Cell Transplant

Human induced pluripotent stem cells (hiPSCs) are a most appealing source for cell replacement therapy in acute brain lesions. We evaluated the potential of hiPSC therapy in stroke by transplanting hiPSC-derived neural progenitor cells (NPCs) into the postischemic striatum. Grafts received host tyrosine hydroxylase-positive afferents and contained developing interneurons and homotopic GABAergic medium spiny neurons that, with time, sent axons to the host substantia nigra. Grafting reversed stroke-induced somatosensory and motor deficits. Grafting also protected the host substantia nigra from the atrophy that follows disruption of reciprocal striatonigral connections. Graft innervation by tyrosine hydoxylase fibers, substantia nigra protection, and somatosensory functional recovery were early events, temporally dissociated from the slow maturation of GABAergic neurons in the grafts and innervation of substantia nigra. This suggests that grafted hiPSC-NPCs initially exert trophic effects on host brain structures, which precede integration and potential pathway reconstruction. We believe that transplantation of NPCs derived from hiPSCs can provide useful interventions to limit the functional consequences of stroke through both neuroprotective effects and reconstruction of impaired pathways

An overview of tissue engineering approaches for management of spinal cord injuries

Severe spinal cord injury (SCI) leads to devastating neurological deficits and disabilities, which necessitates spending a great deal of health budget for psychological and healthcare problems of these patients and their relatives. This justifies the cost of research into the new modalities for treatment of spinal cord injuries, even in developing countries. Apart from surgical management and nerve grafting, several other approaches have been adopted for management of this condition including pharmacologic and gene therapy, cell therapy, and use of different cell-free or cell-seeded bioscaffolds. In current paper, the recent developments for therapeutic delivery of stem and non-stem cells to the site of injury, and application of cell-free and cell-seeded natural and synthetic scaffolds have been reviewed

Grafts of Olfactory Stem Cells Restore Breathing and Motor Functions after Rat Spinal Cord Injury

International audienceStem cells are considered as promising tools to repair diverse tissue injuries. Among the different stem cell types, the “olfactory ectomesenchymal stem cells” (OE-MSCs) located in the adult olfactory mucosa stand as one of the best candidates. Here, we evaluated if OE-MSC grafts could decrease memory impairments due to ischemic injury. OE-MSCs were collected from syngeneic F344 rats. After a two-step global cerebral ischemia, inducing hippocampal lesions, learning abilities were evaluated using an olfactory associative discrimination task. Cells were grafted into the hippocampus 5 weeks after injury and animal’s learning abilities reassessed. Rats were then sacrificed and the brains collected for immunohistochemical analyses. We observed significant impairments in learning and memory abilities following ischemia. However, 4 weeks after OE-MSC grafts, animals displayed learning and memory performances similar to those of controls, while sham rats did not improve them. Immunohistochemical analyses revealed that grafts promoted neuroblast and glial cell proliferation, which could permit to restore cognitive functions. These results demonstrated, for the first time, that syngeneic transplantations of OE-MSCs in rats can restore cognitive abilities impaired after brain injuries and provide support for the development of clinical studies based on grafts of OE-MSCs in amnesic patients following brain injuries