H2S inhibits LiCl/pilocarpine-induced seizures and promotes neuroprotection by regulating TRPV2 expression via the AC3/cAMP/PKA pathway

It is widely acknowledged that epilepsy is a neurological disorder characterized by recurrent and atypical neuronal discharges, resulting in transient dysfunction within the brain. The protective role of hydrogen sulfide (H₂S) in epilepsy has been elucidated by recent studies, but the underlying mechanisms remain poorly understood. To investigate this, the concentration of H₂S was measured by spectrophotometry and a fluorescent probe in LiCl/Pilocarpine (LiCl/Pilo)-induced seizures in rats. The localization of proteins was examined using immunofluorescence. Electroencephalogram and behavioral tests were employed to evaluate the occurrence of seizures. Neuropathological changes in the hippocampus were examined by hematoxylin-eosin staining, Nissl staining, and transmission electron microscopy. Through proteomics and bioinformatics analysis, we identified the differential proteins in the hippocampus of rats following H₂S intervention. Protein changes were detected through western blotting. The results showed that H₂S treatment significantly alleviated seizures and minimized post-seizures neurological damage in rats. Proteomics analysis revealed Adenylate Cyclase 3 (AC3) as a protein potentially targeted by H₂S. Moreover, the AC3 activator forskolin reversed the downregulation effect of H₂S on the AC3/cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/transient receptor potential vanilloid 2 (TRPV2) signaling pathway. In conclusion, H₂S targets and downregulates the expression of AC3, thereby modulating the AC3/cAMP/PKA signaling pathway to regulate the expression of TRPV2 in LiCl/Pilo-induced seizures, ultimately leading to seizure inhibition and neuroprotection.

AC3; H(2)S; PKA; Seizures; TRPV2; cAMP.