GSK-3β inhibition induced neuroprotection, regeneration, and functional recovery after intracerebral hemorrhagic stroke

Abstract

Hemorrhagic stroke is a devastating disease that lacks effective therapies. In the present investigation, we tested 6-bromoindirubin-3¢-oxime (BIO) as a selective glycogen synthase kinase-3b (GSK-3b) inhibitor in a mouse model of intracerebral hemorrhage (ICH). ICH was induced by injection of collagenase IV into the striatum of 8- to 10-week-old C57BL/6 mice. BIO (8 µg/kg, IP) was administered following either an acute delivery (0–2 h delay) or a prolonged regimen (every 48 h starting at 3 days post-ICH). At 2 days post-ICH, the acute BIO treatment significantly reduced the hematoma volume. In the perihematoma regions, BIO administration blocked GSK-3b phosphorylation/activation, increased Bcl-2 and b-catenin levels, and significantly increased viability of neurons and other cell types. The prolonged BIO regimen maintained a higher level of b-catenin, upregulated VEGF and BDNF, and promoted neurogenesis and angiogenesis in peri-injury zones at 14 days after ICH. The BIO treatment also promoted proliferation of neural stem cells (NSCs) and migration of nascent DCX+ neuroblasts from the subventricular zone (SVZ) to the lesioned cortex. BIO improved functional outcomes on both the neurological severity score and rotarod tests. The findings of this study corroborate the neuroprotective and regenerative effects of BIO and suggest that the Wnt/GSK-3b/b-catenin pathway may be explored for the treatment of acute or chronic ICH.