Contralaterally transplanted human embryonic stem cell-derived neural precursor cells (ENStem-A) migrate and improve brain functions in stroke-damaged rats

The transplantation of neural precursor cells (NPCs) is known to be a promising approach to ameliorating behavioral deficits after stroke in a rodent model of middle cerebral artery occlusion (MCAo). Previous studies have shown that transplanted NPCs migrate toward the infarct region, survive and differentiate into mature neurons to some extent. However, the spatiotemporal dynamics of NPC migration following transplantation into stroke animals have yet to be elucidated. In this study, we investigated the fates of human embryonic stem cell (hESC)-derived NPCs (ENStem-A) for 8 weeks following transplantation into the side contralateral to the infarct region using 7.0T animal magnetic resonance imaging (MRI). T2- and T2*-weighted MRI analyses indicated that the migrating cells were clearly detectable at the infarct boundary zone by 1 week, and the intensity of the MRI signals robustly increased within 4 weeks after transplantation. Afterwards, the signals were slightly increased or unchanged. At 8 weeks, we performed Prussian blue staining and immunohistochemical staining using human-specific markers, and found that high percentages of transplanted cells migrated to the infarct boundary. Most of these cells were CXCR4-positive. We also observed that the migrating cells expressed markers for various stages of neural differentiation, including Nestin, Tuj1, NeuN, TH, DARPP-32 and SV38, indicating that the transplanted cells may partially contribute to the reconstruction of the damaged neural tissues after stroke. Interestingly, we found that the extent of gliosis (glial fibrillary acidic protein-positive cells) and apoptosis (TUNEL-positive cells) were significantly decreased in the cell-transplanted group, suggesting that hESC-NPCs have a positive role in reducing glia scar formation and cell death after stroke. No tumors formed in our study. We also performed various behavioral tests, including rotarod, stepping and modified neurological severity score tests, and found that the transplanted animals exhibited significant improvements in sensorimotor functions during the 8 weeks after transplantation. Taken together, these results strongly suggest that hESC-NPCs have the capacity to migrate to the infarct region, form neural tissues efficiently and contribute to behavioral recovery in a rodent model of ischemic stroke.

Human Umbilical Cord Blood Infusion in Paralyzed Rats: Histologic and Behavioral Alterations / 대한척추외과학회지

STUDY DESIGN: Experimental animal study OBJECTIVES: To examine the ability of human umbilical cord blood (hUCB) stem cells to target a zone of injury and to determine the efficacy of hUCB cells to ameliorate the behavioral deficits after a hUCB cell infusion in paralyzed rats. SUMMARY OF LITERTURE: Many groups have investigated the use of stem cells as potential treatments for a CNS injury. hUCB cells have recently been reported to alleviate the behavioral consequences of a stroke injury. MATERIALS AND METHODS: Thirty Sprague Dawley rats were divided into 6 groups (Gr) (Gr 1. SCI (spinal cord injury) + hUCB delivered at one day postinjury, Gr 2. SCI + hUCB delivered at 3 days postinjury, Gr 3. SCI + hUCB delivered at 5 days postinjury, Gr 4. laminectomy + hUCB, Gr 5. SCI only, Gr 6. Laminectomy only). SCI was produced by compressing the spinal cord to the level of the 8-9th thoracic spine for 1 minute with an aneurysm clip that was calibrated to a closing pressure of 50 gms. The hUCB cells (0.5 ml, 1.5x106) were administered intravenously to the rats. The rat was assessed behaviorally at one, two and three weeks using the BBB behavioral scale. Four weeks after the injury, the animals were sacrificed and the hUCB positiveresponse neural cells (mouse anti-human mitochondria monoclonal antibody=MAB 1273) at the injury level observed using optical and fluorescent microscopy. RESULTS: MAB 1273 positive cells were observed in groups 1, 2 and 3 but not in groups 4, 5 and 6. In particular, there were 870 cells distributed over an area of 1.2 mm(2) in group 3. Group 3 showed the most significant recovery over time in the open field exam, and the most improvement in another tests of incline, leg extension, and toe spread compared with group 1 (p<0.01). CONCLUSION: After infusing the hUCB stem cells to SCI rats, it was confirmed that hUCB cells migrate to an injured area and ameliorate the behavioral deficits. A hUCB infusion 5 days after the injury produced best results in terms of the number of cells and motor recovery.