The Neuroprotective Effect Exerted by Oligodendroglial Progenitors on Ischemically Impaired Hippocampal Cells

Oligodendrocyte progenitor cells (OPCs) are the focus of intense research for the purpose of cell replacement therapies in acquired or inherited neurodegenerative disorders, accompanied by ongoing hypo/demyelination. Recently, it has been postulated that these glia-committed cells exhibit certain properties of neural stem cells. Advances in stem cell biology have shown that their therapeutic effect could be attributed to their ability to secret numerous active compounds which modify the local microenvironment making it more susceptible to restorative processes. To verify this hypothesis, we set up an ex vivo co-culture system of OPCs isolated from neonatal rat brain with organotypic hippocampal slices (OHC) injured by oxygen-glucose deprivation (OGD). The presence of OPCs in such co-cultures resulted in a significant neuroprotective effect manifesting itself as a decrease in cell death rate and as an extension of newly formed cells in ischemically impaired hippocampal slices. A microarray analysis of broad spectrum of trophic factors and cytokines expressed by OPCs was performed for the purpose of finding the factor(s) contributing to the observed effect. Three of them-BDNF, IL-10 and SCF-were selected for the subsequent functional assays. Our data revealed that BDNF released by OPCs is the potent factor that stimulates cell proliferation and survival in OHC subjected to OGD injury. At the same time, it was observed that IL-10 attenuates inflammatory processes by promoting the formation of the cells associated with the immunological response. Those neuroprotective qualities of oligodendroglia-biased progenitors significantly contribute to anticipating a successful cell replacement therapy.