Rehabilitation facilitates functional improvement following intravenous infusion of mesenchymal stem cells in the chronic phase of cerebral ischemia in rats.

The primary objective of this study was to investigate the potential facilitating effects of daily rehabilitation for chronic cerebral ischemia following the intravenous infusion of mesenchymal stem cells (MSC) in rats. The middle cerebral artery (MCA) was occluded by intraluminal occlusion using a microfilament (MCAO). Eight weeks after MCAO induction, the rats were used as a chronic cerebral ischemia model. Four experimental groups were studied: Vehicle group (medium only, no cells); Rehab group (vehicle + rehabilitation), MSC group (MSC only); and Combined group (MSC + rehabilitation). Rat MSCs were intravenously infused eight weeks after MCAO induction, and the rats received daily rehabilitation through treadmill exercise for 20 min. Behavioral testing, lesion volume assessment using magnetic resonance imaging (MRI), and histological analysis were performed during the observation period until 16 weeks after MCAO induction. All treated animals showed functional improvement compared with the Vehicle group; however, the therapeutic efficacy was greatest in the Combined group. The combination therapy is associated with enhanced neural plasticity shown with histological analysis and MRI diffusion tensor imaging. These findings provide behavioral evidence for enhanced recovery by combined therapy with rehabilitation and intravenous infusion of MSCs, and may form the basis for the development of clinical protocols in the future.

Synergic Effects of Rehabilitation and Intravenous Infusion of Mesenchymal Stem Cells After Stroke in Rats.

BACKGROUND: Intravenous infusion of mesenchymal stem cells (MSCs) derived from adult bone marrow improves behavioral function in rat stroke models. Rehabilitation therapy through physical exercise also provides therapeutic efficacy for cerebral ischemia. OBJECTIVE: The purpose of this study was to investigate whether synergic effects of daily rehabilitation and intravenous infusion of MSCs has therapeutic effects after stroke in rats. DESIGN: This was an experimental study. METHODS: A permanent middle cerebral artery occlusion (MCAO) was induced by intraluminal vascular occlusion with a microfilament. Four experimental groups were studied: group 1 (vehicle only, n=10), group 2 (vehicle + exercise, n=10), group 3 (MSCs only, n=10), and group 4 (MSCs + exercise, n=10). Rat MSCs were intravenously infused at 6 hours after MCAO, and the rats received daily rehabilitation with treadmill running exercise for 20 minutes. Lesion size was assessed at 1, 14, and 35 days using magnetic resonance imaging. Functional outcome was assessed using the Limb Placement Test. RESULTS: Both combined therapy and MSC infusion reduced lesion volume, induced synaptogenesis, and elicited functional improvement compared with the groups without MSC infusion, but the effect was greater in the combined therapy group. LIMITATIONS: A limitation of this study is that the results were limited to an animal model and cannot be generalized to humans. CONCLUSIONS: The data indicate that the combined therapy of daily rehabilitation and intravenous infusion of MSCs improved functional outcome in a rat MCAO model.