8e Protects against Acute Cerebral Ischemia by Inhibition of PI3Kγ-Mediated Superoxide Generation in Microglia

Area of Science:

• Neuroscience
• Pharmacology
• Immunology

Background:

• Microglial inflammatory response is key in ischemic stroke progression.
• Phosphoinositide 3-kinase gamma (PI3Kγ) is a potential therapeutic target for inflammatory diseases.

Purpose of the Study:

• To assess the efficacy of 8e, a hydrogen sulfide (H₂S)-releasing 3-n-butylphthalide (NBP) derivative, on brain damage and PI3Kγ signaling after cerebral ischemia.
• To investigate the role of the PI3Kγ/AKT/NOX2 signaling pathway in 8e's neuroprotective effects.

Main Methods:

• Transient middle cerebral artery occlusion (tMCAO) model in rats and oxygen-glucose deprivation (OGD) in primary microglia cultures.
• Evaluation of sensorimotor deficits, infarct volume, brain edema, and neural apoptosis.
• Analysis of superoxide release, NADPH oxidase (NOX2) subunit expression, and PI3Kγ/AKT signaling pathway activation.
• Utilized siRNA and pharmacological inhibitors to elucidate the signaling mechanism.

Main Results:

• 8e significantly ameliorated sensorimotor deficits, reduced focal infarction, brain edema, and neural apoptosis post-tMCAO.
• 8e downregulated superoxide release and the expression of NOX2 subunits (p47phox, p-p47phox) and upstream PI3Kγ/AKT signaling in both in vivo and in vitro models.
• Demonstrated that 8e modulates microglial superoxide formation via the PI3Kγ/AKT/NOX2 pathway, thereby preventing neuronal death.

Conclusions:

• 8e exhibits significant neuroprotective effects against ischemic stroke.
• The therapeutic action of 8e involves the inhibition of PI3Kγ-mediated neuroinflammation through the PI3Kγ/AKT/NOX2 signaling pathway.
• 8e is a promising therapeutic candidate for treating ischemic stroke and PI3Kγ-related neuroinflammatory conditions.