Enhanced functional recovery from spinal cord injury in aged mice after stem cell transplantation through HGF induction

The number of elderly patients with spinal cord injury (SCI) is increasing worldwide, representing a serious burden for both the affected patients and the community. Previous studies have demonstrated that neural stem cell (NSC) transplantation is an effective treatment for SCI in young animals. Here we show that NSC transplantation is as effective in aged mice as it is in young mice, even though aged mice exhibit more severe neurological deficits after SCI. NSCs grafted into aged mice exhibited better survival than did those grafted into young mice. Furthermore, we show that the neurotrophic factor HGF plays a key role in the enhanced functional recovery after NSC transplantation observed in aged mice with SCI. The unexpected results of the present study suggest that NSC transplantation is a potential therapeutic modality for SCI, even in elderly patients. Injured and naive mice were anesthetized and transcardially perfused with heparinized saline (5 U/ml) 9 days after injury (n=3 each). Dissected segments of the spinal cord at the Th9 level underwent expression profiling by array.