Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

송호선,심상수,김희래,고명수,정재민,김용호,김명철,황연희,손의동,김윤명,명성호 대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.6

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase A2 (PLA2), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and 0.5 μM melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free PLA2 assay, we failed to observe the change of cPLA2 and sPLA2 activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.

배양 조건이 Candida albicans의 phospholipase 생성에 미치는 영향

신운섭,이경호,박주영,고춘명 대한의진균학회 1997 대한의진균학회지 Vol.2 No.2

Background : The dimorphic yeast, Candida albicans, is considered as a dangerous opportunistic pathogen in immunocompromised hosts. Several phospholipases of C. albicans are known to be secreted into the culture medium. Phospholipases have been proposed as a virulence factor in the pathoenesis of Candida infections. Objective : In order to investigate enzyme production, we examined culture condition of secreted phospholipase production from C. albicans. Methods : C. albicans ATTCC 10231 was cultivated in various media at 37℃ for 3 days. Phospholipase activity was measured by fatty acid soap precipitaiton in plate containing 0.04T lecithin, 0.1 M citrate buffer, pH 4.2 and 1.5% noble agar. Results : Phospholipase was highly induced when C. albicans was cultivated in broth medium(containing glucose 2%, albumin 0.2% and Fe^++ ion 0.01%) and Saboulaud's dextrose agar supplemented with 0.01% sodium deoxycholate. Conclusion : Highly induction of secreted phospholipase by albumin from C. albicans may be play an importans role in tissue invasion in the pathogenesis of C. albicans.

Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

Song, Ho-Sun,Kim, Hee-Rae,Ko, Myoung-Soo,Jeong, Jae-Min,Kim, Yong-Ho,Kim, Myung-Cheul,Hwang, Yeon-Hee,Sohn, Uy-Dong,Gimm, Yoon-Myoung,Myung, Sung-Ho,Sim, Sang-Soo The Korean Society of Pharmacology 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.6

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase $A_2$ ($PLA_2$), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and $0.5\;{\mu}M$ melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free $PLA_2$ assay, we failed to observe tbe change of $cPLA_2$ and $sPLA_2$ activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.

Effect of Extremely Low Frequency Electromagnetic Fields (EMF) on Phospholipase Activity in the Cultured Cells

Ho Sun Song,Hee Rae Kim,Myoung Soo Ko,Jae Min Jeong,Yong Ho Kim,Myung Cheul Kim,Yeon Hee Hwang,Uy Dong Sohn,Yoon-Myoung Gimm,Sung Ho Myung,Sang Soo Sim 대한생리학회-대한약리학회 2010 The Korean Journal of Physiology & Pharmacology Vol.14 No.6

This study was conducted to investigate the effects of extremely low frequency electromagnetic fields (EMF) on signal pathway in plasma membrane of cultured cells (RAW 264.7 cells and RBL 2H3 cells), by measuring the activity of phospholipase A₂ (PLA₂), phospholipase C (PLC) and phospholipase D (PLD). The cells were exposed to the EMF (60 Hz, 0.1 or 1 mT) for 4 or 16 h. The basal and 0.5 ՌM melittin-induced arachidonic acid release was not affected by EMF in both cells. In cell-free PLA₂ assay, we failed to observe the change of cPLA₂ and sPLA₂ activity. Also both PLC and PLD activities did not show any change in the two cell lines exposed to EMF. This study suggests that the exposure condition of EMF (60 Hz, 0.1 or 1 mT) which is 2.4 fold higher than the limit of occupational exposure does not induce phospholipases-associated signal pathway in RAW 264.7 cells and RBL 2H3 cells.

Combined Phospholipase and Lipase Catalysis for Biodiesel Production from Phospholipids-containing Oil

Yang Li,Yanfei Huang,Wei Du,Lingmei Dai,Dehua Liu 한국생물공학회 2015 Biotechnology and Bioprocess Engineering Vol.20 No.5

Free lipase-mediated biodiesel production has been considered to be promising due to its advantages of high catalytic efficiency and lower preparation cost. Exploring the feasibility of free lipase to convert potential low quality oil feedstock into biodiesel is of great significance for further reducing the cost of biodiesel production. However, it is reported that low quality oils usually contain high concentration of phospholipids. Our previous study showed that the presence of high phospholipids content in oil feedstock would lead to poor catalytic performance of free lipase NS81006.Thereby, in order to improve the process, a combined catalysis together with phospholipase Lecitase Ultra and lipase NS81006 was developed in this paper. First, the effect of different factors involved in the process on Lecitase Ultra’s catalytic performance was investigated, then a two-step method via phospholipase-catalyzed phospholipids degradation followed by lipase-catalyzed methanolysis was further attempted to promote the conversion of phospholipids-containing oils for biodiesel production. When using oil containing 2,235 ppm initial phosphorus as feedstock, the final biodiesel yield could reach 96.4%, while the yield without phospholipase was only 76.6%. This work demonstrates that the combined catalysis of phospholipase and free lipase has a great prospect in biodiesel production from high phospholipids-containing oil feedstocks.

당뇨병 백서의 부신 Glomerulosa세포에서 Angiotensin Ⅱ자극후 인지질분해효소 활성의 변화

성연아 梨花女子大學校 醫科大學 醫科學硏究所 1997 EMJ (Ewha medical journal) Vol.20 No.1

연구배경: 당뇨병에서 흔히 고칼륨혈증과 대사성 산혈증을 초래 하는 저aldosterone혈증의 원인은 확실히 밝혀져 있지 않으나 혈중의 renin농도와 ACTH, K^+ 자극에 대한aldosterone의 분비는 다양하였으나 angiotensin Ⅱ(A Ⅱ)자극에 대한 aldosterone의 분비는 공통적으로 감소 되어 있다고 보고되었다. 그러나 이러한 AⅡ 자극 aldosterone분비 감소의 기전은 확실히 밝혀져 있지 않다. 본 연구는 당뇨병을 유발시킨 백서에서 생체와 시험 관내 aldosterone분비의 변화양상을 관찰하고 AⅡ 자 극 aldosterone 분비의 감소가 세포막 신호전달계의 이 상에 의해 나타나는지 밝히기 위해 AⅡ 작용의 세포막 신호 전달계중 세포내칼슘증가와 PKC활성화에 중요한 PLC 및 PLD의 활성의 변화를 관찰하여 당뇨병에서 AⅡ 자극 aldosterone분비변화의 기전을 AⅡ의 신호 전달계중 인지질분해효소 활성화를 중심으로 밝히고 이러한 변호가 인슐린 치료에 의해 교정되는지 규명하고자 하였다. 방 법: Sprague-Dawley 백서를 정상대조군, streptozotocin으로 당뇨병을 유발시킨 군, 당뇨병 유발후 인슐린으로 혈당조절을 한 세군으로 분류하고 실험시작 2주후 회 생시켜 혈중 renin과 aldosterone을 측정하였다. 부신 glomerulosa세포를 분리한 후 시험관내에서 ACTH와 K^+ 자극 aldosterone 분비 반응의 변화 및 AⅡ 자극 aldosterone 분비 반응을 측정하였다. AⅡ 자극후 PLC 및 PLD의 활성을 반영하는 IP_3, PA,PEt, DAG를 측정하였다. 결 과: 1)당뇨병백서의 혈장 renin활성도와 aldsoterone 농도는 정상 대조군 및 인슐린으로 혈당을 조절한 군과 유 의한 차이가 없었다(p<0.05). 2)당뇨병백서의 부신 glomerulosa세포의 기저상태, K^+, ACTH자극 aldosterone 분비는 정상대조군과 차이가 없었으나(p>0.05), AⅡ자극 aldosterone의 분비가 정상대조군과 유의한 차이가 없었다.(p>0.05). 3) AⅡ자극에의한 IP_3와 PA, PET, DAG의 생성은 세균간에 유의한 차이가 없었다.(p>0.05). 결 론: 당뇨병백신에서 부신 glomerulosa세포의 AⅡ자극 aldosterone분비가 감소되며 이러한 AⅡ자극 알도스테론 분비 변화는 인슐린의 치료에 의해 교정되고 PLC와 PLD 활성화후 산물의 생성이 정상군과 차이가 없는 것으로 보아 phospholipase의 활성화이후의 신호 전달체계의 결함에 의할 것으로 생각되었다. Objectives : Diabetic patients develop hypoaldosteronism which frequently caused hyperkalemia and metabolic acidosis and diabetic hypoaldosteronism is associated with selective unresponsiveness of aldosterone to angiotensin Ⅱ(AⅡ), but mechanism of defect in AⅡ stimulated aldosterone response still remain unclear. To elucidate the mechanism of defect in AⅡ stimulated aldosterone response and whether the defect was corrected by insulin treatment. author evaluated the responses of aldosterone production to AⅡ, K^+ and ACTH. I also evaluated the products of phospholipase C(PLC) and phospholipase D(PLD) activation important for increase of intracellular calcium and protein kinase C activation after AⅡ activation in adrenal glomerulosa cells prepared from streptozotocin induced diabetic rats. Methods : Two weeks after induction of diabetes by streptozotocin, rats were sacrificed by decapitation. The aldosterone production to AⅡ, K^+ and ACTH was measured by RIA. Inositol triphosphate(IP_3) and diacylglycerol(DAG) generated by activation of PLC and phosphatidic acid(PA), phosphatidylethanol(PEt) and DAG generated by activation of PLD were measured by anion exchange column and thin layer chromatography. Results : 1) Plasma renin activity and aldosterone level were not different among control rats, untreated and insulin treated diabetic rats. 2) basal, ACTH and K^+-stimulated aldosterone production were similar in cells from the three groups(p>0.05), but AⅡ stimulated aldosterone production was significantly decreased in cells from untreated diabetic rats compared with control and insulin treated diabetic rats(p<0.05). 3) AⅡ-induced IP_3, PA, PEt and DAG generation was similar among the three groups(p>0.05). Conclusion : These results suggested that decreased AⅡ-stimulated aldosterone response was present in glomerulosa cells from strepzptocin induced diabetic rats and reversed by insulin treatments. The main defect of altered AⅡ response of zona glomerulosa might be located in the step distal to the activation of phospholipase.

Quinacrin Induces Cytochrome c-dependent Apoptotic Signaling in Human Cervical Carcinoma Cells

Fasanmade, Adedigbo A.,Owuor, Edward D.,Ee, Rachel P.L.,Qato, Dima,Heller, Mark,Kong, Ah Ng Tony The Pharmaceutical Society of Korea 2001 Archives of Pharmacal Research Vol.24 No.2

Quinacrine (QU), a phospholipase-A2 (PLA-2) inhibitor has been used clinically as a chemotherapeutic adjuvant. To understand the mechanisms leading to its chemotherapeutic effect, we have investigated QU-induced apoptotic signaling pathways in human cervical squamous carcinoma HeLa cells. In this study, we found that QU induced cytochrome c-dependent apoptotic signaling. The release of pro-apoptotic cytochrome c was QU concentration- and time-dependent, and preceded activation of caspase-9 and -3. Flow cytometric FACScan analysis using fluorescence intensities of $DiOC_6$/ demonstrated that QU-induced cytochrome c release was independent of mitochondrial permeability transition (MPT), since the concentrations of QU that induced cytochrome c release did not alter mitochondrial membrane potential (${\blacktriangle}{\Psi}_m$). Moreover, kinetic analysis of caspase activities showed that cytochrome c release led to the activation of caspase-9 and downstream death effector caspase-3, Caspase-3 inhibitor (Ac-DEVD-CHO) partially blocked QU-induced apoptosis, suggesting the importance of caspase-3 in this apoptotic signaling mechanism. Supplementation with arachidonic acid (AA) sustained caspase-3 activation induced by QU. Using inhibitors against cellular arachidonate metabolism of lipooxygenase (Nordihydroxyguaiaretic Acid, NDGA) and cyclooxygenase (5,8,11,14-Eicosatetraynoic Acid, ETYA) demonstrated that QU-induced apoptotic signaling may be dependent on its role as a PLA-2 inhibitor. Interestingly, NDCA attenuated QU-induced cytochrome c release, caspase activity as well as apoptotic cell death. The blockade of cytochrome c release by NDCA was much more effective than that attained with cyclosporin A (CsA), a MPT inhibitor. ETYA was not effective in blocking cytochrome c release, except under very high concentrations. Caspase inhibitor z-VAD blocked the release of cytochrome c suggesting that this signaling event is caspase dependent, and caspase-8 activation may be upstream of the mitochondrial events. In summary, we report that QU induced cytochrome c-dependent apoptotic signaling cascade, which may be dependent on its role as a PLA-2 inhibitor. This apoptotic mechanism induced by QU may contribute to its known chemotherapeutic effects.

Enzymatic characterization of class I DAD1-like acylhydrolase members targeted to chloroplast in <i>Arabidopsis</i>

Seo, Young Sam,Kim, Eun Yu,Kim, Jeong Hoe,Kim, Woo Taek Elsevier 2009 FEBS letters Vol.583 No.13

<P><B>Abstract</B></P><P>In <I>Arabidopsis</I>, there are at least seven class I acylhydrolase members, which have a putative N-terminal chloroplast-targeting signal. Here, we show that all seven class I proteins are localized to the chloroplasts and hydrolyze phosphatidylcholine at the <I>sn</I>-1 position. However, based on their activities toward various lipids, <I>Arabidopsis</I> class I enzymes could be further divided into three sub-groups by substrate specificity, one with phospholipase-specific activity, another with phospholipase and galactolipase activities, and the other with broad lipolytic activity toward phosphatidylcholine, galactolipids, and triacylglycerol. These results suggest that the three sub-groups of class I acylhydrolases have specific roles in chloroplasts.</P>

모형 담즙과 담낭 답즙에서 콜레스테롤 핵형성 촉진 인자로서의 Phospholipase C 의 역할

김정룡(Chung Yong Kim),김용태(Yong Tae Kim),윤용범(Yong Bum Yoon) 대한내과학회 1995 대한내과학회지 Vol.49 No.1

N/A Objectives: There are a number of proteins that may influence cholesterol nucleation in bile, Recently, phospholipase C has been suggested as a nucleation-promoting factor in human gallbladder(GB) bile. However, it is not known whether there is a quantitative difference in phospholipase and normal controls, and whether suppression of phospholipase C in human GB bile might alter the nucleation time. So we tried to investigate the role of phospholipase C as a cholesteol nucleation-promoting factor in model bile and in human GB bile. Methods: To determine if phospholipase C has a capacity to promote nucleation of cholesterol in model bile, nucleation times were compared among model biles which were mixed with serially diluted phospholipase C(0, 10, 100, 1,000, 10,000, 100,000 U /L). To investigate if phospholipase C is a main promoting factor of cholesterol nucleation in human GB bile, nucleation times and phospholipase C activities in GB bile were compared among patients with cholesterol gallstones(n=12), pigment gallstones(n=12), and controls(n=7). The influence of suppression of phospholipase C by EDTA(2 mM) on the nucleation time in GB biles of patients with cholesterol gallstones was also studied. Phospholipese C activity was measured by the release of phosphoryl [H3] choline from the substrate 3H-phosphatidylcholine after delipidation by gel chromatography. Results: Phospholipase C decreased the nucleation time of model bile in a dose dependent way from more than 21 days to 5 days, but the activity in human GB bile was elevated more than that of the controls in only 17% of patients with cholesterol gallstones. Suppression of phospholipase C activity by EDTA did not prolong the nucleation time of the GB bile of the patients with cholesterol gallstones. Conclns1on: Phospholipase C has a capacity to decrease the nucleation time in model bile but it does not play a significant role in cholesterol gallstone formation in human GB bile.

인간 추간판의 섬유륜부 및 수핵부 세포 배양에서 세포의 형질에 따른 phosphollpase A2 의 생성

김동준,왕진만 대한척추외과학회 2000 대한척추외과학회지 Vol.7 No.1

연구계획 : 추간판 세포의 배양에서 세포의 형질에 따른 phospholipas A2의 생성 정도의 차이를 규명한다. 연구목적 : 통증의 발생 기전에서 중요한 역할을 하는 phospholipase A2의 생성과 연관하여, 주로 관계하는 세포 형질과 생성을 촉진하는 조건에 대해 알아보고자 한다. 대상 및 방법 : 변성되지 않은 인체의 추간판에서 외연의 섬유륜부와 중심의 수핵부에서 각각 조직을 채취하여 세포를 배양한다. 배양 7일째에 배양된 세포들을 조직별로 3군씩 나누고 젖산을 0mM(대조군), 1mM, 5mM을 첨가하여 2주간 더 배양한 다음 phospholipase A2의 생성 정도를 Northerm blotting으로 측정한다. 결과 : 수핵 조직에서 채취된 세포들에서는 적은 양의 phospholipase A2가 생성되었다. 반면에 섬유륜 조직의 세포들은 왕성한 phospholipase A2의 생성을 보였다. 첨가된 젖산의 양에 따른 phospholipase A2의 생성 정도는 뚜렷한 차이가 없었다. 결론 : 이런 결과로 볼 때 추간판을 구성하는 조직들 중에서 외연의 섬유륜부 세포들이 phospholipase A2의 생성에 주로 관계하며, 추간판성 통증의 발생에 중요한 역할을 하는 것으로 생각된다. Study Design : Evaluation of phospholipase A2 production according to cell type of human intrevertebral disc. Summary of Literature Review : It was reported that the phospholipase A2 acitvity in human lumbar desc herniation was more active than that in other tissues. Objectives : The purpose of this study was to evaluate the diferences between the cells of anulus fibrosus and nucleus pulposus when lactate was added to the culture medium. Materials and Methods : Cells from the anulus fibrosus and nucleus pulposus of a human intervertebral disc were prepared enzymaitically. After the monolayer was set up, the cells were didvided to three groups and lactate doses of a OmM, 2mM or 5mM were added respectively. At two week after lactate addition the production of phospholipase A2 was measured by Northerm blotting. Results : Cells of nucleus pulposus produced a small amount of phospholipase A2. Those of anulus fibrosus showed a high activity of phospholipase A2 production. The concentration of lactate did not influenced on the production of phospholipase A2. Conclusion : The anulus fibrosus hsa an improtant role in the production of phospholipase A2 and is thought to be related with generation of discogenic pain.