Development of an allogeneic adherent stem cell therapy for treatment of ischemic stroke

Author(s): Robert W. Mays, Cesar V. Borlongan, Takao Yasuhara, Koichi Hara, Mina Maki, James E. Carroll, Robert J. Deans, David C. Hess

To determine the potential for using stem cells in the treatment of ischemic injuries of the central nervous sys-tem, clinically relevant experiments were performed administering human adult adherent bone marrow derived stem cells into a rat model of ischemic stroke. Variables such as the requirement for immunosuppression, route of cell administration, window for therapeutic benefit and optimal cell dosage have all been examined in a series of relevant translational experiments in animals undergoing middle cerebral artery ligation stroke injury. Animals were tested for improvements in locomotor and neurological function at time points as late as 6 months post-cell transplantation and demonstrated sustained statistically significant benefit from a single dose of cells. Following sacrifice, immunohistochemistry was performed on tissues to determine stem cell engraftment and fate, as well as neuroprotection of endogenous tissue at the sites of ischemic injury. The results indicate locomotor and neu-rological improvement correlates with improved neuroprotection and limited retention of the transplanted stem cells, with limited neuronal fate. The observed benefit occurs in a cell dosage dependent fashion suggesting a pharmacological role for the cells when administered intravenously in these injury models.