• Title/Summary/Keyword: cyclase

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Nitric Oxide Production Ability and its Formation Mechanisms in Macrophage TIB 71 Cell Line by Polysaccharide Extracted from Ganoderma lucidum (영지버섯 다당체의 Nitric Oxide 생성능 및 생성기전 연구)

  • 김성환
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.27 no.2
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    • pp.333-337
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    • 1998
  • This study was carried out to get infomation on the nitric oxide production ability and its formation mechanisms of polysaccharides extracted from Ganoderma lucidum(PSG) by using murine macrophage cell line. The cultured mycelial cells of Ganoderma lucidum were extracted by alkali, and than neutralized by acid. The extract were passed through the column of DEAE cellulose for more purification. The neutral fraction was concentrated and precipitated with 95% ethanol. The precipitate was lyophilized and PSG was obtained. The immunomodulating effects of PSG on macrophage were performed by using murine macrophage cell line ATCC TIB 71 cells with PSG 0.5mg. PSG alone could not induce the production of nitrite, but it had a significant potential effect on nitrite secretion when the cells were primed and triggered with BCG and Interferon(IFN)-${\gamma}$. Also it was prominent by using calcium channel blocker(verapamil) and adenylate cyclase activator(forskolin).

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Action of Opiates on LHRH Release in vitro and Adenylate Cyelase Activity by Rat Hypothalamus (시상하부의 is vitro LHRH 분비와 adenylase cyclase 활성에 미치는 opiate의 작용)

  • 김경진;이병주조완규
    • The Korean Journal of Zoology
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    • v.30 no.4
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    • pp.341-350
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    • 1987
  • LHRH분비와 환denylate cyclase활성에 미치는 PGE2, Opioid, 그리고 Ca2+의 영향을 흰쥐의 시상하부 조직을 사용하여 조사하였다. K+(30mM)에 의한 LHR광분비촉진은 Ca2+의존적인데 반하여, PGE2에 의해 촉진되는 LHR노 분비는 세포의 Ca2+농도에 의존하지 않았다. PGE2에 의한 LHR기 분비와 CAMP합성은 PGE2농도(1$\times$10-7M-1$\times$10-4M)에 비례하여 촉진되었으며, $\beta$-endorphin (1x10-3M)은 PGEa에 의한 LHRH 분비촉진과 CAMP합성을 공히 억제하였다. 오피오이드 수용체의 길항제인 Naloxone(Ix10-"M)은 $\beta$-endorphin에 의한 저해효과를 극복시켜서, LHR광 분비와 CAMP합성은 각각 회복되었으나, CAMP합성은 부분적인 회복을 보인 반면에, LHRH분비는 PGE2에 의한 촉진효과보다도 더 활성화되었다. 결론적으로 LHRH분비에 미치는 오퍼오이드의 억제작용은 PGE2-cAMP의 세포내 전달과정을 저해함으로써 유발되는것으로 추정 된다.정 된다.

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Cloning of Isopenicillin N Synthase Gene from Lysobacter lactamgenus

  • Ryu, Jae-Kook;Nam, Doo-Hyun
    • Journal of Microbiology and Biotechnology
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    • v.7 no.6
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    • pp.373-377
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    • 1997
  • The gene for isopenicillin N synthase (cyclase; IPNS) was cloned from Lysobacter lactamgenus using DNA probe amplified with primers based on the consensus sequences of isopenicillin N synthase genes of other ${\beta}$-lactam-producing microorganisms. The genomic library of L. lactamgenus using pUC18 plasmid cloned at the SacI site were screened with the PCR-generated DNA probe and three positive clones were isolated. Enzyme activities in E. coli clones were confirmed by bioassay and HPLC assay. Throughout the functional mapping, it was observed that the gene for isopenicillin N synthase is located at the 1.3-kb XhoI-BamHI fragment of insert of positive clones. Nucleotide sequencing at both ends of the XhoI-BamHI fragment revealed that IPNS of L. lactamgenus has the common amino acid sequences at amino- and carboxy-termini.

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Endoplasmic Reticulum Stress Induces CAP2 Expression Promoting Epithelial-Mesenchymal Transition in Liver Cancer Cells

  • Yoon, Sarah;Shin, Boram;Woo, Hyun Goo
    • Molecules and Cells
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    • v.44 no.8
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    • pp.569-579
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    • 2021
  • Cyclase-associated protein 2 (CAP2) has been addressed as a candidate biomarker in various cancer types. Previously, we have shown that CAP2 is expressed during multi-step hepatocarcinogenesis; however, its underlying mechanisms in liver cancer cells are not fully elucidated yet. Here, we demonstrated that endoplasmic reticulum (ER) stress induced CAP2 expression, and which promoted migration and invasion of liver cancer cells. We also found that the ER stress-induced CAP2 expression is mediated through activation of protein kinase C epsilon (PKCε) and the promotor binding of activating transcription factor 2 (ATF2). In addition, we further demonstrated that CAP2 expression promoted epithelial-mesenchymal transition (EMT) through activation of Rac1 and ERK. In conclusion, we suggest that ER stress induces CAP2 expression promoting EMT in liver cancer cells. Our results shed light on the novel functions of CAP2 in the metastatic process of liver cancer cells.

The FMRFamide Neuropeptide FLP-20 Acts as a Systemic Signal for Starvation Responses in Caenorhabditis elegans

  • Kang, Chanhee;Avery, Leon
    • Molecules and Cells
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    • v.44 no.7
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    • pp.529-537
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    • 2021
  • Most animals face frequent periods of starvation throughout their entire life and thus need to appropriately adjust their behavior and metabolism during starvation for their survival. Such adaptive responses are regulated by a complex set of systemic signals, including hormones and neuropeptides. While much progress has been made in identifying pathways that regulate nutrient-excessive states, it is still incompletely understood how animals systemically signal their nutrient-deficient states. Here, we showed that the FMRFamide neuropeptide FLP-20 modulates a systemic starvation response in Caenorhabditis elegans. We found that mutation of flp-20 rescued the starvation hypersensitivity of the G protein β-subunit gpb-2 mutants by suppressing excessive autophagy. FLP-20 acted in AIB neurons, where the metabotropic glutamate receptor MGL-2 also functions to modulate a systemic starvation response. Furthermore, FLP-20 modulated starvation-induced fat degradation in a manner dependent on the receptor-type guanylate cyclase GCY-28. Collectively, our results reveal a circuit that senses and signals nutrient-deficient states to modulate a systemic starvation response in multicellular organisms.

Effects of Phamacopuncture Therapy Using Cervi Pantotrichum Cornu at BL23.BL52 on the Cerebral Hemodynamics in Rats (신유.지실 녹용약침이 뇌혈류역학에 미치는 영향)

  • Lee, Seok-Jin;Jeong, Hyun-Woo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.23 no.1
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    • pp.50-56
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    • 2009
  • The present study was designed to investigate the effects of Phamacopuncture therapy using Cervi Pantotrichum Cornu (PC) at BL23 BL52 on the regional cerebral blood flow (rCBF) and mean arterial blood pressure (MABP) in normal rats, then the related mechanisms were also investigated. In addition, the present author also investigated the effects of phamacopuncture therapy at BL23.BL52 on the rCBF in cerebral ischemic rats. The results in normal rats were as follows; PC (3 mg/kg and 5 mg/kg) at BL23 BL52 significantly increased rCBF but decreased MABP. This result suggests that PC at BL23 BL52 significantly increased rCBF by dilating pial arterial diameter. Increase of PC (5 mg/kg)-induced rCBF was significantly inhibited by pretreatment with indomethacin (1 mg/kg, i.p.), an inhibitor of cyclooxygenase and methylene blue ($10{\mu}g/kg$, i.p.), an inhibitor of guanylate cyclase. Decrease of PC (5 mg/kg)-induced MABP was significantly increased by pretreatment with methylene blue but was decreased by pretreatment with indomethacin. These results suggested that the action of PC (5 mg/kg) was mediated by guanylate cyclase. The results in cerebral ischemic rats were as follows ; The rCBF was significantly and stably increased by PC (5 mg/kg) during the period of cerebral reperfusion, which contrasted with the findings of rapid and marked increase in Control group. In conclusion, these results suggest that phamacopuncture therapy using Carthami flos at BL23 BL52 can increase rCBF in normal state, and improve stability of rCBF in ischemic state. In addition, the present author also suggest that related mechanisms are involved in guanylate cyclase pathway.

Calcitonin Gene-related Peptide Suppresses Pacemaker Currents by Nitric Oxide/cGMP-dependent Activation of ATP-sensitive K+ Channels in Cultured Interstitial Cells of Cajal from the Mouse Small Intestine

  • Choi, Seok;Parajuli, Shankar Prasad;Yeum, Cheol Ho;Park, Chan Guk;Kim, Man Yoo;Kim, Young Dae;Cha, Kyoung Hun;Park, Young Bong;Park, Jong Seong;Jeong, Han Seong;Jun, Jae Yeoul
    • Molecules and Cells
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    • v.26 no.2
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    • pp.181-185
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    • 2008
  • The effects of calcitonin gene-related peptide (CGRP) on pacemaker currents in cultured interstitial cells of Cajal (ICC) from the mouse small intestine were investigated using the whole-cell patch clamp technique at $30^{\circ}C$. Under voltage clamping at a holding potential of -70 mV, CGRP decreased the amplitude and frequency of pacemaker currents and activated outward resting currents. These effects were blocked by intracellular $GDP{\beta}S$, a G-protein inhibitor and glibenclamide, a specific ATP-sensitive $K^+$ channels blocker. During current clamping, CGRP hyperpolarized the membrane and this effect was antagonized by glibenclamide. Pretreatment with SQ-22536 (an adenylate cyclase inhibitor) or naproxen (a cyclooxygenase inhibitor) did not block the CGRP-induced effects, whereas pretreatment with ODQ (a guanylate cyclase inhibitor) or L-NAME (an inhibitor of nitric oxide synthase) did. In conclusion, CGRP inhibits pacemaker currents in ICC by generating nitric oxide via G-protein activation and so activating ATP-sensitive $K^+$ channels. Nitric oxide- and guanylate cyclase-dependent pathways are involved in these effects.