Hydrogen sulfide (H2S) has been revealed to be a signal molecule with second messenger action in the somatic cells of many tissues, including the reproductive tract. The aim of this study was to address how exogenous H2S acts on the meiotic maturation of porcine oocytes, including key maturation factors such as MPF and MAPK, and cumulus expansion intensity of cumulus-oocyte complexes. We observed that the H2S donor, Na2S, accelerated oocyte in vitro maturation in a dose-dependent manner, following an increase of MPF activity around germinal vesicle breakdown. Concurrently, the H2S donor affected cumulus expansion, monitored by hyaluronic acid production. Our results suggest that the H2S donor influences oocyte maturation and thus also participates in the regulation of cumulus expansion. The exogenous H2S donor apparently affects key signal pathways of oocyte maturation and cumulus expansion, resulting in faster oocyte maturation with little need of cumulus expansion.

• MeSH
• extracelulárním signálem regulované MAP kinasy metabolismus   MeSH
• faktor podporující zrání metabolismus   MeSH
• gasotransmitery farmakologie   MeSH
• kokultivační techniky MeSH
• kultivované buňky MeSH
• kumulární buňky cytologie   metabolismus   MeSH
• meióza účinky léků   MeSH
• oocyty cytologie   metabolismus   MeSH
• prasata MeSH
• sulfan farmakologie   MeSH
• sulfidy farmakologie   MeSH
• zvířata MeSH
• Check Tag
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• extracelulárním signálem regulované MAP kinasy MeSH
• faktor podporující zrání MeSH
• gasotransmitery MeSH
• sodium sulfide MeSH Prohlížeč
• sulfan MeSH
• sulfidy MeSH

For somatic cell nuclear transfer cytoplasts from metaphase II, oocytes are exclusively used. However, it is evident that certain reprogramming activities are present in oocytes even at earlier stages of maturation. These activities are, however, only poorly characterised. The main reason for this is that even the intrinsic oocyte processes are insufficiently understood. The mammalian oocyte is a highly specialised cell that harbours many specific characteristics. One of these is its particularly large size when compared to somatic cells. As the oocyte enters the growth phase its volume, as well as the amount of material, increases considerably. Thus, it is clear that the oocyte must possess the machinery to accomplish this incredible material accumulation. When the growth phase is completed, the transcription ceases and the oocyte becomes transcriptionally inactive. In our study, we have used the model system of oocyte fusion (transcribing x non-transcribing germinal vesicle (GV) stage oocytes) as a substitute for a somatic cell nuclear transfer schemes where the somatic cell nucleus would be introduced into a cytoplast obtained from a GV stage oocyte. We wanted to determine if the fully grown GV stage oocyte could induce reprogramming of transcriptionally active transferred nucleus by suppressing this activity. In order to evaluate possible changes in transcriptional properties after nuclear transfer, we also investigated the mechanism of transcriptional silencing taking place when the oocyte reaches its full size as well as the fate of the components namely of the RNA polymerase II (Pol II) transcriptional and splicing machinery. Here, we show that while the Pol II is degraded in fully grown GV stage oocytes and the splicing proteins undergo significant rearrangement, these oocytes are unable to induce similar changes in transcriptionally active nuclei even after a prolonged culture interval.

• MeSH
• buněčné jádro enzymologie   genetika   MeSH
• cytoplazma enzymologie   MeSH
• histondeacetylasa 1 metabolismus   MeSH
• myši inbrední ICR MeSH
• myši MeSH
• oocyty enzymologie   ultrastruktura   MeSH
• přeprogramování buněk fyziologie   MeSH
• RNA-polymerasa II metabolismus   MeSH
• techniky jaderného přenosu MeSH
• umlčování genů * MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• Hdac1 protein, mouse MeSH Prohlížeč
• histondeacetylasa 1 MeSH
• RNA-polymerasa II MeSH

Aurora kinase A (AURKA), which is a centrosome-localized serine/threonine kinase crucial for cell cycle control, is critically involved in centrosome maturation and spindle assembly in somatic cells. Active T288 phosphorylated AURKA localizes to the centrosome in the late G(2) and also spreads to the minus ends of mitotic spindle microtubules. AURKA activates centrosomal CDC25B and recruits cyclin B1 to centrosomes. We report here functions for AURKA in meiotic maturation of mouse oocytes, which is a model system to study the G(2) to M transition. Whereas AURKA is present throughout the entire GV-stage oocyte with a clear accumulation on microtubule organizing centers (MTOC), active AURKA becomes entirely localized to MTOCs shortly before germinal vesicle breakdown. In contrast to somatic cells in which active AURKA is present at the centrosomes and minus ends of microtubules, active AURKA is mainly located on MTOCs at metaphase I (MI) in oocytes. Inhibitor studies using Roscovitine (CDK1 inhibitor), LY-294002 (PI3K inhibitor) and SH-6 (PKB inhibitor) reveal that activation of AURKA localized on MTOCs is independent on PI3K-PKB and CDK1 signaling pathways and MOTC amplification is observed in roscovitine- and SH-6-treated oocytes that fail to undergo nuclear envelope breakdown. Moreover, microinjection of Aurka mRNA into GV-stage oocytes cultured in 3-isobutyl-1-methyl xanthine (IBMX)-containing medium to prevent maturation also results in MOTC amplification in the absence of CDK1 activation. Overexpression of AURKA also leads to formation of an abnormal MI spindle, whereas RNAi-mediated reduction of AURKA interferes with resumption of meiosis and spindle assembly. Results of these experiments indicate that AURKA is a critical MTOC-associated component involved in resumption of meiosis, MTOC multiplication, proper spindle formation and the metaphase I-metaphase II transition.

• MeSH
• aparát dělícího vřeténka metabolismus   MeSH
• Aurora kinasa A MeSH
• blastodisk metabolismus   MeSH
• buněčný cyklus genetika   fyziologie   MeSH
• buňky NIH 3T3 MeSH
• cyklin-dependentní kinasy metabolismus   fyziologie   MeSH
• fosfatidylinositol-3-kinasy metabolismus   fyziologie   MeSH
• HeLa buňky MeSH
• kinasy Aurora MeSH
• lidé MeSH
• meióza genetika   fyziologie   MeSH
• myši inbrední BALB C MeSH
• myši inbrední C57BL MeSH
• myši MeSH
• oocyty enzymologie   fyziologie   MeSH
• organizační centrum mikrotubulů metabolismus   MeSH
• protein-serin-threoninkinasy genetika   metabolismus   fyziologie   MeSH
• protoonkogenní proteiny c-akt metabolismus   fyziologie   MeSH
• vazba proteinů MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• AURKA protein, human MeSH Prohlížeč
• Aurka protein, mouse MeSH Prohlížeč
• Aurora kinasa A MeSH
• cyklin-dependentní kinasy MeSH
• kinasy Aurora MeSH
• protein-serin-threoninkinasy MeSH
• protoonkogenní proteiny c-akt MeSH

CDK1 is a pivotal regulator of resumption of meiosis and meiotic maturation of oocytes. CDC25A/B/C are dual-specificity phosphatases and activate cyclin-dependent kinases (CDKs). Although CDC25C is not essential for either mitotic or meiotic cell cycle regulation, CDC25B is essential for CDK1 activation during resumption of meiosis. Cdc25a -/- mice are embryonic lethal and therefore a role for CDC25A in meiosis is unknown. We report that activation of CDK1 results in a maturation-associated decrease in the amount of CDC25A protein, but not Cdc25a mRNA, such that little CDC25A is present by metaphase I. In addition, expression of exogenous CDC25A overcomes cAMP-mediated maintenance of meiotic arrest. Microinjection of Gfp-Cdc25a and Gpf-Cdc25b mRNAs constructs reveals that CDC25A is exclusively localized to the nucleus prior to nuclear envelope breakdown (NEBD). In contrast, CDC25B localizes to cytoplasm in GV-intact oocytes and translocates to the nucleus shortly before NEBD. Over-expressing GFP-CDC25A, which compensates for the normal maturation-associated decrease in CDC25A, blocks meiotic maturation at MI. This MI block is characterized by defects in chromosome congression and spindle formation and a transient reduction in both CDK1 and MAPK activities. Lastly, RNAi-mediated reduction of CDC25A results in fewer oocytes resuming meiosis and reaching MII. These data demonstrate that CDC25A behaves differently during female meiosis than during mitosis, and moreover, that CDC25A has a function in resumption of meiosis, MI spindle formation and the MI-MII transition. Thus, both CDC25A and CDC25B are critical for meiotic maturation of oocytes.

• MeSH
• AMP cyklický metabolismus   MeSH
• exprese genu MeSH
• fosfatasy cdc25 analýza   metabolismus   MeSH
• meióza * MeSH
• myši MeSH
• oocyty chemie   cytologie   enzymologie   MeSH
• zvířata MeSH
• Check Tag
• myši MeSH
• ženské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Research Support, N.I.H., Extramural MeSH
• Názvy látek
• AMP cyklický MeSH
• Cdc25a protein, mouse MeSH Prohlížeč
• Cdc25b protein, mouse MeSH Prohlížeč
• fosfatasy cdc25 MeSH