scholarly journals Induction and Signaling of an Apoptotic Response Typified by DNA Laddering in the Defense Response of Oats to Infection and Elicitors

2001 ◽  
Vol 14 (4) ◽  
pp. 477-486 ◽  
Author(s):  
Yasuomi Tada ◽  
Shingo Hata ◽  
Yoko Takata ◽  
Hitoshi Nakayashiki ◽  
Yukio Tosa ◽  
...  
Keyword(s):  
Protein Kinase ◽  
Dna Cleavage ◽  
De Novo ◽  
Calcium Ionophore ◽  
Cysteine Proteases ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Dna Laddering ◽  
Chitin And Chitosan ◽  
Induced Apoptosis

Cells in the primary leaves of oats displayed internucleosomal DNA cleavage in response to incompatible crown rust infection. DNA laddering also was evident in leaves treated with calcium ionophore A23187, nonspecific elicitors such as chitin and chitosan oligomers, and victorin, which functions as a specific elicitor in Pc-2/Vb containing oat leaves. The nuclei in a victorin-treated susceptible oat line were positive for the TUNEL assay. These elicitors clearly induced a 28-kDa nuclease (p28) in addition to three constitutive nucleases of 33, 24, and 22 kDa. Activation of p28 preceded the appearance of DNA laddering and possibly was mediated by de novo synthesis and/or cysteine protease activity. Pharmacological studies showed that the induction of DNA laddering was associated with oxidative stress, Ca2+ influx, and serine and cysteine proteases. Protein kinase and calmodulin activities did not seem to be involved in the induction of DNA laddering by victorin, whereas kinase-mediated signals were involved in DNA laddering induced by A23187. Protein kinase, calmodulin, G-protein activities, and Ca2+ influx, however, are involved in phytoalexin production. Our results imply that p28 is a possible nuclease candidate responsible for the induction of DNA laddering. The results also demonstrated that the mediators involved in the induction of apoptosis depended on the type of stimuli, whereas p28 and serine and cysteine proteases commonly are associated with each elicitor-induced apoptosis.

scholarly journals A role for protein kinase C in the membrane fusion necessary for platelet granule secretion

Blood ◽  
1989 ◽  
Vol 74 (7) ◽  
pp. 2405-2413 ◽  
Author(s):  
JM Gerrard ◽  
LL Beattie ◽  
J Park ◽  
SJ Israels ◽  
A McNicol ◽  
...  
Keyword(s):  
Protein Kinase C ◽  
Protein Kinase ◽  
Membrane Fusion ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ultrastructural Changes ◽  
Ionophore A23187 ◽  
Kinase C ◽  
Granule Secretion ◽  
Dimethyl Amiloride

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.

scholarly journals Cross-regulation of cortisol secretion by adrenocorticotropin and platelet-activating factor in perfused guinea pig adrenals

2007 ◽  
Vol 195 (1) ◽  
pp. 29-38
Author(s):  
Toshio Shimada ◽  
Taeko Hirose ◽  
Itsuro Matsumoto ◽  
Tadaomi Aikawa
Keyword(s):  
Protein Kinase ◽  
Guinea Pig ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Cortisol Response ◽  
Cortisol Secretion ◽  
Induced Signal ◽  
Dependent Processes

We examined the cross-regulation of signaling between ACTH-and platelet-activating factor (PAF)-mediated steroidogenesis in the perfused guinea pig adrenal gland. Our method of in situ perfusion using an artificial medium can evaluate whether cortisol secretion in response to ACTH and PAF is interactive. Treating adrenal glands with 100 pg/ml ACTH diminished the subsequent cortisol response to 10 nM PAF. By contrast, PAF resulted in subsequent potentiation of ACTH-induced cortisol secretion. A mixture of 50 μM l-α-1-oleoyl-2-acetyl-sn-glycerol (OAG), an activator of protein kinase C (PKC), and 3.3 μM calcium ionophore (A23187), or 10 μM forskolin (FRK) diminished the cortisol response to PAF, whereas that to ACTH was unaffected. Each of PAF, ACTH, or FRK eliminated the cortisol response to OAG plus A23187, whereas that to FRK was unaffected. These data show that the protein kinase A (PKA)-dependent processes activated by ACTH or FRK can interfere with PAF-induced signal transduction at receptor and post-receptor levels. In contrast, PKC-dependent processes activated by PAF promoted ACTH-signaling at receptor and post-receptor level. Cross-regulation between processes activated by PAF receptor–PKC and by ACTH receptor–PKA might function in the multifactorial regulation of adrenocortical steroidogenesis.

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

1993 ◽  
Vol 137 (2) ◽  
pp. 335-340 ◽  
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

scholarly journals Platelet-activating factor acts on cortisol secretion by perfused guinea-pig adrenals via calcium-/phospholipid-dependent mechanisms

2005 ◽  
Vol 184 (2) ◽  
pp. 381-391 ◽  
Author(s):  
Toshio Shimada ◽  
Taeko Hirose ◽  
Itsuro Matsumoto ◽  
Tadaomi Aikawa
Keyword(s):  
Protein Kinase ◽  
Guinea Pig ◽  
Platelet Activating Factor ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Breakdown Product ◽  
Ionophore A23187 ◽  
Cortisol Secretion ◽  
Cortisol Responses ◽  
Paf Receptor

Bilateral adrenals of the guinea pig were perfused in situ with an artificial medium equilibrated with 95% O2/5% CO2. Platelet-activating factor (PAF) induced biphasic cortisol responses, which reached a maximum at 10 nM PAF and declined at 100 nM. The effect of the PAF receptor antagonists CV-3988 and CV-6209 on PAF-stimulated cortisol secretion was examined. Prior exposure of adrenal glands to 10 μM CV-3988 or a simultaneous incubation with 10 μM CV-6209 abolished the cortisol response to 10 nM PAF. Lyso-PAF (a PAF precursor and breakdown product) did not affect cortisol secretion. Concentrations of 5–12.5 μM 1-(5-isoquinolinesulfonyl)-2-methylpiperazine dihydrochloride (H-7), a protein kinase C (PKC) inhibitor, abolished subsequent cortisol secretion in response to 10 nM PAF. N-[2-(Methylamino)ethyl]-5-isoquinoline sulfonamide dihydrochloride (H-8), a protein kinase A inhibitor, was less effective. A calcium ionophore (A23187) at 3.3 and 10 μM increased cortisol secretion, but the activator of PKC, l-α-1-oleoyl-2-acetyl-sn-3-glycerol (OAG), at 50 μM had no effect. When infused simultaneously, OAG (50 μM) and A23187 (3.3 μM) stimulated cortisol secretion synergistically. The secretory response of cortisol to repeated infusions of adrenocortico-trophin (100 pg/ml) or forskolin (10 μM) was essentially reproducible. By contrast, cortisol secretion in response to repeated infusions of PAF (10 nM) or OAG plus A23187 was not reproducible and the second response was diminished compared with the first. Our findings suggest that PAF plays a role in the regulation of steroidogenesis via a mechanism mediated by the PAF receptor and PKC.

scholarly journals 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 ◽  
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.

scholarly journals Endothelial Cell “Memory” of Inflammatory Stimulation: Human Venular Endothelial Cells Store Interleukin 8 in Weibel-Palade Bodies

1998 ◽  
Vol 188 (9) ◽  
pp. 1757-1762 ◽  
Author(s):  
Barbara Wolff ◽  
Alan R. Burns ◽  
James Middleton ◽  
Antal Rot
Keyword(s):  
Endothelial Cells ◽  
Secretory Pathway ◽  
De Novo ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Inflammatory Stimuli ◽  
Regulated Secretory Pathway ◽  
Von Willebrand ◽  
Willebrand Factor

The expression and secretion of interleukin (IL)-8, the prototype member of the C-X-C subfamily of chemokines, can be induced by diverse inflammatory stimuli in many cells, including endothelial cells (EC). Upon de novo synthesis, IL-8 localizes intracellularly in the Golgi apparatus, from where it is secreted. In addition to this constitutive secretory pathway, we describe a depot storage and separate regulated secretory pathway of IL-8 in EC. The prolonged stimulation of primary human EC with inflammatory mediators resulted in the accumulation of IL-8 in Weibel-Palade bodies, where it colocalized with von Willebrand factor. IL-8 was retained in these storage organelles for several days after the removal of the stimulus and could be released by EC secretagogues such as phorbol myristate acetate, the calcium ionophore A23187, and histamine. These findings suggest that storage of IL-8 in Weibel-Palade bodies may serve as the EC “memory” of a preceding inflammatory insult, which then enables the cells to secrete IL-8 immediately without de novo protein synthesis.

scholarly journals Calcium ionophore A23187 as a regulator of gene expression in mammalian cells.

1986 ◽  
Vol 103 (6) ◽  
pp. 2145-2152 ◽  
Author(s):  
E Resendez ◽  
J Ting ◽  
K S Kim ◽  
S K Wooden ◽  
A S Lee
Keyword(s):  
Mammalian Cells ◽  
De Novo ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Similar Response ◽  
Calmodulin Antagonist ◽  
Induction Process ◽  
Continuous Presence ◽  
Lower Magnitude

The calcium ionophore A23187 can reversibly induce the expression of two glucose-regulated genes, p3C5 and p4A3. This induction requires a continuous presence of the ionophore for over 2 h. Although extracellular Ca2+ is important for the optimal effect of A23187, it is not necessary for the induction, since a similar response with a lower magnitude can be triggered in cells cultured in low Ca2+ medium buffered with EGTA. Both the basal and induced levels of p3C5 and p4A3 transcripts can be modulated by the calmodulin antagonist W-7, indicating the involvement of Ca2+/calmodulin-associated pathways. In addition, the sensitivity of the A23187 induction to cycloheximide suggests that the induction process is dependent on de novo protein synthesis.

Involvement of protein kinase C in mouse mammary gland development

1986 ◽  
Vol 109 (1) ◽  
pp. 29-34 ◽  
Author(s):  
J. J. Caulfield ◽  
F. F. Bolander
Keyword(s):  
Protein Kinase C ◽  
Mammary Gland ◽  
Protein Kinase ◽  
Milk Protein ◽  
Calcium Ionophore ◽  
Calcium Ionophore A23187 ◽  
Ionophore A23187 ◽  
Kinase C ◽  
Protein Kinase C Activity ◽  
Biochemical Differentiation

ABSTRACT The relationship between kinase C activity and mammary gland differentiation was investigated by following kinase activity throughout the mouse reproductive cycle and by pharmacologically perturbing the kinase, while monitoring biochemical differentiation. Protein kinase C activity declined during pregnancy and remained low throughout lactation, suggesting an inverse relationship with milk protein expression. This negative association was further supported by the use of quercetin (50–100 μmol/l) and gossypol (50 μmol/l), which are both protein kinase C inhibitors. These compounds doubled α-lactalbumin levels in mammary explants cultured with hormones. However, a phorbol ester, known to activate protein kinase C, had no effect on α-lactalbumin production, although it did stimulate this milk protein 2·5-fold in the presence of the calcium ionophore, A23187. In the absence of raised calcium levels, protein kinase C activity therefore appeared to be inversely correlated with biochemical differentiation; but, in the presence of increased calcium concentrations, both calcium and the kinase acted synergistically to augment hormone-induced α-lactalbumin expression. J. Endocr. (1986) 109, 29–34

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