Protein kinase C dependent and independent activation of phospholipase A2under calcium ionophore (A23187) exposure in rabbit pulmonary arterial smooth muscle cells

Abstract The addition of 1-oleoyl-2-acetylglycerol (OAG), or phorbol-12- myristate-13-acetate (PMA) to platelets induced the phosphorylation of a 47,000 dalton protein (47 Kd), fusion of granule membranes with membranes of the surface connected canalicular system, the formation of large vesicles and the secretion of serotonin. 1-(5- isoquinolinesulfonyl)-2-methyl-piperazine (H7), and sphingosine, inhibitors of protein kinase C, significantly inhibited the ultrastructural changes and the phosphorylation of 47 Kd. N-(2- guanidinoethyl)-5-isoquinolinesulfonamide (HA1004), structurally similar to H7, but a weaker inhibitor of protein kinase C, did not attenuate these responses to OAG or to PMA. H7, but not HA1004, also markedly inhibited secretion induced by the synergistic combination of OAG and the calcium ionophore A23187. Amiloride and 5-(N,N dimethyl)- amiloride, inhibitors of the Na+/H+ transporter, did not inhibit the ultrastructural response and the protein phosphorylation induced by OAG, or the secretion induced by the combination of A23187 and OAG. The results link the activation of protein kinase C by diglycerides to the labilization and fusion of granule membranes important for secretion.

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Protein kinase C activation and calcium mobilization decrease prolactin release from human decidual cells in early pregnancy

Journal of Endocrinology ◽

10.1677/joe.0.1370335 ◽

1993 ◽

Vol 137 (2) ◽

pp. 335-340 ◽

Cited By ~ 3

Author(s):

T. Kubota ◽

S. Kamada ◽

M. Taguchi ◽

S. Sakamoto ◽

T. Aso

Keyword(s):

Protein Kinase C ◽

Protein Kinase ◽

Early Pregnancy ◽

Calcium Ionophore ◽

Calcium Ionophore A23187 ◽

Calcium Mobilization ◽

Ionophore A23187 ◽

Prolactin Release ◽

Kinase C ◽

Decidual Cells

ABSTRACT The present study was undertaken to investigate the effects of protein kinase C (PKC) activation and calcium mobilization on the release of prolactin from human decidual cells in early pregnancy. Decidua obtained from patients in early pregnancy was enzymatically dispersed and cultured with phorbol myristate acetate (PMA) and calcium ionophore A23187 in a cell culture system. Prolactin in the medium was measured by enzyme-immunoassay. PMA, a PKC activator, dose-dependently attenuated the release of prolactin from cultured decidual cells, while a PKC inhibitor, H7, significantly (P < 0·001) diminished the effect of PMA on prolactin release. PMA had no effect on cell numbers or DNA synthesis in the decidual cells during culture. It did not significantly increase the generation of inositol phosphate in decidual cells prelabelled with myo[3H]inositol and it had no effect on intracellular calcium concentration ([Ca2 + ]i). Calcium ionophore A23187, a Ca2 +-mobilizing agent, also significantly (P<0·001) attenuated the release of prolactin and potentiated the PMA-induced suppression of prolactin release from decidual cells. These findings suggest that activation of PKC and mobilization of Ca2+ may be involved in regulating prolactin release from human decidual cells. The PMA-induced suppression of prolactin release is not triggered by phosphoinositide hydrolysis nor by the increase in [Ca2 + ]i in decidual cells. Journal of Endocrinology (1993) 137, 335–340

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PROTEIN KINASE C ACTIVATES BK CHANNELS IN PULMONARY ARTERIAL SMOOTH MUSCLE VIA CGMP-DEPENDENT PROTEIN KINASE

Cardiovascular Pathology ◽

10.1016/j.carpath.2004.03.122 ◽

2004 ◽

Vol 13 (3) ◽

pp. 43

Author(s):

Scott A Barman ◽

Mary L Meadows ◽

Shu Zhu ◽

Richard E White

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Bk Channels ◽

Dependent Protein Kinase ◽

Cgmp Dependent Protein Kinase ◽

Kinase C ◽

Dependent Protein ◽

Pulmonary Arterial ◽

Pulmonary Arterial Smooth Muscle

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Reactive oxygen-mediated contraction in pulmonary arterial smooth muscle: cellular mechanisms

Canadian Journal of Physiology and Pharmacology ◽

10.1139/y91-058 ◽

1991 ◽

Vol 69 (3) ◽

pp. 383-388 ◽

Cited By ~ 42

Author(s):

N. Jin ◽

C. S. Packer ◽

R. A. Rhoades

Keyword(s):

Smooth Muscle ◽

Protein Kinase C ◽

Protein Kinase ◽

Reactive Oxygen ◽

Oxygen Species ◽

Cellular Mechanisms ◽

Kinase C ◽

Pulmonary Arterial ◽

Pulmonary Arterial Smooth Muscle ◽

Oxidase Reaction

Reactive oxygen species (at least relatively high doses) cause contraction of pulmonary arterial smooth muscle. The objective of the present study was to elucidate the possible cellular mechanisms involved in reactive oxygen-mediated contraction. Isolated arterial rings from Sprague–Dawley rats were placed in tissue baths containing Earle's balanced salt solution. The maximum active force production (Po) in response to 80 mM KCl was obtained. All other responses were normalized as percentages of Po for comparative purposes. Exposure to reactive oxygen (generated from either the xanthine oxidase reaction (XO) or the glucose oxidase reaction) resulted in pulmonary arterial muscle developing mean active tension of 17.1 ± 3.0% Po. This contraction was independent of extracellular calcium, since it was not affected by verapamil (a calcium channel blocker) or by placement of the arterial muscle in calcium-free media. Phentolamine (an α1-receptor blocker) and propranolol (a β-receptor blocker) did not diminish the response to XO. Ryanodine (a SR calcium release inhibitor), while reducing the response to norepinephrine, did not affect the response to XO. However, H-7 (an inhibitor of protein kinase C) decreased the XO-mediated contraction by 49%. These results indicate that while Ca2+ may not be involved as a second messenger, protein kinase C activity appears to play a role in the transduction pathway of reactive oxygen species mediated contraction of pulmonary arterial smooth muscle.Key words: muscle calcium, α1-receptor, ryanodine, protein kinase C, vascular smooth muscle, oxygen radicals, verapamil.

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Protein kinase C regulates proliferation of mast cells and the expression of the mRNAs of fos and jun proto-oncogenes during activation by IgE-Ag or calcium ionophore A23187

Blood ◽

10.1182/blood.v78.9.2354.bloodjournal7892354 ◽

1991 ◽

Vol 78 (9) ◽

pp. 2354-2364

Author(s):

D Baranes ◽

E Razin

Keyword(s):

Protein Kinase C ◽

Mast Cells ◽

Protein Kinase ◽

Calcium Ionophore ◽

Calcium Ionophore A23187 ◽

Prolonged Treatment ◽

Ionophore A23187 ◽

Short Term ◽

Kinase C ◽

Short Term Exposure

Short-term stimulation (up to 16 hours) of interleukin-3 (IL-3)- dependent mouse bone marrow-derived mast cells, Abelson transformed mouse liver-derived mast cells, or rat basophilic leukemia cells by either IgE-Ag or calcium ionophore A23187 resulted in inhibition of their proliferation as measured by 3H-thymidine incorporation and MTT (tetrazolium) assays, and in accumulation of the mRNAs of c-fos, c-jun, junB and slightly of junD proto-oncogenes. The involvement of protein kinase C (PKC) in these responses was investigated by using several approaches of enzyme activity regulation. Direct activation of the PKC was achieved by short-term exposure of the cells to the PKC-specific activator phorbol 12-myristate-13-acetate (PMA). Inhibition of PKC activity was obtained by either prolonged treatment of the cells with PMA or by exposure of the cells to the PKC inhibitors H-7 and staurosporine. The results showed the following: (1) Short-term exposure of mast cells to PMA was sufficient to induce inhibition of proliferation. (2) An increase in PKC activity was associated with a decrease in the proliferation of IgE-dinitrophenol (DNP) or calcium ionophore A23187-stimulated cells. (3) A direct correlation was found between the increase in PKC activity and the increase in the level of the mRNAs of the jun proto-oncogenes in cells activated by both stimuli mentioned. (4) While an increase in PKC activity was associated with the upregulation of the level of c-fos mRNA during calcium ionophore A23187 stimulation, it showed the opposite effect on the expression of the mRNA of this proto-oncogene when the cells were triggered by IgE- DNP. Therefore, we concluded that PKC plays various roles in the expression of the mRNA of c-fos in activated mast cells depending on the stimulus involved. In addition, the expression of the mRNA of c-jun and junB proto-onogenes is not coordinately regulated with that of c- fos during immunologic stimulation. This discordancy, which is associated with the increase in PKC activity in mast cells, may play a role in the regulation of the transcription of AP-1-responsive genes, and therefore could be associated with the regulation of proliferation of these cells.

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