A quantitative study of the gllal cell response to brain injury after intracerebral and intravenous transplantation of bone marrow stromal cells
Experimental studies have shown that bone marrow stromal cells (BMSCs) promote functional recovery after traumatic brain injury. The beneficial effects of BMSCs therapy were demonstrated after intravenous, intraarterial and intracerebral transplantation of these cells. A reasonable explanation for the benefit provided by BMSCs is that these cells stimulate regenerative changes in the damaged brain, including glial remodeling. The aim of the present study was to determine and compare the time course of the astrocyte and microglial/ macrophage cell reaction to cerebral cortex injury after intracerebral and intravenous administration of BMSCs. Female Wistar rats were subjected to cerebral cortex injury followed by the injection of BMSCs or PBS directly to the injury site or to the tail vein. Using histology and immunohistochemistry, the distribution of astrocytes and microglia/macrophages was analyzed in the injured cerebral cortex. BMSCs treatment affected glial cell response to brain injury. The effects of BMSCs activity were dependent on the site of their administration. Intracerebral transplantation of BMSCs showed significant effect on the astrocyte response whereas intravenous route of BMSCs administration increased especially the microglia/ macrophages number in the injured brain. The results suggest that implanted cells can enhance the restorative processes in the injured brain through the stimulation and modulation of the cellular response to injury.