Role Of Vitro-expanded CD34~+Cells On Hypoxic-ischemic Brain In Neonatal Rat Model

Objective:This research was mainly to investigate the therapeutical effect of vitro-expanded CD34+cells on hypoxic-ischemic brain in neonatal rat model, and to briefly discuss the treatment mechanism. Additionally, we also compared the treatment effect among human umbilical cord blood mononuclear cells (MNCs) and CD34+cells, and hence determine the most effective cell type to treat hypoxic-ischemic brain injury, aiming to provided a reference for the treatment of cerebral palsy disease in clinical.Methods:1) Referred to Rice et al, cerebral palsy model of neonatal rat was produced by unilateral carotid artery ligation combined with hypoxia. Three weeks after this model successfully produced, we observed the changes of their weight, behavior and pathological brain tissue. We also detected the expression changes of apoptosis-related genes in brain tissue and the transcription factor NF-κB p50and p65.2) At Day7after this model successfully produced, MNCs, CD34+cells and the vitro-expanded progeny of CD34+cells were transplanted into HI-injured animals intravenously(via the jugular vein). Two weeks after transplantation, we observed the changes of their weight, behavior and pathological brain tissue. We also examined the expression changes of apoptosis-related genes by RT-PCR and NF-κB by Western blot. Results:1) The mean weight of HI-vehicle group was decreased significantly. Hyposic-ischemic brain damage resulted in abnomal behavior. The ipsilateral cerebral hemisphere of damage appearred liquefaction and its brain parenchymal was significantly reduced, while the contralateral cerebral hemisphere showed no liquefaction. The expressions of apoptosis-related genes (TNFα, TNFR1, TNFR2, Fas and CD40) and NF-κB p50and p65were increased in the ipsilateral cerebral tissues. The consistency and repeatability of our models were reliable and the success rate of modeling was83%.2) Compared with the injury group, the weight of rats in the three therapical groups were significantly increased, the damages of their brain tissues were alleviated, and the expressions of apoptosis-related genes and transcription factor NF-κB p50and p65were decreased. The therapeutic efficacy of the vitro-expanded CD34+cells superiored to that of the MNCs, while the treatment efficacy of the MNCs was better than that of the CD34+cells.Conclusion:The application of the one-side common carotid artery ligation combined with hypoxia to produce cerebral palsy model in neonatal rats showed same injury degree as well as reliable stability, and the success rate of modeling was high. MNCs, CD34+cells and the vitro-expanded progeny of CD34+cells were all resultful to some degree for the cerebral palsy models in neonatal rats, while the treatment efficacy of the vitro-expanded progeny of CD34+cells significantly superiored to CD34+cells.