Antioxidants stimulate meiosis resumption, but inhibit mitogen-activated protein kinase phosphorylation and further cell cycle progression in porcine oocytes

2000 ◽  
Vol 12 (8) ◽  
pp. 383 ◽  
Author(s):  
Q. Y. Sun ◽  
L. Lai ◽  
R. S. Prather ◽  
H. Schatten
Keyword(s):  
Map Kinase ◽  
Germinal Vesicle ◽  
Fluorescein Isothiocyanate ◽  
Nordihydroguaiaretic Acid ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Germinal Vesicle Breakdown ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation ◽  
Dose Dependent

In the present study the effects of two cell-permeant antioxidants, 2(3)-tert-butyl-4-hydroxyanisole (BHA) and nordihydroguaiaretic acid (NDGA), on porcine oocyte meiosis resumption, chromatin behaviour and spindle assembly were investigated. The antioxidants BHA and NDGA stimulated meiosis resumption in a dose-dependent manner in both cumulus-enclosed and denuded porcine oocytes. Afterin vitro culture for 8 h, few oocytes underwent germinal vesicle breakdown (GVBD) in control groups, whereas GVBD occurred in high percentages of oocytes treated with BHA or NDGA at concentrations that inhibit GVBD in rodent oocytes, although mitogen-activated protein (MAP) kinase was not phosphorylated as revealed by Western immunoblots. Orcein staining and fluorescein isothiocyanate-anti-· -tubulin labelling showed that chromosome and spindle formation, respectively, and further meiosis progression were inhibited 20 and 25 h after culture. Instead, chromatin was highly condensed or existed in scattered condensed clusters. Correspondingly, MAP kinase phosphorylation was inhibited by both BHA and NDGA in a dose-dependent manner. The inhibitory effects of BHA on meiosis completion and MAP kinase phosphorylation was reversible. These results suggest that, unlike in rodent oocytes, antioxidants stimulate GVBD in the absence of MAP kinase activation, but inhibit MAP kinase phosphorylation, meiotic apparatus formation and thus the further progression of the meiosis of porcine oocytes.

Mitogen-activated protein kinase in human eggs

Zygote ◽  
1999 ◽  
Vol 7 (2) ◽  
pp. 181-185 ◽  
Author(s):  
Qing-Yuan Sun ◽  
Zeev Blumenfeld ◽  
Sara Rubinstein ◽  
Shlomit Goldman ◽  
Yael Gonen ◽  
...  
Keyword(s):  
Map Kinase ◽  
Mammalian Species ◽  
Germinal Vesicle ◽  
Mitogen Activated Protein Kinase ◽  
Early Embryos ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation ◽  
Cycle Regulation ◽  
Kinase Expression

Mitogen-activated protein (MAP) kinase in human eggs has been investigated by using immunoblotting with both anti-Active MAPK and anti-ERK2 antibodies. The results showed that the main form of MAP kinase was p42ERK2. It was in a dephosphorylated form in oocytes at the germinal vesicle stage, but fully phosphorylated in unfertilised mature eggs. MAP kinase phosphorylation was significantly decreased when pronuclei were formed after intracytoplasmic sperm injection. Neither MAP kinase expression nor activity was detected in morphologically degenerated eggs. Although MAP kinase still existed in early embryos arrested at the 8-cell or morula stages, little, if any, activity could be detected. These data suggest that MAP kinase may play an important role in the cell cycle regulation of human eggs, as in other mammalian species.

cAMP inhibits mitogen-activated protein (MAP) kinase activation and resumption of meiosis, but exerts no effects after spontaneous germinal vesicle breakdown (GVBD) in mouse oocytes

1999 ◽  
Vol 11 (2) ◽  
pp. 81 ◽  
Author(s):  
Q. Y. Sun ◽  
Q. Lu ◽  
H. Breitbart ◽  
D. Y. Chen
Keyword(s):  
Map Kinase ◽  
Map Kinases ◽  
Specific Inhibitor ◽  
Germinal Vesicle ◽  
Germinal Vesicle Breakdown ◽  
Kinase Activation ◽  
Protein Map ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation ◽  
Pkc Activation

Various signaling molecules have been implicated in the oocyte G2/MII transition, including protein kinase C (PKC), cAMP and mitogen-activated protein (MAP) kinases. However, the cross-talk among these signaling pathways has not been elucidated. The present study demonstrates that both germinal vesicle break down (GVBD) and MAP kinase phosphorylation (activation) are inhibited when intraoocyte cAMP is increased by treating the GV-intact oocytes with dibutyryl cyclic AMP (dbcAMP), forskolin, or isobutylmethylxanthine (IBMX). Okadaic acid, a specific inhibitor of protein phosphatase-1 and -2A, completely overcame this effect. Calphostin C, a specific inhibitor of PKC, accelerated both GVBD and MAP kinase phosphorylation, and this effect was attenuated by increased intraoocyte cAMP, whereas PKC activation inhibited these events. Once GVBD occurred, the progression of oocyte maturation and MAP kinase phosphorylation were independent of cAMP. These results indicate that an increase in intraoocyte cAMP, in synergy with PKC activation, initiates a cascade of events resulting in inhibition of MAP kinase phosphorylation and GVBD in the mouse oocyte.

Involvement of PLA2, COX and LOX in Rhinella arenarum oocyte maturation

Zygote ◽  
2013 ◽  
Vol 22 (4) ◽  
pp. 440-445 ◽  
Author(s):  
Maria Eugenia Ortiz ◽  
Marta Inés Bühler ◽  
Liliana Isabel Zelarayán
Keyword(s):  
Oocyte Maturation ◽  
Germinal Vesicle ◽  
Nordihydroguaiaretic Acid ◽  
Ovarian Response ◽  
Similar Response ◽  
Dependent Manner ◽  
Germinal Vesicle Breakdown ◽  
Cox Inhibitors ◽  
Rhinella Arenarum ◽  
Dose Dependent

SummaryIn Rhinella arenarum, progesterone is the physiological nuclear maturation inducer that interacts with the oocyte surface and starts a cascade of events that leads to germinal vesicle breakdown (GVBD). Polyunsaturated fatty acids and their metabolites produced through cyclooxygenase (COX) and lipoxygenase (LOX) pathways play an important role in reproductive processes. In amphibians, to date, the role of arachidonic acid (AA) metabolites in progesterone (P4)-induced oocyte maturation has not been clarified. In this work we studied the participation of three enzymes involved in AA metabolism – phospholipase A2 (PLA2), COX and LOX in Rhinella arenarum oocyte maturation. PLA2 activation induced maturation in Rhinella arenarum oocytes in a dose-dependent manner. Oocytes when treated with 0.08 μM melittin showed the highest response (78 ± 6% GVBD). In follicles, PLA2 activation did not significantly induce maturation at the assayed doses (12 ± 3% GVBD). PLA2 inhibition with quinacrine prevented melittin-induced GVBD in a dose-dependent manner, however PLA2 inactivation did not affect P4-induced maturation. This finding suggests that PLA2 is not the only phospholipase involved in P4-induced maturation in this species. P4-induced oocyte maturation was inhibited by the COX inhibitors indomethacin and rofecoxib (65 ± 3% and 63 ± 3% GVBD, respectively), although COX activity was never blocked by their addition. Follicles showed a similar response following the addition of these inhibitors. Participation of LOX metabolites in maturation seems to be correlated with seasonal variation in ovarian response to P4. During the February to June period (low P4 response), LOX inhibition by nordihydroguaiaretic acid or lysine clonixinate increased maturation by up to 70%. In contrast, during the July to January period (high P4 response), LOX inhibition had no effect on hormone-induced maturation.

scholarly journals Activation of mitogen-activated protein kinase during meiotic maturation in porcine oocytes

Zygote ◽  
1995 ◽  
Vol 3 (3) ◽  
pp. 265-271 ◽  
Author(s):  
Maki Inoue ◽  
Kunihiko Naito ◽  
Fugaku Aoki ◽  
Yutaka Toyoda ◽  
Eimei Sato
Keyword(s):  
Protein Kinase ◽  
Map Kinase ◽  
Kinase Activity ◽  
Polar Body ◽  
Germinal Vesicle ◽  
Mitogen Activated Protein Kinase ◽  
Meiotic Maturation ◽  
Germinal Vesicle Breakdown ◽  
First Polar Body ◽  
Mitogen Activated Protein

SummaryTo investigate the involvement of mitogen-activated protein kinase(MAP kinase) in meiotic maturation of porcine oocytes, we assayed MAP kinase activity using basic protein(MBP) as a substrate. MAP kinase activity was low during the germinal vesicle stage, 0–20 h of culture. An abrupt increase was observed at metaphase I(30 h of culture), and activity remained significantly higher than that at 0 h until 50 h of culture, with a transient slight decrease at the time of first polar body extrusion (40 h). Detection of the kinase activity by an in-gel phosphorylation assay confirmed that the 42 and 44 kDa MAP kinases were significantly activated in 45 h cultured oocytes but not in 0 h oocytes, and just slightly in 20 h oocytes. In immunoblotting, however, the 42 and 44 kDa bands were detected in 0, 20 and 45 h cultured oocytes. Furthermore, the signal strength of the two bands did not change during the period of culture, but shifted up to 45 h, indicating that the activation of MAP kinase depended not on the synthesis but on the phosphorylation of this enzyme. These results suggest that the activation of MAP kinase is involved in the regulation of meiotic maturation of porcine oocytes, and especially in the regulation after germinal vesicle breakdown.

Functional Role of p38 Mitogen Activated Protein Kinase in Platelet Activation induced by a Thromboxane A2 Analogue and by 8-iso-prostaglandin F2 α

2002 ◽  
Vol 87 (05) ◽  
pp. 888-898 ◽  
Author(s):  
Stefania Gaino ◽  
Valeria Zuliani ◽  
Rosa Tommasoli ◽  
Donatella Benati ◽  
Riccardo Ortolani ◽  
...  
Keyword(s):  
Map Kinase ◽  
Platelet Activation ◽  
Tyrosine Kinases ◽  
Actin Polymerization ◽  
Shape Change ◽  
Specific Inhibitor ◽  
P38 Map Kinase ◽  
Mitogen Activated Protein Kinase ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation

SummaryWe investigated similarities in the signaling pathways elicited by the F2 isoprostane 8-iso-PGF2α and by low doses of U46619 to induce platelet activation. Both 0.01-0.1 µmol/L U46619 and 0.01-1 µmol/L 8-isoPGF2α triggered shape change and filopodia extension, as well as adhesion to immobilized fibrinogen of washed platelets. At these doses the two platelet agonists failed to trigger secretion and aggregation, which were however induced by higher doses of U46619 (0.1-1 µmol/L). SB203580 (1-10 µmol/L), a specific inhibitor of the p38 mitogen activated protein (MAP) kinase blunted platelet shape change and adhesion induced by 0.05-1 µmol/L 8-iso-PGF2α and by 0.01 µmol/L U46619. These platelet responses were also inhibited by 20 µmol/L cytochalasin D, an inhibitor of actin polymerization, and 50 µmol/L piceatannol, an inhibitor of the Syk tyrosine kinases. Both 8-iso-PGF2α and U46619-induced p38 MAP kinase phosphorylation in suspended platelets and this was inhibited by piceatannol, indicating that Syk activation occurs upstream p38 MAP kinase phosphorylation. These findings suggest that the signaling pathway triggered by both 8-iso-PGF2α and low concentrations of U46619 to induce platelet adhesion and shape change implicates Syk, the p38 MAP kinase, and actin polymerization.

Involvement of endogenous nitric oxide in angiotensin II-induced activation of vascular mitogen-activated protein kinases

2007 ◽  
Vol 293 (4) ◽  
pp. H2403-H2408 ◽  
Author(s):  
Guo-Xing Zhang ◽  
Yukiko Nagai ◽  
Toshitaka Nakagawa ◽  
Hiroshi Miyanaka ◽  
Yoshihide Fujisawa ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Angiotensin Ii ◽  
Map Kinase ◽  
Map Kinases ◽  
No Synthase ◽  
Dependent Manner ◽  
Ang Ii ◽  
No Donor ◽  
Mitogen Activated Protein ◽  
Kinase Phosphorylation

Angiotensin II (ANG II) is a powerful activator of mitogen-activated protein (MAP) kinase cascades in cardiovascular tissues through a redox-sensitive mechanism. Nitric oxide (NO) is considered to antagonize the vasoconstrictive and proarteriosclerotic actions of ANG II. However, the role of endogenous NO in ANG II-induced redox-sensitive signal transduction is not yet clear. In this study using catheterized, conscious rats, we found that acute intravenous administration of NG-nitro-l-arginine methyl ester (l-NAME; 5 mg/kg) enhanced phosphorylation of aortic MAP kinases extracellular signal regulated kinase (ERK) 1/2 and p38, which were suppressed only partially by a superoxide dismutase mimetic (Tempol), whereas ANG II-induced MAP kinase phosphorylation was markedly suppressed by Tempol. FK409, a NO donor, had little effect on vascular MAP kinase phosphorylation. On the other hand, acute exposure to a vasoconstrictor dose of ANG II (200 ng·kg−1·min−1 iv) failed to enhance phosphorylation of aortic MAP kinases in the chronically l-NAME-treated rats, whereas the vasoconstrictor effect of ANG II was not affected by l-NAME treatment. Furthermore, three different inhibitors of NO synthase suppressed, in a dose-dependent manner, ANG II-induced MAP kinase phosphorylation in rat vascular smooth muscle cells, which was closely linked to superoxide generation in cells. These results indicate the involvement of endogenous NO synthase in ANG II-induced signaling pathways, leading to activation of MAP kinase, and that NO may have dual effects on the vascular MAP kinase activation associated with redox sensitivity.

scholarly journals Cyclic Adenosine 3′,5′-Monophosphate-Dependent Activation of Mitogen-Activated Protein Kinase in Cumulus Cells Is Essential for Germinal Vesicle Breakdown of Porcine Cumulus-Enclosed Oocytes

Endocrinology ◽  
2005 ◽  
Vol 146 (10) ◽  
pp. 4437-4444 ◽  
Author(s):  
Cheng-Guang Liang ◽  
Li-Jun Huo ◽  
Zhi-Sheng Zhong ◽  
Da-Yuan Chen ◽  
Heide Schatten ◽  
...  
Keyword(s):  
Mapk Pathway ◽  
Germinal Vesicle ◽  
Cumulus Cells ◽  
Mitogen Activated Protein Kinase ◽  
Pde4 Inhibitor ◽  
Germinal Vesicle Breakdown ◽  
Germinal Vesicles ◽  
Mitogen Activated Protein ◽  
Culture Models ◽  
Cell Type Specific

MAPK plays an important role during meiotic maturation in mammalian oocytes, whereas the necessity of MAPK during meiotic resumption in porcine oocytes is still controversial. Here, by applying the method of ultracentrifugation to move the opaque lipid droplets to the edge of the oocyte, therefore allowing clear visualization of porcine germinal vesicles, oocytes just before germinal vesicle breakdown (GVBD) and those that had just undergone GVBD were selected for the assay of MAPK activation. Our results showed that phosphorylation of MAPK in oocytes occurred after GVBD in all three different culture models: spontaneous maturation model, inhibition-induction maturation model, and normal maturation model. Moreover, we found that activation of MAPK in cumulus cells but not in oocytes was essential for GVBD in cumulus-enclosed oocytes. Then the cross-talk between cAMP and MAPK in cumulus cells was investigated by using cell-type-specific phosphodiesterase (PDE) isoenzyme inhibitors. Our results showed that PDE3 subtype existed in oocytes, whereas PDE4 subtype existed in cumulus cells. PDE3 inhibitor prevented meiotic resumption of oocytes, whereas PDE4 inhibitor enhanced the ability of FSH or forskolin to activate MAPK in cumulus cells. We propose that increased cAMP resulting from inhibition of PDE3 in oocytes blocks GVBD, whereas increased cAMP resulting from inhibition of PDE4 activates MAPK pathway in cumulus cells, which is essential for GVBD induction.

Mitogen-activated protein kinase activity and microtuble organisation are altered by protein synthesis inhibition in maturing porcine oocytes

Zygote ◽  
1996 ◽  
Vol 4 (3) ◽  
pp. 191-198 ◽  
Author(s):  
Maki Inoue ◽  
Kunihiko Naito ◽  
Taisuke Nakayama ◽  
Eimei Sato
Keyword(s):  
Protein Synthesis ◽  
Map Kinase ◽  
Kinase Activity ◽  
Germinal Vesicle ◽  
Protein Kinase Activity ◽  
Protein Synthesis Inhibition ◽  
Germinal Vesicle Breakdown ◽  
Kinase Activation ◽  
Synthesis Inhibition ◽  
Mitogen Activated Protein

SummaryPreviously we have shown that mitogen-activated protein (MAP) kinase activity abruptly increases at the first metaphase (M1) and remains significantly higher than that at the germinal vesicle (GV) stage until the second metaphase (M2) in porcine oocytes cultured in vitro. The present paper describes how the mechanism of the blockage of meiotic maturation by protein sythesis inhibition involves MAP kinase regulation. Cycloheximide arrested both germinal vesicle breakdown (GVBD) and the normal transition from M1 to M2. MAP kinase activation was also reduced in these maturation-inhibited oocytes. By using immunofluorescence microscopy with the monoclonal antibody raised against rat α-tubulin, we showed that cycloheximide caused morphological abnormality in a spindle at M1, but not at M2. All these results indicate that in porcine oocytes: (1) GV blockage by protein synthesis inhibition involves the suppression of both histone H1 kinase and MAP kinase activation, (2) during the transition from M1 to M2, maintenance of a normal metaphasic spindle and high MAP kinase activity require protein synthesis, and (3) once the M2 cytoskeletal structures have been completed, and/or after the ‘critical period’, cytostatic factor activity is independent of protein synthesis.

scholarly journals Characterization of a serum response factor-like protein in Saccharomyces cerevisiae, Rlm1, which has transcriptional activity regulated by the Mpk1 (Slt2) mitogen-activated protein kinase pathway.

1997 ◽  
Vol 17 (5) ◽  
pp. 2615-2623 ◽  
Author(s):  
Y Watanabe ◽  
G Takaesu ◽  
M Hagiwara ◽  
K Irie ◽  
K Matsumoto
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Protein Kinase ◽  
Map Kinase ◽  
Transcriptional Activation ◽  
Transcriptional Activity ◽  
Mitogen Activated Protein Kinase ◽  
Dependent Manner ◽  
Mads Box ◽  
Mitogen Activated Protein

The Mpk1 (Slt2) mitogen-activated protein (MAP) kinase has been implicated in several biological processes in Saccharomyces cerevisiae. The Rlm1 protein, a member of the MADS box family of transcription factors, functions downstream of Mpk1 in the pathway. To characterize the role of Rlm1 in mediating the transcriptional activation by the Mpk1 pathway, we constructed a LexA-Rlm1 deltaN chimera in which sequences, including the MADS box domain of the Rlm1 protein, were replaced by the LexA DNA binding domain and tested the ability of this chimera to activate a LexA operator-controlled reporter gene. In this assay, the Rlm1 protein was found to activate transcription in a manner regulated by the Mpk1 pathway. The Mpk1 protein kinase phosphorylated Rlm1 deltaN in vitro and the LexA-Rlm1 deltaN chimera protein was phosphorylated in vivo in a Mpk1-dependent manner. These results suggest that Mpk1 regulates the transcriptional activity of Rlm1 by directly phosphorylating it. We identified a Mpk1-like protein kinase, Mlp1, as an Rlm1-associated protein by using the yeast two-hybrid system. Overexpression of MLP1 suppresses the caffeine-sensitive phenotype of the bck1 delta mutation. The additivity of the mlp1 delta defect with the Mpk1 delta defect with regard to the caffeine sensitivity, combined with the results of genetic epistasis experiments, suggested that the activity of Rlm1 is regulated independently by Mpk1 MAP kinase and the Mlp1 MAP kinase-like kinase.

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