Voluntary exercise enhances survival and migration of neural progenitor cells after intracerebral haemorrhage in mice

Abstract

Primary objective: This study explored the long-term effects of exercise on the proliferation, survival and migration of endogenous neural progenitor cells (NPCs) in the subventricular zone (SVZ) of the brain after intracerebral haemorrhage (ICH).Research design: ICH was induced by an injection of collagenase into the striatum. Animals in the voluntary running exercise group ran freely on a running wheel for 1, 3 and 6 weeks following the induction of ICH.Methods and procedure: Immunohistochemical labelling was performed to incorporate specific cell markers, such as Ki67 (proliferating cells), 5-bromodeoxyuridien (BrdU; surviving newborn cells) and doublecortin (DCX; neuroblasts or migrating cells).Main outcomes and results: Voluntary exercise for 3 and 6 weeks sustained more Ki67- or BrdU-immunostained cells in the SVZ after ICH than in the brains of sedentary mice. DCX-immunostained cells were more prominent in the striatum of the group that had exercised for 6 weeks compared to the time-matched sedentary group. Moreover, it was observed that proliferating green fluorescent protein (GFP)-positive cells that were infected with retrovirus were located more distally from the injection site in the exercise group than in the sedentary group.Conclusions: These data indicate that long-term exercise may enhance the proliferation and survival of NPCs and their migration toward injured areas, suggesting that exercise may contribute to neuronal injury recovery in cell-based therapies after ICH.