Effects Of Exogenous Hydrogen Sulfide On β-amyloid Peptides-induced Autophagy

Objective The Neuro-2a cells were treated with Aβ25-35 peptides to setup an AD cell model in present work. To explore the effects of different concentrations of H2 S on autophagy induced by toxic Aβ25-35 peptides and to elucidate the possible mechanism.Methods The Neuro-2a cells were randomly divided into control group,Aβ25-35 treatment group, Aβ25-35+Na HS group, Aβ25-35+3-MA group, Na HS group and Aβ25-35+Na HS+ NVP-BEZ235 group. In Aβ25-35+ Na HS group and Aβ25-35+3-MA group, Na HS and 3-MA were pretreated for 2h respectly, then followed 24 h co-incubation with Aβ25-35, and after pre-adminitered Na HS,NVP-BEZ235 was adminitered for 0.5 h before Aβ25-35 was given in Aβ25-35+Na HS+ NVP-BEZ235 group. MTT assay was used to detect the viability of Neuro-2a cells. The expression of the autophagy related proteins including Beclin-1, LC3 and p62 was measured by western blot.Immunofluorescence was used to detect the expression and distribution of LC3. The formation of autophagosomes was determined by transmission electron microscopy(TEM).Results(1)After administered with Aβ25-35, the cell viability declined(P<0.05), the expression of Beclin-1 and LC3- Ⅱ increased, while the expression of P62 decreased(P<0.05), and the number of autophagsomes increased under fluorescence microscope and electron microscope compared with control group.(2)In contrast with Aβ25-35 group, the cell viability improved in cells pre-treatment with 3-MA or Na HS(P<0.05),meanwhile, the expression of Beclin-1 and LC3-Ⅱ reduced, P62 increased(P<0.05), and the number of autophagosomes decreased.( 3) The expression of p-Akt and p-m TOR in Aβ25-35+Na HS group is more than that in Aβ25-35group(P<0.05), however, by comparison with Aβ25-35+Na HS group,the expression level of p-Akt and p-m TOR reduced after given the specific PI3K/Akt pathway Inhibitor NVP-BEZ235(P<0.05).Conclusion The exogenous H2 S could protect against Aβ25-35-induced cytotoxicity, probably related to the activation of PI3K/Akt/m TOR pathways to inhibit Aβ25-35-induced cell autophagy.