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.

• Klíčová slova
• Xenopus laevis, cell cycle, hydrogen sulfide, meiosis, oocyte,
• 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
• Názvy látek
• 3-mercaptopyruvate sulphurtransferase MeSH Prohlížeč
• CDC25C protein, human MeSH Prohlížeč
• CDK1 protein, Xenopus MeSH Prohlížeč
• cyklin B MeSH
• cystathionin-beta-synthasa MeSH
• cystathionin-gama-lyasa MeSH
• faktor podporující zrání MeSH
• fosfatasy cdc25 MeSH
• katalasa MeSH
• proteinkinasy MeSH
• proteiny buněčného cyklu MeSH
• proteiny Xenopus MeSH
• reaktivní formy kyslíku MeSH
• sodium bisulfide MeSH Prohlížeč
• sulfan MeSH
• sulfidy MeSH
• sulfurtransferasy MeSH
• superoxiddismutasa MeSH

We study effects of oscillatory convective flow in extracellular space on the velocity of chemical signal propagation having a form of a front wave above a cellular layer. We found that the time-averaged propagation velocity under oscillatory flow for a particular Péclet number amplitude is slower than the velocity under steady laminar flow regime for the same value of the Péclet number, but significantly faster than under no-flow conditions. We derive asymptotic values of the propagation velocity and asymptotic characteristics of the corresponding concentration fronts in high- and low-frequency regimes and show that the reason for the observed velocity increase under the oscillatory flow stems from a nonlinear dependence of the propagation velocity on the Péclet number, particularly from the convex character of the dependence. Our findings suggest that the specific responses of cellular cultures to different flow conditions in the extracellular space (for example, expression of atherosclerosis protective genes under steady laminar flow but not under oscillatory flow) is a consequence of a nonlinear coupling between the extracellular transport and complex intracellular reaction cascades forming a positive feedback loop of the autocrine signaling. This mechanism can operate independently of, or in conjunction with, a direct stress-sensing due to mechanotransduction.

• MeSH
• autokrinní signalizace * MeSH
• biologické modely * MeSH
• hydrodynamika * MeSH
• konvekce * MeSH
• lidé MeSH
• nelineární dynamika MeSH
• zvířata MeSH
• Check Tag
• lidé MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

We study effects of convective transport on a chemical front wave representing a signal propagation at a simple (single layer) epithelium by means of mathematical modeling. Plug flow and laminar flow regimes were considered. We observed a nonmonotonous dependence of the propagation velocity on the ligand receptor binding constant under influence of the convective transport. If the signal propagates downstream, the region of high velocities becomes much broader and spreads over several orders of magnitude of the binding constant. When the convective transport is oriented against the propagating signal, either velocity of the traveling front wave is slowed down or the traveling front wave can stop or reverse the direction of propagation. More importantly, chemical signal in epithelial systems influenced by the convective transport can propagate almost independently of the ligand-receptor binding constant in a broad range of this parameter. Furthermore, we found that the effects of the convective transport becomes more significant in systems where either the characteristic dimension of the extracellular space is larger/comparable with the spatial extent of the ligand diffusion trafficking or the ligand-receptor binding/ligand diffusion rate ratio is high.

• MeSH
• biologické modely * MeSH
• epitel metabolismus   MeSH
• ligandy MeSH
• mezibuněčné signální peptidy a proteiny metabolismus   MeSH
• signální transdukce * MeSH
• transport proteinů MeSH
• zpětná vazba fyziologická MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• ligandy MeSH
• mezibuněčné signální peptidy a proteiny MeSH