Bradykinin and vasopressin activate phospholipase D in rat Leydig cells by a protein kinase C-dependent mechanism

1993 ◽  
Vol 136 (1) ◽  
pp. 119-126 ◽  
Author(s):  
A. M. Vinggaard ◽  
H. S. Hansen
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase D ◽  
Leydig Cells ◽  
Platelet Activating Factor ◽  
Ionophore A23187 ◽  
Dependent Manner ◽  
Kinase C ◽  
Dependent Mechanism

ABSTRACT In the present study we report that bradykinin stimulated phospholipase D activity in rat Leydig cells. Bradykinin added for 8 min stimulated choline formation in a dose-dependent manner and, in the presence of ethanol, bradykinin (100 nmol/l) stimulated transphosphatidylation by phospholipase D resulting in the formation of phosphatidylethanol. This stimulation was abolished after down-regulation of protein kinase C by long-term pretreatment for 22 h with phorbol 12-myristate 13-acetate (PMA). The stimulation of phospholipase D by the simultaneous addition for 8 min of maximum concentrations of PMA and vasopressin (AVP), PMA and bradykinin, or AVP and bradykinin produced no additive phosphatidylethanol or choline response, suggesting that AVP, bradykinin and PMA stimulated phospholipase D-catalysed phosphatidylcholine hydrolysis by a similar protein kinase C-dependent mechanism. Furthermore, LH (10 ng/ml), insulin (500 nmol/l), GH (100 ng/ml), interleukin-1β (5 U/ml) and platelet-activating factor (200 nmol/l) were found not to activate phospholipase D, whereas the Ca2+ ionophore A23187 (10 μmol/l) stimulated phosphatidylethanol formation, suggesting that Ca2+ might be a regulator of phospholipase D in Leydig cells. Journal of Endocrinology (1993) 136, 119–126

Endothelin activation of phospholipase D: dual modulation by protein kinase C and Ca2+

1993 ◽  
Vol 264 (5) ◽  
pp. F845-F853
Author(s):  
M. M. Friedlaender ◽  
D. Jain ◽  
Z. Ahmed ◽  
D. Hart ◽  
R. L. Barnett ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase D ◽  
Intracellular Signaling ◽  
Dependent Manner ◽  
Concentration Dependent Manner ◽  
Kinase C ◽  
Eta Receptor ◽  
Ca2 Channels ◽  
Stimulation Of

Previous work from this laboratory has identified an endothelin (ET) type A (ETA) receptor on cultured rat renal medullary interstitial cells (RMIC), coupled to phosphatidylinositol-specific phospholipase C (PI-PLC), dihydropyridine-insensitive receptor-operated Ca2+ channels, and phospholipase A2. The current studies explored a role for ET stimulation of phosphatidylcholine-specific phospholipase D (PC-PLD) in intracellular signaling of this cell type. ET stimulated PLD activation, as measured by phosphatidic acid (PA) or phosphatidylethanol (PEt) accumulation, in a time- and concentration-dependent manner. Inhibition of diacylglycerol (DAG) kinase by ethylene glycol dioctanoate or 6-(2)4-[(4-fluorophenyl)-phenylmethylene]-1-piperadinyl]ethy l-7-methyl-5H - thiaxolo-[3,2-alpyrimidin]-5-one (R 59022) failed to blunt PA accumulation, indicating that PLD, and not DAG, was the source of PA. Inhibition of PA phosphohydrolase (PAP) by propranolol increased late accumulation of PA, suggesting that the prevailing metabolic flow was in the direction of PA to DAG. Phorbol 12-myristate 13-acetate (PMA) augmented ET-evoked PEt accumulation, whereas downregulation of protein kinase C (PKC) obviated agonist-induced PEt production. PMA augmentation of PLD activity proceeded independent of cytosolic free Ca2+ concentration. Ca2+ derived from either intracellular or extracellular sources enhanced ET-related PEt accumulation but was without effect in PKC-downregulated cells. Collectively, these observations indicate that ET stimulates PLD production in RMIC. PKC is the major regulator of this process, with Ca2+ playing a secondary, modulatory role. In addition, these data suggest that PC-PLD is coupled to the ETA receptor.

Erythropoietin and testicular steroidogenesis: the role of second messengers

1995 ◽  
Vol 132 (1) ◽  
pp. 103-108 ◽  
Author(s):  
Carlo Foresta ◽  
Roberto Mioni ◽  
Paola Bordon ◽  
Francesco Gottardello ◽  
Andrea Nogara ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Leydig Cells ◽  
Second Messengers ◽  
Indirect Evidence ◽  
Calcium Flux ◽  
Dependent Manner ◽  
Kinase C ◽  
Testicular Steroidogenesis

Foresta C, Mioni R, Bordon P, Gottardello F, Nogara A, Rossato M. Erythropoietin and testicular steroidogenesis: the role of second messengers. Eur J Endocrinol 1995;132:103–8. ISSN 0804–4643 It has been demonstrated that erythropoietin (EPO) influences rat and human Leydig cell steroidogenesis, stimulating testosterone production through a direct and specific receptor-mediated mechanism. The aim of this study was to investigate the mechanism by which recombinant human erythropoietin (rHuEPO) exerts its stimulatory effect on rat Leydig cells. Recombinant human EPO did not induce, at any dose tested (10−10 to 10−13 mol/l), an increase in either cAMP or cGMP, suggesting that in Leydig cells the effect of rHuEPO does not involve the adenylate or guanylate–cyclase systems. The role of transmembrane calcium flux in rHuEPO-stimulated steroidogenesis was studied by evaluating the effect of calcium channel blocker, verapamil, and by the 45Ca2+ uptake method. Verapamil did not influence rHuEPO-induced testosterone secretion and rHuEPO did not modify calcium recycling, indicating that calcium transmembrane flux is not involved in the rHuEPO effect. The protein kinase C inhibitor staurosporine (10, 30, 100 and 300 nmol/l) inhibited rHuEPO-stimulated testicular steroidogenesis in a dose-dependent manner. This indirect evidence suggests that the stimulatory effect of rHuEPO on rat Leydig cells may involve protein kinase C activation. Carlo Foresta, Institute of Internal Medicine, Via Ospedale Civile 105, 35128 Padova, Italy

scholarly journals Synthesis of intracellular histamine in platelets is associated with activation of protein kinase C, but not with mobilization of Ca2+

1991 ◽  
Vol 273 (2) ◽  
pp. 405-408 ◽  
Author(s):  
S P Saxena ◽  
C Robertson ◽  
A B Becker ◽  
J M Gerrard
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Human Platelets ◽  
Ionophore A23187 ◽  
Dependent Manner ◽  
Kinase C ◽  
Histamine Synthesis ◽  
Ic50 Values ◽  
Induced Aggregation ◽  
Pkc Activation

In previous reports, we have provided evidence indicating that newly formed histamine is an intracellular messenger in human platelets. The involvement of protein kinase C (PKC) and intracellular calcium (Ca2+i) in the synthesis of histamine was investigated. Human platelets were stimulated by phorbol 12-myristate 13-acetate (PMA), collagen and the Ca2+ ionophore A23187, with or without the PKC inhibitor staurosporine. Aggregation, histamine synthesis and phosphorylation of pleckstrin (47 kDa; P47) and myosin light chain (20 kDa; P20) proteins were monitored. Staurosporine inhibited PMA- and collagen-induced aggregation, histamine synthesis and phosphorylation of 47 kDa and 20 kDa proteins in a dose-dependent manner. For PMA, median inhibitory concentrations (IC50 values) for staurosporine inhibition of aggregation, histamine synthesis and phosphorylation were similar, suggesting that histamine synthesis induced by this agonist may be a consequence of PKC activation. Conversely, collagen-stimulated histamine synthesis was inhibited by staurosporine at concentrations significantly higher than those required to inhibit aggregation (P less than 0.005) or pleckstrin phosphorylation (P less than 0.01), indicating the possible involvement of non-PKC mechanism(s) in the synthesis of histamine induced by this agonist. A23187 failed to induce the synthesis of intracellular histamine in platelets, whereas staurosporine blocked A23187-induced aggregation and phosphorylation of the 20 kDa protein at significantly higher concentrations than those needed to inhibit PKC. When platelets were stimulated with a combination of A23187 and PMA, the increase in platelet histamine was less than that with PMA alone. The results provide evidence that the synthesis of intracellular histamine in platelets occurs as a consequence of PKC activation and may be down-regulated under conditions where there is a substantial rise in [Ca2+]i.

scholarly journals Sustained Receptor Stimulation Leads to Sequestration of Recycling Endosomes in a Classical Protein Kinase C- and Phospholipase D-dependent Manner

2009 ◽  
Vol 284 (33) ◽  
pp. 22322-22331 ◽  
Author(s):  
Jolanta Idkowiak-Baldys ◽  
Aleksander Baldys ◽  
John R. Raymond ◽  
Yusuf A. Hannun
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase D ◽  
Dependent Manner ◽  
Receptor Stimulation ◽  
Recycling Endosomes ◽  
Kinase C

Long-Term Changes in Excitability Induced by Protein Kinase C Activation in Aplysia Sensory Neurons

1998 ◽  
Vol 79 (3) ◽  
pp. 1210-1218 ◽  
Author(s):  
Frédéric Manseau ◽  
Wayne S. Sossin ◽  
Vincent F. Castellucci
Keyword(s):  
Protein Synthesis ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Sensory Neurons ◽  
Dependent Manner ◽  
Kinase C ◽  
Long Term Changes ◽  
Protein Kinase C Activation ◽  
Time Point

Manseau, Frédéric, Wayne S. Sossin, and Vincent F. Castellucci. Long-term changes in excitability induced by protein kinase C activation in Aplysia sensory neurons. J. Neurophysiol. 79: 1210–1218, 1998. Protein kinases A (PKA) and C (PKC) play a central role as intracellular transducers during simple forms of learning in Aplysia. These two proteins seem to cooperate in mediating the different forms of plasticity underlying behavioral modifications of defensive reflexes in a state- and time-dependent manner. Although short- and long-term changes in the synaptic efficacy of the connections between mechanosensory neurons and motoneurons of the reflex have been well characterized, there is also a distinct intermediate phase of plasticity that is not as well understood. Biochemical and physiological experiments have suggested a role for PKC in the induction and expression of this form of facilitation. In this report, we demonstrate that PKC activation can induce both intermediate- and long-term changes in the excitability of sensory neurons (SNs). Short application of 4β-phorbol ester 12,13-dibutyrate (PDBU), a potent activator of PKC, produced a long-lasting increase in the number of spikes fired by SNs in response to depolarizing current pulses. This effect was observed in isolated cell culture and in the intact ganglion; it was blocked by a selective PKC inhibitor (chelerythrine). Interestingly, the increase in excitability measured at an intermediate-term time point (3 h) after treatment was independent of protein synthesis, while it was disrupted at the long-term (24 h) time point by the general protein synthesis inhibitor, anisomycin. In addition to suggesting that PKC as well as PKA are involved in long-lasting excitability changes, these findings support the idea that memory formation involves multiple stages that are mechanistically distinct at the biochemical level.

Long-term regulation of Na(+)-H+ exchange in vascular smooth muscle cells: role of protein kinase C

1991 ◽  
Vol 260 (3) ◽  
pp. C562-C569 ◽  
Author(s):  
M. Mitsuka ◽  
B. C. Berk
Keyword(s):  
Smooth Muscle ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Vascular Smooth Muscle ◽  
Kinetic Properties ◽  
Dependent Manner ◽  
Kinase C ◽  
Measured Exposure

Regulation of intracellular pH (pHi) plays an important role in vascular smooth muscle cell (VSMC) contractile tone and growth. We have shown that pHi in proliferating VSMC is more alkaline (7.25) than in growth-arrested cells (7.10). To study the Na(+)-H+ exchanger in the growth-dependent regulation of VSMC pHi, ethylisopropylamiloride (EIPA)-sensitive Na+ influx was measured. Exposure of growth-arrested VSMC to 10% serum initially increased Na+ influx (145% of baseline at 30 min), which then decreased (52% of baseline at 24 h). Serum-induced alterations in the kinetic properties of the Na(+)-H+ exchanger were studied by analysis of its external Na+ binding site properties. Exposure of growth-arrested VSMC to 10% serum for 24 h increased the Km for external Na+ from 54 to 380 mM, with a change in the Vmax from 155 to 199 nmol Na+.mg protein-1.min-1. The change in Km was due to activation of protein kinase C (PKC). Phorbol 12,13-dibutyrate caused a 48% decrease in EIPA-sensitive influx, the inactive 4 alpha-phorbol 12,13-didecanoate had no effect, and the PKC inhibitor sphingosine reversed the effect. Therefore, the Na(+)-H+ exchanger in VSMC is regulated in a growth-dependent manner via PKC.

scholarly journals Platelet phospholipase D is activated by protein kinase C via an integrin αIIbβ3-independent mechanism

1995 ◽  
Vol 310 (2) ◽  
pp. 623-628 ◽  
Author(s):  
E A Martinson ◽  
S Scheible ◽  
A Greinacher ◽  
P Presek
Keyword(s):  
Protein Kinase C ◽  
Platelet Aggregation ◽  
Protein Kinase ◽  
Phospholipase D ◽  
Major Protein ◽  
Ionophore A23187 ◽  
Type I ◽  
Specific Product ◽  
Kinase C ◽  
Fibrinogen Binding

Blood platelets contain phospholipase D (PLD) that is rapidly activated following platelet stimulation. It is currently unclear, however, where PLD fits into the signalling cascade that leads to aggregation and secretion. Therefore we investigated the mechanism of activation of PLD in human platelets, using the formation of the PLD-specific product phosphatidylethanol as a measure of PLD activity. PLD was activated by a number of platelet agonists that also cause the activation of protein kinase C, including thrombin, collagen, the Ca2+ ionophore A23187 and the thromboxane A2-mimetic U46619. Phorbol 12-myristate 13-acetate (PMA), a direct activator of protein kinase C, also increased PLD activity. A selective inhibitor of protein kinase C, Ro-31-8220, totally blocked the stimulation of PLD by thrombin or PMA under conditions in which it also inhibited phosphorylation of pleckstrin, the major protein kinase C substrate in platelets. Ro-31-8220 additionally inhibited A23187-stimulated PLD activity, indicating that Ca2+ activation of PLD also occurs via a protein kinase C-dependent pathway. In the presence of the fibrinogen antagonist peptide RGDS, which inhibits fibrinogen binding to integrin alpha IIb beta 3 and allows little or no aggregation to occur, thrombin- and PMA-stimulated PLD activity was still observed, indicating that PLD activation is not simply a consequence of platelet aggregation. Furthermore, these agonists were able to stimulate PLD in platelets from a Glanzmann's thrombasthenia type I patient lacking the integrin alpha IIb beta 3 complex, which indicates that activation of PLD is also independent of the recruitment of integrin alpha IIb beta 3. Taken together, our results show that PLD is activated by a pathway involving protein kinase C, and suggest that PLD might be involved in signal transduction events occurring upstream of integrin alpha IIb beta 3 activation and fibrinogen binding, which are prerequisites for full platelet aggregation.

Thromboxane A2-stimulated phospholipase D in osteoblast-like cells: possible involvement of PKC

1995 ◽  
Vol 269 (3) ◽  
pp. E524-E529 ◽  
Author(s):  
J. Shinoda ◽  
A. Suzuki ◽  
Y. Oiso ◽  
O. Kozawa
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Phospholipase D ◽  
Inositol Phosphates ◽  
Specific Inhibitor ◽  
Thromboxane A2 ◽  
Dependent Manner ◽  
Kinase C ◽  
Protein Kinase C Inhibitor ◽  
Dose Dependent

We examined the effect of thromboxane A2 (TxA2) on phosphatidylcholine-hydrolyzing phospholipase D activity in osteoblast-like MC3T3-E1 cells. 9,11-Epithio-11,12-methanothromboxane A2 (STA2), a stable analogue of TxA2, stimulated the formations of both choline and inositol phosphates in a dose-dependent manner in the range between 10 nM and 10 microM. The formation of choline stimulated by a combination of STA2 and 12-O-tetradecanoylphorbol 13-acetate (TPA), a protein kinase C-activating phorbol ester, was not additive. 1-(5-Isoquinolinyl-sulfonyl)-2-methylpiperazine (H-7), an inhibitor of protein kinases, suppressed the formation of choline induced by STA2 as well as that by TPA, but 20 microM N-(2-guanidinoethyl)-5-isoquinolinesulfonamide (HA-1004), a control for H-7 as a protein kinase C inhibitor, had little effect. Calphostin C, a potent and specific inhibitor of protein kinase C, also suppressed the formation of choline induced by STA2. The STA2-induced formation of choline was significantly reduced by chelating extracellular Ca2+ with ethylene glycol-bis(beta-amino-ethyl ether)-N,N,N',N'-tetraacetic acid. STA2 dose dependently stimulated 45Ca2+ influx from extracellular space. STA2 stimulated DNA synthesis of MC3T3-E1 cells and increased the number of these cells. These results suggest that TxA2 stimulates phospholipase D in osteoblast-like cells, resulting in the direction of their proliferation, and that the activation of protein kinase C is involved in the stimulation of phospholipase D.

Phospholipase A(2) and its products are involved in the purinergic receptor-mediated translocation of protein kinase C in CHO-K1 cells

2000 ◽  
Vol 113 (8) ◽  
pp. 1335-1343
Author(s):  
Y. Shirai ◽  
K. Kashiwagi ◽  
N. Sakai ◽  
N. Saito
Keyword(s):  
Plasma Membrane ◽  
Protein Kinase C ◽  
Protein Kinase ◽  
Purinergic Receptor ◽  
Phospholipase A ◽  
Ionophore A23187 ◽  
Dependent Manner ◽  
Kinase C ◽  
Pkc Epsilon ◽  
Phospholipase A 2

The signal transduction involved in the purinergic stimuli-induced activation of protein kinase C (PKC) in CHO-K1 cells was investigated. Purinergic stimuli such as adenosine triphosphate and uridine triphosphate induced a transient translocation of PKC epsilon, gamma, and delta from the cytoplasm to the plasma membrane. These translocations were blocked by an inhibitor of phosphatidylinositol-specific phospholipase C (PLC), but not by an inhibitor of phosphatidylcholine-specific PLC. A diacylglycerol (DAG) analogue also induced reversible translocations of PKC gamma, epsilon, and delta from the cytoplasm to the plasma membrane, while the calcium ionophore A23187 caused a similar translocation of only the gamma subtype. These results confirm that the hydrolysis of phosphatidylinositol-2-phosphate by PLC and the subsequent generation of DAG and increase in Ca(2+)are involved in the purinergic stimuli-induced translocation of PKC. A DAG antagonist, 1-o-hexadecyl-2-o-acetyl-glycerol, blocked the DAG analogue-induced translocations of all PKC subtypes tested but failed to inhibit the purinergic stimuli-induced translocations of PKC epsilon and gamma. The DAG antagonist could not block the ATP- and UTP-induced translocation of PKC epsilon even in the absence of extracellular Ca(2+). Co-application of the DAG antagonist and a phospholipase A(2) (PLA(2)) inhibitor such as aristolochic acid, arachidonyltrifluoromethyl ketone, or bromoenol lactone inhibited the purinergic receptor-mediated translocation of PKC epsilon although each PLA(2) inhibitor alone did not block the translocation. In contrast to the epsilon subtype, ATP-induced translocation of PKC gamma was observed in the presence of both the PLA(2) inhibitor and the DAG antagonist. However, it is noteworthy that re-translocation of PKC gamma was hastened by the PLA(2) inhibitor. Furthermore products of PLA(2), such as lysophospholipids and fatty acids, induced the translocation of PKC gamma and epsilon in a dose dependent manner, but not delta. These results indicate that, in addition to PLC and DAG, PLA(2) and its products are involved in the purinergic stimuli-induced translocation of PKC epsilon and gamma in CHO-K1 cells. Each subtype of PKC in CHO-K1 cell is individually activated in response to a purinergic stimulation.

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