Abstract WP107: Optogenetic Stimulation of Human Neural Stem Cell Grafts In Ischemic Brain
Optogenetically engineered neural stem cells (NSCs) provide a targeted approach to probe the role of neural circuits NSC-based cell therapy in experimental stroke models. A large body of work provides evidence that the therapeutic benefits of NSC grafts are mediated by replacement of cells lost to injury or disease and by secretion of neurotrophic and regenerative factors. Currently the potential of the grafted cells to modulate local circuits and to modify motor performances in animal model of ischemic brain injury is not well understood. This study explores whether optogenetic stimulation of NSC grafts will modulate neural differentiation and integration into the local circuitry.
We isolated multipotent NSCs from human embryonic stem cells. The NSCs were transduced with lentiviral vectors carrying the channelrodopsin-2 (ChR2) gene fused with enhanced yellow fluorescent protein (ChR2-EYFP) under the EF1alpha promoter. The ChR2 expression and response of the NSC progeny to blue light stimulation (470 nm) was confirmed in vitro. To test the function of these cells in stroke model, Sprague Dawley rats were subjected to middle cerebral artery occlusion (65 minutes). One week later, immunosuppressed rats received transplantation of NSCs (2 x 105) into the ischemic boundary zone in the striatum. Chronic optogenetic stimulation of the grafted cells was carried out daily after transplantation for 1 month. Five animal groups were established: vehicle, vehicle with stimulation, NSC transplant with chronic stimulation, NSC transplant without chronic stimulation and NSC with control (non-ChR2) vector. Animals in all groups were tested weekly for their motor performance through testing spontaneous forelimb use during lateral exploratory movement and the vibrissae-elicited forelimb-placing test. Preliminary results suggest that animals that received chronic stimulation showed an enhanced sensorimotor performance in comparison to animals that did not receive stimulation. The effects of long-term optogenetically-controlled stimulation of the grafted cells on the cellular differentiation and functional recovery in animals with ischemic brain injury will be presented.
- © 2012 by American Heart Association, Inc.