Neuronal protective effect of Artemisinin in ischemic stroke: Achieved by blocking lysine demethylase 1A-mediated demethylation of sphingosine kinase 2

Artemisinin (ART), a natural product isolated from the traditional Chinese plant Artemisia annua L., has shown neuroprotective properties in addition to its well-established antimalarial activities. This study investigates the therapeutic effect of ART in ischemic stroke (IS) and delves into its functional mechanism. Bioinformatics analyses revealed lysine demethylase 1A (KDM1A) as a promising target of ART aberrantly overexpressed in the context of IS. Increased KDM1A expression was detected in oxygen-glucose deprivation/reoxygenation (OGD/R)-treated hippocampal neurons and transient middle cerebral artery occlusion (tMCAO)-challenged mice. Treatment with ART reduced KDM1A protein level, thus protecting mouse hippocampal neurons from OGD/R-induced oxidative stress and apoptosis. In vivo, ART reduced infarct size, reduced brain content, enhanced neurological function, and enhanced neuronal survival in tMCAO. Regarding the downstream cascade, KDM1A was found to repress transcription of sphingosine kinase 2 (SPHK2) by removing H3K4me2 modification near the SPHK2 promoter. Either KDM1A overexpression or SPHK2 knockdown abrogated the neuroprotective effects of ART. The ample evidence of this study suggests that ART fulfills neuroprotective functions in the context of IS by protecting SPHK2 from KDM1A-mediated transcription repression, highlighting ART as a promising regimen for the treatment of IS.