Cerebroprotective actions of hydrogen sulfide in the epileptic brain in newborn pigs

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.

The Role of Hydrogen Sulfide in Regulation of Cell Death following Neurotrauma and Related Neurodegenerative and Psychiatric Diseases

Injuries of the central (CNS) and peripheral nervous system (PNS) are a serious problem of the modern healthcare system. The situation is complicated by the lack of clinically effective neuroprotective drugs that can protect damaged neurons and glial cells from death. In addition, people who have undergone neurotrauma often develop mental disorders and neurodegenerative diseases that worsen the quality of life up to severe disability and death. Hydrogen sulfide (H₂S) is a gaseous signaling molecule that performs various cellular functions in normal and pathological conditions. However, the role of H₂S in neurotrauma and mental disorders remains unexplored and sometimes controversial. In this large-scale review study, we examined the various biological effects of H₂S associated with survival and cell death in trauma to the brain, spinal cord, and PNS, and the signaling mechanisms underlying the pathogenesis of mental illnesses, such as cognitive impairment, encephalopathy, depression and anxiety disorders, epilepsy and chronic pain. We also studied the role of H₂S in the pathogenesis of neurodegenerative diseases: Alzheimer's disease (AD) and Parkinson's disease (PD). In addition, we reviewed the current state of the art study of H₂S donors as neuroprotectors and the possibility of their therapeutic uses in medicine. Our study showed that H₂S has great neuroprotective potential. H₂S reduces oxidative stress, lipid peroxidation, and neuroinflammation; inhibits processes associated with apoptosis, autophagy, ferroptosis and pyroptosis; prevents the destruction of the blood-brain barrier; increases the expression of neurotrophic factors; and models the activity of Ca²⁺ channels in neurotrauma. In addition, H₂S activates neuroprotective signaling pathways in psychiatric and neurodegenerative diseases. However, high levels of H₂S can cause cytotoxic effects. Thus, the development of H₂S-associated neuroprotectors seems to be especially relevant. However, so far, all H₂S modulators are at the stage of preclinical trials. Nevertheless, many of them show a high neuroprotective effect in various animal models of neurotrauma and related disorders. Despite the fact that our review is very extensive and detailed, it is well structured right down to the conclusions, which will allow researchers to quickly find the proper information they are interested in.