CD133 cells from human umbilical cord blood reduce cortical damage and promote axonal growth in neonatal rat organ co-cultures exposed to hypoxia

To evaluate the effect of CD133⁺ cells (endothelial progenitor cells) on the hypoxia-induced suppression of axonal growth of cortical neurons and the destruction of blood vessels (endothelial cells), we used anterograde axonal tracing and immunofluorescence in organ co-cultures of the cortex and the spinal cord from 3-day-old neonatal rats. CD133⁺ cells prepared from human umbilical cord blood were added to the organ co-cultures after hypoxic insult, and axonal growth, vascular damage and apoptosis were evaluated. Anterograde axonal tracing with 1,1′-dioctadecyl-3,3,3′,3′-tetramethylindocarbocyanine perchlorate was used to analyze axonal projections from the cortex to the spinal cord. Immunolabeling co-cultured tissues of the cortex and the spinal cord were used to investigate the effect of CD133⁺ cells on the survival of blood vessels and apoptosis in the brain cortex. Hypoxia remarkably suppressed axonal growth in organ co-cultures of the cortex and the spinal cord, and this suppression was significantly restored by the addition of CD133⁺ cells. CD133⁺ cells also reduced the hypoxia-induced destruction of the cortical blood vessels and apoptosis. CD133⁺ cells had protective effects on hypoxia-induced injury of neurons and blood vessels of the brain cortex in vitro. These results suggest that CD133⁺ cell transplantation may be a possible therapeutic intervention for perinatal hypoxia-induced brain injury.