Electroacupuncture promotes myelin repair in the corpus callosum region of cerebral ischemic rats by modulating microglia activation and polarization.

BACKGROUND

Ischemic stroke can damage the cerebral white matter, resulting in myelin loss and neurological deficits. Moreover, microglial activation plays an important role in ischemic stroke; therefore, inhibiting microglial activation has become an effective therapeutic target for ischemic stroke.

OBJECTIVE

This study aimed to investigate the effects of electroacupuncture (EA) on microglial activation and polarization, and the role of oligodendrocyte genesis in myelin reformation after ischemic stroke.

METHODS

A rat model of permanent middle cerebral artery occlusion (p-MCAO) was established and treated with EA. The reparative effect of EA on corpus callosum (CC) injury in p-MCAO rats was evaluated using a nesting assay, Luxol fast blue staining, immunofluorescence staining, and Western blot. Additionally, quantitative real-time polymerase chain reaction was employed to measure inflammatory factors IL-1β and IL-10 expression levels.

RESULTS

The results showed that p-MCAO rats exhibited significantly impaired nesting ability, severe myelin loss in the CC region, reduced Olig2 protein expression, activated microglia, and predominately M1-type microglial polarization. EA treatment improved nesting behavior, mitigated myelin loss, enhanced Olig2 expression, suppressed excessive microglial activation, downregulated IL-1β, and upregulated IL-10 expression levels.

CONCLUSIONS

These findings indicate that EA facilitates myelin repair in ischemic cerebral white matter by suppressing M1 microglial polarization, inducing an M2 phenotypic shift, modulating inflammatory responses, and enhancing oligodendrocyte regeneration.