Nicotinamide Administration Improves Remyelination after Stroke

الملخص EN

Aims.

Stroke is a leading cause of morbidity and mortality.

This study aimed to determine whether nicotinamide administration could improve remyelination after stroke and reveal the underlying mechanism.

Methods.

Adult male C57BL/6J mice were intraperitoneally (i.p.) administered with nicotinamide (200 mg/kg, daily) or saline after stroke induced by photothrombotic occlusion of the middle cerebral artery.

FK866 (3 mg/kg, daily, bis in die), an inhibitor of NAMPT, and ANA-12 (0.5 mg/kg, daily), an antagonist of tropomyosin-related kinase B (TrkB), were administered intraperitoneally 1 h before nicotinamide administration.

Functional recovery, MRI, and histological assessment were performed after stroke at different time points.

Results.

The nicotinamide-treated mice showed significantly lower infarct area 7 d after stroke induction and significantly higher fractional anisotropy (FA) in the ipsilesional internal capsule (IC) 14 d after stroke induction than the other groups.

Higher levels of NAD+, BDNF, and remyelination markers were observed in the nicotinamide-treated group.

FK866 administration reduced NAD+ and BDNF levels in the nicotinamide-treated group.

ANA-12 administration impaired the recovery from stroke with no effect on NAD+ and BDNF levels.

Furthermore, lesser functional deficits were observed in the nicotinamide-treated group than in the control group.

Conclusions.

Nicotinamide administration improves remyelination after stroke via the NAD+/BDNF/TrkB pathway.