Protective Effect of Hydrogen Sulfide is Mediated by Negative Regulation of Epigenetic Histone Acetylation in Parkinson's Disease

Introduction: Derangements in monoaminergic transmission in the substantia nigra with disturbed signaling in the hypothalamic-pituitary-adrenal axis are the major characteristics of Parkinson's disease (PD). It has been reported that the administration of hydrogen sulfide (HS) is in practice to treat PD because of its redundant nature in regulating various neuronal signals. Hence, the current investigation was performed to evaluate the hypothesis that HS might exert protective action via the inhibition of epigenetic histone acetylation.

Material And Methods: To test this notion, 6-hydroxydopamine (6-OHDA) was used to induce PD and sodium hydrogen sulfide (SHS) was used as a HS donor and tubastatin A (TSA) was tested in an rat model to delineate the signaling mechanism.

Results: Induction of PD in rats demonstrated elevated oxidative stress with an evidenced decrease in antioxidant enzymes, while elevated pro-inflammatory cytokines and inflammatory mediators were observed in the striatum of PD rats compared to controls. On the other hand, elevated ( < 0.01) levels of dopamine, 3,4-dihydroxyphenylacetic acid (DOPAC), mRNA transcript of HDAC-2, -3, -4, -6 and total histone deacetylase (HDAC) were found with reduced levels of histone acetyltransferase (HAT) in the brain tissues of PD induced rats.

Conclusions: Diversely, HS exposure reversed these alterations with reduced HDAC activity. Further, PD rats treated with HDAC inhibitor showed a dramatic upsurge in the level of tyrosine hydroxylase, with a decreased level of glial fibrillary acidic protein, α-synuclein, tumor necrosis factor α, and other cytokines. Thus the results of the study suggest that HS exerts protection via inhibition of HDAC.