Types of purinoceptors and phospholipase A2 involved in the activation of the platelet-activating factor-dependent transacetylase activity and arachidonate release by ATP in endothelial cells

Maria Luisa Balestrieri, Kafait Malik, Ciro Balestrieri, Ten Ching Lee

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Abstract

Acyl analogs of PAF are the major products synthesized during agonist stimulation of endothelial cells. We have previously shown that PAF: 1-acyl- 2-lyso-sn-glycero-3-phosphocholine transacetylase in calf pulmonary artery endothelial cells is activated by ATP through protein phosphorylation, and the increase in transacetylase activity by ATP contributes to the biosynthesis of acyl analogs of PAF (J. Biol. Chem. 272, 17431-17437, 1997). To understand the mechanism(s) by which ATP stimulates acyl analogs of PAF production, we have identified the subtypes of the purinergic receptor that are linked to the activation of two enzymes involved in the generation of acyl analogs of PAF, namely, transacetylase and phospholipase A2. Experiments with transient transfection of the cells with antisense and sense thio-oIigonucleotide to cytosolic phospholipase A2 (cPLA2) were also performed to evaluate whether downstream activation of cPLA2 is involved in ATP-receptor mediated induction of arachidonate release and synthesis of radylacetyl-GPC. We found that the P(2u)/P2Y2 receptor, which recognizes a pyrimidine nucleotide, UTP, as well as purine nucleotides, shows a potency profile of UTP > ATP = ATPγS > 2-methylthio-ATP in mediating the activation of PAF: lysophospholipid transacetylase. On the other hand, ADPβS and 2- methylthio-ATP have similar potencies as ATP but have lower potencies than UTP and ATPγS in stimulating the release of arachidonate. These results suggest that both P(2u)/P2Y2 and P(2y)/P2Y1 receptor subtypes promote arachidonate release. In addition, transient transfection of endothelial cells with cPLA2 antisense but not the sense thio-oligonucleotide inhibited the stimulation of arachidonate release and [3H]acetate incorporation into radyl[3H]acetyl-GPC. Thus, our data suggest that a receptor-mediated process is involved in the activation of transacetylase for the induced synthesis of acyl analogs of PAF in endothelial cells. Furthermore, it is likely that cPLA2 supplies the lysophospholipids as substrates for the transacetylation reaction.

Original languageEnglish (US)
Pages (from-to)363-375
Number of pages13
JournalProstaglandins and Other Lipid Mediators
Volume56
Issue number5-6
DOIs
StatePublished - Dec 1 1998

Fingerprint

Purinergic Receptors
Platelet Activating Factor
Cytosolic Phospholipases A2
Phospholipases A2
Endothelial cells
Endothelial Cells
Adenosine Triphosphate
Chemical activation
Uridine Triphosphate
Lysophospholipids
Transfection
Purinergic P2Y2 Receptors
Purinergic P2Y1 Receptors
Pyrimidine Nucleotides
Purine Nucleotides
Purinergic P2 Receptors
Phosphorylation
Enzyme Activation
Phosphorylcholine
Biosynthesis

All Science Journal Classification (ASJC) codes

  • Biochemistry
  • Endocrinology

Cite this

@article{b8d2997f6a524173804ba47ba44b809c,
title = "Types of purinoceptors and phospholipase A2 involved in the activation of the platelet-activating factor-dependent transacetylase activity and arachidonate release by ATP in endothelial cells",
abstract = "Acyl analogs of PAF are the major products synthesized during agonist stimulation of endothelial cells. We have previously shown that PAF: 1-acyl- 2-lyso-sn-glycero-3-phosphocholine transacetylase in calf pulmonary artery endothelial cells is activated by ATP through protein phosphorylation, and the increase in transacetylase activity by ATP contributes to the biosynthesis of acyl analogs of PAF (J. Biol. Chem. 272, 17431-17437, 1997). To understand the mechanism(s) by which ATP stimulates acyl analogs of PAF production, we have identified the subtypes of the purinergic receptor that are linked to the activation of two enzymes involved in the generation of acyl analogs of PAF, namely, transacetylase and phospholipase A2. Experiments with transient transfection of the cells with antisense and sense thio-oIigonucleotide to cytosolic phospholipase A2 (cPLA2) were also performed to evaluate whether downstream activation of cPLA2 is involved in ATP-receptor mediated induction of arachidonate release and synthesis of radylacetyl-GPC. We found that the P(2u)/P2Y2 receptor, which recognizes a pyrimidine nucleotide, UTP, as well as purine nucleotides, shows a potency profile of UTP > ATP = ATPγS > 2-methylthio-ATP in mediating the activation of PAF: lysophospholipid transacetylase. On the other hand, ADPβS and 2- methylthio-ATP have similar potencies as ATP but have lower potencies than UTP and ATPγS in stimulating the release of arachidonate. These results suggest that both P(2u)/P2Y2 and P(2y)/P2Y1 receptor subtypes promote arachidonate release. In addition, transient transfection of endothelial cells with cPLA2 antisense but not the sense thio-oligonucleotide inhibited the stimulation of arachidonate release and [3H]acetate incorporation into radyl[3H]acetyl-GPC. Thus, our data suggest that a receptor-mediated process is involved in the activation of transacetylase for the induced synthesis of acyl analogs of PAF in endothelial cells. Furthermore, it is likely that cPLA2 supplies the lysophospholipids as substrates for the transacetylation reaction.",
author = "Balestrieri, {Maria Luisa} and Kafait Malik and Ciro Balestrieri and Lee, {Ten Ching}",
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T1 - Types of purinoceptors and phospholipase A2 involved in the activation of the platelet-activating factor-dependent transacetylase activity and arachidonate release by ATP in endothelial cells

AU - Balestrieri, Maria Luisa

AU - Malik, Kafait

AU - Balestrieri, Ciro

AU - Lee, Ten Ching

PY - 1998/12/1

Y1 - 1998/12/1

N2 - Acyl analogs of PAF are the major products synthesized during agonist stimulation of endothelial cells. We have previously shown that PAF: 1-acyl- 2-lyso-sn-glycero-3-phosphocholine transacetylase in calf pulmonary artery endothelial cells is activated by ATP through protein phosphorylation, and the increase in transacetylase activity by ATP contributes to the biosynthesis of acyl analogs of PAF (J. Biol. Chem. 272, 17431-17437, 1997). To understand the mechanism(s) by which ATP stimulates acyl analogs of PAF production, we have identified the subtypes of the purinergic receptor that are linked to the activation of two enzymes involved in the generation of acyl analogs of PAF, namely, transacetylase and phospholipase A2. Experiments with transient transfection of the cells with antisense and sense thio-oIigonucleotide to cytosolic phospholipase A2 (cPLA2) were also performed to evaluate whether downstream activation of cPLA2 is involved in ATP-receptor mediated induction of arachidonate release and synthesis of radylacetyl-GPC. We found that the P(2u)/P2Y2 receptor, which recognizes a pyrimidine nucleotide, UTP, as well as purine nucleotides, shows a potency profile of UTP > ATP = ATPγS > 2-methylthio-ATP in mediating the activation of PAF: lysophospholipid transacetylase. On the other hand, ADPβS and 2- methylthio-ATP have similar potencies as ATP but have lower potencies than UTP and ATPγS in stimulating the release of arachidonate. These results suggest that both P(2u)/P2Y2 and P(2y)/P2Y1 receptor subtypes promote arachidonate release. In addition, transient transfection of endothelial cells with cPLA2 antisense but not the sense thio-oligonucleotide inhibited the stimulation of arachidonate release and [3H]acetate incorporation into radyl[3H]acetyl-GPC. Thus, our data suggest that a receptor-mediated process is involved in the activation of transacetylase for the induced synthesis of acyl analogs of PAF in endothelial cells. Furthermore, it is likely that cPLA2 supplies the lysophospholipids as substrates for the transacetylation reaction.

AB - Acyl analogs of PAF are the major products synthesized during agonist stimulation of endothelial cells. We have previously shown that PAF: 1-acyl- 2-lyso-sn-glycero-3-phosphocholine transacetylase in calf pulmonary artery endothelial cells is activated by ATP through protein phosphorylation, and the increase in transacetylase activity by ATP contributes to the biosynthesis of acyl analogs of PAF (J. Biol. Chem. 272, 17431-17437, 1997). To understand the mechanism(s) by which ATP stimulates acyl analogs of PAF production, we have identified the subtypes of the purinergic receptor that are linked to the activation of two enzymes involved in the generation of acyl analogs of PAF, namely, transacetylase and phospholipase A2. Experiments with transient transfection of the cells with antisense and sense thio-oIigonucleotide to cytosolic phospholipase A2 (cPLA2) were also performed to evaluate whether downstream activation of cPLA2 is involved in ATP-receptor mediated induction of arachidonate release and synthesis of radylacetyl-GPC. We found that the P(2u)/P2Y2 receptor, which recognizes a pyrimidine nucleotide, UTP, as well as purine nucleotides, shows a potency profile of UTP > ATP = ATPγS > 2-methylthio-ATP in mediating the activation of PAF: lysophospholipid transacetylase. On the other hand, ADPβS and 2- methylthio-ATP have similar potencies as ATP but have lower potencies than UTP and ATPγS in stimulating the release of arachidonate. These results suggest that both P(2u)/P2Y2 and P(2y)/P2Y1 receptor subtypes promote arachidonate release. In addition, transient transfection of endothelial cells with cPLA2 antisense but not the sense thio-oligonucleotide inhibited the stimulation of arachidonate release and [3H]acetate incorporation into radyl[3H]acetyl-GPC. Thus, our data suggest that a receptor-mediated process is involved in the activation of transacetylase for the induced synthesis of acyl analogs of PAF in endothelial cells. Furthermore, it is likely that cPLA2 supplies the lysophospholipids as substrates for the transacetylation reaction.

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