OBJECTIVETo study the effect of intracerebral transplantation of bone marrow stromal cells (BMSCs) on brain white matter of neonatal rats with hypoxic-ischemic brain damage (HIBD).

METHODSThirty-four 7-day-old neonatal rats were randomly assigned to three groups: normal control (n=10), HIBD (n=12) and HIBD+BMSCs transplantation (n=12). The HIBD and the HIBD+BMSCs transplantation group rats were subjected to left carotid artery ligation, followed by hypoxia exposure for 2 hrs, in order to induce HIBD. The rats in the HIBD+BMSCs transplantation group received transplantation of BMSCs labeled nucleus with Hochest 33324 into the left hippocampus 24 hrs after HIBD induction. Myelin basic protein (MBP) expression in the left corpus callosum and the subcortical white matter and the number of oligodendrocyte precursors positively stained O4 in the left periventricular area and the subcortical white matter were detected by immunohistochemistry at ages of 45 days.

RESULTSThe labeled BMSCs survived and were found mainly in the left hemisphere 37 days after transplantation. The positive rate of O4 expressed by the transplanted BMSCs was 3.70+/-1.09%. More hypomyelination in the left corpus callosum and the subcortical white matter, and less number of O4 positive oligodendrocytes in the left periventricular area and the subcortical white matter were found in the HIBD group compared with the normal control group (P<0.01). The HIBD rats receiving BMSCs transplantation had increased O4 positive oligodendrocytes in the left periventricular area and the subcortical white matter and improved MBP immunoreactivity in the left corpus callosum and the subcortical white matter compared with the HIBD group (P<0.01).

CONCLUSIONSIntracerebral transplantation of BMSCs can improve brain white matter damage in neonatal rats with HIBD.