Protective effect of hydrogen sulphide against 6-OHDA-induced cell injury in SH-SY5Y cells involves PKC/PI3K/Akt pathway

BACKGROUND AND PURPOSE Hydrogen sulphide (H2S) is a novel neuromodulator. The present study aimed to investigate the protective effect of H2S against cell injury induced by 6-hydroxydopamine (6-OHDA), a selective dopaminergic neurotoxin often used to establish a model of Parkinson's disease for studying the underlying mechanisms of this condition. EXPERIMENTAL APPROACH Cell viability in SH-SY5Y cells was measured using MTT assay. Western blot analysis and pharmacological manipulation were employed to study the signalling mechanisms. KEY RESULTS Treatment of SH-SY5Y cells with 6-OHDA (50-200 μM) for 12 h decreased cell viability. Exogenous application of NaHS (an H2S donor, 100-1000 μM) or overexpression of cystathionine β-synthase (a predominant enzyme to produce endogenous H2S in SH-SY5Y cells) protected cells against 6-OHDA-induced cell apoptosis and death. Furthermore, NaHS reversed 6-OHDA-induced loss of tyrosine hydroxylase. Western blot analysis showed that NaHS reversed the down-regulation of PKCα, ε and Akt and the up-regulation of PKCδ in 6-OHDA-treated cells. Blockade of PKCα with Gö6976 (2 μM), PKCε with EAVSLKPT (200 μM) or PI3K with LY294002 (20 μM) reduced the protective effects of H2S. However, inhibition of PKCδ with rottlerin (5 μM) failed to affect 6-OHDA-induced cell injury. These data suggest that the protective effects of NaHS mainly resulted from activation of PKCα, ε and PI3K/Akt pathway. In addition, NaHS-induced Akt phosphorylation was significantly attenuated by Gö6976 and EAVSLKPT, suggesting that the activation of Akt by NaHS is PKCα, ε-dependent. CONCLUSIONS AND IMPLICATIONS H2S protects SH-SY5Y cells against 6-OHDA-induced cell injury by activating the PKCα, ε/PI3K/Akt pathway.