The role of hydrogen sulfide (H2S) is addressed in Xenopuslaevis oocytes. Three enzymes involved in H2S metabolism, cystathionine β-synthase, cystathionine γ-lyase, and 3-mercaptopyruvate sulfurtransferase, were detected in prophase I and metaphase II-arrested oocytes and drove an acceleration of oocyte meiosis resumption when inhibited. Moreover, meiosis resumption is associated with a significant decrease in endogenous H2S. On another hand, a dose-dependent inhibition was obtained using the H2S donor, NaHS (1 and 5 mM). NaHS impaired translation. NaHS did not induce the dissociation of the components of the M-phase promoting factor (MPF), cyclin B and Cdk1, nor directly impacted the MPF activity. However, the M-phase entry induced by microinjection of metaphase II MPF-containing cytoplasm was diminished, suggesting upstream components of the MPF auto-amplification loop were sensitive to H2S. Superoxide dismutase and catalase hindered the effects of NaHS, and this sensitivity was partially dependent on the production of reactive oxygen species (ROS). In contrast to other species, no apoptosis was promoted. These results suggest a contribution of H2S signaling in the timing of amphibian oocytes meiosis resumption.
- MeSH
- apoptóza účinky léků MeSH
- cyklin B metabolismus MeSH
- cystathionin-beta-synthasa antagonisté a inhibitory metabolismus MeSH
- cystathionin-gama-lyasa antagonisté a inhibitory metabolismus MeSH
- cytoplazma metabolismus MeSH
- faktor podporující zrání metabolismus MeSH
- fosfatasy cdc25 metabolismus MeSH
- katalasa metabolismus MeSH
- meióza účinky léků MeSH
- metafáze účinky léků MeSH
- oocyty chemie enzymologie metabolismus MeSH
- profáze meiózy I účinky léků MeSH
- proteinkinasy metabolismus MeSH
- proteiny buněčného cyklu metabolismus MeSH
- proteiny Xenopus metabolismus MeSH
- reaktivní formy kyslíku metabolismus MeSH
- signální transdukce účinky léků MeSH
- sulfan metabolismus MeSH
- sulfidy metabolismus farmakologie MeSH
- sulfurtransferasy antagonisté a inhibitory metabolismus MeSH
- superoxiddismutasa metabolismus MeSH
- viabilita buněk účinky léků MeSH
- Xenopus laevis MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Nitric Oxide (NO) has been involved in both intra- and extra-cellular signaling pathways in a wide range of organisms, and can be detected in some reproductive tissues. Based upon previous results reporting that NO-donor SNAP (s-nitroso-n-acetyl penicillamine) promoted the release from the metaphase II-anaphase II block in amphibian eggs, the aim of the present study was to assess the influence of SNAP on the activation of the molecular mechanisms triggering meiotic resumption of Xenopus oocytes, analogous to G2/M transition of the cell cycle. A high concentration of SNAP (2.5 mM) was found to inhibit the appearance of the white spot (meiotic resumption) and promoted alteration of spindle morphogenesis leading to atypical structures lacking bipolarity and correct chromosomes equatorial alignment. The medium acidification (pH = 4) promoted by SNAP specifically impacted the white spot occurrence. However, even when pH was restored to 7.4 in SNAP medium, observed spindles remained atypical (microtubule disorganization), suggesting SNAP impacted spindle assembly regardless of the pH. n-Acetyl-d,l-penicillamine disulfide, a degradation product of SNAP with the same molecular characteristics, albeit without release of NO, yielded spindle assemblies typical of metaphase II suggesting the specificity of NO action on meiotic spindle morphogenesis in Xenopus oocytes.
- MeSH
- aparát dělícího vřeténka účinky léků MeSH
- chromozomy metabolismus MeSH
- donory oxidu dusnatého farmakologie MeSH
- meióza účinky léků MeSH
- morfogeneze účinky léků MeSH
- oocyty cytologie účinky léků MeSH
- S-nitroso-N-acetylpenicilamin farmakologie MeSH
- Xenopus laevis MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
Nitric oxide (NO) is identified as a signaling molecule involved in many cellular or physiological functions including meiotic maturation and parthenogenetic activation of mammalian oocytes. We observed that nitric oxide donor SNAP was potent to induce parthenogenetic activation in Xenopus eggs. NO-scavenger CPTIO impaired the effects of SNAP, providing evidence for the effects of the latter to be specific upon NO release. In Xenopus eggs, SNAP treatment induced pigment rearrangement, pronucleus formation and exocytosis of cortical granules. At a biochemical level, SNAP exposure lead to MAPK and Rsk inactivation within 30 minutes whereas MPF remained active, in contrast to calcium ionophore control where MPF activity dropped rapidly. MAPK inactivation could be correlated to pronuclear envelope reformation observed. In SNAP-treated eggs, a strong increase in intracellular calcium level was observed. NO effects were impaired in calcium-free or calcium limited medium, suggesting that that parthenogenetic activation of Xenopus oocytes with a NO donor was mainly calcium-dependent.
- MeSH
- aktivace enzymů účinky léků MeSH
- aparát dělícího vřeténka účinky léků metabolismus MeSH
- benzoáty farmakologie MeSH
- donory oxidu dusnatého farmakologie MeSH
- faktor podporující zrání metabolismus MeSH
- imidazoly farmakologie MeSH
- kinetika MeSH
- mitogenem aktivované proteinkinasy metabolismus MeSH
- morfogeneze účinky léků MeSH
- ovum cytologie účinky léků metabolismus MeSH
- oxid dusnatý metabolismus MeSH
- partenogeneze MeSH
- progesteron farmakologie MeSH
- S-nitroso-N-acetylpenicilamin farmakokinetika MeSH
- vápník metabolismus MeSH
- Xenopus laevis metabolismus MeSH
- zvířata MeSH
- Check Tag
- ženské pohlaví MeSH
- zvířata MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
