• Title/Summary/Keyword: phospholipase A2

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Effects of Ginsenosides on the Mechanism of Histamine Release in the Guinea Pig Lung Mast Cells Activated by Specific Antigen-Antibody Reactions

  • Ro, Jai-Youl;Ahn, Young-Soo;Kim, Kyung-Hwan
    • The Korean Journal of Physiology and Pharmacology
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    • v.1 no.4
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    • pp.445-456
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    • 1997
  • We previously reported that some components of ginsenosides decreased mediator releases evoked by the activation of mast cells with specific antigen-antibody reactions. This study aimed to assess the effects of ginsenosides ($Rb_2$, Re) on the mechanism of histamine release in the mast cell activation. We partially purified guinea pig lung mast cells by using enzyme digestion, the rough and the discontinuous percoll density gradient method. Mast cells were sensitized with $IgG_1$ and challenged with ovalbumin (OA). Histamine was assayed by fluorometric analyzer, leukotrienes by radioimmunoassay. Phospholipase D (PLD) activity was assessed more directly by the production of $[^3H]phosphatidylbutanol$ (PBut) which was produced by PLD-mediated transphosphatidylation in the presence of butanol. The amount of 1,2- diacylglycerol (DAG) were measured by the $[^3H]DAG$ labeled with $[^3H]palmitic$ acid or $[^3H]myristic$ acid. Pretreatment of $Rb_2$ ($300\;{\mu}g$) significantly decreased histamine release by 60%, but Re ($300\;{\mu}g$) increased histamine release by 34%. Leukotrienes release in $Rb_2$ was decreased by 40%, Re was not affected in the leukotrienes release during mast cell activations. An increasing PLD activity during mast cell activation was decreased by the dose-dependent manner in the pretreatment of $Rb_2$, but Re pretreatment facilitated the increased PLD activity during mast cell activation. The amount of DAG produced by phospholipase C (PLC) activity was decreased by $Rb_2$ pretreatment, but Re pretreatment was not affected. The amount of mass DAG was decreased by $Rb_2$ and Re pretreatment during mast cell activation. The data suggest that $Rb_2$ purified from Korean Red Ginseng Radix inhibits the DAG which is produced by the activation of mast cells with antigen-antibody reactions via both phosphatidylinositide-PLC and phosphatidylcholine-PLD systems, and then followed by the inhibition of histamine release. However, Re increases histamine release by stimulation of DAG production, which is mediated by phosphatidylcholine-PLD system rather than by phosphatidylinositide-PLC system, but inhibits the mass DAG production. Thus, it could be inferred that other mechanisms play a role in the increase of histamine release during mast cell activation.

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Combinatorial Fine-Tuning of Phospholipase D Expression by Bacillus subtilis WB600 for the Production of Phosphatidylserine

  • Huang, Tingting;Lv, Xueqin;Li, Jianghua;Shin, Hyun-dong;Du, Guocheng;Liu, Long
    • Journal of Microbiology and Biotechnology
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    • v.28 no.12
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    • pp.2046-2056
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    • 2018
  • Phospholipase D has great commercial value due to its transphosphatidylation products that can be used in the food and medicine industries. In order to construct a strain for use in the production of PLD, we employed a series of combinatorial strategies to increase PLD expression in Bacillus subtilis WB600. These strategies included screening of signal peptides, selection of different plasmids, and optimization of the sequences of the ribosome-binding site (RBS) and the spacer region. We found that using the signal peptide amyE results in the highest extracellular PLD activity (11.3 U/ml) and in a PLD expression level 5.27-fold higher than when the endogenous signal peptide is used. Furthermore, the strain harboring the recombinant expression plasmid pMA0911-PLD-amyE-his produced PLD with activity enhanced by 69.03% (19.1 U/ml). We then used the online tool \RBS Calculator v2.0 to optimize the sequences of the RBS and the spacer. Using the optimized sequences resulted in an increase in the enzyme activity by about 26.7% (24.2 U/ml). In addition, we found through a transfer experiment that the retention rate of the recombinant plasmid after 5 generations was still 100%. The final product, phosphatidylserine (PS), was successfully detected, with transphosphatidylation selectivity at 74.6%. This is similar to the values for the original producer.

Activation of Phospholipase Cγ by Nitric Oxide in Choriocarcinoma Cell Line, BeWo Cells (Choriocarcinoma 세포주 BeWo 세포에서 nitric oxide에 의한 phospholipase Cγ 의 활성)

  • 차문석;곽종영
    • Journal of Life Science
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    • v.13 no.6
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    • pp.849-855
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    • 2003
  • Nitric oxide (NO) plays an important role as a signaling molecule in the proliferation of placenta trophoblasts. In this study, we investigated the effect of NO on the activation of phospholipase C (PLC) in BeWo cells, choriocar-cinoma cell line. Sodium nitroprusside (SNP), an agent to produce NO spontaneously in cells, alone increased $[^3H]$ thymidine incorporation of BeWo cells, indicating NO stimulates proliferation of the cells. NO-induced proliferation of BeWo cells was blocked by U73122, an inhibitor of PLC, suggesting that NO-induced PLC activation is involved in the cell proliferation. NO also stimulated extracellular signal-regulated kinase (ERK) in BeWo cells, indicated by increased phosphorylation of ERK1/2 in Western blotting using anti-phospho-ERK1/2 antibody. NO-induced phos-phorylation of ERK1/2 was not abrogated by U73122. $PLC\gamma_1$l but not$PLC\gamma_2$ was tyrosine phosphorylated by SNP in immunoprecipitation assay using anti-$PLC\gamma_1$/$PLC\gamma_2$ antibodies, and SNP-induced phosphorylation of $PLC\gamma_1$ was abrogated by pre-treatment of cells with genistein and PD98059, indicating that NO induced-phosphorylation of $PLC\gamma_1$ is mediated by ERK. These results suggest that NO stimulates the proliferation of BeWo cells through ERK and $PLC\gamma_1$.

Inhibition of Phospholipase $C{\Upsilon}1$ and Cancer Cell Proliferation by Lignans and Flavans from Machilus thunbergii

  • Lee, Ji-Suk;Kim, Jin-Woong;Yu, Young-Uck;Kim , Young-Choong
    • Archives of Pharmacal Research
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    • v.27 no.10
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    • pp.1043-1047
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    • 2004
  • Thirteen compounds were isolated from the $CH_2Cl_2$ fraction of Machilus thunbergii as phospholipase $C{\Upsilon}1\;(PLC{\Upsilon}1)$ inhibitors. These compounds were identified as nine lignans, two neolignans, and two flavans by spectroscopic analysis. Of these, 5,7-di-O-methyl-3',4'-methylenated (-)-epicatechin (12) and 5,7,3'-tri-O-methyl (-)-epicatechin (13) have not been reported previously in this plant. In addition, seven compounds, machilin A (1), (-)-sesamin (3), machilin G (5), (+)-galbacin (9), licarin A (10), (-)-acuminatin (11) and compound 12 showed dose-dependent potent inhibitory activities against $PLC{\Upsilon}1$ in vitro with $IC_{50}$ values ranging from 8.8 to 26.0 ${\mu}M$. These lignans, neolignans, and flavans are presented as a new class of $PLC{\Upsilon}1$ inhibitors. The brief study of the structure activity relationship of these compounds suggested that the benzene ring with the methylene dioxy group is responsible for the expression of inhibitory activities against $PLC{\Upsilon}1$. Moreover, it is suggested that inhibition of $PLC{\Upsilon}1$ may be an important mechanism for an antiproliferative effect on the human cancer cells. Therefore, these inhibitors may be utilized as cancer chemotherapeutic and chemopreventive agents.

Overexpression of ginseng patatin-related phospholipase pPLAIIIβ alters the polarity of cell growth and decreases lignin content in Arabidopsis

  • Jang, Jin Hoon;Lee, Ok Ran
    • Journal of Ginseng Research
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    • v.44 no.2
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    • pp.321-331
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    • 2020
  • Background: The patatin-related phospholipase AIII family (pPLAIIIs) genes alter cell elongation and cell wall composition in Arabidopsis and rice plant, suggesting diverse commercial purposes of the economically important medicinal ginseng plant. Herein, we show the functional characterization of a ginseng pPLAIII gene for the first time and discuss its potential applications. Methods: pPLAIIIs were identified from ginseng expressed sequence tag clones and further confirmed by search against ginseng database and polymerase chain reaction. A clone showing the highest homology with pPLAIIIβ was shown to be overexpressed in Arabidopsis using Agrobacterium. Quantitative polymerase chain reaction was performed to analyze ginseng pPLAIIIβ expression. Phenotypes were observed using a low-vacuum scanning electron microscope. Lignin was stained using phloroglucinol and quantified using acetyl bromide. Results: The PgpPLAIIIβ transcripts were observed in all organs of 2-year-old ginseng. Overexpression of ginseng pPLAIIIβ (PgpPLAIIIβ-OE) in Arabidopsis resulted in small and stunted plants. It shortened the trichomes and decreased trichome number, indicating defects in cell polarity. Furthermore, OE lines exhibited enlarged seeds with less number per silique. The YUCCA9 gene was downregulated in the OE lines, which is reported to be associated with lignification. Accordingly, lignin was stained less in the OE lines, and the expression of two transcription factors related to lignin biosynthesis was also decreased significantly. Conclusion: Overexpression of pPLAIIIβ retarded cell elongation in all the tested organs except seeds, which were longer and thicker than those of the controls. Shorter root length is related to auxinresponsive genes, and its stunted phenotype showed decreased lignin content.

Role of Group II Phospholipase $A_2$ in the Pulmonary Oxidative Stress of the Acute Lung Injury Induced by Gut Ischemia-Reperfusion (장의 허혈-재관류로 유도된 급성 폐손상에서 산화성 스트레스에 관여하는 group II phospholipase $A_2$의 역할)

  • Jheon, Sang-Hoon;Kim, Keun;Lee, Sang-Cheol;Kim, Seong-Eun;Lee, Young-Man;Lee, Jong-Tae
    • Journal of Chest Surgery
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    • v.35 no.7
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    • pp.501-510
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    • 2002
  • Background: The various pathogeneses of acute respiratory distress syndrome have been suggested but not established yet. In the present study, the role of group II phospholipase $A_2$($PLA_2$) in the pathogenesis of gut ischemia-reperfusion(I/R) induced acute lung injury (ALI), especially in the pulmonary oxidative stress with infiltration of neutrophils was investigated. Material and Method: To induce ALI, reperfusion of mesentery was done for 120 min after clamping of superior mesenteric artery for 60 min in Sprague-Dawley rats that weighed about 300g. To exmaine the role of group II $PLA_2$ in ALI, especially endothelial injury associated with the action of neutrophils, lung myeloperoxidase activity, lung leak index, bronchoalveolar lavage fluid protein were measured, and pulmonary $PLA_2$ activity changes in gut I/R were also measured. The role of group II $PLA_2$in the neutrophilic generation of free radicals was assessed by inhibiting group II $PLA_2$ with rutin, manoalide and scalaradial. Furthermore, to verify the oxidative stress in the lung, histologic and free radical detecting cytochemical electron microscopy were done. Result: After reperfusion, ALI was developed with accumulation of neutrophils in the lung, which was confirmed by the increase of myeloperoxidase activity, lung leak index and bronchoalveolar lavage protein (p<0.001). The pulmonary and intestinal group II $PLA_2$ activities significantly increased after gut I/R which were reversed by rutin(p<0.001). In vitro, cytochrome-c reduction assay denoted the inhibitory effects of rutin, scalaradial and manoalide on the production of free radicals from isolated human neutrophils. Histologically, neutrophilic accumulation and pericapillary edema in the lung after gut I/R was detected by light microscopy which was suppressed by rutin. In $CeCl_3$ cytochemical electron microscopy, the increased production of hydrogen peroxide in the lung after gut I/R was confirmed and also the production of hydrogen peroxide was decreased by rutin. Conclusion: On the basis of these experimental results, the inhibition of group II $PLA_2$ seemed to mitigate gut I/R-induced ALI by suppressing the production of free radicals from the infiltrated neutrophils. Collectively, group II $PLA_2$ seems to play a crucial role in gut I/R-induced ALI by neutrophilic oxidative stress.

Effects of Samchulkunbi-tang in Cultured Interstitial Cells of Cajal of Murine Small Intestine

  • Kim, Jung Nam;Kwon, Young Kyu;Kim, Byung Joo
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.27 no.1
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    • pp.112-117
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    • 2013
  • We studied the modulation of pacemaker activities by Samchulkunbi-tang (SCKB) in cultured interstitial cells of Cajal (ICC) from murine small intestine with the whole-cell patch-clamp technique. Externally applied SCKB produced membrane depolarization in the current-clamp mode. The pretreatment with $Ca^{2+}$-free solution and thapsigargin, a $Ca^{2+}$-ATPase inhibitor in endoplasmic reticulum, abolished the generation of pacemaker potentials and suppressed the SCKB-induced action. The application of flufenamic acid (a nonselective cation channel blocker) abolished the generation of pacemaker potentials by SCKB. However, the application of niflumic acid (a chloride channel blocker) did not inhibit the generation of pacemaker potentials by SCKB. In addition, the membrane depolarizations were inhibited by not only GDP-${\beta}$-S, which permanently binds G-binding proteins, but also U-73122, an active phospholipase C inhibitor. These results suggest that SCKB modulates the pacemaker activities by nonselective cation channels and external $Ca^{2+}$ influx and internal $Ca^{2+}$ release via G-protein and phospholipase C-dependent mechanism. Therefore, the ICC are targets for SCKB and their interaction can affect intestinal motility.

Systemic Review: The Study on Bee Venom Related to Cancer in PubMed (암관련 봉독 연구에 대한 고찰-PubMed를 이용한 Medline 검색)

  • Yun, Hyoun-Seok;Lee, Jae-Dong;Lee, Yun-Ho
    • Journal of Acupuncture Research
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    • v.17 no.4
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    • pp.69-78
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    • 2000
  • Objective : To research the trends of the study related to bee venom and cancer, and to establish the hereafter direction of the study on bee venom herbal acupuncture. Method : We searched in PubMed, with bee venom and cancer(in English, with abstract) Results : 1. We searched 28 Journals, 36 Papers. the frequency of Journals and Papers was as follows: Biochem Biophys Res Commun(4 Papers), FEBS Lett(3), Life Sci, Proc Natl Acad Sci USA, J Immunol(each 2), other 23 Journals(each 1). 2. The pattern of the study was as follows: Review article(3 Journals, 3 Papers), Epidemiologic study(1, 1), Experimental study(24, 32) In vivo 1, 1), In vitto(24, 31) 3. The involved components of bee venom were as follows: Melittin(20), Apamin(8), Phospholipase A2(3), Melittin & Phospholipase A2(3), Melittin& Tertiapin(1). 4. The involved cancer was as follows: leukemia(9), tumor(5), neuroblastoma(4), pituitary tumor and pheochromocytoma(each 3), lymphoma, astrocytoma, glioma and lung cancer(small cell carcinoma)(eacn 2), bladder carcinoma, pancreatic cancer, breast carcinoma, ovarian carcinoma and spuamous cell carcinoma(each 1) Conclusion : We concluded that the most frequent pattern of the study was in vitro experimental study with peptide components of bee venom and the most frequeni invovled cancer was leukemia.

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