Abstract
Stimulation of human endothelial cells (EC) by thrombin elicits a rapid increase of intracellular free Ca2+ [(Ca2+]i), platelet-activating factor (PAF) production and 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF):acetyl-CoA acetyltransferase (EC 2.3.1.67) activity. The treatment of EC with thrombin leads to a 90% decrease in the cytosolic protein kinase C (PKC) activity; this dramatic decline is accompanied by an increase of the enzymatic activity in the particulate fraction. The role of PKC in thrombin-mediated PAF synthesis has been assessed: (1) by the blockade of PKC activity with partially selective inhibitors (palmitoyl-carnitine, sphingosine and H-7); (2) by chronic exposure of EC to phorbol 12-myristate 13-acetate (PMA), which results in down-regulation of PKC. In both cases, a strong inhibition of thrombin-induced PAF production is observed, suggesting obligatory requirement of PKC activity for PAF synthesis. It is suggested that PKC regulates EC phospholipase A2 (PLA2) activity as thrombin-induced arachidonic acid (AA) release is 90% inhibited in PKC-depleted cells. Brief exposure of EC to PMA strongly inhibits thrombin-induced [Ca2+]i rise, acetyltransferase activation and PAF production, suggesting that, in addition to the positive forward action, PKC provides a negative feedback control over membrane signalling pathways involved in the thrombin effect on EC. Forskolin and iloprost, two agents that increase the level of cellular cAMP in EC, are very effective in inhibiting thrombin-evoked cytosolic Ca2+ rise, acetyltransferase activation and PAF production; this suggests that endogenously generated prostacyclin (PGI2) may modulate the synthesis of PAF in human endothelial cells.
| Original language | English |
|---|---|
| Pages (from-to) | 55-64 |
| Number of pages | 10 |
| Journal | Biochimica et Biophysica Acta - Molecular Cell Research |
| Volume | 1093 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - Jun 7 1991 |
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Keywords
- Calcium ion
- cyclic AMP
- Endothelium
- PAF synthesis
- Protein kinase C
- Thrombin
ASJC Scopus subject areas
- Biophysics
- Cell Biology
- Molecular Biology
Cite this
Protein kinase C and cyclic AMP modulate thrombin-induced platelet-activating factor synthesis in human endothelial cells. / Heller, Regine; Bussolino, Federico; Ghigo, Dario; Garbarino, Giovanni; Schröder, Henning; Pescarmona, Gianpiero; Till, Uwe; Bosia, Amalia.
In: Biochimica et Biophysica Acta - Molecular Cell Research, Vol. 1093, No. 1, 07.06.1991, p. 55-64.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Protein kinase C and cyclic AMP modulate thrombin-induced platelet-activating factor synthesis in human endothelial cells
AU - Heller, Regine
AU - Bussolino, Federico
AU - Ghigo, Dario
AU - Garbarino, Giovanni
AU - Schröder, Henning
AU - Pescarmona, Gianpiero
AU - Till, Uwe
AU - Bosia, Amalia
PY - 1991/6/7
Y1 - 1991/6/7
N2 - Stimulation of human endothelial cells (EC) by thrombin elicits a rapid increase of intracellular free Ca2+ [(Ca2+]i), platelet-activating factor (PAF) production and 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF):acetyl-CoA acetyltransferase (EC 2.3.1.67) activity. The treatment of EC with thrombin leads to a 90% decrease in the cytosolic protein kinase C (PKC) activity; this dramatic decline is accompanied by an increase of the enzymatic activity in the particulate fraction. The role of PKC in thrombin-mediated PAF synthesis has been assessed: (1) by the blockade of PKC activity with partially selective inhibitors (palmitoyl-carnitine, sphingosine and H-7); (2) by chronic exposure of EC to phorbol 12-myristate 13-acetate (PMA), which results in down-regulation of PKC. In both cases, a strong inhibition of thrombin-induced PAF production is observed, suggesting obligatory requirement of PKC activity for PAF synthesis. It is suggested that PKC regulates EC phospholipase A2 (PLA2) activity as thrombin-induced arachidonic acid (AA) release is 90% inhibited in PKC-depleted cells. Brief exposure of EC to PMA strongly inhibits thrombin-induced [Ca2+]i rise, acetyltransferase activation and PAF production, suggesting that, in addition to the positive forward action, PKC provides a negative feedback control over membrane signalling pathways involved in the thrombin effect on EC. Forskolin and iloprost, two agents that increase the level of cellular cAMP in EC, are very effective in inhibiting thrombin-evoked cytosolic Ca2+ rise, acetyltransferase activation and PAF production; this suggests that endogenously generated prostacyclin (PGI2) may modulate the synthesis of PAF in human endothelial cells.
AB - Stimulation of human endothelial cells (EC) by thrombin elicits a rapid increase of intracellular free Ca2+ [(Ca2+]i), platelet-activating factor (PAF) production and 1-O-alkyl-2-lyso-sn-glycero-3-phosphocholine (lyso-PAF):acetyl-CoA acetyltransferase (EC 2.3.1.67) activity. The treatment of EC with thrombin leads to a 90% decrease in the cytosolic protein kinase C (PKC) activity; this dramatic decline is accompanied by an increase of the enzymatic activity in the particulate fraction. The role of PKC in thrombin-mediated PAF synthesis has been assessed: (1) by the blockade of PKC activity with partially selective inhibitors (palmitoyl-carnitine, sphingosine and H-7); (2) by chronic exposure of EC to phorbol 12-myristate 13-acetate (PMA), which results in down-regulation of PKC. In both cases, a strong inhibition of thrombin-induced PAF production is observed, suggesting obligatory requirement of PKC activity for PAF synthesis. It is suggested that PKC regulates EC phospholipase A2 (PLA2) activity as thrombin-induced arachidonic acid (AA) release is 90% inhibited in PKC-depleted cells. Brief exposure of EC to PMA strongly inhibits thrombin-induced [Ca2+]i rise, acetyltransferase activation and PAF production, suggesting that, in addition to the positive forward action, PKC provides a negative feedback control over membrane signalling pathways involved in the thrombin effect on EC. Forskolin and iloprost, two agents that increase the level of cellular cAMP in EC, are very effective in inhibiting thrombin-evoked cytosolic Ca2+ rise, acetyltransferase activation and PAF production; this suggests that endogenously generated prostacyclin (PGI2) may modulate the synthesis of PAF in human endothelial cells.
KW - Calcium ion
KW - cyclic AMP
KW - Endothelium
KW - PAF synthesis
KW - Protein kinase C
KW - Thrombin
UR - http://www.scopus.com/inward/record.url?scp=0025728323&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025728323&partnerID=8YFLogxK
U2 - 10.1016/0167-4889(91)90138-N
DO - 10.1016/0167-4889(91)90138-N
M3 - Article
C2 - 1710933
AN - SCOPUS:0025728323
VL - 1093
SP - 55
EP - 64
JO - Biochimica et Biophysica Acta - Molecular Cell Research
JF - Biochimica et Biophysica Acta - Molecular Cell Research
SN - 0167-4889
IS - 1
ER -