Transplantation of differentiated bone marrow stromal cells promotes motor functional recovery in rats with stroke

Objective: To investigate the effects of transplantation into rats with stroke of bone marrow-derived mesenchymal stem cells (MSCs) induced by brain-derived neurotrophic factor (BDNF). Materials and methods: MSCs were harvested from 6-week-old Sprague-Dawley male rats, and transplanted into adult Sprague-Dawley male rats with transient middle cerebral artery occlusion. At 48 hours after stroke, the adult rats, weighing 250-280 g, were injected via the tail vein with 1 x 10(7) MSCs or MSCs induced by BDNF (BDNF-MSCs) suspended in 1 ml phosphate-buffered saline. All animals underwent the neurological function test for 14 days. Infarct volume and blood-brain barrier permeability assay were assessed on day 14 post-middle cerebral artery occlusion. Western blotting and immunohistochemical staining were used to detect the protein expression of neuron-specific enolase (NSE). Results: Both BDNF-MSCs and MSCs produced improvement in neurological deficits compared with vehicle controls on day 14 (P<0.05). In particular, the group transplanted with BDNF-MSCs exhibited significant recovery of motor function compared with the group transplanted with MSCs alone (P<0.05). Both BDNF-MSCs and MSCs, but particularly the former, reduced infarct volume, improved blood-brain barrier dysfunction, reduced serum NSE levels, activated the NSE activity, and inhibited neuronal apoptosis in the ischemic boundary zone. Conclusions: BDNF-MSCs might contribute to the motor function improvement partly by reducing neuronal damage via upregulating the NSE expression level and inhibiting neuronal apoptosis.