scholarly journals Cerebrospinal Fluid Secretory Ca2+-Dependent Phospholipase A2 Activity Is Increased in Alzheimer Disease

2009 ◽  
Vol 55 (12) ◽  
pp. 2171-2179 ◽  
Author(s):  
Sonia Chalbot ◽  
Henrik Zetterberg ◽  
Kaj Blennow ◽  
Tormod Fladby ◽  
Inge Grundke-Iqbal ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Alzheimer Disease ◽  
Phospholipase A2 ◽  
Microtiter Plate ◽  
Pla2 Activity ◽  
Activity Assay ◽  
Proinflammatory Mediators ◽  
Spla2 Activity ◽  
Phospholipase A2 Activity ◽  
Microtiter Plate Format

Abstract Background: The phospholipase A2 (PLA2) family comprises multiple isoenzymes that vary in their physicochemical properties, cellular localizations, calcium sensitivities, and substrate specificities. Despite these differences, PLA2s share the ability to catalyze the synthesis of the precursors of the proinflammatory mediators. To investigate the potential of PLA2 as a biomarker in screening neuroinflammatory disorders in both clinical and research settings, we developed a PLA2 assay and determined the predominant types of PLA2 activity in cerebrospinal fluid (CSF). Methods: We used liposomes composed of a fluorescent probe (bis-Bodipy® FL C11-PC [1,2-bis-(4,4- difluoro-5,7-dimethyl-4-bora-3a,4a-diaza-s-indacene-3-undecanoyl)-sn-glycero-3-phosphocholine]) and 1,2-dioleoyl-l-α-phosphatidylcholine as a substrate to measure CSF PLA2 activity in a 96-well microtiter plate format. We established the type of CSF PLA2 activity using type-specific inhibitors of PLA2. Results: Using 5 μL CSF per assay, our PLA2 activity assay was reproducible with CVs <15% in 2 CSF samples and for recombinant secretory Ca2+-dependent PLA2 (sPLA2) in concentrations ranging from 0.25 to 1 μmol/L. This PLA2 assay allowed identification of sPLA2 activity in lumbar CSF from healthy individuals 20–77 years old that did not depend on either sex or age. Additionally, CSF sPLA2 activity was found to be increased (P = 0.0008) in patients with Alzheimer disease. Conclusions: Adult human CSF has sPLA2 activity that can be measured reliably with the assay described. This enzyme activity in the CSF is independent of both sex and age and might serve as a valuable biomarker of neuroinflammation, as we demonstrated in Alzheimer disease.

scholarly journals Cerebrospinal fluid secretory Ca2+-dependent phospholipase A2 activity: A biomarker of blood–cerebrospinal fluid barrier permeability

2010 ◽  
Vol 478 (3) ◽  
pp. 179-183 ◽  
Author(s):  
Sonia Chalbot ◽  
Henrik Zetterberg ◽  
Kaj Blennow ◽  
Tormod Fladby ◽  
Inge Grundke-Iqbal ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Phospholipase A2 ◽  
Barrier Permeability ◽  
Phospholipase A2 Activity

P3-173: Determination of a specific lipoprotein-associated phospholipase A2 activity in human cerebrospinal fluid

2010 ◽  
Vol 6 ◽  
pp. S500-S500
Author(s):  
Liang Ye ◽  
Tina Li ◽  
Daniel Lee ◽  
Curtis Huang ◽  
Chenbing Guan ◽  
...  
Keyword(s):  
Cerebrospinal Fluid ◽  
Phospholipase A2 ◽  
Human Cerebrospinal Fluid ◽  
Phospholipase A2 Activity

Decreased phospholipase A2 activity in cerebrospinal fluid of patients with dementia

2008 ◽  
Vol 115 (8) ◽  
pp. 1173-1179 ◽  
Author(s):  
Stefan Smesny ◽  
Susan Stein ◽  
Ingo Willhardt ◽  
Jürgen Lasch ◽  
Heinrich Sauer
Keyword(s):  
Cerebrospinal Fluid ◽  
Phospholipase A2 ◽  
Phospholipase A2 Activity

Advantages of the lipoprotein-associated phospholipase A2 activity assay

2016 ◽  
Vol 49 (1-2) ◽  
pp. 172-175 ◽  
Author(s):  
Leslie J. Donato ◽  
Jeffrey W. Meeusen ◽  
Heidi Callanan ◽  
Amy K. Saenger ◽  
Allan S. Jaffe
Keyword(s):  
Phospholipase A2 ◽  
Activity Assay ◽  
Phospholipase A2 Activity

Enhanced Phospholipase A2 Activity In Cholesterol-Enriched Platelets From Rabbits Fed A Cholesterol-Enriched Diet

1981 ◽  
Author(s):  
A J McLeod ◽  
M Johnson ◽  
K E Sucklino ◽  
P Walton
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Serum Cholesterol ◽  
Control Diet ◽  
Molar Ratio ◽  
Control Group ◽  
Pla2 Activity ◽  
Rate Limiting ◽  
Phospholipase A2 Activity

Phospholipase A2(PLA2) could be the rate-limiting enzyme in the metabolism of arachidonic acid (AA) derived from membrane phospholipid to thromboxane A2 (TXA2). Mal- ondialdehyde (MDA) production, which is considered to be an index of TXA2 synthesis, is increased in platelets which have been enriched in cholesterol by incubation with cholesterol-rich phospholipid dispersions in vitro.Rabbits were fed a diet supplemented with 0.5% w/w cholesterol for 4 weeks after which serum cholesterol was determined and the platelets examined and compared with rabbits fed a control diet. The cholesterol:phospholipid molar ratio (c/p) in the platelets, MDA production (stimulated by AA (imM) and basal) and PLA2 activity were estimated. PLA2 activity was estimated by measuring the % inversion by resuspended washed platelets of 1-acyl-2-(l- 14C)arachidonyl phosphatidylcholine to (1- 14C)arachidonic acid on stimulation with collagen (2μg/ml). Serum cholesterol in the cholesterol-fed group (n=9) was 488 ± 104 mg/ 100ml compared with the control group (n=3) which was 34 ± 4.7 mg/l00ml. Platelets from the cholesterol-fed rabbits showed a 20% increase in C/P (p<0.05); basal and AA stimulated MDA production was increased by 40% and 27% respectively compared with platelets from the control group. PLA2 activity was 1.26% conversion to products in the cholesterol-enriched platelets compared with 0.10% in the control platelets. This increase in activity was significant (p < 0.05).These results suggest that increased AA metabolism in cholesterol-enriched platelets may in part be due to increased PLA2 activity. This may reflect a physical effect of cholesterol on the platelet membrane predisposing arachidonyl phosphatidylcholine to PLA2 catalysed hydrolysis.

Interleukin-1beta stimulates phospholipase A2 activity in adult rat ventricular myocytes

1997 ◽  
Vol 272 (2) ◽  
pp. C450-C456 ◽  
Author(s):  
J. McHowat ◽  
S. Liu
Keyword(s):  
Arachidonic Acid ◽  
Phospholipase A2 ◽  
Ventricular Myocytes ◽  
Arachidonic Acid Release ◽  
Pla2 Activity ◽  
Rat Ventricular Myocytes ◽  
Adult Rat ◽  
Acid Release ◽  
Cytosolic Pla2 ◽  
Phospholipase A2 Activity

We have examined whether interleukin (IL)-1beta modulates phospholipase A2 (PLA2) activity in ventricular myocytes. PLA2 activity was measured in isolated membrane and cytosol fractions with (16:0,[3H]18:1) plasmenylcholine and (16:0,[3H]18:1) phosphatidylcholine in the absence and presence of Ca2+. When measured in the absence of Ca2+ with plasmenylcholine, exposure to 5 ng/ml IL-1beta caused an increase in membrane-associated PLA2 activity for 10 min that returned to basal levels by 20 min. In the presence of Ca2+ with phosphatidylcholine, IL-1beta had no effect on membrane-associated PLA2 but decreased cytosolic PLA2 activity. Additionally, IL-1beta caused an increase in arachidonic acid release in 20 min. Pretreatment with E-6-(bromomethylene)tetrahydro-3-(1-naphthalenyl)-2H-pyran-2-one, a selective Ca2+-independent PLA2 inhibitor, blocked IL-1beta-induced increases in both PLA2 activity and arachidonic acid release. Exposure to IL-1 receptor antagonist (IL-1RA) alone had no effect on membrane-associated PLA2 activity. When incubated with IL-1beta, IL-1RA inhibited the IL-1beta-enhanced PLA2 activity. These results show that, via activation of its receptors, IL-1beta stimulates specifically membrane-associated Ca2+-independent plasmalogen-selective PLA2 in rat ventricular myocytes.

scholarly journals Mutational Analysis of Narrow Pores at the Fivefold Symmetry Axes of Adeno-Associated Virus Type 2 Capsids Reveals a Dual Role in Genome Packaging and Activation of Phospholipase A2 Activity

2005 ◽  
Vol 79 (4) ◽  
pp. 2528-2540 ◽  
Author(s):  
Svenja Bleker ◽  
Florian Sonntag ◽  
Jürgen A. Kleinschmidt
Keyword(s):  
Phospholipase A2 ◽  
Virus Type ◽  
Mutational Analysis ◽  
Pla2 Activity ◽  
Genome Packaging ◽  
Adeno Associated Virus ◽  
Conserved Residues ◽  
Axes Of Symmetry ◽  
Phospholipase A2 Activity

ABSTRACT Adeno-associated virus type 2 (AAV2) capsids show 12 pores at the fivefold axes of symmetry. We mutated amino acids which constitute these pores to investigate possible functions of these structures within the AAV2 life cycle. Mutants with alterations in conserved residues were impaired mainly in genome packaging or infectivity, whereas few mutants were affected in capsid assembly. The packaging phenotype was characterized by increased capsid-per-genome ratios. Analysis of capsid-associated DNA versus encapsidated DNA revealed that this observation was due to reduced and not partial DNA encapsidation. Most mutants with impaired infectivity showed a decreased capability to expose their VP1 N termini. As a consequence, the activation of phospholipase A2 (PLA2) activity, which is essential for efficient infection, was affected on intact capsids. In a few mutants, the exposure of VP1 N termini and the development of PLA2 activity were associated with enhanced capsid instability, which is obviously also deleterious for virus infection. Therefore, PLA2 activity seems to be required on intact capsids for efficient infection. In conclusion, these results suggest that the pores at the fivefold axes function not only as portals for AAV2 single-stranded DNA packaging but also as channels for presentation of the PLA2 domain on AAV2 virions during infection.

Phospholipase A2 activity of crocodile serum

2009 ◽  
Vol 30 (1) ◽  
pp. 119-125 ◽  
Author(s):  
Timo Nevalainen ◽  
Kieran Scott ◽  
Grahame Webb ◽  
S. Charlie Manolis ◽  
Sumolya Kanchanapangka ◽  
...  
Keyword(s):  
Escherichia Coli ◽  
Catalytic Activity ◽  
Oleic Acid ◽  
Phospholipase A2 ◽  
Geographical Location ◽  
Pla2 Activity ◽  
Serum Samples ◽  
Crocodylus Porosus ◽  
The Difference ◽  
Phospholipase A2 Activity

AbstractThe catalytic activity of phospholipase A2 (PLA2) was measured in serum samples from 32 crocodiles in Thailand and Australia by a method using 14C-oleic acid-labelled autoclaved Escherichia coli membranes as a substrate. The highest PLA2 activity was measured in the serum of Crocodylus siamensis (n = 9, mean ± SD), 13.3 ± 3.1 U/l followed by hybrid C. siamensis × C. porosus (n = 6), 10.4 ± 8.7 U/l and Crocodylus porosus (n = 17), 4.3 ± 3.0 U/l. The difference between C. siamensis and C. porosus was highly significant (P < 0.001). The gender of the animals and the geographical location of the crocodile farms were not significant variables affecting serum PLA2 levels. It was concluded that PLA2 is present in crocodilian serum and may have an antimicrobial role.

scholarly journals AKTIVITAS FOSFOLIPASE-A2 SEKRETORIS PLASMA TROMBOSITOPENIA DEMAM BERDARAH DENGUE

2018 ◽  
Vol 17 (1) ◽  
pp. 12
Author(s):  
Endang Retnowati K ◽  
Wiyanda Hidayati S ◽  
Liana .
Keyword(s):  
Phospholipase A2 ◽  
Proinflammatory Cytokines ◽  
Pearson Correlation ◽  
World Health ◽  
Assay Method ◽  
Secretory Phospholipase A2 ◽  
Secretory Phospholipase ◽  
Spla2 Activity ◽  
The Mean ◽  
Phospholipase A2 Activity

Infected macrophages by dengue virus will produce phospholipase-A2 (PLA2) enzyme, that can promote arachidonic acidmetabolism that produce inflammatory mediators, causing endhothelial damage and severe plasma leakage. Capillary endothelialdamage can cause platelet adhesion and aggregation, so that many platelets will be consumed. The role of sPLA2 (secretoryphospholipase-A2), which is a part of PLA2 in dengue and thrombocytopenia up to now has not been widely studied. The objective ofthe study is to analyze the association between the activity of plasma secretory phospholipase-A2 and the degree of thrombocytopeniain DHF adult patients. the study is carried out by a cross sectional, observational analytical study on 45 hospitalized adult patientssuffering dengue hemorrhagic fever in the Tropical Infection Ward, Department of Internal Medicine, Dr. Soetomo Hospital Surabaya,which has been conducted from February–December 2009. The diagnosis of Dengue Haemorrhagic Fever (DHF) was based on the1997 World Health Organization (WHO) criteria, that minimally had one positive serology marker of dengue. Venous blood wastaken from the patient for examining the activity of secretory phospholipase-A2 by correlated enzyme assay method, and plateletcount using automated hematology analyzer. The results of the secretory phospholipase-A2 activity and degree of thrombocytopeniawere analyzed by Pearson correlation test to determine the correlation between the two variables. In this study so far was foundthat the secretory phospholipase-A2 activity in DHF patients was 36.9–195.6 unit/mL (mean 97.49 unit/mL, SD 30.06 unit/mL).The mean of secretory phospholipase-A2 activity was increased according to the degree of thrombocytopenia severity. The mean ofsecretory phospholipase-A2 activities were 91.65 unit/mL, 98.94 unit/mL, and 110.47 unit/mL. The degree of thrombocytopeniawas divided into mild, moderate, and severe. Most of the patients showed mild thrombocytopenia. The sPLA2 activity in this studywas increased in DHF patients with second day of fever, and then decreased at the third and forth day of fever, and increased inDBD patients suffering fifth day of fever. The statistical analyzes show a non significant correlation between secretory phospholipaseA2 activity and degree of thrombocytopenia (p = 0.579). This result may be caused by several factors which influencing thethrombocytopenia in DHF, such as bone marrow suppression, dengue viral serotype, influence of cytosolic phospholipase-A2 (cPLA2)activity, and other proinflammatory cytokines which in this study could not be controlled. Statistical analyzes show a significantcorrelation between sPLA2 activity and the day of fever (p = 0.04). Further studies should have to be carried out in order to knowthe pattern of sPLA2 activity in DHF grade I, II, III, and IV, and to know the influence of other proinflammatory cytokines and viralserotypes in sPLA2 activities.

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