Cell-based therapies for ischemic stroke

Abstract

Cell-based therapies have been developed as novel therapies for ischemic stroke. Cell-based therapies are divided into 2 groups; one is stimulation of endogenous neural stem cells, and the other is exogenous (stem) cell transplantation. In the former strategy, several drugs has been investigated as stimulants for endogenous neural stem cells, besides now it has been clear exogenous cell transplantation also induce stimulation of endogenous neural stem cells. In the later strategy, exogenous (stem) cell transplantation is separated based on the type of transplanted cells; non-neural (stem) cells and neural stem cells. Transplantation of non-neural (stem) cells, such as “mesenchymal stem cells” or “mononuclear cells” is thought it will work through several mechanisms such as modulation of inflammation, neuroprotection and promotion of endogenous neurogenesis, etc. Now there are several ongoing clinical trials to evaluate transplantation of non-neural (stem) cells, and these cells can be considered as “drug” which provides several mechanisms other than neural replacement. On the other hand, neural stem cells are believed they possess not only the mechanisms which non-neural (stem) cells have but also the effect of neural replacement. Therefore, transplantation of neural stem cells will be epoch-making therapy if it works through the effect of neural replacement. However there are still problems to solve before clinical trials. In the future, we have to combine the existing therapies and novel cell-based therapies, and moreover it will be important to select the optimal cases for each therapy.