H2S inhibits neuron apoptosis induced by anoxia-reoxygenation through cAMP-mediated PI3-K/Akt/P70S6K kinase cell-survival signaling pathways

AIM: To investigate the effect of hydrogen sulfide on neuron apoptosis through PI₃-K/Akt/P70S6K cell-survival signal transduction pathways after neuron anoxia-reoxygenation.METHODS: Newborn (24-48 h) Wistar rats were decapitated.The hippocampus tissue was dissected and cells were suspended.Cells were plated at 1.0×10⁸ cells/L on poly-dlysine-treated 96-well (100 μL/well) plates and 6-well (2 mL/well) plates.Cells were used after 7 days.For anoxia-reoxygenation (oxygen glucose deprivation,OGD) experiments,cells were washed three times in a glucose-free balanced salt solution (BSS).They were then placed in deoxygenated glucose-free medium and cultured under 95% N₂,5% CO₂ in an anaerobic chamber equilibrated to 37 ℃ and 100% humidity for 45 min.OGD was terminated by replacement of stored medium and by returning the cultures to a standard incubator maintained at 37 ℃ in 95% air,5% CO₂.In experimental group,cells were respectively carried out OGD,OGD+150 μmol/L NaHS,OGD+150 μmol/L NaHS+10 μmol/L triciribin,OGD+150 μmol/L NaHS+10 nmol/L rapamycin and OGD+150 μmol/L NaHS+10 μmol/L triciribin+10 nmol/L rapamycin.Control cells were cultured normally.24 h later,neuron viability and apoptosis were measured.The level of cAMP and protein expression of PI₃-K,Akt and P70S6K were detected.RESULTS: NaHS enhanced concentration of cAMP and expression of PI₃-K,Akt and P70S6K.Meanwhile,increased neuron viability and decreased neuron apoptosis (P<0.01 vs group C or group I/R) were observed.Triciribin inhibited Akt and P70S6K,as well as increased neuron apoptosis and decreased neuron viability (P<0.05,P<0.01 vs group NaHS).Rapamycin inhibited P70S6K,as well as increased neuron apoptosis and decreased neuron viability (P<0.05,P<0.01 vs group NaHS).CONCLUSION: H₂S inhibits hippocampus neuron apoptosis and protects neuron from anoxia-reoxygenation injury through cAMP-mediated PI₃-K/Akt/P70S6K kinase cell-survival signaling pathways.