine. The inhibitory effect of isoproterenol on the tortoise intestine, however, was selectively blocked by nethalide, and the stimulatory effect of 5-HT on the rectal part of the tortoise was blocked by methysergide. 3) In the presence of 5-HT, the stimulatory effect of DMPP on the tortoise intestine was remarkably attenuated, whereas that of acetylcholine and $BaCl_2$ was little affected. In the presence of isoproterenol, the stimulatory effect of acetylcholine and $BaCl_2$ were affected, but that of DMPP was little affected. 4) Large dose of 5-HT($10^{-4}$g/ml) produced inhibitory effect on the strips from the distal part of the isolated colon of the rat, rabbit and guinea pig, when the strips had been exposed to 5-HT($10^{-4}$g/ml), methysergide or phen`oxybenzamine. 5) Bretylium, as well as nethalide, abolished or remarkably reduced, in a few cases of the experiments, the inhibitory effect of the large dose of 5-HT on the distal part of the colon, whereas morphine did not affect it. 6) The ileal strips of the guinea pig also showed relaxation, as in the colonic strips, having been exposed to the large dose of 5-HT or phenoxybenzamine. This effect, however, was not obsered in the case of the rabbit ileum. 7) The property of the action-site of 5-HT in the tortoise intestine seemd to be different from the 5-HT receptors which have been revealed by several investigators. 8) Adrenergic component seemed to be participated in the inhibitory effect of 5-HT on the colon of the rat and rabbit.

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