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 (H(2)S) is a novel neuromodulator. The present study aimed to investigate the protective effect of H(2)S 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 microM) for 12 h decreased cell viability. Exogenous application of NaHS (an H(2)S donor, 100-1000 microM) or overexpression of cystathionine beta-synthase (a predominant enzyme to produce endogenous H(2)S 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 PKCalpha, epsilon and Akt and the up-regulation of PKCdelta in 6-OHDA-treated cells. Blockade of PKCalpha with Gö6976 (2 microM), PKCepsilon with EAVSLKPT (200 microM) or PI3K with LY294002 (20 microM) reduced the protective effects of H(2)S. However, inhibition of PKCdelta with rottlerin (5 microM) failed to affect 6-OHDA-induced cell injury. These data suggest that the protective effects of NaHS mainly resulted from activation of PKCalpha, epsilon 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 PKCalpha, epsilon-dependent. CONCLUSIONS AND IMPLICATIONS: H(2)S protects SH-SY5Y cells against 6-OHDA-induced cell injury by activating the PKCalpha, epsilon/PI3K/Akt pathway.