The measurement of lysosomal phospholipase A2 activity in plasma
A deficiency of lysosomal phospholipase A2 (LPLA2) causes macrophage-associated phospholipidosis, suggesting that the enzyme is important in the lipid catabolism. Because LPLA2 is secreted by macrophages, extracellular LPLA2 activity may potentially reflect a change in macrophage activation. In this...
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doaj-069ba00e217240a9ad0a1594159f66262021-04-28T06:01:48ZengElsevierJournal of Lipid Research0022-22752010-08-0151824642470The measurement of lysosomal phospholipase A2 activity in plasmaAkira Abe0Robert Kelly1James A. Shayman2Nephrology Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109Nephrology Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109To whom correspondence should be addressed; Nephrology Division, Department of Internal Medicine, University of Michigan, Ann Arbor, MI 48109A deficiency of lysosomal phospholipase A2 (LPLA2) causes macrophage-associated phospholipidosis, suggesting that the enzyme is important in the lipid catabolism. Because LPLA2 is secreted by macrophages, extracellular LPLA2 activity may potentially reflect a change in macrophage activation. In this report, the detection of LPLA2 activity in plasma was established by the measurement of the transacylase activity of LPLA2 under acidic conditions. No transacylase activity of LPLA2 was detected in normal human plasma when the plasma was incubated with liposomes consisting of 1,2-dioleoylphosphatidylcholine/sulfatide/N-acetylsphingosine (NAS) at pH 4.5. However, the transacylase activity in the plasma was detected when liposomes consisting of 1,2-dioleoylphosphatidylglycerol/NAS were used as a substrate. To establish the specificity of the assay, ceramide transacylase activity was detected in the plasma of wild-type mice. By contrast, the plasma obtained from LPLA2-knockout mice had no measurable transacylase activity under the same conditions. The enzymatic activity of recombinant LPLA2 was inhibited by treatment with methylarachidonylfluorophosphonate. The inhibitor also suppressed the transacylase activity observed in both normal human and wild-type mouse plasma, establishing that the transacylase activity observed in plasma is due to LPLA2. Plasma LPLA2 activity may be a useful bioassay marker for the identification of LPLA2-related disorders.http://www.sciencedirect.com/science/article/pii/S002222752037084Xlysosomal phospholipase A2-knockout mousegroup XV phospholipase A2serumdioleoylphosphatidylglycerolN-acetylsphingosine1-O-acyl-N-acetylsphingosine |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
Akira Abe Robert Kelly James A. Shayman |
spellingShingle |
Akira Abe Robert Kelly James A. Shayman The measurement of lysosomal phospholipase A2 activity in plasma Journal of Lipid Research lysosomal phospholipase A2-knockout mouse group XV phospholipase A2 serum dioleoylphosphatidylglycerol N-acetylsphingosine 1-O-acyl-N-acetylsphingosine |
author_facet |
Akira Abe Robert Kelly James A. Shayman |
author_sort |
Akira Abe |
title |
The measurement of lysosomal phospholipase A2 activity in plasma |
title_short |
The measurement of lysosomal phospholipase A2 activity in plasma |
title_full |
The measurement of lysosomal phospholipase A2 activity in plasma |
title_fullStr |
The measurement of lysosomal phospholipase A2 activity in plasma |
title_full_unstemmed |
The measurement of lysosomal phospholipase A2 activity in plasma |
title_sort |
measurement of lysosomal phospholipase a2 activity in plasma |
publisher |
Elsevier |
series |
Journal of Lipid Research |
issn |
0022-2275 |
publishDate |
2010-08-01 |
description |
A deficiency of lysosomal phospholipase A2 (LPLA2) causes macrophage-associated phospholipidosis, suggesting that the enzyme is important in the lipid catabolism. Because LPLA2 is secreted by macrophages, extracellular LPLA2 activity may potentially reflect a change in macrophage activation. In this report, the detection of LPLA2 activity in plasma was established by the measurement of the transacylase activity of LPLA2 under acidic conditions. No transacylase activity of LPLA2 was detected in normal human plasma when the plasma was incubated with liposomes consisting of 1,2-dioleoylphosphatidylcholine/sulfatide/N-acetylsphingosine (NAS) at pH 4.5. However, the transacylase activity in the plasma was detected when liposomes consisting of 1,2-dioleoylphosphatidylglycerol/NAS were used as a substrate. To establish the specificity of the assay, ceramide transacylase activity was detected in the plasma of wild-type mice. By contrast, the plasma obtained from LPLA2-knockout mice had no measurable transacylase activity under the same conditions. The enzymatic activity of recombinant LPLA2 was inhibited by treatment with methylarachidonylfluorophosphonate. The inhibitor also suppressed the transacylase activity observed in both normal human and wild-type mouse plasma, establishing that the transacylase activity observed in plasma is due to LPLA2. Plasma LPLA2 activity may be a useful bioassay marker for the identification of LPLA2-related disorders. |
topic |
lysosomal phospholipase A2-knockout mouse group XV phospholipase A2 serum dioleoylphosphatidylglycerol N-acetylsphingosine 1-O-acyl-N-acetylsphingosine |
url |
http://www.sciencedirect.com/science/article/pii/S002222752037084X |
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