Research Of Myelin Reparation Following Oligodendrocyt Type2 Astrocyte Progenitor Cells Intraventricular Transplantation In Neonatal Rats With Periventricular Lerkomalacia

Objective To evaluate the brain changes following exdogenous O2A progenitors labeled intraventricular transplantation in neonatal rats with perventricular leukomalacia(PVL).To provide the theoretical bases of transplantation O2A progenitors in treatment of demyelinating disease.Methods1. O2A progenitors were cultured and purified by shaking for twice and the defined culture medium from rat cerebral tissue and identified by immunofluorescent staining.2. The PVL model was established by the ligation of common carotid artery bilaterally. We used HE staining,premature oligodendrocyte marker O4 and TUNEL double imunofluorescence staining ways to investigate the pathologic manifestation, apoptosis of oligodendrocyte .Inspections were made for maturation of physical Characteristics such as weight, eye opening.Motor test were carried once a day till 49d after surgry.3. O2A progenitors were prepared from P2 neonatal rat cerebrum.Three–day–old neonatal rats were randomly divided into Three groups: PVL, PVL + PBS, PVL + O2A progenitors. Intraventricular transplantation of exdogenous O2A progenitors performed 72h after PVL operation. The amount of MBP(myelin basic protein,MBP) evaluation was undertaken by Western blot at 7, 14 and 28 days after transplantation. Morris water mase test was made at 7 week after birth.Results1. O2A progenitors were small and have one or two fine processes, 95% of the total cells were A2B5-positive O2A progenitors. O2A progenitor cells had bipotential differentiation features, they could differentiate into oligodendrocytes or type–2–strocytes according to the ingredient of the culture medium.2. The Morris water maze test showed that the rats of model groups had spatial learning and memory cognition defect. The difference were statistically significant.3. Pathologic changes of white matter injury showed rarefaction,liquefaction and microglia hyperplasia by HE staining.4. Most of apoptotic cells were premature oligodendrocyte with marker O4 by confocal microscopy.5. The Morris water maze test showed that the rats of PVL + O2A progenitors groups had spatial learning and memory cognition improved. The differences were statistically significant.6. The amount of MBP increased than PVL and PVL + PBS by Western blot at 7 ,14 and 28 days after transplantation. The difference were statistically significant. The differences between PVL and PVL + PBS were no statistically significant.Conclusions1. O2A progenitors were cultured and purified by shaking for twice and the defined culture medium is suitable and effective.2. A Three -day-old neonatal rat model for PVL that is similar to pathological change of PVL in human preterm infants with mainly late oligodendrocyte precursors in brain white matter is successfully established by the ligation of common carotid artery bilaterally.3. In summary, our results indicate that intraventricular transplantation of O2A progenitors can apparently improve myelin reparation. Indirectly indicate that O2A progenitors have an intrinsic ability to populate the injury brain, with appropriate migration, nontumorigenic integration in white matter, and differentiation into myelinating oligodendrocytes. Our findings suggested that intraventricular transp– lantation of O2A progenitors is of a great potential feasibility for the treatment of PVL in premature infants.