H2S Protects Hippocampal Neurons from Anoxia-Reoxygenation Through cAMP-Mediated PI3K/Akt/p70S6K Cell-Survival Signaling Pathways

The study aims to investigate the effect of hydrogen sulfide (H2S) on the phosphatidylinositol 3-kinase (PI3K)/Akt/p70 ribosomal S6 kinase (p70S6K) signal transduction pathway after oxygen glucose deprivation/reoxygenation (OGD/R) in the rat hippocampus. Newborn Wister rats were decapitated under anesthesia, and hippocampal tissue was dissected. Cells were plated at 1.0 x 10(5) cells/mL on polylysine-treated 96-well and 6-well plates. After 7 days in culture, cells were randomly assigned to six groups: control, OGD/R, sodium hydrosulfide (NaHS) following OGD/R, NaHS/triciribine following OGD/R, NaHS/rapamycin following OGD/R, and NaHS/triciribine/rapamycin following OGD/R. Neuronal purity and cell viability were assessed in each group, as well as apoptosis and expression of cyclic adenosine 3', 5'-monophosphate (cAMP), PI3K, Akt, and p70S6K. NaHS enhanced cAMP concentration and expression of PI3K, Akt, and p70S6K. In addition, neuronal viability was increased and apoptotic neuronal numbers decreased (P < 0.01). Triciribine inhibited Akt and p70S6K, as well as decreased cell survival and viability compared with the NaHS group (P < 0.05 or P < 0.01). Rapamycin resulted in decreased p70S6K expression and neuronal viability, as well as increased number of apoptotic neurons compared with the NaHS group (P < 0.05 or P < 0.01). H2S acted via cAMP-mediated PI3K/Akt/p70S6K signal transduction pathways to inhibit hippocampal neuronal apoptosis and protect neurons from OGD/R-induced injury.