Stem cell transplantation offers a promising regenerative therapy for cerebral ischemia and other CNS disorders. Of the several cell types for cell-based therapeutics, induced pluripotent stem (iPS) cells have received a great deal of attention due to their ability to develop into neurons and non-neuronal cells, the possibility of autologous transplantation and the lack of ethical controversies. These cells created by viral vectors of genomic integration, unfortunately, have a potential risk of tumor growth. In addition, current methods of cell delivery are either invasive or inefficient; transplanted cells suffer from poor cell survival in the host ischemic brain and insufficient homing to the lesion site. Based on our recent progress in stroke therapy using stem cells and neural progenitor cells (NPCs) and the experience in intranasal drug/trophic factor delivery, we now propose to test intranasal delivery of virus-free human iPS-NPCs pretreated with hypoxic preconditioning (HP) as a non-invasive and brain specific transplantation method for enhanced therapeutic benefits after focal ischemic stroke.
Specific Aim 1 will examine the promoting effect of HP strategy and CXCR-4 expression in human iPS-NPCs on directed cell migration in vitro. Gene regulation and differentiation of HP-treated, CXCR-4 and/or FAK expressing cells will be examined.
Specific Aim 2 will test the therapeutic effects of the strategies in Aim 1 in our unique barrel cortex stroe model of mice, with the expectation of improved survival, differentiation, and enhanced homing of iPS- NPCs to the ischemic cortex after intranasal delivery.
Specific Aim 3 will examine neural network repair and functional recovery after the iPS-NPC therapy for restoration of the intracortical and thalamocortical connections and sensorimotor activity after the focal ischemic damage. This investigation takes advantage of the complementary expertise in our collaborative team and is based on recently developed novel strategies in stem cell research and stroke therapy. Our ultimate goal is to develop a non-invasive yet highly effective and more efficient cell-based therapy for clinical treatment of ischemic stroke.
Although stem cell transplantation offers a promising therapy for ischemic stroke, several issues such as potential risk of tumor growth, inefficient cell delivey methods, low numbers of transplanted cells that can survive and home to the lesion site, have hindered efficacy of cell- based therapy. We will test a novel intranasal cell delivery method using hypoxic preconditioned neural progenitor cells derived from virus-free/vector-free human iPS cells. We hypothesize that via the intranasal route, cells can bypass the blood brain barrier and directly reach brain tissues and the migration of transplanted cells can be increased via higher expression of the chemoattractant signaling involving SDF-1, CXCR4 and/or FAK.
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